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Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
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1

A new arrangement of AC/DC converters for high direct-current applications  

Science Conference Proceedings (OSTI)

A novel AC/DC converter designed for high-output direct currents and tight output voltage regulations is introduced. The proposed converter exhibits good efficiency and very low output voltage ripple. In order to verify the performances of the four-stage ... Keywords: AC/DC converter, FFT, electrical distribution systems, high direct-current

Francesco Muzi; Luigi Passacantando

2008-04-01T23:59:59.000Z

2

Improvements in power quality and efficiency with a new AC/DC high current converter  

Science Conference Proceedings (OSTI)

A very flexible AC/DC converter featuring high-output current, reduced voltage ripple and highly adjustable current control is described. The whole system consists of four stages and uses a proper switching technique in conjunction with a feedback control ... Keywords: AC/DC converter, FFT, electrical distribution systems, high direct-current, power quality

Francesco Muzi; Luigi Passacantando

2008-05-01T23:59:59.000Z

3

Stabilizing technique for AC-DC boost PFC converter based on time delay feedback  

Science Conference Proceedings (OSTI)

It is well known that the ac-dc power factor correction (PFC) boost preregulator can present instability at the line frequency. This nonlinear phenomenon can jeopardize the system performances by increasing the total harmonic distortion and decreasing ... Keywords: ac-dc converters, line frequency instability, power factor correction (PFC), time delay feedback (TDF)

Abdelali El Aroudi; Mohamed Orabi

2010-01-01T23:59:59.000Z

4

Control of Parallel-Connected Bidirectional AC-DC Converters in Stationary Frame for Microgrid  

E-Print Network (OSTI)

Control of Parallel-Connected Bidirectional AC-DC Converters in Stationary Frame for Microgrid-- With the penetration of renewable energy in modern power system, microgrid has become a popular application worldwide. In this paper, parallel-connected bidirectional converters for AC and DC hybrid microgrid application

Teodorescu, Remus

5

A Generalized Class of Stationary Frame-Current Controllers for Grid-Connected AC–DC Converters  

E-Print Network (OSTI)

Within power systems, high-power pulsewidth-modulated ac-dc converters are used in flexible ac transmission systems controllers and for interfacing renewable energy sources to the grid. These converters traditionally ...

Hwang, J. George

6

ac/dc power converter for batteries and fuel cells. Annual report  

SciTech Connect

The overall objective of the EPRI RP841-1 program is the design of an advanced power converter for use in both battery energy storage and fuel cell generation systems in the 1980's. This goal will be accomplished by expansion of United's existing FCG-1 fuel cell power conditioning inverter into a high-efficiency inverter--rectifier system employing improved commutation circuits and advanced (1980's) semiconductor devices capable of operating over wider dc voltage ranges. A separate but concurrent program for the U.S. Department of Energy (DOE) -- E(49-18)2122 -- is examining augmentation of the present FCG-1 inverter for operation as an inverter--rectifier with battery systems; feasibility and operating characteristics have been demonstrated. United's activities and accomplishments in the EPRI RP841-1 program include revision of the preliminary specification for ac/dc conversion equipment contained in the Statement of Work, survey of seven semiconductor manufacturers to project characteristics of 1980's thyristors, screening of fifteen commutation concepts and selection of the two most promising options for experimental evaluation, and modifications of existing experimental power pole hardware to evaluate the selected advanced commutation circuits. 34 figures, 3 tables.

Rosati, R.W. (ed.)

1978-08-01T23:59:59.000Z

7

AC-DC Difference  

Science Conference Proceedings (OSTI)

... The NIST ac-dc Difference Project provides US industry with the essential link between ac ... Facilities/Tools Used: ... NIST CNST Nanofabrication facility. ...

2012-08-09T23:59:59.000Z

8

Design and operating experience of an ac-dc power converter for a superconducting magnetic energy storage unit  

DOE Green Energy (OSTI)

The design philosophy and the operating behavior of a 5.5 kA, +-2.5 kV converter, being the electrical interface between a high voltage transmission system and a 30 MJ superconducting coil, are documented in this paper. Converter short circuit tests, load tests under various control conditions, dc breaker tests for magnet current interruption, and converter failure modes are described.

Boenig, H.J.; Nielsen, R.G.; Sueker, K.H.

1984-01-01T23:59:59.000Z

9

Available Transfer Capability Calculation for AC/DC Systems with VSC-HVDC  

Science Conference Proceedings (OSTI)

In this paper, the voltage source converter is equivalently represented by voltage source model, thus the model of voltage source converter--high voltage direct current (VSC-HVDC) system suitable for optimal power flow is established. Each control mode ... Keywords: available transfer capability, voltage source converter, AC/DC systems, sequential quadratic programming method

Guoqing Li; Jian Zhang

2010-06-01T23:59:59.000Z

10

A Multi-Level Grid Interactive Bi-directional AC/DC-DC/AC Converter and a Hybrid Battery/Ultra-capacitor Energy Storage System with Integrated Magnetics for Plug-in Hybrid Electric Vehicles  

DOE Green Energy (OSTI)

This study presents a bi-directional multi-level power electronic interface for the grid interactions of plug-in hybrid electric vehicles (PHEVs) as well as a novel bi-directional power electronic converter for the combined operation of battery/ultracapacitor hybrid energy storage systems (ESS). The grid interface converter enables beneficial vehicle-to-grid (V2G) interactions in a high power quality and grid friendly manner; i.e, the grid interface converter ensures that all power delivered to/from grid has unity power factor and almost zero current harmonics. The power electronic converter that provides the combined operation of battery/ultra-capacitor system reduces the size and cost of the conventional ESS hybridization topologies while reducing the stress on the battery, prolonging the battery lifetime, and increasing the overall vehicle performance and efficiency. The combination of hybrid ESS is provided through an integrated magnetic structure that reduces the size and cost of the inductors of the ESS converters. Simulation and experimental results are included as prove of the concept presenting the different operation modes of the proposed converters.

Onar, Omer C [ORNL

2011-01-01T23:59:59.000Z

11

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS  

E-Print Network (OSTI)

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca~nizares A dissertation submitted . . . . . . . . . . . . . 4 1.3.2 AC/DC Transient Energy Functions . . . . . . . . . . . . . . 6 2 System Modelling 8 2

Cañizares, Claudio A.

12

Power upgrading of transmission line by combining AC-DC transmission  

Science Conference Proceedings (OSTI)

Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep sufficient margin against transient instability. With the scheme proposed in this project, it is possible to load these lines very close to their thermal ... Keywords: extra high voltage (EHV)transmission, flexible ac transmission system (FACTS), power system computer-aided design(PSCAD), simultaneous ac-dc power transmission

Jarupula Somlal

2010-07-01T23:59:59.000Z

13

Stabilizing control of parallel AC-DC power transmission systems by approximate switching curve  

SciTech Connect

A method to improve the transient stability of bulk power transmission system is presented. The method stabilizes the control of parallel ac-dc transmission systems using an approximate switching curve. The optimal switching curve is approximated by a power series and the resulting switching curve is determined independent of type and duration of faults that occur to the system. In addition, coefficients of the switching curve can be calculated on a off-line basis which allows use of simple on-line algebraic calculations in emergency conditions.

Ichiyanagi, K.; Kobayashi, H.; Kakehu, H.

1980-01-01T23:59:59.000Z

14

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS  

E-Print Network (OSTI)

This thesis presents a thorough analysis of saddle-node bifurcations for power system dynamic models, including a third order representation of high voltage direct current (HVDC) transmission, classic ac generator dynamics with reactive flows, and voltage and frequency dependent load models. Extensions of the Point of Collapse and Continuation methods, initially used in ac system voltage stability studies, are applied to the determination of these bifurcation points. These methods are compared and used for calculating bus voltage profiles (“nose ” curves) and collapse points on ac/dc systems of up to 2158 buses, considering a variety of operational limits and controls, namely, ac/dc regulating transformer tap limits, voltage and reactive power limits, and area interchange control. AC generator reactive power limits, HVDC firing angle limits and voltage dependent current order limits (VDCOL) are shown to affect the stability and loadability of these systems. A vector Lyapunov function approach is employed to define a system wide energy function that can be used for stability analysis. This thesis describes the derivation

Claudio A. Cañizares

1991-01-01T23:59:59.000Z

15

POINT OF COLLAPSE METHODS APPLIED TO AC/DC POWER SYSTEMS  

E-Print Network (OSTI)

This paper describes an extension of the Point of Collapse method developed for ac systems studies to the determination of saddle-node bifurcations in power systems including high voltage direct current (HVDC) transmission. Bus voltage profiles are illustrated for an ac/dc test system, which significantly differ from the profiles of pure ac systems for typical system models. In particular, voltage dependent current order limits (VD-COLs) are shown to affect the voltage profiles ("nose" curves) and the loadability margin of the system. It is also shown that Hopf bifurcations, which are not possible in purely ac lossless systems with second-order generator models, become plausible when the dynamics for the HVDC system are included.

Claudio A. Cañizares; Fernando L. Alvarado; et al.

1992-01-01T23:59:59.000Z

16

Point of Collapse and Continuation Methods for Large AC/DC Systems  

E-Print Network (OSTI)

This paper describes the implementation of both Point of Collapse (PoC) methods and continuation methods for the computation of voltage collapse points (saddle-node bifurcations) in large ac/dc systems. A comparison of the performance of these methods is presented for real systems of up to 2158 buses. The paper discusses computational details of the implementation of the PoC and continuation methods, and the unique challenges encountered due to the presence of high voltage direct current (HVDC) transmission, area interchange power control, regulating transformers, and voltage and reactive power limits. The characteristics of a robust PoC power ow program are presented, and its application to detection and solution of voltage stability problems is demonstrated.

Claudio A. Cañizares; Fernando L. Alvarado

1993-01-01T23:59:59.000Z

17

Experimental studies and computer simulation of the control of energy transfer using inductor-converter bridges  

DOE Green Energy (OSTI)

An inductor-converter bridge (ICB) is a solid state DC-AC-DC power converter system for bidirectional, controllable, energy transfer between two coils. The ICB is suitable for supplying large pulsed power to such magnets as the superconducting equilibrium field coil of the proposed tokamak power reactors from another superconducting energy storage coil.

Hirano, M.; Kustom, R.L.

1984-03-01T23:59:59.000Z

18

Bang-bang-type optimal constant current control of parallel ac-dc power transmission systems  

SciTech Connect

The transient stability of an ac-dc hybrid system can be improved greatly by controlling the power flow of the dc transmission line. In this study the optimal changeover curve of dc current setting value on the phase plane with a quadratic curve are approximated. The coefficients of this curve are calculated in advance taking into account the loading condition of the power system and hence the proposed control scheme can be used for emergency control of the power system. The main conclusions from this study were that: to facilitate transient stability analysis, the dc transmission line is represented by equivalent load admittances, which vary every second with the operating condition of the transmission line; the action of the speed governor increases the damping coefficient of the power system and reduces the control time which means that the admissible range of the dc current setting value can be reduced by increasing the governor gain; and the optimal change-over curve of the dc current setting value is approximated by a quadratic curve, whose coefficients can be calculated in advance taking into account the loading condition of the power system. The suboptimal changeover curve thus obtained makes it possible to change the setting value of dc current without time delay in emergency condition. While the case of three-phase short-circuit fault was specifically discussed, it is possible to extend the results obtained to the case of successful or unsuccessful reclosing. The proposed method could also be applied to multimachine systems by using equivalent network reduction methods.

Kobayashi, H.; Ichiyanagi, K.

1977-01-01T23:59:59.000Z

19

Sensorless Direct Torque Control For Salient Pole PMSM Based on Extended Kalman Filter Fed By AC/DC/AC Converter  

E-Print Network (OSTI)

, Algeria Abstract -- In this paper, a new sensorless Interior Permanent Magnet Synchronous Motor (IPMSM. Key words-- DTC; sensorless control; extended Kalman filter; Permanent Magnet Synchronous Motor; boost-rectifier. I. INTRODUCTION Permanent magnet synchronous motors (PMSMS) are widely used in many applications

Paris-Sud XI, Université de

20

Eisenhower Halts Nuclear Weapons Testing | National Nuclear Security  

National Nuclear Security Administration (NNSA)

Eisenhower Halts Nuclear Weapons Testing | National Nuclear Security Eisenhower Halts Nuclear Weapons Testing | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > Eisenhower Halts Nuclear Weapons Testing Eisenhower Halts Nuclear Weapons Testing August 22, 1958 Washington, DC Eisenhower Halts Nuclear Weapons Testing

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

A Stabilization of Frequency Oscillations in a Parallel AC-DC Interconnected Power System via an HVDC Link  

E-Print Network (OSTI)

This paper presents a new application of High Voltage Direct Current (HVDC) link to stabilization of frequency oscillations in a parallel AC-DC interconnected power system. When an interconnected AC power system is subjected to a large load with rapid change, system frequency may be considerably disturbed and becomes oscillatory. By utilizing the system interconnections as the control channels of HVDC link, the tie-line power modulation of HVDC link through interconnections is applicable for stabilizing the frequency oscillations of AC systems. In the design of power modulation controller, the technique of overlapping decompositions and the eigenvalue assignment are applied to establish the state feedback control scheme. To evaluate control effects, a linearized model of a parallel AC-DC interconnected system, including a power modulation controller of HVDC link, is investigated by simulation study. Simulation results show that the proposed controller is not only effective in damping out frequency oscillations, but also capable of alleviating the transient frequency swing caused by a large load disturbance.

Issarachai Ngamroo

2002-01-01T23:59:59.000Z

22

Eisenhower Halts Nuclear Weapons Testing | National Nuclear Security...  

NLE Websites -- All DOE Office Websites (Extended Search)

Eisenhower Halts Nuclear Weapons Testing | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency...

23

DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models...

24

Halting_Title_XVII_Nuclear_Loan_Guarantees.pdf  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Friends of the Earth ♦ Greenpeace ♦ South Carolina Chapter-Sierra Club ♦ NC Waste Friends of the Earth ♦ Greenpeace ♦ South Carolina Chapter-Sierra Club ♦ NC Waste Awareness and Reduction Network ♦ Georgia Women's Action for New Directions ♦ Nuclear Information and Resource Service ♦ Beyond Nuclear ♦ NIRS-Southeast ♦ AP1000 Oversight Group October 19, 2009 Secretary of Energy Chu U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 Mr. Richard Frantz Director, Loan Guarantee Program U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 NRC Reveals AP1000 Nuclear Reactor Design Problems, DOE Must Halt Issuance of Conditional Loan Guarantees to Utilities Pursuing AP1000 Dear Secretary of Energy Chu and Director Frantz: In a surprise move with potentially serious impacts, the Nuclear Regulatory Commission

25

DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Air Conditioner and Heat Pump Models Shown to Violate Minimum Efficiency Standards DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump...

26

Enhancement of AC/DC system performance by modulation of a proposed multiterminal DC system in the Southwestern U. S  

SciTech Connect

Modulation of power transmitted over a proposed multiterminal dc system to provide effective stability enhancement of a large ac system in the Southwestern U.S. is demonstrated in this paper. This proposed multiterminal dc system connecting the Phoenix, Mead and Los Angeles areas could be in parallel with an Extra High-Voltage (EHV) ac transmission network which could be operating at heavy loading conditions. Studies indicated that the utilization of large power and reactive power modulation on the dc system can provide transient stability enhancements and ac system damping. The resultant system damping can be significantly improved when compared to the performance of the ac system prior to the addition of the dc system. The application of modulation permits the release of converter station vars to support the ac system voltage and thus reduces the required capability of voltage support devices.

Lee, R.L.; Zollman, D.; Tang, J.F.; Hsu, J.C.; Hunt, J.R.; Burton, R.S.; Fletcher, D.E.

1986-01-01T23:59:59.000Z

27

Dispersing the Gaseous Protoplanetary Disc and Halting Type II Migration  

E-Print Network (OSTI)

More than 30 extra-solar Jupiter-like planets have shorter periods than the planet Mercury. It is generally accepted that they formed further out, past the ’snow line ’ (?1 AU), and migrated inwards. In order to be driven by tidal torques from the gaseous disc, the disc exterior to the planet had to contain about a planetary mass. The fact that the planets stopped migrating means that their outer disc was removed. We suggest, following the simulation by Bate et al. (2003), that the outer disc was accreted by the planet. This not only halts migration but removes the outer disc for planets interior to about 2 AU. The disc further out could have been removed by photoevaporation (Matsuyama et al. 2003). Furthermore, as also shown by Bate et al. (op cit) this process also provides an upper limit to planetary masses in agreement with the analysis of observed planetary masses by Zucker & Mazeh (2002). In this scenario, the endgame is a race. The central star is accreting the inner disc and the planet, while the planet is accreting the outer disc. The planet survives if it accretes its outer disc before being accreted by the star. The winner is determined solely by the ratio of the mass of the outer disc to the local surface density of the disc. Some planets are certainly eaten by the central star. Subject headings: extrasolar planets, Jupiter 1.

M. Lecar; D. D. Sasselov

2003-01-01T23:59:59.000Z

28

DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and  

NLE Websites -- All DOE Office Websites (Extended Search)

Orders AeroSys to Halt Distribution of Inefficient Air Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models March 30, 2010 - 10:05am Addthis Today, the Department of Energy announced that it is requiring AeroSys, Inc. to stop distributing two product models - one air conditioner and one heat pump - that DOE testing found to consume more energy than allowed under federal efficiency standards. This is the latest step in the Department's investigation into whether AeroSys has been selling products in the U.S. that violate minimum appliance efficiency standards. This is the first time that the Department of Energy has told a company or manufacturer that it must halt the distribution of products that fail to

29

DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Orders AeroSys to Halt Distribution of Inefficient Air Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models March 30, 2010 - 10:05am Addthis Today, the Department of Energy announced that it is requiring AeroSys, Inc. to stop distributing two product models - one air conditioner and one heat pump - that DOE testing found to consume more energy than allowed under federal efficiency standards. This is the latest step in the Department's investigation into whether AeroSys has been selling products in the U.S. that violate minimum appliance efficiency standards. This is the first time that the Department of Energy has told a company or manufacturer that it must halt the distribution of products that fail to

30

Latest AC-DC News  

Science Conference Proceedings (OSTI)

... over the course of a week, using several different protocols. The agreement between the two systems was excellent:-0.1 nV at 10 V, with an ...

2011-10-03T23:59:59.000Z

31

DOE Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Manufacturers to Halt Sales of Heat Pumps and Air Manufacturers to Halt Sales of Heat Pumps and Air Conditioners Violating Minimum Appliance Standards DOE Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners Violating Minimum Appliance Standards June 3, 2010 - 2:17pm Addthis Today, the Department of Energy announced that three manufacturers -- Aspen Manufacturing, Inc., Summit Manufacturing, and Advanced Distributor Products -- must stop distributing 61 heat pump models and 1 air conditioner model that DOE has determined do not comply with federal energy conservation standards. The manufacturers also must notify all of their customers that have been sold noncompliant units. The Department determined that these models were noncompliant based on certification information submitted to DOE for these manufacturers.

32

DOE Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Requires Manufacturers to Halt Sales of Heat Pumps and Air Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners Violating Minimum Appliance Standards DOE Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners Violating Minimum Appliance Standards June 3, 2010 - 2:17pm Addthis Today, the Department of Energy announced that three manufacturers -- Aspen Manufacturing, Inc., Summit Manufacturing, and Advanced Distributor Products -- must stop distributing 61 heat pump models and 1 air conditioner model that DOE has determined do not comply with federal energy conservation standards. The manufacturers also must notify all of their customers that have been sold noncompliant units. The Department determined that these models were noncompliant based on certification information submitted to DOE for these manufacturers.

33

DOE Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Requires Manufacturers to Halt Sales of Heat Pumps and Air Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners Violating Minimum Appliance Standards DOE Requires Manufacturers to Halt Sales of Heat Pumps and Air Conditioners Violating Minimum Appliance Standards June 3, 2010 - 12:00am Addthis Washington, DC - Today, the Department of Energy announced that three manufacturers -- Aspen Manufacturing, Inc., Summit Manufacturing, and Advanced Distributor Products -- must stop distributing 61 heat pump models and 1 air conditioner model that DOE has determined do not comply with federal energy conservation standards. The manufacturers also must notify all of their customers that have been sold noncompliant units. The Department determined that these models were noncompliant based on certification information submitted to DOE for these manufacturers.

34

DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Orders AeroSys to Halt Distribution of Inefficient Air Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models Shown to Violate Minimum Efficiency Standards DOE Orders AeroSys to Halt Distribution of Inefficient Air Conditioner and Heat Pump Models Shown to Violate Minimum Efficiency Standards March 30, 2010 - 12:00am Addthis WASHINGTON, DC - Today, the Department of Energy announced that it is requiring AeroSys, Inc. to stop distributing two product models - one air conditioner and one heat pump - that DOE testing found to consume more energy than allowed under federal efficiency standards. This is the latest step in the Department's investigation into whether AeroSys has been selling products in the U.S. that violate minimum appliance efficiency standards. This is the first time that the Department of Energy has told a

35

Discussion on the control method of the inductor-converter bridge by simulation and experiment  

DOE Green Energy (OSTI)

With the development of the superconducting magnet as an energy storage unit, pulsed power loads between superconducting magnets of increasing magnitude up to several hundred megawatts or more appear within the realm of possibility. An energy storage unit that is independent of the power grid can be used in applications where the pulsed power required from the power grid may cause a hazardous effect on the power system. An energy transfer system between the storage and the load units eliminates the disturbance on the power grid. An inductor-converter bridge is proposed for such a purpose. The inductor-converter bridge (ICB) is a solid state DC-AC-DC converter system for reversible energy transfer between two high-inductance inductors. The converter thyristors are naturally commutated by a set of wye-connected capacitors on the AC lines of the circuit. The circuit is designed so that, in every converter cycle, a very small fraction of the magnet energy is stored in these capacitors. The characteristics of the inductor-converter bridge are briefly summarized as follows: low energy loss, reversibility of the energy transfer direction, controllability of the energy transfer rate, and no conversion to another energy form.

Hirano, M.; Kustom, R.L.

1983-07-01T23:59:59.000Z

36

Session 2b Hingorani  

Science Conference Proceedings (OSTI)

... Fuel Cell Flywheel Variable Speed Hydro Super Capacitor ... Utility Supply AC/DC Converter Battery or Flywheel Storage HF Converter ...

2012-09-24T23:59:59.000Z

37

A Bidirectional High-Power-Quality Grid Interface With a Novel Bidirectional Noninverted Buck Boost Converter for PHEVs  

Science Conference Proceedings (OSTI)

Plug-in hybrid electric vehicles (PHEVs) will play a vital role in future sustainable transportation systems due to their potential in terms of energy security, decreased environmental impact, improved fuel economy, and better performance. Moreover, new regulations have been established to improve the collective gas mileage, cut greenhouse gas emissions, and reduce dependence on foreign oil. This paper primarily focuses on two major thrust areas of PHEVs. First, it introduces a grid-friendly bidirectional alternating current/direct current ac/dc dc/ac rectifier/inverter for facilitating vehicle-to-grid (V2G) integration of PHEVs. Second, it presents an integrated bidirectional noninverted buck boost converter that interfaces the energy storage device of the PHEV to the dc link in both grid-connected and driving modes. The proposed bidirectional converter has minimal grid-level disruptions in terms of power factor and total harmonic distortion, with less switching noise. The integrated bidirectional dc/dc converter assists the grid interface converter to track the charge/discharge power of the PHEV battery. In addition, while driving, the dc/dc converter provides a regulated dc link voltage to the motor drive and captures the braking energy during regenerative braking.

Onar, Omer C [ORNL

2012-01-01T23:59:59.000Z

38

G I A. J. Brcslill, Director halt:: Protection Ci&ieerirG Divisio:l  

Office of Legacy Management (LM)

G G I A. J. Brcslill, Director halt:: Protection Ci&ieerirG Divisio:l H. Glauberrrrr: iiealt;: Protection &;'ineeri::i: Division SURVEY OF IIOOD BUILDING DECO~iTX.fIi~ATIO.:i . 'L. KSH: 3G I viz&Led t.:e Hood Buildiiig on July 3, 1763 wit:. Lr. R. C;iamberli!: axd NY. F. M!sce of the &scac..zetts Institute of Teci:;iolozy, Occupational Medical Service, Mr. R. Hoxell, Massac::usetIs Insti.t.ule of Tec:fioloGy, Btlilding Maintenance, and NE. P. Russo of Cx-Rad, to perform a fhal radiatioi: survey of the site remairs. Tr.e building was completely denolisi:ed except for t e baseme:% vizlls a:.d sections of tiie colicrete flax. All ~buildir;;: materials aid debris assodiated witri the demolition p?&se ilad bee:: removed from '~:ie si.Le a;ld properly

39

Stressing of turbine-generator-exciter shafts by variable-frequency currents superimposed on DC currents in asynchronous HVDC links and following disturbances at converter stations  

SciTech Connect

Ripple currents on the DC side of both HVDC synchronous and asynchronous. Links together with cleared HVDC and AC system disturbances can excite in some circumstances onerous torsional vibrations in large steam generator shafts. The problem has assumed importance in recent months on account of the HVDC Link between Scotland and Northern Ireland going ahead, on account of the proposed Eire/Wales Link, and because AC/DC/AC couplers are to be installed extensively to interconnect the East and West European Grid Systems. This paper discusses and analyses excitation of shaft torsional vibrations in steam turbine-generator-exciter shafts in close proximity to HVDC converter stations by (1) variable-frequency ripple currents superimposed on the DC currents in asynchronous Links, and (2) disturbances at bi-polar converter stations. The time response and tables show that for the systems studied variable-frequency ripple currents superimposed on the DC current in asynchronous Links can excite shaft torsional vibrations, the very small noncharacteristic currents could result in onerous shaft torques which might damage the machine, and that DC line faults at converter stations in close proximity of steam turbine-generator units can excite onerous turbine-generator shaft torsional response. Detailed simulation of the HVDC converter and generator is necessary for precise assessments of shaft torsional response following HVDC converter station faults. 500MW, 660MW, 1000MW and 1300MW machines are considered in the analyses that are made.

Hammons, T.J.; Bremner, J.J. (Univ. of Glasgow (United Kingdom))

1994-09-01T23:59:59.000Z

40

Interleaved power converter  

DOE Patents (OSTI)

A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

Zhu, Lizhi (Canton, MI)

2007-11-13T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Universal thermochemical energy converter  

DOE Patents (OSTI)

Disclosed are methods and apparatus for a thermochemical closed cycle employing a polyatomic, chemically active working fluid for converting heat energy into useful work.

Labinov, Solomon Davidovich (Oak Ridge, TN); Sand, James R. (Oak Ridge, TN); Conklin, James C. (Knoxville, TN); VanCoevering, James (Oak Ridge, TN); Courville, George E. (Oak Ridge, TN)

2001-01-01T23:59:59.000Z

42

Microminiature thermionic converters  

DOE Patents (OSTI)

Microminiature thermionic converts (MTCs) having high energy-conversion efficiencies and variable operating temperatures. Methods of manufacturing those converters using semiconductor integrated circuit fabrication and micromachine manufacturing techniques are also disclosed. The MTCs of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. Existing prior art thermionic converter technology has energy conversion efficiencies ranging from 5-15%. The MTCs of the present invention have maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

King, Donald B. (Albuquerque, NM); Sadwick, Laurence P. (Salt Lake City, UT); Wernsman, Bernard R. (Clairton, PA)

2001-09-25T23:59:59.000Z

43

Digital scale converter  

DOE Patents (OSTI)

A digital scale converter is provided for binary coded decimal (BCD) conversion. The converter may be programmed to convert a BCD value of a first scale to the equivalent value of a second scale according to a known ratio. The value to be converted is loaded into a first BCD counter and counted down to zero while a second BCD counter registers counts from zero or an offset value depending upon the conversion. Programmable rate multipliers are used to generate pulses at selected rates to the counters for the proper conversion ratio. The value present in the second counter at the time the first counter is counted to the zero count is the equivalent value of the second scale. This value may be read out and displayed on a conventional seven-segment digital display.

Upton, Richard G. (Oak Ridge, TN)

1978-01-01T23:59:59.000Z

44

STR_ConvertFormats  

Science Conference Proceedings (OSTI)

... 16. 17, True, AlngDat, dd-mmm-yy, ! Convert ... 18. 19, True, AlngDatTim, dd-mmm-yy hh:mm:ss, True, True, True, True, True, True, ! Display ...

2012-03-06T23:59:59.000Z

45

The Demand Side: Behavioral Patterns and Unpicked Low-Hanging Fruit  

U.S. Energy Information Administration (EIA) Indexed Site

The Demand Side: Behavioral Patterns and The Demand Side: Behavioral Patterns and Unpicked Low-Hanging Fruit James Sweeney Stanford University Director Precourt Energy Efficiency Center (Née: Precourt Institute for Energy Efficiency) Professor, Management Science and Engineering 6 Source: McKinsey & Co. Increased commercial space Gasoline Price Controls Compact Fluorescent Penetration LED: Traffic Lights, Task Lighting Appliance Energy Labeling Gasoline Rationing Much Incandescent Lighting Congestion Pricing Personal Computer Penetration Optimized Building Construction Overly Strict Building Standards Pigouvian Energy Tax Reduced Cost Decreased Energy Use "Smart" Regional Land Development Reformed Fuel Efficiency Standards Some Rail Rapid Transit Systems Efficient AC-DC Converters Halt SUV

46

Vector generator scan converter  

DOE Patents (OSTI)

High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O (input/output) channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardward for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold.

Moore, James M. (Livermore, CA); Leighton, James F. (Livermore, CA)

1990-01-01T23:59:59.000Z

47

Vector generator scan converter  

DOE Patents (OSTI)

High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.

Moore, J.M.; Leighton, J.F.

1988-02-05T23:59:59.000Z

48

Thermionic energy converters  

DOE Patents (OSTI)

A thermionic device for converting nuclear energy into electrical energy comprising a tubular anode spaced from and surrounding a cylindrical cathode, the cathode having an outer emitting surface of ruthenium, and nuclear fuel on the inner cylindrical surface. The nuclear fuel is a ceramic composition of fissionable material in a metal matrix. An axial void is provided to collect and contain fission product gases.

Monroe, Jr., James E. (Timonium, MD)

1977-08-09T23:59:59.000Z

49

Liquid metal thermal electric converter  

DOE Patents (OSTI)

A liquid metal thermal electric converter which converts heat energy to electrical energy. The design of the liquid metal thermal electric converter incorporates a unique configuration which directs the metal fluid pressure to the outside of the tube which results in the structural loads in the tube to be compressive. A liquid metal thermal electric converter refluxing boiler with series connection of tubes and a multiple cell liquid metal thermal electric converter are also provided.

Abbin, Joseph P. (Albuquerque, NM); Andraka, Charles E. (Albuquerque, NM); Lukens, Laurance L. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

50

Conceptual HALT (Hydrate Addition at Low Temperature) scaleup design: Capital and operating costs: Part 5. [Hydrate addition at low temperature for the removal of SO/sub 2/  

SciTech Connect

Hydrate addition at low temperature (or the HALT process) is a retrofit option for moderate SO/sub 2/ removal efficiency in coal burning utility plants. This dry FGD process involves injecting calcium based dry hydrate particles into flue gas ducting downstream of the air preheater where the flue gas temperature is typically in the range of 280-325/degree/F. This report is comprised of the conceptual scaleup design of the HALT process to a 180 MW and a 500 MW coal fired utility station followed by detailed capital and operating cost estimates. A cost sensitivity analysis of major process variables for the 500 MW unit is also included. 1 fig.

Babu, M.; Kerivan, D.; Hendrick, C.; Kosek, B.; Tackett, D.; Golightley, M.

1988-12-01T23:59:59.000Z

51

Cycloidal Wave Energy Converter  

SciTech Connect

This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

Stefan G. Siegel, Ph.D.

2012-11-30T23:59:59.000Z

52

DC systems with transformerless converters  

Science Conference Proceedings (OSTI)

A technical and economic feasibility study of HVDC systems without converter transformers is presented. The presentation includes proposed solutions to the drawback related to the absence of galvanic separation between the ac and dc systems, if the converter transformers are eliminated. The results show that HVDC systems without converter transformers are both technically and economically feasible. The cost savings can be substantial.

Vithayathil, J.J.; Mittlestadt, W. [Bonneville Power Administration, Portland, OR (United States); Bjoerklund, P.E. [ABB Power Systems AB, Ludvika (Sweden)

1995-07-01T23:59:59.000Z

53

Bidirectional buck boost converter  

DOE Patents (OSTI)

A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero. 20 figs.

Esser, A.A.M.

1998-03-31T23:59:59.000Z

54

Template for EPIC  

NLE Websites -- All DOE Office Websites (Extended Search)

of Work Explore functionality and performance of the bidirectional three-phase ac-dc microgrid-interface converter for the mediumhigh voltage applications, through the functional...

55

Advanced converter reactors  

SciTech Connect

Advanced converter reactors (ACRs) of primary US interest are those which can be commercialized within about 20 years, and are: Advanced Light-Water Reactors, Spectral-Shift-Control Reactors, Heavy-Water Reactors (CANDU type), and High-Temperature Gas-Cooled Reactors. These reactors can operate on uranium, thorium, or uranium-thorium fuel cycles, but have the greatest fuel utilization on thorium type cycles. The water reactors tend to operate more economically on uranium cycles, while the HTGR is more economical on thorium cycles. Thus, the HTGR had the greatest practical potential for improving fuel utilization. If the US has 3.4 to 4 million tons U/sub 3/O/sub 8/ at reasonable costs, ACRs can make important contributions to maintaining a high nuclear power level for many decades; further, they work well with fast breeder reactors in the long term under symbiotic fueling conditions. Primary nuclear data needs of ACRs are integral measurements of reactivity coefficients and resonance absorption integrals.

Kasten, P.R.

1979-01-01T23:59:59.000Z

56

Operation and Reference Manual for the NIST AC-DC ...  

Science Conference Proceedings (OSTI)

... D. The green START button is left in its ... Clicking on the lower right corner again renders these ... by the calibration program are in tab-delimited ASCII ...

2012-10-24T23:59:59.000Z

57

Greenhouse Gases Converted to Fuel  

NLE Websites -- All DOE Office Websites (Extended Search)

Greenhouse Greenhouse Gases Converted to Fuel Greenhouse Gases Converted to Fuel carbon-conversion-fig-1.jpg Key Challenges: An important strategy for reducing global CO2 emissions calls for capturing the greenhouse gas and converting it to fuels and chemicals. Although researchers working toward that goal demonstrated in 1992 such a reaction in the lab, a key outstanding scientific challenge was explaining the details of how the reaction took place - its "mechanism." Why it Matters: An important potential strategy for reducing global CO2 emissions calls for capturing the greenhouse gas and converting it electrochemically to fuels and chemicals. Accomplishments: Computation to explain how carbon dioxide can be converted to small organic molecules with little energy input. The

58

Ris-R-1118(EN) Power Control for Wind Tur-  

E-Print Network (OSTI)

storage or with an AC/DC converter and battery storage. The AC/DC converter can either be an "add-on" type installations, the cost of the power control is paid back as added wind power capacity value and saved grid reinforcement costs. Different systems for controlling the power output from a wind farm connected to a weak

59

Array Converter | Open Energy Information  

Open Energy Info (EERE)

Converter Converter Jump to: navigation, search Name Array Converter Place Sunnyvale, California Zip 94086 Product US manufacturer of micro-inverters. Coordinates 32.780338°, -96.547405° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":32.780338,"lon":-96.547405,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

60

Multilevel converters for power system applications  

SciTech Connect

Multilevel converters are emerging as a new breed of power converter options for power system applications. These converters are most suitable for high voltage high power applications because they connect devices in series without the need for component matching. One of the major limitations of the multilevel converters is the voltage unbalance between different levels. To avoid voltage unbalance between different levels, several techniques have been proposed for different applications. Excluding magnetic-coupled converters, this paper introduces three multilevel voltage source converters: (1) diode-clamp, (2) flying-capacitors, and (3) cascaded inverters with separate dc sources. The operation principle, features, constraints, and potential applications of these converters will be discussed.

Lai, J.S.; Stovall, J.P. [Oak Ridge National Lab., TN (United States); Peng, F.Z. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

1995-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Portable convertible blast effects shield  

DOE Patents (OSTI)

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

2007-05-22T23:59:59.000Z

62

Portable convertible blast effects shield  

DOE Patents (OSTI)

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

2010-10-26T23:59:59.000Z

63

Portable convertible blast effects shield  

DOE Patents (OSTI)

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A. (Livermore, CA)

2011-03-15T23:59:59.000Z

64

Converting Petroleum Coke to Electricity  

E-Print Network (OSTI)

Changes in oil refining technology and economics are driving refiners to utilize thermal processes to maximize the conversion of heavy crude oil components to clean products. Since the primary unit operation to accomplish this objective is the coking unit, more cokers are being built, and existing cokers are being operated to maximum capacity utilization. SRI recently completed an assignment for a refiner interested in converting the by-product fluid coke from his unit to electricity. This paper presents the operating history of US based plants converting petroleum coke to electricity, and presents generic economics for the conversion process utilizing three primary technologies available: conventional pulverized coke combustion, atmospheric fluidized bed combustion, and coke gasification combined cycle power production.

Pavone, A.

1992-04-01T23:59:59.000Z

65

Auxiliary resonant DC tank converter  

SciTech Connect

An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

Peng, Fang Z. (Knoxville, TN)

2000-01-01T23:59:59.000Z

66

Converting Energy to Medical Progress  

Office of Scientific and Technical Information (OSTI)

Converting Converting to April 2001 An introduction to the unique research funded by the Medical Sciences Division Biological and Environmental Research (BER) Office of Science, U.S. Department of Energy Nuclear Medicine E v e r y w h e r e i n He a l t h c a r e A n d s o do e s B E R N u c l e a r M e d i c i n e H e lps P a t i e n t s the Office of Biological and Environmental Research (BER) of the United States Department of Energy (DOE) has been investing to advance environmental and biomedical knowledge connected to energy. The BER Medical Sciences program fosters research to develop beneficial applications of nuclear technologies for medical diagnosis and treatment of many diseases. Today, nuclear medicine helps millions of patients annually in the United States. Nearly every nuclear medicine scan or test used today was made possible by

67

Converting Energy to Medical Progress  

NLE Websites -- All DOE Office Websites (Extended Search)

Converting Converting to April 2001 An introduction to the unique research funded by the Medical Sciences Division Biological and Environmental Research (BER) Office of Science, U.S. Department of Energy Nuclear Medicine E v e r y w h e r e i n He a l t h c a r e A n d s o do e s B E R N u c l e a r M e d i c i n e H e lps P a t i e n t s the Office of Biological and Environmental Research (BER) of the United States Department of Energy (DOE) has been investing to advance environmental and biomedical knowledge connected to energy. The BER Medical Sciences program fosters research to develop beneficial applications of nuclear technologies for medical diagnosis and treatment of many diseases. Today, nuclear medicine helps millions of patients annually in the United States. Nearly every nuclear medicine scan or test used today was made possible by

68

Technical Report NREL/TP-550-44082  

E-Print Network (OSTI)

gas DC direct current DC/DC DC-to-DC DERTF Distributed Energy Resources Test Facility DI de. This AC/DC power converter is undergoing upgrades that are expected to further increase the energy capture.............. 49 Figure 5-7: Realized and planned increase in energy capture from generation 1 through 3 AC/DC

69

Thermionic converter emitter support arrangement  

DOE Green Energy (OSTI)

This document discusses a support provided for use in a thermionic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end is supported by a spring structure that includes a pair of Belleville springs, and the spring structure is supported by a support structure fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element at the front end, a larger metal main support at the rear end that is attached to the housing, and with a ceramic layer between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer captured between the Belleville springs. 7 figs.

Allen, D.T.

1989-07-06T23:59:59.000Z

70

High Power Converters for Efficient Transmission Solutions  

Science Conference Proceedings (OSTI)

... Single Valve Double Valve Quadruple Valve ... Includes 14 x 250 MVA 1-phase converter ... Serves 80 x 5 MW offshore wind turbine generators ...

2013-03-01T23:59:59.000Z

71

Energy Converting Article and Method of Making  

A graded composite having a first energy-converting surface layer of carbon bonded carbon fiber (CBCF) for absorbing light, RF, microwaves, ...

72

Converting Unconditioned Basement to Conditioned Space - Code...  

NLE Websites -- All DOE Office Websites (Extended Search)

Conditioned Space - Code Notes Converting a basement to conditioned space increases the living space of a house. As with most construction activities, the conversion or...

73

Voltage Source Converter Technology for Offshore Grids.  

E-Print Network (OSTI)

??This master thesis has investigated the possible application of voltage source converters (VSC) for the interconnection of offshore installations, i.e. wind farms and petroleum platforms,… (more)

Vormedal, Pål Kristian Myhrer

2010-01-01T23:59:59.000Z

74

Vacuum-insulated catalytic converter  

DOE Patents (OSTI)

A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

Benson, David K. (Golden, CO)

2001-01-01T23:59:59.000Z

75

GTRI's Convert program | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

program | National Nuclear Security Administration program | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog GTRI's Convert program Home > About Us > Our Programs > Nonproliferation > Global Threat Reduction Initiative > GTRI's Convert program GTRI's Convert program One of Global Threat Reduction Initiative's (GTRI) three key pillars is

76

Waveguide mode converter and method using same  

DOE Patents (OSTI)

A waveguide mode converter converts electromagnetic power being transmitted in a TE.sub.0n or a TM.sub.0n mode, where n is an integer, to an HE.sub.11 mode. The conversion process occurs in a single stage without requiring the power to pass through any intermediate modes. The converter comprises a length of circular corrugated waveguide formed in a multiperiod periodic curve. The period of the curve is selected to couple the desired modes and decouple undesired modes. The corrugation depth is selected to control the phase propagation constant, or wavenumbers, of the input and output modes, thereby preventing coherent coupling to competing modes. In one embodiment, both the period and amplitude of the curve may be selectively adjusted, thereby allowing the converter to be tuned to maximize the conversion efficiency.

Moeller, Charles P. (Del Mar, CA)

1990-01-01T23:59:59.000Z

77

International Peirce-Smith Converting Centennial  

Science Conference Proceedings (OSTI)

... and G. Guzman D. Full Utilization of the Matte Converting Process Energy for Operatiing ... Injection Techniques, Modeling and Process Control. Peirce-Smith ... M. Marinigh. Increasing Capacity and Productivity in the Metals Markets through.

78

Radio frequency digital to analog converter  

E-Print Network (OSTI)

Dynamic performance of high speed, high resolution digital-to-analog converters (DACs) is limited by distortion at the data switching instants. Inter-symbol interference (ISI), imperfect timing synchronization and clock ...

Luschas, Susan, 1975-

2003-01-01T23:59:59.000Z

79

Integrated optical analog-to-digital converter  

E-Print Network (OSTI)

An optically-sampled frequency-demultiplexed wideband analog-to-digital converter (ADC) which has potential to exceed the performance of electronic ADCs by orders of magnitude is studied analytically and numerically. The ...

Khilo, Anatol

2008-01-01T23:59:59.000Z

80

Energy Performance Evaluation of Photovoltaic Power Converters  

Science Conference Proceedings (OSTI)

This work investigates test methods to compare the energy performance of different competing photovoltaic (PV) power converter technologies and topologies. New power converter approaches and technology are regularly introduced in the market, with promises to harness more energy than their competitors. To independently evaluate the performance of these technologies, the Electric Power Research Institute (EPRI) is analyzing existing standards, as well as experimenting with various performance ...

2013-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

ANALOG-TO-DIGITAL DATA CONVERTER  

DOE Patents (OSTI)

Electrical apparatus is described, particularly useful in telemetry work, for converting analog signals into electrical pulses and recording them. An electronic editor commands the taking of signal readings at a frequency which varies according to linearity of the analog signal being converted. Readings of information signals are recorded, along with time base readings and serial numbering, if desired, on magnetic tape and the latter may be used to operate a computer or the like. Magnetic tape data may be transferred to punched cards.

Rodgers, G.W.; Althouse, J.E.; Anderson, D.P.; Bussey, G.R.; Minnear, L.H.

1960-09-01T23:59:59.000Z

82

Alternative Fuels Data Center: Michigan Converts Vehicles to Propane,  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Michigan Converts Michigan Converts Vehicles to Propane, Reducing Emissions to someone by E-mail Share Alternative Fuels Data Center: Michigan Converts Vehicles to Propane, Reducing Emissions on Facebook Tweet about Alternative Fuels Data Center: Michigan Converts Vehicles to Propane, Reducing Emissions on Twitter Bookmark Alternative Fuels Data Center: Michigan Converts Vehicles to Propane, Reducing Emissions on Google Bookmark Alternative Fuels Data Center: Michigan Converts Vehicles to Propane, Reducing Emissions on Delicious Rank Alternative Fuels Data Center: Michigan Converts Vehicles to Propane, Reducing Emissions on Digg Find More places to share Alternative Fuels Data Center: Michigan Converts Vehicles to Propane, Reducing Emissions on AddThis.com... April 27, 2013

83

State Energy Program Helping Arkansans Convert to Compressed...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

State Energy Program Helping Arkansans Convert to Compressed Natural Gas State Energy Program Helping Arkansans Convert to Compressed Natural Gas January 25, 2012 - 4:30pm Addthis...

84

Isolated and soft-switched power converter  

DOE Patents (OSTI)

An isolated and soft-switched power converter is used for DC/DC and DC/DC/AC power conversion. The power converter includes two resonant tank circuits coupled back-to-back through an isolation transformer. Each resonant tank circuit includes a pair of resonant capacitors connected in series as a resonant leg, a pair of tank capacitors connected in series as a tank leg, and a pair of switching devices with anti-parallel clamping diodes coupled in series as resonant switches and clamping devices for the resonant leg. The power converter is well suited for DC/DC and DC/DC/AC power conversion applications in which high-voltage isolation, DC to DC voltage boost, bidirectional power flow, and a minimal number of conventional switching components are important design objectives. For example, the power converter is especially well suited to electric vehicle applications and load-side electric generation and storage systems, and other applications in which these objectives are important. The power converter may be used for many different applications, including electric vehicles, hybrid combustion/electric vehicles, fuel-cell powered vehicles with low-voltage starting, remote power sources utilizing low-voltage DC power sources, such as photovoltaics and others, electric power backup systems, and load-side electric storage and generation systems.

Peng, Fang Zheng (Knoxville, TN); Adams, Donald Joe (Knoxville, TN)

2002-01-01T23:59:59.000Z

85

Thermionic converters using cylindrical refractory metal emitters  

DOE Green Energy (OSTI)

The construction and operation of four converters is described. Two converters using tantalum emitters operated satisfactorily but temperatures of the order of 2500 deg K were necessary to obtain power densities of 6 watts/cm2. Closer spaced diodes using molybdenum emitters were not initially successful due to internal short circuiting; this was caused partly by evaporated films but mainly by liquid caesium. One of these diodes was modified and yielded 2.6 watts/cm2 at 1610 deg K. (auth)

Bainton, K.F.

1964-09-15T23:59:59.000Z

86

Provably secure convertible undeniable signatures with unambiguity  

Science Conference Proceedings (OSTI)

This paper shows some efficient and provably-secure convertible undeniable signature schemes (with both selective conversion and all conversion), in the standard model and discrete logarithm setting. They further satisfy unambiguity, which is traditionally ... Keywords: anonymous signatures, discrete logarithm, selective/all conversion, standard model, undeniable signatures

Le Trieu Phong; Kaoru Kurosawa; Wakaha Ogata

2010-09-01T23:59:59.000Z

87

Multilevel converters for large electric drives  

SciTech Connect

Traditional two-level high frequency pulse width modulation (PWM) inverters for motor drives have several problems associated with their high frequency switching which produces common-mode voltage and high voltage change (dV/dt) rates to the motor windings. Multilevel inverters solve these problems because their devices can switch at a much lower frequency. Two different multilevel topologies are identified for use as a converter for electric drives, a cascade inverter with separate dc sources and a back-to-back diode clamped converter. The cascade inverter is a natural fit for large automotive all electric drives because of the high VA ratings possible and because it uses several levels of dc voltage sources which would be available from batteries or fuel cells. The back to back diode damped converter is ideal where a source of ac voltage is available such as a hybrid electric vehicle. Simulation and experimental results show the superiority of these two converters over PWM based drives.

Tolbert, L.M.; Peng, F.Z.

1997-11-01T23:59:59.000Z

88

A square root analog to digital converter to optimally convert photonic signals for computed tomography  

E-Print Network (OSTI)

The arrival of photons at a given location is a Poisson process with an associated shot noise which rises with the square root of the number of photons received. An analog-to-digital converter (ADC) with a square root ...

Bieniosek, Matthew (Matthew F.)

2010-01-01T23:59:59.000Z

89

Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Landfills Convert Landfills Convert Biogas Into Renewable Natural Gas to someone by E-mail Share Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable Natural Gas on Facebook Tweet about Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable Natural Gas on Twitter Bookmark Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable Natural Gas on Google Bookmark Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable Natural Gas on Delicious Rank Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable Natural Gas on Digg Find More places to share Alternative Fuels Data Center: Landfills Convert Biogas Into Renewable Natural Gas on AddThis.com... May 25, 2013 Landfills Convert Biogas Into Renewable Natural Gas

90

Component technology for Stirling power converters  

DOE Green Energy (OSTI)

NASA Lewis Research Center has organized a component technology program as part of the efforts to develop Stirling converter technology for space power applications. The Stirling space power program is part of the NASA High Capacity Power Project of the Civil Space Technology Initiative (CSTI). NASA Lewis is also providing technical management for a DOE/Sandia program to develop Stirling converters for solar terrestrial power producing electricity for the utility grid. The primary contractors for the space power and solar terrestrial programs develop component technologies directly related to their program goals. This Lewis component technology effort, while coordinated with the main programs, aims at longer term issues, advanced technologies, and independent assessments. This paper will present an overview of work on linear alternators, engine/alternator/load interactions and controls, heat exchangers, materials, life and reliability, and bearings.

Thieme, L.G.

1994-09-01T23:59:59.000Z

91

APPARATUS FOR CONVERTING HEAT INTO ELECTRICITY  

DOE Patents (OSTI)

This patent shows an apparatus for converting heat to electricity. It includes a galvanic cell having an anodic metal anode, a fused salt electrolyte, and a hydrogen cathode having a diffusible metal barrier of silver-- palladium alloy covered with sputtered iron on the side next to the fused electrolyte. Also shown is a regenerator for regenerating metal hydride produced by the galvanic cell into hydrogen gas and anodic metal, both of which are recycled. (AEC)

Crouthamel, C.E.; Foster, M.S.

1964-01-28T23:59:59.000Z

92

Spectral converters and luminescent solar concentrators  

E-Print Network (OSTI)

In this paper we present a comprehensive theoretical description of molecular spectral converters in the specific context of Luminescent Solar Concentrators (LSCs). The theoretical model is an extension to a three-level system interacting with a solar radiation bath of the standard quantum theory of atomic radiative processes. We derive the equilibrium equations of the conversion process and provide specific examples of application of this principle to the development of solar concentration devices.

Petra F. Scudo; Luigi Abbondanza; Roberto Fusco

2009-07-21T23:59:59.000Z

93

Spectral converters and luminescent solar concentrators  

E-Print Network (OSTI)

In this paper we present a comprehensive theoretical description of molecular spectral converters in the specific context of Luminescent Solar Concentrators (LSCs). The theoretical model is an extension to a three-level system interacting with a solar radiation bath of the standard quantum theory of atomic radiative processes. We derive the equilibrium equations of the conversion process and provide specific examples of application of this principle to the development of solar concentration devices.

Scudo, Petra F; Fusco, Roberto

2009-01-01T23:59:59.000Z

94

Fuzzy Logic Controller for Enhancement of Transient Stability in Multi Machine AC-DC Power Systems  

Science Conference Proceedings (OSTI)

This paper discusses the impact of HVDC on Power System Stability and proposes a new type of control mechanism based on Fuzzy set theory to augment dynamic performance of a multi-machine power system. To have good damping characteristics over a wide ... Keywords: HVDC, Power System Stability, Multi-Machine Stability, Fuzzy Logic Controller

M. Uma Vani; P. V. Ramana Rao

2010-11-01T23:59:59.000Z

95

A VECTOR ENERGY FUNCTION APPROACH FOR SECURITY ANALYSIS OF AC/DC SYSTEMS  

E-Print Network (OSTI)

This paper examines dynamic behavior in system models that reflect reasonably detailed (third order) HVDC dynamics along with ac system models that include reactive flows, and frequency and voltage dependent load models. A vector Lyapunov function approach is employed to define a system wide energy function that can be used for general security analysis. The paper describes the derivation of individual component Lyapunov functions for simplified models of HVDC links connected to "infinitely strong" ac systems, along with a standard ac only system Lyapunov function. A novel method of obtaining weighting coefficients to sum these components for the overall system energy function is proposed. Use of the new energy function for transient stability and security analysis is illustrated in a test system.

Christopher L. DeMarco; Claudio A. Cañizares

1992-01-01T23:59:59.000Z

96

Optimal design of mixed AC-DC distribution systems for commercial buildings.  

E-Print Network (OSTI)

??With the advent of inexpensive computing and efficient power electronics, the load mix in commercial buildings has experienced a fundamental shift away from almost exclusively… (more)

Frank, Stephen M.

2013-01-01T23:59:59.000Z

97

AC/DC Smart Control and Power Sharing of DC Distribution Systems.  

E-Print Network (OSTI)

?? The purpose of this research is to develop a grid connected DC distribution system to ensure efficient integration of different alternate sources to the… (more)

Elshaer, Mohamed A

2012-01-01T23:59:59.000Z

98

Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Virginia Converts Virginia Converts Vehicles to Propane in Spotsylvania County to someone by E-mail Share Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in Spotsylvania County on Facebook Tweet about Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in Spotsylvania County on Twitter Bookmark Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in Spotsylvania County on Google Bookmark Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in Spotsylvania County on Delicious Rank Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in Spotsylvania County on Digg Find More places to share Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in Spotsylvania County on AddThis.com...

99

Alternative Fuels Data Center: Empire Coachworks Converts Limousines to  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Empire Coachworks Empire Coachworks Converts Limousines to Natural Gas to someone by E-mail Share Alternative Fuels Data Center: Empire Coachworks Converts Limousines to Natural Gas on Facebook Tweet about Alternative Fuels Data Center: Empire Coachworks Converts Limousines to Natural Gas on Twitter Bookmark Alternative Fuels Data Center: Empire Coachworks Converts Limousines to Natural Gas on Google Bookmark Alternative Fuels Data Center: Empire Coachworks Converts Limousines to Natural Gas on Delicious Rank Alternative Fuels Data Center: Empire Coachworks Converts Limousines to Natural Gas on Digg Find More places to share Alternative Fuels Data Center: Empire Coachworks Converts Limousines to Natural Gas on AddThis.com... Jan. 14, 2010 Empire Coachworks Converts Limousines to Natural Gas

100

Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Atlanta Airport Atlanta Airport Converts Shuttles to CNG to someone by E-mail Share Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Facebook Tweet about Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Twitter Bookmark Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Google Bookmark Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Delicious Rank Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Digg Find More places to share Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on AddThis.com... Sept. 9, 2012 Atlanta Airport Converts Shuttles to CNG L earn how an Atlanta company saves money and conserves fuel with compressed natural gas airport shuttles.

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Veolia Transportation Veolia Transportation Converts Taxi Fleet to Propane to someone by E-mail Share Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to Propane on Facebook Tweet about Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to Propane on Twitter Bookmark Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to Propane on Google Bookmark Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to Propane on Delicious Rank Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to Propane on Digg Find More places to share Alternative Fuels Data Center: Veolia Transportation Converts Taxi Fleet to Propane on AddThis.com... Aug. 17, 2013 Veolia Transportation Converts Taxi Fleet to Propane

102

2008 High-Megawatt Power Converter Technology R&D ...  

Science Conference Proceedings (OSTI)

... 2008 High-Megawatt Power Converter Technology R&D Roadmap Workshop. NIST, Gaithersburg, MD. April 8, 2008. On ...

2013-05-30T23:59:59.000Z

103

Solid state transport-based thermoelectric converter - Energy ...  

A solid state thermoelectric converter includes a thermally insulating separator layer, ... Advanced Materials; Biomass and Biofuels; Building Energy Efficiency;

104

Voltage balanced multilevel voltage source converter system  

SciTech Connect

A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

1997-01-01T23:59:59.000Z

105

Voltage balanced multilevel voltage source converter system  

SciTech Connect

Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

Peng, F.Z.; Lai, J.S.

1997-07-01T23:59:59.000Z

106

Solar-energy-process-converter system  

SciTech Connect

A solar-energy-process-converter system whereby the energy from the sun is accumulated and projected by a parabolic reflector so as to impinge upon a cluster of thermocouples to create electrical energy for activating an electrolysis unit through which hydrogen and oxygen are generated and stored. The system can also include a steam-turbine electrical-generator plant that is adapted to be operated by the burning of the hydrogen and oxygen, and the gases can further be used to establish heat to drive a thermocouple electrical-generator plant, wherein the stored hydrogen is further employed as a fuel for vehicle and other engines.

Shinn, W.A.

1981-01-20T23:59:59.000Z

107

Single Inductor Dual Output Buck Converter  

E-Print Network (OSTI)

The portable electronics market is rapidly migrating towards more compact devices with multiple functionalities. Form factor, performance, cost and efficiency of these devices constitute the factors of merit of devices like cell phones, MP3 players and PDA's. With advancement in technology and more intelligent processors being used, there is a need for multiple high integrity voltage supplies for empowering the systems in portable electronic devices. Switched mode power supplies (SMPS's) are used to regulate the battery voltage. In an SMPS, maximum area is taken by the passive components such as the inductor and the capacitor. This work demonstrates a single inductor used in a buck converter with two output voltages from an input battery with voltage of value 3V. The main focus areas are low cross regulation between the outputs and supply of completely independent load current levels while maintaining desired values (1.2V,1.5V) within well controlled ripple levels. Dynamic hysteresis control is used for the single inductor dual output buck converter in this work. Results of schematic and post layout simulations performed in CADENCE prove the merits of this control method, such as nil cross regulation and excellent transient response.

Eachempatti, Haritha

2009-05-01T23:59:59.000Z

108

Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Golden Eagle Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG to someone by E-mail Share Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG on Facebook Tweet about Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG on Twitter Bookmark Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG on Google Bookmark Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG on Delicious Rank Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG on Digg Find More places to share Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG on AddThis.com...

109

Converting syncrudes to transportation fuels: Appendix 1  

DOE Green Energy (OSTI)

Syncrudes derived from oil shale and those produced in direct coal liquefaction processes can be converted to transportation fuels using modern commercial hydroprocessing technology. Upgrading routes typically consist of hydrogen addition and removal of heteroatom and inorganic impurities. This paper reviews refining routes and discusses the properties of finished transportation fuel products (gasoline, jet fuel, diesel) produced from syncrudes. Fuels produced from bituminous coal, subbituminous coal, and lignite are contrasted with those produced from oil shale and petroleum. Transportation fuels from shale oil resemble those from waxy petroleum crudes. Upgraded products from liquids made in H-Coal, EDS, and SRC-II direct coal liquefaction processes are low in paraffin content and consist mainly of cyclic hydrocarbons. As a result, the latter have some unusual and desirable properties for transportation fuels. 14 refs., 8 figs., 8 tabs.

Sullivan, R.F.; O'Rear, D.J.; Frumkin, H.A.

1981-01-01T23:59:59.000Z

110

Converting energy from fusion into useful forms  

E-Print Network (OSTI)

If fusion power reactors are to be feasible, it will still be necessary to convert the energy of the nuclear reaction into usable form. The heat produced will be removed from the reactor core by a primary coolant, which might be water, helium, molten lithium-lead, molten lithium-containing salt, or CO2. The heat could then be transferred to a conventional Rankine cycle or Brayton (gas turbine) cycle. Alternatively it could be used for thermochemical processes such as producing hydrogen or other transport fuels. Fusion presents new problems because of the high energy neutrons released. These affect the selection of materials and the operating temperature, ultimately determining the choice of coolant and working cycle. The limited temperature ranges allowed by present day irradiated structural materials, combined with the large internal power demand of the plant, will limit the overall thermal efficiency. The operating conditions of the fusion power source, the materials, coolant, and energy conversion system w...

Kovari, M; Jenkins, I; Kiely, C

2014-01-01T23:59:59.000Z

111

Modular Power Converters for PV Applications  

DOE Green Energy (OSTI)

This report describes technical opportunities to serve as parts of a technological roadmap for Shoals Technologies Group in power electronics for PV applications. There are many different power converter circuits that can be used for solar inverter applications. The present applications do not take advantage of the potential for using common modules. We envision that the development of a power electronics module could enable higher reliability by being durable and flexible. Modules would have fault current limiting features and detection circuits such that they can limit the current through the module from external faults and can identify and isolate internal faults such that the remaining modules can continue to operate with only minimal disturbance to the utility or customer. Development of a reliable, efficient, low-cost, power electronics module will be a key enabling technology for harnessing more power from solar panels and enable plug and play operation. Power electronics for computer power supplies, communication equipment, and transportation have all targeted reliability and modularity as key requirements and have begun concerted efforts to replace monolithic components with collections of common smart modules. This is happening on several levels including (1) device level with intelligent control, (2) functional module level, and (3) system module. This same effort is needed in power electronics for solar applications. Development of modular units will result in standard power electronic converters that will have a lower installed and operating cost for the overall system. These units will lead to increased adaptability and flexibility of solar inverters. Incorporating autonomous fault current limiting and reconfiguration capabilities into the modules and having redundant modules will lead to a durable converter that can withstand the rigors of solar power generation for more than 30 years. Our vision for the technology roadmap is that there is no need for detailed design of new power converters for each new application or installation. One set of modules and controllers can be pre-developed and the only design question would be how many modules need to be in series or parallel for the specific power requirement. Then, a designer can put the modules together and add the intelligent reconfigurable controller. The controller determines how many modules are connected, but it might also ask for user input for the specific application during setup. The modules include protection against faults and can reset it, if necessary. In case of a power device failure, the controller reconfigures itself to continue limited operation until repair which might be as simple as taking the faulty module out and inserting a new module. The result is cost savings in design, maintenance, repair, and a grid that is more reliable and available. This concept would be a perfect fit for the recently announced funding opportunity announcement (DE-FOA-0000653) on Plug and Play Photovoltaics.

Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL

2012-05-01T23:59:59.000Z

112

Integrated Solar Power Converters: Wafer-Level Sub-Module Integrated DC/DC Converter  

Science Conference Proceedings (OSTI)

Solar ADEPT Project: CU-Boulder is developing advanced power conversion components that can be integrated into individual solar panels to improve energy yields. The solar energy that is absorbed and collected by a solar panel is converted into useable energy for the grid through an electronic component called an inverter. Many large, conventional solar energy systems use one, central inverter to convert energy. CU-Boulder is integrating smaller, microinverters into individual solar panels to improve the efficiency of energy collection. The University’s microinverters rely on electrical components that direct energy at high speeds and ensure that minimal energy is lost during the conversion process—improving the overall efficiency of the power conversion process. CU-Boulder is designing its power conversion devices for use on any type of solar panel.

None

2012-02-09T23:59:59.000Z

113

Manufacturing cost of flame heated thermionic converters. Topical report  

DOE Green Energy (OSTI)

The cost of thermionic converters has been estimated in support of the cost calculations for thermionic topping of central station powerplants. These calculations supersede the previous calculations made in 1975 and use a design concept similar to the current configuration of flame-heated converters. The cost of converters was estimated by obtaining quotations from manufactureres whenever possible. The selling cost was found to be $110 per kilowatt.

LaRue, G.; Miskolczy, G.

1979-04-01T23:59:59.000Z

114

Modeling and Controller Design of a Wind Energy Conversion System Including a Matrix Converter.  

E-Print Network (OSTI)

??In this thesis, a grid-connected wind-energy converter system including a matrix converter is proposed. The matrix converter, as a power electronic converter, is used to… (more)

Barakati, Seyed Masoud

2008-01-01T23:59:59.000Z

115

GTRI's Convert Program: Minimizing the Use of Highly Enriched...  

NLE Websites -- All DOE Office Websites (Extended Search)

Flickr RSS Twitter YouTube GTRI's Convert Program: Minimizing the Use of Highly Enriched Uranium | National Nuclear Security Administration Our Mission Managing the Stockpile...

116

Improvements on Converter Operating Practice at Mufulira Smelter ...  

Science Conference Proceedings (OSTI)

Abstract Scope, With the commisioning of the 850,000 tonnes of Concentrate treated per annum capacity Isasmelt in September 2006 the Converter section ...

117

Research Projects to Convert Captured CO2 Emissions to Useful...  

NLE Websites -- All DOE Office Websites (Extended Search)

July 06, 2010 Research Projects to Convert Captured CO2 Emissions to Useful Products Six Projects Selected by DOE Will Further Important Technologies for Helping Reduce CO2...

118

Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Chu announced six projects that aim to find ways of convert captured carbon dioxide (CO2) emissions from industrial sources into useful products. The innovative projects -...

119

Method of converting an existing vehicle powertrain to a hybrid ...  

A method of converting an existing vehicle powertrain including a manual transmission to a hybrid powertrain system with an automated powertrain transmission. The ...

120

Design and Testing of a Thermoacoustic Power Converter .  

E-Print Network (OSTI)

??Thermoacoustic engines convert heat into acoustic pressure waves with no moving parts; this inherently results in high reliability, low maintenance and low manufacturing costs. Significant… (more)

Telesz, Mark P.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Converting sensitive waste into cleaner energy  

DOE Green Energy (OSTI)

The destruction of sensitive unclassified information (SUI) has always been expensive due to the need for special controls to ensure its protection from disclosure to unauthorized persons. The sensitive documents were shredded, buried at the landfill, or sent to a recycling company. The Department of Energy (DOE) Idaho National Engineering and Environmental Laboratory (INEEL), operated by Lockheed Martin Idaho Technologies Company (LMITCO), has created an innovative method to dispose of its sensitive unclassified paper waste which has security, economic, and environmental benefits. A new cubing facility at the INEEL converts office and industrial waste into compact cubes which are then combined with coal and burned as a source of heat and process steam to run the Idaho Chemical Processing Plant (ICPP) facility. The process-engineered fuel, consisting of 25% cubes and 75% coal, bums cleaner than coal with lower emissions of sulfur dioxide and nitrogen oxides. The alternative fuel also reduces fuel costs, eliminates paying a recycling company, reduces the expense of landfill disposal, increases the life of the landfill, and provides energy to operate a large facility. The Operations Security (OPSEC) team capitalized on this waste to energy technology by recommending that the large quantities of sensitive information (documents) generated at the INEEL be disposed of in this manner. In addition to the economic and environmental benefits, this disposal method minimizes the vulnerabilities of SUI from disclosure to unauthorized personnel. The {open_quotes}cuber{close_quotes} technology has potential application in government and industry for protection of SUI.

Schriner, D.; Skinner, R.

1997-10-01T23:59:59.000Z

122

Converter-fed subsea motor drives  

SciTech Connect

A subsea adjustable-speed motor fed via a long cable in range of several tens of kilometers between the converter and the motor are analyzed by simulations. Due to resonance, one critical frequency range occurs where significant generation of harmonics from the inverter should be avoided. A voltage source inverter is more feasible than a current source inverter since it is easier to modify the output waveform in order to avoid resonance problems. The resistive voltage drop in the long cable reduces the air-gap torque of the motor particular at low frequencies. This causes a problem for the start-up of the motor due to stiction torque. A start-up strategy is envisaged which is a compromise between voltage boost, inverter current, and transformer core dimensions. In normal operation mode the inverter voltage is proportional to the frequency. An open speed lop is used which keeps the system stable for potential load variations. The results from a 1-MW full-scale system test are summarized.

Raad, R.O.; Raphael, H.B. [Statoil, Stavanger (Norway); Henriksen, T. [Norwegian Electric Power Research Inst., Trondheim (Norway); Hadler-Jacobsen, A. [Framo Engineering AS, Nesttun (Norway)

1996-09-01T23:59:59.000Z

123

Ocean tide energy converter having improved efficiency  

Science Conference Proceedings (OSTI)

A tide motor useful for converting periodic rising and falling water levels to useful work such as electric power generation includes a primary piston having a large enclosed chamber that can selectively be filled with air for generation of upward thrust when submerged in rising tidal water or filled with water for generating downward gravitational thrust when the piston is suspended in air above a dropping tidal water level. Cyclic filling and emptying of the chamber is programmed to coordinate piston positions and water level positions, and the piston can be locked in either up or down position to achieve maximum flotation and gravitational thrust forces. An auxiliary tidal piston that can be locked in a down position has an upper water chamber provided with flood valves and an air filled, sealed flotation chamber below. The auxiliary piston is located near the primary piston, and is designed to have positive buoyancy when its respective chambers are filled with water and air. The lower area of the water chamber of the auxiliary piston is connected to the lower area of the primary piston chamber by a valve conduit so the primary piston chamber can be filled with water at its high position while it is locked up by releasing the auxiliary piston to float upwardly with its water chamber filled, and placing the primary and auxiliary piston chambers in communication with each other so water flows from the latter into the former until the primary piston chamber is filled with water before it begins its downward stroke after the water level has dropped below it. After the primary piston has completed its downward stroke, its interior chamber is drained and sealed in preparation for its next upward stroke on the next rising tide, and the water chamber of the auxiliary piston is refilled in preparation for the next cycle of operation.

Rainey, D.E.

1980-01-29T23:59:59.000Z

124

Converting hard copy documents for electronic dissemination  

SciTech Connect

Since the advent of computer systems, the goal of a paperless office, and even a paperless society, has been pursued. While the normal paper flow in an organization is far from totally automated, particularly for items requiring signatures or authorizations, electronic information dissemination is becoming an almost simple task. The reasons for providing on-line documents are many and include faster and easier access for everyone, elimination of printing costs, reduction of wasted shelf and desk space, and the security of having a centrally-located, always up-to-date document. New computer software even provides the user with the ability to annotate documents and to have bookmarks so that the old scribbled-in and dog-eared manual can be replaced without loosing this `customizability`. Moreover, new hypermedia capabilities mean that documents can be read in a non-linear fashion and can include color figures and photographs, audio, and even animation sequences, capabilities which exceed those of paper. The proliferation of network-based information servers, coupled with the growth of the Internet, has enticed academic, governmental, and even commercial organizations to provide increasing numbers of documents and data bases in electronic form via the network, not just to internal staff, but to the public as well. Much of this information, which includes everything from mundane company procedures to spiffy marketing brochures, was previously published only in hard copy. Converting existing documents to electronic form and producing only electronic versions of new documents poses some interesting challenges to the maintainer or author.

Hoffman, F.

1994-12-31T23:59:59.000Z

125

Radio Interference From HVDC Converter Stations, Modeling and Characterization  

Science Conference Proceedings (OSTI)

High-voltage direct-current converter stations generate electromagnetic interference (EMI) that can affect the performance of nearby electronic equipment. A prototype computer program that calculates EMI characteristics in the 5-500-kHz range will enable utility engineers to determine the extent of such interference during the design stage of a converter station.

1986-12-16T23:59:59.000Z

126

Adaptive decentralised control of parallel DC-DC converter systems  

Science Conference Proceedings (OSTI)

In this paper, we develop a robust controller for parallel DC-DC converter system by combining the adaptive backstepping technique and decentralised control. The voltages and currents of all converters are coupled with each other. The parallel DC-DC ...

Jing Zhou

2012-08-01T23:59:59.000Z

127

Learning/teaching graphical user interface based power electronic converters  

Science Conference Proceedings (OSTI)

This paper presents an intuitive graphical user interface for simulation of various topologies of power electronic converters. The simulator is developed using the GUIDE tool of MATLAB®, which acts as a front-end interface that can be ... Keywords: MATLAB®/SIMULINK®, converter design, power electronics teaching tool

S. Doolla; T. S. Bhatti

2006-01-01T23:59:59.000Z

128

The frequency dependent impedance of an HVdc converter  

Science Conference Proceedings (OSTI)

A linear and direct method of determining the frequency dependent impedance of a 12 pulse HVdc converter is presented. Terms are developed for both the dc and ac side impedances of the converter, including the effect of the firing angle control system, the commutation period, and the variability of the commutation period. The impedance predictions are verified by dynamic simulation.

Wood, A.R.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)

1995-07-01T23:59:59.000Z

129

Magnet Technology for Power Converters: Nanocomposite Magnet Technology for High Frequency MW-Scale Power Converters  

Science Conference Proceedings (OSTI)

Solar ADEPT Project: CMU is developing a new nanoscale magnetic material that will reduce the size, weight, and cost of utility-scale PV solar power conversion systems that connect directly to the grid. Power converters are required to turn the energy that solar power systems create into useable energy for the grid. The power conversion systems made with CMU’s nanoscale magnetic material have the potential to be 150 times lighter and significantly smaller than conventional power conversion systems that produce similar amounts of power.

None

2012-02-27T23:59:59.000Z

130

MHK Technologies/The DEXAWAVE wave energy converter | Open Energy  

Open Energy Info (EERE)

DEXAWAVE wave energy converter DEXAWAVE wave energy converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage The DEXAWAVE wave energy converter.jpg Technology Profile Primary Organization Dexawave Technology Readiness Level Click here TRL 7 8 Open Water System Testing Demonstration and Operation Technology Description The DEXAWAVE wave energy converter has a simple construction It consists of two rigid pontoons hinged together using a patented hinge The one pontoon can pivot relative to the other There is a hydraulic power take off system on top of the converter generating up to 250 kW Technology Dimensions Technology Nameplate Capacity (MW) 25 Device Testing Scale Test *At present our 1 to 5 scale model is working the waters outside the Danish port of Hanstholm collecting valuable data about the waves and currents that are constantly pounding the structure

131

State Energy Program Helping Arkansans Convert to Compressed Natural Gas |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

State Energy Program Helping Arkansans Convert to Compressed State Energy Program Helping Arkansans Convert to Compressed Natural Gas State Energy Program Helping Arkansans Convert to Compressed Natural Gas January 25, 2012 - 4:30pm Addthis The Arkansas Energy Office recently launched a Compressed Natural Gas Conversion Rebate Program, which provides incentives for fleets and individuals to purchase and/or convert their Arkansas-licensed vehicles to compressed natural gas (CNG). | All Rights Reserved. The Arkansas Energy Office recently launched a Compressed Natural Gas Conversion Rebate Program, which provides incentives for fleets and individuals to purchase and/or convert their Arkansas-licensed vehicles to compressed natural gas (CNG). | All Rights Reserved. Grayson Bryant Project Officer -- State Energy Program

132

MHK Technologies/Magnetohydrodynamic MHD Wave Energy Converter MWEC | Open  

Open Energy Info (EERE)

Magnetohydrodynamic MHD Wave Energy Converter MWEC Magnetohydrodynamic MHD Wave Energy Converter MWEC < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Magnetohydrodynamic MHD Wave Energy Converter MWEC.jpg Technology Profile Primary Organization Scientific Applications Research Associates Inc SARA Technology Resource Click here Wave Technology Type Click here Point Absorber - Submerged Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description The Magnetohydrodynamic MHD Wave Energy Converter couples the up down motion of heave based systems A shaft transfers wave motion to the MHD generator which is deep underwater The shaft forces the conducting fluid through a set of powerful permanent magnets creating a low voltage high current electrical energy An electrical inverter converts the electrical energy to commercial quality 60 Hz AC power

133

A computer program for HVDC converter station RF noise calculations  

SciTech Connect

HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

1994-04-01T23:59:59.000Z

134

A study of Schwarz converters for nuclear powered spacecraft  

DOE Green Energy (OSTI)

High power space systems which use low dc voltage, high current sources such as thermoelectric generators, will most likely require high voltage conversion for transmission purposes. This study considers the use of the Schwarz resonant converter for use as the basic building block to accomplish this low-to-high voltage conversion for either a dc or an ac spacecraft bus. The Schwarz converter has the important assets of both inherent fault tolerance and resonant operation and parallel operation in modular form is possible. A regulated dc spacecraft bus requires only a single stage converter while a constant frequency ac bus requires a cascaded Schwarz converter configuration. If the power system requires constant output power from the dc generator, then a second converter is required to route unneeded power to a ballast load.

Stuart, T.A. [Univ. of Toledo, OH (United States); Schwarze, G.E. [Lewis Research Center, Cleveland, OH (United States)

1994-09-01T23:59:59.000Z

135

Fission converter heat removal and safety under accident conditions  

Science Conference Proceedings (OSTI)

The design and safety of the heat removal system of the Massachusetts Institute of Technology (MIT) design for a fission converter-based epithermal beam is discussed in this paper. Plate-type reactor fuel elements, used in the MIT research reactor (MITR-II), are also used for the fission converter. This fission converter-based beam provides epithermal neutron fluxes at the patient position in excess of 10{sup 10} n/cm{sup 2}s with very low contamination of fast neutrons and gamma rays.

Sutharshan, B.; Todreas, N.E.; Harling, O.K. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

1996-12-31T23:59:59.000Z

136

Prediction of core saturation instability at an HVDC converter  

SciTech Connect

Core saturation instability has occurred on several HVDC schemes resulting from interactions between second harmonic and dc quantities (voltages and currents) on the ac side of the converter and fundamental frequency quantities on the dc side of the converter. The instability can be reinforced by unbalanced saturation of the converter transformers. The paper presents an analytical method which can be used to quickly screen ac and dc system operating conditions to predict where core saturation instability is likely to occur. Analytical results have been confirmed using the digital transients simulation program PSCAD/EMTDC.

Burton, R.S. [Teshmont Consultants, Inc., Winnipeg, Manitoba (Canada); Fuchshuber, C.F. [Alberta Power Ltd., Edmonton, Alberta (Canada); Woodford, D.A. [Manitoba HVDC Research Centre, Winnipeg, Manitoba (Canada); Gole, A.M. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)

1996-10-01T23:59:59.000Z

137

A prototype ASIC buck converter for LHC upgrades  

E-Print Network (OSTI)

Given the larger number of channels and the need for reduced material budget in the SLHC trackers, alternatives to the present power distribution scheme have to be explored. In this context we are envisaging a new architecture based on custom switching converters able to work in the high radiation and high magnetic field environment of the experiments. A prototype converter has been designed and integrated in an ASIC. This includes the fundamental building blocks of a buck converter that can be used in later and more complete designs and even in different topologies. Design techniques and functional tests of the prototype will be discussed.

Michelis, S; Allongue, B; Blanchot, G; Fuentes, C; Kayal, M

2008-01-01T23:59:59.000Z

138

MHK Technologies/Tunneled Wave Energy Converter TWEC | Open Energy  

Open Energy Info (EERE)

Tunneled Wave Energy Converter TWEC Tunneled Wave Energy Converter TWEC < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tunneled Wave Energy Converter TWEC.jpg Technology Profile Primary Organization SeWave Ltd Project(s) where this technology is utilized *MHK Projects/TWEC Project Technology Resource Click here Wave Technology Type Click here Oscillating Water Column Technology Readiness Level Click here TRL 1-3: Discovery / Concept Definition / Early Stage Development & Design & Engineering Technology Description The Tunneled Wave Energy Converter TWEC utilizes the OWC principle through its use of a proposed bored out tunnel within a cliff side of the Faroe Islands Technology Dimensions Device Testing Date Submitted 10/8/2010 << Return to the MHK database homepage

139

Converting DOE Technical Standards to Voluntary Consensus Standards...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE-TSPP-8-2013 DOE TECHNICAL STANDARDS September 2013 PROGRAM PROCEDURES CONVERTING DOE TECHNICAL STANDARDS TO VOLUNTARY CONSENSUS STANDARDS U.S. Department of Energy Office of...

140

Converting Unconditioned Garage to Conditioned Space - Code Notes |  

NLE Websites -- All DOE Office Websites (Extended Search)

Converting Unconditioned Garage to Conditioned Space - Code Notes Converting Unconditioned Garage to Conditioned Space - Code Notes Converting an existing unconditioned garage to conditioned space is a popular strategy for increasing the living space of a house. Typically, the conversion or remodeling must be done in compliance with construction codes in force at the time the remodel permit is issued. Compliance shall be demonstrated by meeting the requirements of the 2009 International Energy Conservation Code. Publication Date: Thursday, December 15, 2011 cn_converting_unconditioned_garage_to_conditioned_space.pdf Document Details Document Number: PNNL-SA-83069 Prepared by: Pacific Northwest National Laboratory for the U.S. Department of Energy Building Energy Codes Program Focus: Compliance Building Type: Residential

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Enterprise converting buses to biodiesel | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Enterprise converting buses to biodiesel Enterprise converting buses to biodiesel Enterprise converting buses to biodiesel April 1, 2010 - 6:48pm Addthis Paul Lester Communications Specialist, Office of Energy Efficiency and Renewable Energy Rental car customers may be able to breathe a little easier during their next trip to the airport. Alamo Rent A Car, Enterprise Rent-A-Car, and National Car Rental, all brands operated by the subsidiaries of Enterprise Holdings, are converting their airport shuttle buses to run on biodiesel fuel. The move is a good one for the environment, and will ultimately reduce the company's carbon emissions. "We are saving 420,000 gallons of petroleum diesel," says Lee Broughton, director of corporate identity and sustainability for Enterprise Holdings. Hydrocarbon and particulate matter emissions will plummet, making the air

142

MHK Technologies/The Crestwing Wave Energy Converter | Open Energy  

Open Energy Info (EERE)

Crestwing Wave Energy Converter Crestwing Wave Energy Converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage The Crestwing Wave Energy Converter.jpg Technology Profile Primary Organization Waveenergyfyn Technology Resource Click here Wave Technology Type Click here Attenuator Technology Readiness Level Click here TRL 7 8 Open Water System Testing Demonstration and Operation Technology Description The connected pontoons swing around the hinge when the top of the waves passes under the floats The pontoons relative motion is converted into usable energy through a linear PTO system The pontoons are pushed upwards from the below passing wave and again dragged down by the same passing wave Complex hydrodynamic conditions occur under the pontoons when the wave formation pushes the unit up and down simultaneously The energy from waves can be divided into fifty percent potential energy and fifty percent kinetic energy Crestwing absorbs both the potential energy as the kinetic energy which is the back ground for the high efficiency

143

Implementation of control system for hydrokinetic energy converter  

Science Conference Proceedings (OSTI)

At Uppsala University, a research group is investigating a system for converting the power in freely flowing water using a verticalaxis turbine directly connected to a permanent magnet generator. An experimental setup comprising a turbine, a generator, ...

Katarina Yuen, Senad Apelfröjd, Mats Leijon

2013-01-01T23:59:59.000Z

144

Monolithic series-connected gallium arsenide converter development  

DOE Green Energy (OSTI)

We report the development of monolithic GaAs photovoltaic devices intended to convert light generated by a laser or other bright source to electricity. The converters described here can provide higher operating voltage than is possible using a single-junction converter, owing to use of a monolithic circuit that forms a planar series-connected string of single-junction sub-cells. This planar monolithic circuit is arranged to deliver the desired voltage and current during operation at the maximum power point. The paper describes two-, six-, and twelve-junction converters intended for illumination by a laser diode with a wavelength of 0.8 {mu}m. Design and characterization data are presented for optical power in the range of 100 mW to 1 W. The best conversion efficiency exceeds 50%. 9 refs., 4 figs., 2 tabs.

Spitzer, M.B.; McClelland, R.W.; Dingle, B.D.; Dingle, J.E.; Hill, D.S. (Kopin Corp., Taunton, MA (United States)); Rose, B.H. (Sandia National Labs., Albuquerque, NM (United States))

1991-01-01T23:59:59.000Z

145

10-MW GTO converter for battery peaking service  

SciTech Connect

A bidirectional 18-pulse voltage source converter utilizing gate turn-off thyristors (GTO's) is described. The converter, which is rated 10 MVA, was placed in service in early 1988 to connect an energy storage battery to a utility grid. The converter is rated and controlled to operate in all four quadrants (discharge, charge, leading vars, or lagging vars) at the full 10-MVA rating. It is capable of independent rapid control of real and reactive power with a transient response of 16 ms to changes in commanded value of real or reactive power. Thus it is usable as a reactive power controller (static var control), voltage control, frequency control, power system stabilizer, or as a real power peaking station. For use as a reactive power controller only, no battery would be needed. The design, construction, control, and application of the converter are described, and performance data taken at factory power test and at the installation are given.

Walker, L.H. (Drive Development Engineering, Drive Systems, General Electric Co., Salem, VA (US))

1990-01-01T23:59:59.000Z

146

Method for converting uranium oxides to uranium metal  

DOE Green Energy (OSTI)

A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

Duerksen, Walter K. (Norris, TN)

1988-01-01T23:59:59.000Z

147

step 1: retrieve usage step 2: convert usage  

E-Print Network (OSTI)

planet #12;step 2: convert usage data to ghg electricity conversion EPA eGRID database provides state by state data on: lbs CO2 / MWh lbs NOx / MWH eGRID Massachusetts ­ specific conversion factors only

Paulsson, Johan

148

Method for converting uranium oxides to uranium metal  

DOE Patents (OSTI)

A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixtures is then cooled to a temperature less than -100/sup 0/C in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

Duerksen, W.K.

1987-01-01T23:59:59.000Z

149

California's program converts biomass residues to energy  

SciTech Connect

This paper provides a brief introduction to the emerging biomass fuel industry in California and includes descriptions of California's biomass potential, California's biomass development program, and legislation that expands the state's developmental efforts in biomass commercialization. California's agriculture and forest industries residues were discussed. These residues can be converted to energy, and now, through California's aggressive development program, more residues will be converted. (DP)

Ward, P.F.

1980-01-01T23:59:59.000Z

150

Bi-directional power control system for voltage converter  

DOE Patents (OSTI)

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

Garrigan, Neil Richard (Niskayuna, NY); King, Robert Dean (Schenectady, NY); Schwartz, James Edward (Slingerlands, NY)

1999-01-01T23:59:59.000Z

151

Bi-directional power control system for voltage converter  

DOE Patents (OSTI)

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.

Garrigan, N.R.; King, R.D.; Schwartz, J.E.

1999-05-11T23:59:59.000Z

152

A new multi-motor drive system based on two-stage direct power converter.  

E-Print Network (OSTI)

??The two-stage AC to AC direct power converter is an alternative matrix converter topology, which offers the benefits of sinusoidal input currents and output voltages,… (more)

Kumar, Dinesh

2011-01-01T23:59:59.000Z

153

Modeling, Analysis and Stabilization of Converter-Dominated Power Distribution Grids.  

E-Print Network (OSTI)

??The energy sector is moving towards extensive use of power electronic (PE) converters to interface distributed generation (DG) units and modern converter-interfaced loads (CILs). Therefore,… (more)

Radwan, Amr A A

2012-01-01T23:59:59.000Z

154

MHK Technologies/Tide Current Converter | Open Energy Information  

Open Energy Info (EERE)

Tide Current Converter Tide Current Converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tide Current Converter.jpg Technology Profile Primary Organization Neptune Systems Technology Resource Click here Current Technology Type Click here Oscillating Wave Surge Converter Technology Readiness Level Click here TRL 1 3 Discovery Concept Def Early Stage Dev Design Engineering Technology Description The Tide Current Converter is based on the direct interaction between a magnetic electric and fluid flow field when a conductive fluid moves through a magnetic field electrical power is generated directly inside the fluid volume In this marine application the sea water itself is the conductive fluid A static antenna like structure generates the magnetic fields and at the same time taps the electrical power from the fluid current The configuration resembles a dynamo the sea water being the rotor and the antenna the stator The main advantage of the Magnetohydrodynamics MHD conversion is the absence of moving mechanical drive train components which make contemporary systems vulnerable and maintenance demanding

155

Maryland Abuzz with Retrofit Converts | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Abuzz with Retrofit Converts Abuzz with Retrofit Converts Maryland Abuzz with Retrofit Converts January 7, 2010 - 2:06pm Addthis Joshua DeLung Tim Kenny got a college degree in fisheries biology, but his real passion lies in something he's spent the last 20 years doing - helping American families in Maryland, Pennsylvania and Washington, D.C. He makes his living in the clean energy economy by finding ways people can save money on their energy bills and make their homes cleaner, safer and more comfortable. About four years ago, he started Housewarmers, a business that performs energy audits and weatherization work on the homes of everyday clientele. Tim also helps community action agencies complete weatherization work as a contractor through a separate nonprofit business, C&O Conservation, for

156

A high-efficiency thermoelectric converter for space applications  

DOE Green Energy (OSTI)

This paper presents a concept for using high-temperature superconducting materials in thermoelectric generators (SCTE) to produce electricity at conversion efficiencies approaching 50% of the Carrot efficiency. The SCTE generator is applicable to systems operating in temperature ranges of high-temperature superconducting materials and thus would be a low-grade converter. Operating in cryogenic temperature ranges provides the advantage of inherently increasing the limits of the Carrot efficiency. Potential applications are for systems operating in space where the ambient temperatures are in the cryogenic temperature range. The advantage of using high-temperature superconducting material in a thermoelectric converter is that it would significantly reduce or eliminate the Joule heating losses in a thermoelectric element. This paper investigates the system aspects and the material requirements of the SCTE converter concept, and presents a conceptual design and an application for a space power system.

Metzger, J.D. [Westinghouse Savannah River Co., Aiken, SC (United States); El-Genk, M.S. [New Mexico Univ., Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies

1990-12-31T23:59:59.000Z

157

NETL: News Release - Converting Emissions into Energy - Three Companies to  

NLE Websites -- All DOE Office Websites (Extended Search)

September 14, 2000 September 14, 2000 Converting Emissions into Energy - Three Companies To Develop Technologies for Tapping Coal Mine Methane Methane, the chief constituent of natural gas, is a potent greenhouse gas, and millions of cubic feet of it escape daily from active coal mines. Now, three projects selected the U.S. Department of Energy propose new ways to capture the gas and convert it to useful energy -- reducing an environmental threat while adding to the nation's supplies of clean natural gas and electric power. The National Energy Technology Laboratory, the Energy Department's chief field site for its fossil energy research program, has selected: Appalachian-Pacific Coal Mine Methane Power Co., LLC, Arlington, VA, to work with West Virginia University Research Corp., Morgantown, WV, and Invitation Energy, Mannington, WV, to convert coal mine methane from mines in Marion County, WV, and surrounding areas into liquefied natural gas (LNG) to fuel heavy trucks.

158

MHK Technologies/Seatricity wave energy converter | Open Energy Information  

Open Energy Info (EERE)

Seatricity wave energy converter Seatricity wave energy converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Seatricity wave energy converter.jpg Technology Profile Primary Organization Seatricity Project(s) where this technology is utilized *MHK Projects/Seatricity Antigua *MHK Projects/Seatricity Orkney Technology Resource Click here Wave Technology Type Click here Attenuator Technology Readiness Level Click here TRL 7/8: Open Water System Testing & Demonstration & Operation Technology Description In the simplest terms, a float travels up and down with the waves and operates a pump to pressurise sea water which is piped ashore. Many individual pumps are connected together to produce substantial amounts of pressurized water. Once ashore the pressurized sea water is used to drive a standard hydroelectric turbine to produce electricity.

159

A high-efficiency thermoelectric converter for space applications  

DOE Green Energy (OSTI)

This paper presents a concept for using high-temperature superconducting materials in thermoelectric generators (SCTE) to produce electricity at conversion efficiencies approaching 50% of the Carrot efficiency. The SCTE generator is applicable to systems operating in temperature ranges of high-temperature superconducting materials and thus would be a low-grade converter. Operating in cryogenic temperature ranges provides the advantage of inherently increasing the limits of the Carrot efficiency. Potential applications are for systems operating in space where the ambient temperatures are in the cryogenic temperature range. The advantage of using high-temperature superconducting material in a thermoelectric converter is that it would significantly reduce or eliminate the Joule heating losses in a thermoelectric element. This paper investigates the system aspects and the material requirements of the SCTE converter concept, and presents a conceptual design and an application for a space power system.

Metzger, J.D. (Westinghouse Savannah River Co., Aiken, SC (United States)); El-Genk, M.S. (New Mexico Univ., Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies)

1990-01-01T23:59:59.000Z

160

Quartz crystal microbalance based on passive frequency to voltage converter  

SciTech Connect

In dynamics of evaporation or drying of microdrops from a solid surface, a faster and precise quartz crystal microbalance (QCM) is needed. The fast QCM based on frequency to voltage converter is an attractive and powerful tool in the investigation of the dynamic regime of evaporation to translate the frequency shift in terms of a continuous voltage change. The frequency shift monitoring in fast QCM applications is a real challenge for electronic processing interface. Originally developed as a frequency shift processing interface, this novel passive frequency to voltage converter can produce faster, stable, and accurate results in regard to the QCM sensor behavior. In this article, the concept and circuit of passive frequency to voltage converter will be explained followed by static and dynamic characterization. Experimental results of microdrops evaporation will be given.

Burda, Ioan; Tunyagi, Arthur [Department of Physics, Babes-Bolyai University, Cluj-Napoca, 400084 (Romania)

2012-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Combustor design tool for a gas fired thermophotovoltaic energy converter  

DOE Green Energy (OSTI)

Recently, there has been a renewed interest in thermophotovoltaic (TPV) energy conversion. A TPV device converts radiant energy from a high temperature incandescent emitter directly into electricity by photovoltaic cells. The current Department of Energy sponsored research involves the design, construction and demonstration of a prototype TPV converter that uses a hydrocarbon fuel (such as natural gas) as the energy source. As the photovoltaic cells are designed to efficiently convert radiant energy at a prescribed wavelength, it is important that the temperature of the emitter be nearly constant over its entire surface. The US Naval Academy has been tasked with the development of a small emitter (with a high emissivity) that can be maintained at 1,756 K (2,700 F). This paper describes the computer spreadsheet model that was developed as a tool to be used for the design of the high temperature emitter.

Lindler, K.W.; Harper, M.J. [Naval Academy, Annapolis, MD (United States). Naval Architecture, Ocean and Marine Engineering Dept.

1995-07-01T23:59:59.000Z

162

Applications and benefits of catalytic converter thermal management  

DOE Green Energy (OSTI)

A catalytic converter thermal management system (TMS) using variable-conductance vacuum insulation and phase-change thermal storage can maintain the converter temperature above its operating temperature for many hours, allowing most trips to begin with minimal ``cold-start`` emissions. The latest converter TMS prototype was tested on a Ford Taurus (3.0 liter flex-fuel engine) at Southwest Research Institute. Following a 24-hour soak, the FTP-75 emissions were 0.031, 0.13, and 0.066 g/mile for NMHC, CO, and NOx, respectively. Tests were also run using 85% ethanol (E85), resulting in values of 0.005, 0.124, and 0.044 g/mile, and 0.005 g/mile NMOG. Compared to the baseline FTP levels, these values represent reductions of 84% to 96% for NMHC, NMOG, and CO.

Burch, S.D.; Keyser, M.A.; Colucci, C.P.; Potter, T.F.; Benson, D.K.; Biel, J.P.

1996-07-01T23:59:59.000Z

163

Liquid metal thermal-electric converter electrode development  

DOE Green Energy (OSTI)

This report describes work done in support of distributed receiver technology development. Dish-electric systems are being pursued in an effort to circumvent the need for energy transport by providing for heat-to-electricity energy conversion by individual heat engines at the focal point of parabolic dish concentrators. The Liquid Metal Thermal-Electric Converter is an engine that can convert thermal energy to electricity without the need for moving parts. The report documents the results of contracted work in the development of a long-lifetime, high-performance electrode for LMTEC, including the materials prepared for it. 17 refs., 20 figs., 3 tabs.

Martinez, J.I. (ed.)

1988-02-01T23:59:59.000Z

164

Process for converting cellulosic materials into fuels and chemicals  

DOE Patents (OSTI)

A process for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system.

Scott, Charles D. (Oak Ridge, TN); Faison, Brendlyn D. (Knoxville, TN); Davison, Brian H. (Knoxville, TN); Woodward, Jonathan (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

165

Pre-converted nitric oxide gas in catalytic reduction system  

DOE Patents (OSTI)

A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO.sub.2 in the presence of O.sub.2. The second stage serves to convert NO.sub.2 to environmentally benign gases that include N2, CO2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO.sub.2 in the presence of O.sub.2 and includes platinum/alumina, e.g., Pt/Al.sub.2 O.sub.3 catalyst. A flow of hydrocarbons (C.sub.x H.sub.y) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO.sub.2 from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO.sub.2 to N2, CO2, and H.sub.2 O, and includes a gamma-alumina .gamma.-Al.sub.2 O.sub.3. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the second catalyst.

Hsiao, Mark C. (Livermore, CA); Merritt, Bernard T. (Livermore, CA); Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA)

1999-01-01T23:59:59.000Z

166

Research on MPPT for Solar Cells Based on Flyback Converter  

Science Conference Proceedings (OSTI)

A voltage source and rheostat are successfully used to simulate the solar cell's character in this paper. Its feasibility is analyzed theoretically. The basic principle of the maximum power point tracking (MPPT) is described. An improved disturbance ... Keywords: solar cells, maximum power point tracking (MPPT), flyback converter

Zhang Housheng

2010-05-01T23:59:59.000Z

167

A summary of North American HVDC converter station reliability specifications  

SciTech Connect

This paper summarizes Reliability, Availability, and Maintainability (RAM) specifications that were issued for thyristor based HVDC converter stations in service in North America. A total of twenty project specifications are summarized. A detailed summary by project is shown with specific quantitative requirements categorized. Definitions of terms, representative design principles, and formulas used in calculating RAM parameters contained in existing reliability specifications are presented.

Vancers, I. (ABB Power Systems Inc., Los Angeles, CA (United States)); Hormozi, F.J. (Los Angeles Dept. of Water and Power, CA (United States))

1993-07-01T23:59:59.000Z

168

Energy Savings Assessment for Digital-to-Analog Converter Boxes  

SciTech Connect

The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.

Cheung, Hoi Ying Iris; Meier, Alan; Brown, Richard

2011-01-18T23:59:59.000Z

169

Cycling firing method for bypass operation of bridge converters  

DOE Patents (OSTI)

The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

Zabar, Zivan (99-72 66th Rd., Apt. 9N, Forest Hills, NY 11375)

1982-01-01T23:59:59.000Z

170

A Dual Supply Buck Converter with Improved Light Load Efficiency  

E-Print Network (OSTI)

Power consumption is the primary concern in battery-operated portable applications. Buck converters have gained popularity in powering portable devices due to their compact size, good current delivery capability and high efficiency. However, portable devices are operating under light load condition for the most of the time. Conventional buck converters suffer from low light-load efficiency which severely limits battery lifetime. In this project, a novel technique for buck converter is proposed to reduce the switching loss by reducing the effective input supply voltage at light load. This is achieved by switching between two different input voltages (3.3V and 1.65V) depending on the output current value. Experimental results show that this technique improves the efficiency at light loads by 18.07%. The buck voltage possesses an output voltage of 0.9V and provides a maximum output current of 400mA. The buck converter operates at a switching frequency of 1MHz. The prototype was fabricated using 0.18µm CMOS technology, and occupies a total active area of 0.6039mm^2.

Chen, Hui

2013-05-01T23:59:59.000Z

171

Apparatus for converting biomass to a pumpable slurry  

DOE Patents (OSTI)

An apparatus used in the pretreatment of wood chips in a process for converting biomass to a liquid hydrocarbonaceous fuel. The apparatus functions to break down the wood chips to a size distribution that can be readily handled in a slurry form. Low maintenance operation is obtained by hydrolyzing the chips in a pressure vessel having no moving parts.

Ergun, Sabri (Hillsborough, CA); Schaleger, Larry L. (Oakland, CA); Wrathall, James A. (Berkeley, CA); Yaghoubzadeh, Nasser (El Cerrito, CA)

1986-01-01T23:59:59.000Z

172

SELECTING FUELS WITHIN ENVIRONMENTAL IMPACT REQUIREMENTS: CONVERTING A  

E-Print Network (OSTI)

SELECTING FUELS WITHIN ENVIRONMENTAL IMPACT REQUIREMENTS: CONVERTING A PRESENT COMBUSTION SYSTEM fossil fuels. Next, the alternative fuels with large po tential energy recovery are selected and presentDIIsrCDUICTOI SCIIU, ! i ItFUS£_pu- ;1II-'NfU1MTJ: 'U.)'// PIr I It \\I I ' I Ir-SUIIDDU\\N. £DI

Columbia University

173

Minimizing power pulsations in a free piston energy converter  

E-Print Network (OSTI)

A Free Piston Energy Converter (FPEC) is a combination of a linear combustion engine and a linear electrical machine. This type of converter has many potential advantages like high efficiency, low fuel consumption and low emissions, which make it suitable for a series hybrid vehicle. However, the generated power pulsates due to the reciprocating motion of the translator. This paper presents a comparative study on how different generator force profiles affect the electric power pulsations produced by the FPEC. In addition, the influence of these profiles on translator motion and the needed power converter current is investigated. A dynamic free piston model is used for the investigation. Results show that the generator force profile has a major impact on the power pulsation amplitude and peak current demand. Thus the chosen force profile will affect dimensioning of power converter, electrical machine and energy storage. Furthermore, loading the translator heavily in the beginning or end of the stroke seems to affect the peak translator velocity more than evenly distributed load profiles.

Jörgen Hansson; Mats Leksell; Fredrik Carlsson

2005-01-01T23:59:59.000Z

174

Elimination of Harmonics in a Multilevel Converter for HEV Applications  

E-Print Network (OSTI)

possible solu- tions are found. Keywords­ Hybrid Electric Vehicles, Multilevel Convert- ers, Harmonic Elimination, Resultants I. Introduction Designs for heavy duty hybrid-electric vehicles (HEVs) that have large electric drives such as tractor trailers, trans- fer trucks, or military vehicles will require advanced

Tolbert, Leon M.

175

Control and Power Management of Converter Fed Microgrids  

E-Print Network (OSTI)

1 Control and Power Management of Converter Fed Microgrids Charles K. Sao, Member, IEEE, and Peter in parallel in a VSC fed microgrid. Each current controlled VSC in such a microgrid has its own VPD/FQB controller that sets its current references to regulate the voltage and frequency of a common microgrid bus

Lehn, Peter W.

176

Automated Synthesis Tool for Design Optimization of Power Electronic Converters  

E-Print Network (OSTI)

Designers of power electronic converters usually face the challenge of having multiple performance indices that must be simultaneously optimized, such as maximizing efficiency while minimizing mass or maximizing reliability while minimizing cost. The experienced engineer applies his or her judgment to reduce the number of possible designs to a manageable number of feasible designs for which to prototype and test; thus, the optimality of this design-space reduction is directly dependent upon the experience, and expertise and biases of the designer. The practitioner is familiar with tradeoff analysis; however, simple tradeoff studies can become difficult or even intractable if multiple metrics are considered. Hence a scientific and systematic approach is needed. In this dissertation, a multi-objective optimization framework is presented as a design tool. Optimization of power electronic converters is certainly not a new subject. However, when limited to off-the-shelf components, the resulting system is really optimized only over the set of commercially available components, which may represent only a subset of the design space; the reachable space limited by available components and technologies. While this approach is suited to cost-reduce an existing design, it offers little insight into design possibilities for greenfield projects. Instead, this work uses the Technology Characterization Methods (TCM) to broaden the reachable design space by considering fundamental component attributes. The result is the specification for the components that create the optimal design rather than an evaluation of an apriori selected set of candidate components. A unique outcome of this approach is that new technology development vectors may emerge to develop optimized components for the optimized power converter. The approach presented in this work uses a mathematical descriptive language to abstract the characteristics and attributes of the components used in a power electronic converter in a way suitable for multi-objective and constrained optimization methods. This dissertation will use Technology Characterization Methods (TCM) to bridge the gap between high-level performance attributes and low-level design attributes where direct relationship between these two does not currently exist. The loss and size models for inductors, capacitors, IGBTs, MOSFETs and heat sinks will be used to form objective functions for the multi-objective optimization problem. A single phase IGBT-based inverter is optimized for efficiency and volume based on the component models derived using TCM. Comparing the obtained designs to a design, which can be made from commercial off-the-shelf components, shows that converter design can be optimized beyond what is possible from using only off-the-shelf components. A module-integrated photovoltaic inverter is also optimized for efficiency, volume and reliability. An actual converter is constructed using commercial off-the-shelf components. The converter design is chosen as close as possible to a point obtained by optimization. Experimental results show that the converter modeling is accurate. A new approach for evaluation of efficiency in photovoltaic converter is also proposed and the front-end portion of a photovoltaic converter is optimized for this efficiency, as well as reliability and volume.

Mirjafari, Mehran

2013-05-01T23:59:59.000Z

177

Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn is converted  

E-Print Network (OSTI)

Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn the wind doesn't blow? Wind Power on the Community Scale Renewable Energy Research Laboratory, University Energy Research Laboratory brings you this series of fact sheets about Wind Power on the community scale

Massachusetts at Amherst, University of

178

A function based fuzzy controller for VSC-HVDC system to enhance transient stability of AC/DC power system  

Science Conference Proceedings (OSTI)

This paper presents a robust function based optimized fuzzy controller for VSC-HVDC transmission link operating in parallel with an AC transmission line connecting a synchronous generator to infinite bus. A two input one output methodology based optimized ...

Niranjan Nayak; Sangram Kesari Routray; Pravat Kumar Rout

2011-12-01T23:59:59.000Z

179

Hardware model of a shipboard zonal electrical distribution system (ZEDS) : alternating current/direct current (AC/DC)  

E-Print Network (OSTI)

A hardware model of a shipboard electrical distribution system based on aspects of the DDG 51 Flight IIA, Arleigh Burke class, 60Hz Alternating Current (AC) and the future direct current (DC), zonal electrical distribution ...

Tidd, Chad N. (Chad Norman)

2010-01-01T23:59:59.000Z

180

Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Yellow Cab Converts Yellow Cab Converts Taxis to Propane in Columbus, Ohio to someone by E-mail Share Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in Columbus, Ohio on Facebook Tweet about Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in Columbus, Ohio on Twitter Bookmark Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in Columbus, Ohio on Google Bookmark Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in Columbus, Ohio on Delicious Rank Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in Columbus, Ohio on Digg Find More places to share Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in Columbus, Ohio on AddThis.com... July 9, 2011 Yellow Cab Converts Taxis to Propane in Columbus, Ohio

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181

NETL: News Release - Secretary Chu Announces Six Projects to Convert  

NLE Websites -- All DOE Office Websites (Extended Search)

2, 2010 2, 2010 Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products $106 Million Recovery Act Investment Will Reduce CO2 Emissions and Mitigate Climate Change Washington, D.C. - U.S. Energy Secretary Steven Chu announced today the selections of six projects that aim to find ways of converting captured carbon dioxide (CO2) emissions from industrial sources into useful products such as fuel, plastics, cement, and fertilizers. Funded with $106 million from the American Recovery and Reinvestment Act -matched with $156 million in private cost-share -today's selections demonstrate the potential opportunity to use CO2 as an inexpensive raw material that can help reduce carbon dioxide emissions while producing useful by-products that Americans can use.

182

NREL: News - NREL to Help Convert Methane to Liquid Diesel  

NLE Websites -- All DOE Office Websites (Extended Search)

113 113 NREL to Help Convert Methane to Liquid Diesel Advanced research project could lead to lower greenhouse emissions, new life for spent gas and oil wells January 3, 2013 The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) will help develop microbes that convert methane found in natural gas into liquid diesel fuel, a novel approach that if successful could reduce greenhouse gas emissions and lower dependence on foreign oil. The amount of natural gas simply flared or vented from oil wells globally is enormous - equal to one-third of the amount of petroleum used in the United States each year. And every molecule of methane vented to the atmosphere in that process has the global-warming capacity of 12 molecules of carbon dioxide.

183

GTRI's Convert Program: Minimizing the Use of Highly Enriched Uranium |  

National Nuclear Security Administration (NNSA)

Program: Minimizing the Use of Highly Enriched Uranium | Program: Minimizing the Use of Highly Enriched Uranium | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > Media Room > Fact Sheets > GTRI's Convert Program: Minimizing the Use of ... Fact Sheet GTRI's Convert Program: Minimizing the Use of Highly Enriched Uranium Apr 12, 2013

184

Planar LTCC transformers for high voltage flyback converters: Part II.  

Science Conference Proceedings (OSTI)

This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)

2009-02-01T23:59:59.000Z

185

Catalyst for converting synthesis gas to liquid motor fuels  

DOE Patents (OSTI)

The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

Coughlin, Peter K. (Yorktown Heights, NY)

1986-01-01T23:59:59.000Z

186

MHK Technologies/OCEANTEC Wave Energy Converter | Open Energy Information  

Open Energy Info (EERE)

Wave Energy Converter Wave Energy Converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage OCEANTEC Wave Energy Converter.jpg Technology Profile Primary Organization OCEANTEC Energias Marinas S L Technology Resource Click here Wave Technology Type Click here Attenuator Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description OCEANTEC Marine Energy Company Ltd owned by Iberdrola and TECNALIA is developing a sensor for wave energy technology type Spanish attenuator Floating body oscillates due to wave excitation in its main DOF pitch Mooring system allows the body to weathervane so that it is faced to the predominant wave propagation direction Main advantage capture system completely encapsulated free of contact with sea water A flywheel continuously spins under the action of an electric motor Z The pitching motion of the WEC caused by wave action is transformed into an alternating precession in the longitudinal hull axis X A coupling device transforms this precession into an unidirectional rotation of higher frequency that is used to feed a conventional electric generator

187

Analog-to-digital converter with data processing  

DOE Patents (OSTI)

This device incorporates an analog-digital converter including a data processing section which can be used to perform data processing on digitized data as is generated, off-line from the system processor. It consists of a 12 bit analog to digital converter for generating discrete digital data representative of an input analog signal, a data bus coupled to receive the digital data as is generated, a 512 Kbyte memory RAM to store the digitized data, and a system bus coupled to the data processing element for outputting the result of the performed operation. This is the first device with analog to digital converters and memory. It is the first module to be designed to the VXIbus format. This device is the first to incorporate an averaging circuit in the design. It has a sealed analog module (outputs the sum and difference of the log signals for both the X and the Y axis of the beam position module), memory channels, four averaging channels the programmable trigger and digitizer clock logic, and a VXIbus interface. This device is useful in the fields of data acquisition, data processing, communication systems, instrumentation and electronics.

Jones, A.

1993-01-01T23:59:59.000Z

188

Frequency converter development for the National Ignition Facility  

SciTech Connect

The design of the National Ignition Facility (NIF) incorporates a type I/type II third harmonic generator to convert the 1.053-{micro}m fundamental wavelength of the laser amplifier to a wavelength of 0.351 {micro}m for target irradiation. To understand and control the tolerances in the converter design, we have developed a comprehensive error budget that accounts for effects that are known to influence conversion efficiency, including variations in amplitude and phase of the incident laser pulse, temporal bandwidth of the incident laser pulse, crystal surface figure and bulk non-uniformities, angular alignment errors, Fresnel losses, polarization errors and crystal temperature variations. The error budget provides specifications for the detailed design of the NIF final optics assembly (FOA) and the fabrication of optical components. Validation is accomplished through both modeling and measurement, including full-scale Beamlet tests of a 37-cm aperture frequency converter in a NIF prototype final optics cell. The prototype cell incorporates full-perimeter clamping to support the crystals, and resides in a vacuum environment as per the NIF design.

Auerbach, J M; Barker, C E; Burkhart, S C; Couture, S A; DeYoreo, J J; Hackel, L A; Hibbard, R L; Liou, L W; Norton, M A; Wegner, P J; Whitman, P A

1998-10-30T23:59:59.000Z

189

Trimode Power Converter optimizes PV, diesel and battery energy sources  

SciTech Connect

Conservatively, there are 100,000 localities in the world waiting for the benefits that electricity can provide, and many of these are in climates where sunshine is plentiful. With these locations in mind a prototype 30 kW hybrid system has been assembled at Sandia to prove the reliability and economics of photovoltaic, diesel and battery energy sources managed by an autonomous power converter. In the Trimode Power Converter the same power parts, four IGBT`s with an isolation transformer and filter components, serve as rectifier and charger to charge the battery from the diesel; as a stand-alone inverter to convert PV and battery energy to AC; and, as a parallel inverter with the diesel-generator to accommodate loads larger than the rating of the diesel. Whenever the diesel is supplying the load, an algorithm assures that the diesel is running at maximum efficiency by regulating the battery charger operating point. Given the profile of anticipated solar energy, the cost of transporting diesel fuel to a remote location and a five year projection of load demand, a method to size the PV array, battery and diesel for least cost is developed.

O`Sullivan, G. [Abacus Controls, Inc., Somerville, NJ (United States); Bonn, R.; Bower, W. [Sandia National Labs., Albuquerque, NM (United States)

1994-07-01T23:59:59.000Z

190

Two U.S. University Research Reactors to be Converted From Highly...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

are here Home Two U.S. University Research Reactors to be Converted From Highly Enriched Uranium to Low-Enriched Uranium Two U.S. University Research Reactors to be Converted...

191

Blind calibration of timing skew in time-interleaved analog-to-digital converters  

E-Print Network (OSTI)

The performance of time-interleaved analog-to-digital converters is often significantly degraded by timing mismatch errors. We develop methods for performing blind calibration of such converters, i.e., for estimating the ...

Divi, Vijay

192

Design and characterization of a radio-frequency dc/dc power converter  

E-Print Network (OSTI)

The use of radio-frequency (RF) amplifier topologies in dc/dc power converters allows the operating frequency to be increased by more than two orders of magnitude over the frequency of conventional converters. This enables ...

Jackson, David A. (David Alexander)

2005-01-01T23:59:59.000Z

193

A Decentralized Protection Scheme for Converters Utilizing a DC-link Inductor  

E-Print Network (OSTI)

, and B. Ooi. Force commutated HVDC and SVC based on phase-shifted multi-converter modules. IEEE Trans

Lipo, Thomas

194

Custom DC-DC converters for distributing power in SLHC trackers  

E-Print Network (OSTI)

A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficiently distribute power to the on-detector electronics of SLHC trackers. A comparative analysis of different promising converter topologies is presented, leading to the choice of a magneticbased buck converter as a first conversion stage followed by an on-chip switched capacitors converter. An overall efficiency above 80% is estimated for the practical implementation proposed.

Allongue, B; Blanchot, G; Faccio, F; Fuentes, C; Mattavelli, P; Michelis, S; Orlandis, S; Spiazzi, G

2008-01-01T23:59:59.000Z

195

Light-weight DC to very high voltage DC converter  

DOE Patents (OSTI)

A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

1998-01-01T23:59:59.000Z

196

Light-weight DC to very high voltage DC converter  

DOE Patents (OSTI)

A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

Druce, R.L.; Kirbie, H.C.; Newton, M.A.

1998-06-30T23:59:59.000Z

197

Harmonic measurements from a group connected generator HVdc converter scheme  

SciTech Connect

A recent CIGRE document published in ELECTRA has described the potential benefits of a direct connection of generators to HVdc converters. While many theoretical contributions have been made, no practical test data has become available so far. This paper reports on harmonic tests carried out at the Benmore end of the New Zealand HVdc link operating as a group connected scheme. It was found that the measured harmonic current levels were well below specified generator ratings. Dynamic simulation accurately predicted the harmonic currents whereas the results of a steady state formulation were less reliable.

Macdonald, S.J.; Enright, W.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand); O`Brien, M.T.

1995-10-01T23:59:59.000Z

198

Bi-Directional DC-DC Converter for PHEV Applications  

DOE Green Energy (OSTI)

Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

Abas Goodarzi

2011-01-31T23:59:59.000Z

199

Fast-scale bifurcation . . . converters and effects of incompatible periodicities  

E-Print Network (OSTI)

In this paper, we derive the discrete-time model for the power-factor-correction (PFC) buck-boost converter in terms of a stroboscopic switching map. Fast-scale instability is analysed through a fold diagram, which exposes the periodicity of the operation as well as the locations of the critical phase angles of the line voltage at which instability begins to occur along a half-line cycle. The asymmetrical locations of the critical phase angles along a half-line cycle is explained in terms of ‘underdeveloped’ bifurcation. Border collision bifurcations are observed and analysed in detail.

Jianlong Zou; Xikui Ma; Chi K. Tse; Dong Dai

2006-01-01T23:59:59.000Z

200

dc-to-ac power converter for fuel cell system  

SciTech Connect

As the interface between fuel cells and the utility line, a self-commutated inverter is preferred to a line-commutated inverter because of its easy controllability. Using the gate turn off (GTO) thyristors, this inverter can have high efficiency and simple circuit configurations. This paper describes the design features and test results of the dc-to-ac power converter, which is principally composed of four-phase transistor chopper and 12-pulse GTO inverter, for a 50kW experimental fuel cell power system. Furthermore, new GTO inverter which improves the circuit efficiency is presented. Special emphasis is placed on a detailed analysis and evaluation of this GTO inverter.

Kawabata, T.; Asaeda, T.; Hamasaki, Y.; Yutani, T.

1983-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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201

Multi-Stage Converters: A New Technology for Traction Drive Juan W. Dixon  

E-Print Network (OSTI)

of this drive is that the switching frequency of the Main converter is at the fundamental frequency, reducing will be the Slaves. The Main Converter works at the lower switching frequency (fundamental frequency), which, and A. Tahri, "Multilevel Converters and VAR Compensation", Chapter 25, Power Electronics Handbook

Rudnick, Hugh

202

Microgrid Power Electronic Converters: State of the Art and Future Challenges  

E-Print Network (OSTI)

Microgrid Power Electronic Converters: State of the Art and Future Challenges M. Jamil, B. Hussain converters used in microgrids. The paper focuses primarily on grid connected converters. Different topologies as they are variable in nature. Distributed generators (DG), including renewable sources, within microgrids can help

203

A Single Transistor Three Phase Resonant Switch For High Quality  

E-Print Network (OSTI)

Existing 34, ac-dc low-harmonic rectiifiers are costly and require complex control schemes to minimize input current harmonics. Introduced here are three new classes of low cost 34, ac-dc high power factorllow harmonic controlled rectifiers. These are derived from parent dc-dc convrter topologies containing boost-type inputs, buck-type inputs and qwsi resonant zero-current-switch (ZCS) buck-type inputs. With a single active switch in addition to the diode bridge rectijier, the converters are capable of drawing a high quality input current waveform naturally at nearly unity power factor. Thus a simple 34, ac-dc high paver factor rechifie7 is obtained. Simulation and experimental results are supplied to demonstrate the validity of the concept. 1.

Esam Ismail; Robert W. Erickson

1992-01-01T23:59:59.000Z

204

Present State and Future Plan of MCF Research in China  

E-Print Network (OSTI)

engineering capability Main experimental results Research Plan in next 2-5 years ITER-CN Activities Future were achieved on HL-2A tokamak #12;Outline EAST HL-2A Tokamak EAST Tokamak Physical engineering System(50%), HV Substation Materials (100%), AC-DC Converter (62%) · SWIP: Blanket FW (10%) &Shield (40

205

Accurate Modeling and Prediction of Energy Availability in Energy Harvesting Real-Time Embedded Systems  

E-Print Network (OSTI)

on the type of energy harvesting technology, ECM1 can be either DC/DC or AC/DC converter. ECM2 is usually a DC/DCAccurate Modeling and Prediction of Energy Availability in Energy Harvesting Real-Time Embedded}@binghamton.edu Abstract -- Energy availability is the primary subject that drives the research innovations in energy

Qiu, Qinru

206

Triple voltage dc-to-dc converter and method  

DOE Patents (OSTI)

A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

Su, Gui-Jia (Knoxville, TN)

2008-08-05T23:59:59.000Z

207

EMISSIONS REDUCTIONS USING HYDROGEN FROM PLASMATRON FUEL CONVERTERS  

DOE Green Energy (OSTI)

Substantial progress in engine emission control is needed in order to meet present and proposed regulations for both spark ignition and diesel engines. Tightening regulations throughout the world reflect the ongoing concern with vehicle emissions. Recently developed compact plasmatron fuel converters have features that are suitable for onboard production of hydrogen for both fuel pretreatment and for exhaust aftertreatment applications. Systems that make use of these devices in conjunction with aftertreatment catalysts have the potential to improve significantly prospects for reduction of diesel engine emissions. Plasmatron fuel converters can provide a rapid response compact means to transform efficiently a wide range of hydrocarbon fuels into hydrogen rich gas. They have been used to reform natural gas [Bromberg1], gasoline [Green], diesel [Bromberg2] and hard-to-reform biofuels [Cohn1] into hydrogen rich gas (H2 + CO). The development of these devices has been pursued for the purpose of reducing engine exhaust pollutants by providing hydrogen rich gas for combustion in spark ignition and possibly diesel engines, as shown in Figure 1 [Cohn2]. Recent developments in compact plasmatron reformer design at MIT have resulted in substantial decreases in electrical power requirements. These new developments also increase the lifetime of the electrodes.

Bromberg, L

2000-08-20T23:59:59.000Z

208

NETL: News Release - Converting Coal Wastes to Clean Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

November 28, 2000 November 28, 2000 Converting Coal Wastes to Clean Energy DOE to Scale Up 3 Projects That Upgrade Coal Fines, Wastes PITTSBURGH, PA - Three new technologies that can help the nation's coal industry turn waste into energy are now ready for scale up, the U.S. Department of Energy said today. MORE INFO Solid Fuels & Feedstocks Program Each of the three recover carbon-rich materials that in the past have been discarded during coal mining and cleaning operations. Using innovative approaches, the technologies remove unwanted water and other impurities and upgrade the waste materials into clean-burning fuels for power plants. The three were first selected for smaller-scale research in August 1998 as part of the Energy Department's Fossil Energy "solid fuels and feedstocks"

209

Neutronic design studies for the MIT fission converter beam  

SciTech Connect

Currently available epithermal neutron beams at the Massachusetts Institute of Technology (MIT) are not sufficiently intense to meet the anticipated demand for boron neutron capture therapy (BNCT) treatments if initial, currently in progress clinical trials of BNCT prove successful. Indeed, they are not really adequate for extensive (phase-III) clinical trials. To fulfill this need, a high-intensity, high-quality fission converter-based epithermal neutron beam for BNCT has been designed for the MIT Research Reactor, (MITR-II). This epithermal neutron beam, capable of delivering treatments in a few minutes with negligible beam background contamination, would be installed in the present thermal column and hohlraum of the MITR-II.

Kiger, W.S. III; Harling, O.K. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

1996-12-31T23:59:59.000Z

210

A Study of Radiative Bottomonium Transitions using Converted Photons  

SciTech Connect

The authors use (111 {+-} 1) million {Upsilon}(3S) and (89 {+-} 1) million {Upsilon}(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions betwen bottomonium states using photons that have been converted to e{sup +}e{sup -} pairs by the detector material. They observe {Upsilon}(3S) {yields} {gamma}{chi}{sub b0,2}(1P) decay, make precise measurements of the branching fractions for {chi}{sub b1,2}(1P, 2P) {yields} {gamma}{Upsilon}(1S) and {chi}{sub b1,2}(2P) {yields} {gamma}{Upsilon}(2S) decays, and search for radiative decay to the {eta}{sub b}(1S) and {eta}{sub b}(2S) states.

Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-08-15T23:59:59.000Z

211

Low Head, Vortex Induced Vibrations River Energy Converter  

DOE Green Energy (OSTI)

Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) is a novel, demonstrated approach to extracting energy from water currents. This invention is based on a phenomenon called Vortex Induced Vibrations (VIV), which was first observed by Leonardo da Vinci in 1504AD. He called it ‘Aeolian Tones.’ For decades, engineers have attempted to prevent this type of vibration from damaging structures, such as offshore platforms, nuclear fuel rods, cables, buildings, and bridges. The underlying concept of the VIVACE Converter is the following: Strengthen rather than spoil vortex shedding; enhance rather than suppress VIV; harness rather than mitigate VIV energy. By maximizing and utilizing this unique phenomenon, VIVACE takes this “problem” and successfully transforms it into a valuable resource for mankind.

Bernitsas, Michael B.; Dritz, Tad

2006-06-30T23:59:59.000Z

212

Fluoride-containing wastewater converted to synthetic fluorspar  

Science Conference Proceedings (OSTI)

In the manufacture of uranium hexafluoride, sulfur hexafluoride, iodine pentafluoride, and antimony pentafluoride, the Allied Corporation's Metropolis Works (Metropolis, IL) generates approximately 250,000 gpd of process wastewater which contains substantial amounts of soluble fluoride. Most of the wastewater is also acidic. Alkaline waste and hydrated lime (calcium hydroxide) in a pair of neutralizers are used to precipitate the soluble fluoride as calcium fluoride. Due to the alkalinity, the material is considered a hazardous waste. The limited availability of land suitable for the construction of impoundment basins and the potential for eventual seepage from the basins presented a challenge to the management and technical staff at the Metropolis Works situation on-site. Efforts were directed toward developing a process to convert the calcium fluoride waste into a useful product. Excess lime waste could be converted to 90% CaF/sub 2/ by neutralizing the lime with hydrofluoric acid. The 90% CaF/sub 2/, closely resembling fluorspar, would be able to be used directly at other Allied plants as a substitute for natural fluorspar in the production of anhydrous hydrofluoric (AHF) acid. Engineering efforts to design a full-scale plant for the recovery of CaF/sub 2/ began in mid-1980. Construction of the plant begin in July, 1981. Since startup in mid-1982, the full scale recovery plant has been in continuous operation. Design capacity is 8000 tons/yr of synthetic fluorspar. The synthetic fluorspar is directly replacing an equivalent amount of imported natural fluorspar in the production of anhydrous hydrofluoric acid. Total cost to construct the CaF/sub 2/ recovery plant was $4.3 million. Currently realized cost savings of about $1 million/yr give the project an expected payback period of under five years.

Cipolla, A.J.; Shields, E.J.; Wickersham, C.P.; Toy, D.A.

1985-11-01T23:59:59.000Z

213

U-120: RSA SecurID Software Token Converter Unspecified Buffer Overflow  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

0: RSA SecurID Software Token Converter Unspecified Buffer 0: RSA SecurID Software Token Converter Unspecified Buffer Overflow Vulnerability U-120: RSA SecurID Software Token Converter Unspecified Buffer Overflow Vulnerability March 8, 2012 - 7:00am Addthis PROBLEM: RSA SecurID Software Token Converter Unspecified Buffer Overflow Vulnerability PLATFORM: RSA SecurID Software Token Converter 2.x ABSTRACT: Successful exploitation may allow execution of arbitrary code. reference LINKS: Secunia Advisory SA48297 CVE-2012-0397 IMPACT ASSESSMENT: High Discussion: A vulnerability has been reported in RSA SecurID Software Token Converter, which can be exploited by malicious people to compromise a user's system. Impact: An unspecified error can be exploited to cause a buffer overflow. Solution: Update to version 2.6.1. Addthis Related Articles

214

MHK Technologies/Oceanlinx Mark 3 Wave Energy Converter | Open Energy  

Open Energy Info (EERE)

Oceanlinx Mark 3 Wave Energy Converter Oceanlinx Mark 3 Wave Energy Converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Oceanlinx Mark 3 Wave Energy Converter.jpg Technology Profile Primary Organization Oceanlinx Project(s) where this technology is utilized *MHK Projects/GPP Namibia *MHK Projects/Greenwave Rhode Island Ocean Wave Energy Project *MHK Projects/Hawaii *MHK Projects/Oceanlinx Maui *MHK Projects/Port Kembla *MHK Projects/Portland Technology Resource Click here Wave Technology Type Click here Oscillating Water Column Technology Readiness Level Click here TRL 5/6: System Integration and Technology Laboratory Demonstration Technology Description The Oceanlinx Mark 3 Wave Energy Converter is a floating multi Oscilating Water Chamber Wave Energy Converter. The airflow generated by the OWC passes through a patented Denniss Auld turbine which converts the bidirectional airflow of the OWC to a unidirectional rotation of the axial flow turbine which in turn drives a generator.

215

Cooling-tower rebuild, treatment overhaul halt fouling  

SciTech Connect

Partial fixes over a period of time were insufficient to meet cooling requirements at this four-tower powerplant. The eventual remedy involved complete fill replacement and chemistry-program revision. Cooling-tower performance hinges on many factors. Assuming the proper water and air distribution and unhindered operation of spray nozzles, pumps, valves, etc, fill design is the key element. However, a decade of experience at Keystone station (operated by Pennsylvania Electric Co for a consortium of East Coast utilities) showed that more than just changing to a fouling-resistant fill was required to provide and maintain design performance. As described in this article, careful analysis, revision, and continuous monitoring of the chemical water-treatment program were needed as well. At each of Keystone's two units, two natural-draft, hyperbolic towers provide cooling for main-condenser circulating water and service water. The 325-ft-tall towers are counter-current flow, and measure 247 ft across the basin. Film-type fill originally installed in the towers consisted of assemblies of fiber-cement board, 9 ft deep in the center and 7 ft in the peripheral regions. Fiber-cement was also the construction material used in the drift eliminators, and in the piping connected to concrete distribution flumes within the towers.

Gall, G.P.

1993-02-01T23:59:59.000Z

216

Institutional Arrangements for Effective Groundwater Management to Halt Land Subsidence  

E-Print Network (OSTI)

In the Upper Galveston Bay region of the Texas coastal zone, water from naturally replenished underground aquifers provides much of the freshwater supply for municipal, industrial and agricultural needs. The availability of these easily accessible low cost freshwater supplies has contributed to the building of a strong and dynamic economic base. However use of these common water supplies in excess of natural replenishment has resulted in a gradual but accelerated and irreversible subsidence of the land surface throughout the region. The cause is long term and due to collective use of groundwater. This natural phenomenon generally exhibits the range of characteristics expected when the carrying capacity of valuable common property resources is exceeded under dynamic socio-economic use pressures. These characteristics include competing and conflicting resource use, externalities (socioeconomic and environmental impacts) and complex social, legal and political dilemmas. Regional use of groundwater in excess of the "safe" production potential of the underground water bearing system has caused physical and economic losses in the coastal areas. Surface subsidence in excess of 8.5 feet has resulted in serious socio-economic and environmental impacts because of the loss of land elevations in already low shoreland areas. Bay waters have permanently inundated previously valuable commercial, industrial, recreational, municipal and private property. Subsidence has increased the susceptibility of much of the region to destruction through tidal surges generated by tropical storms and hurricanes. Conceivably, the somewhat inchoate interests of approximately 350,000 persons and large numbers of state and private enterprises located in susceptible coastal areas are affected. The natural phenomenon of subsidence, and its technical solution decreased groundwater use and/or use of alternative surface water supplies, pose difficult institutional questions and equity issues both to public and private sectors that as yet remain unanswered and unresolved. Traditionally, groundwater has been treated as a free good or at least a relatively cheap one. Since owners of private property overlying the water bearing system are afforded legal proprietary interest in the water in Texas, the regional groundwater resources have been developed and used primarily on an individual, uncoordinated basis with little or no concern for the relationship between extraction and natural replenishment, or regard for any collateral effects of groundwater use. Social costs are unregistered under such an arrangement and only private costs are considered by users. Institutions governing the use and allocation of groundwater resources were primitive or nonexistent. Therefore, effective action to arrest the ever increasing overdraft was absent. With increased water use, however, subsidence related costs have become apparent. For many years the majority of groundwater users ignored the subsidence problem since it was thought to affect and indeed was only felt by a minority of local land owners and waters users bordering on coastal bays and other water courses. Even though the implication (for example, hurricane threat) of subsidence to the region was recognized, an internal cost differential between groundwater and surface water sources hindered voluntary conversion to the higher cost surface water by the collectivity of groundwater users. Aggregate social costs generated by overuse of groundwater exceeded the aggregate price differential, but these social costs were largely unregistered. They were felt only by a minority of community interests in a manner disproportionate to their use of the groundwater. Logically, therefore, intensive use of inexpensive groundwater continued. Although industrial, municipal, agricultural and private interests were interrelated through the common use of the aquifer, a basis for collective action was difficult because of conflicting interests. In the early 1970's a movement bega

Brah, W. L.; Jones, L. L.

1978-01-01T23:59:59.000Z

217

Halting_Title_XVII_Nuclear_Loan_Guarantees.pdf  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

fuels producers backed by DOE loan guarantees were unable to compete with falling oil prices and therefore defaulted on billions of dollars of loans. This time, DOE claims to...

218

Subsea pipeline gets welded branch without halting flow  

Science Conference Proceedings (OSTI)

In October 1994, a 16 in. welded branch was installed without interruption to production onto Wintershall Noordzee BV`s 36-in. gas pipeline from the K13-A platform in the Dutch sector of the North Sea to Den helder, The Netherlands. The procedure is the first successfully to combine hyperbaric welding and subsea hot tapping without interruption to production. Developers of new fields can now consider exporting product without interrupting existing production and through existing infrastructure even if no convenient tie-in locations exist. Unocal evaluated export options and established that the most attractive alternative was to export gas into the Wintershall 36-in. K13-A to Den Helder pipeline. Various options for installing a branch included the following: flooding the pipeline and installing a conventional tee; stopping production and installing a welded branch followed by hot tapping; and continuing production and installing a welded branch followed by hot tapping. The chosen scheme was to retrofit a subsea side-tap assembly. This was achieved by installation of a welded branch followed by hot tapping into the 36-in. pipeline. The paper describes location determination, schedules, onshore preparation, and offshore work.

West, A.; Hutt, G. [Stolt Comex Seaway Ltd., Aberdeen (United Kingdom); Starsmore, R. [Wintershall Noordzee B.V., Den Helder (Netherlands)

1995-12-11T23:59:59.000Z

219

An Integrated Onboard Charger and Accessary Power Converter for Plug-in Electric Vehicles  

SciTech Connect

Abstract: In this paper, an integrated onboard battery charger and accessary dc-dc converter for plug-in electric vehicles (PEVs) is presented. The idea is to utilize the already available traction drive inverters and motors of a PEV as the frond converter of the charger circuit and the transformer of the 14 V accessary dc-dc converter to provide galvanic isolation. The topology was verified by modeling and experimental results on a 5 kW charger prototype

Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

2013-01-01T23:59:59.000Z

220

Design and characterization of a 0.35 micron CMOS voltage-to-current converter  

Science Conference Proceedings (OSTI)

This work presents the design and characterization of a CMOS voltage-to-current (V-I) converter with a current range from -100 ?A to 100 ?A. The V-I converter has a power consumption of approximately 0.6 mW and its final area was 0.022 mm2 ... Keywords: current reference, system on chip, voltage-to-current converter

Genival Mariano de Araujo; Heider Marconi G. Madureira; José Camargo da Costa

2009-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

What are Ccf, Mcf, Btu, and therms? How do I convert prices in ...  

U.S. Energy Information Administration (EIA)

Natural Gas Conversion Calculator. Last updated: March 20, 2013. Other FAQs about Conversion & Equivalents. How do I convert between short tons and metric tons?

222

How do I convert between short tons and metric tons? - FAQ - U ...  

U.S. Energy Information Administration (EIA)

Other FAQs about Conversion & Equivalents. How do I convert between short tons and metric tons? How do I compare heating fuels?

223

Bibliography on overvoltage protection and insulation coordination of HVDC converter stations, 1979-1989  

Science Conference Proceedings (OSTI)

This bibliography is a listing of references on the subject of overvoltage protection and insulation coordination of HVDC converter stations, for the years 1979 through 1989.

Not Available

1991-04-01T23:59:59.000Z

224

Gasification is used to convert a solid feedstock, such as coal...  

NLE Websites -- All DOE Office Websites (Extended Search)

can be captured and disposed of or converted to useful products more easily with gasification-based technologies compared to conventional combustion of solid feedstocks....

225

Index of /~jborwein/Expbook/Manuscript/Graphics files/please_convert  

E-Print Network (OSTI)

Index of /~jborwein/Expbook/Manuscript/Graphics files/please_convert. Icon Name Last modified Size Description. [DIR] Parent Directory - [DIR] ...

226

New Family of Multilevel Matrix Converters for Wind Power Applications: Final Report, July 2002 - March 2006  

DOE Green Energy (OSTI)

The goal of this project was to develop a new modular multilevel matrix converter for wind power applications and to demonstrate a working scale model in the laboratory.

Erickson, R.; Angkititrakul, S.; Almazeedi, K.

2006-12-01T23:59:59.000Z

227

Thermal analysis and testing of a vacuum insulated catalytic converter  

DOE Green Energy (OSTI)

Based on a recent US Environmental Protection Agency (EPA) study, about 95% of all trips start after a cold-soak period of 16 hours or less. By preserving the heat in the catalyst between trips, exhaust gases could be processed without warm-up delay and without the usual cold-start emissions. Vacuum insulation and phase-change thermal storage have been incorporated into a catalytic converter design to enhance its heat-retention time. Laboratory testing of a bench-scale prototype showed that a ``light off`` temperature (above 350 C) could be maintained during a 10-hour cold soak. Design improvements currently being tested should increase this heat-retention time to more than 16 hours. The thermal conductance of the vacuum insulation will be made continuously variable to prevent overheating and excessive thermal cycling. This approach to thermal management may be more durable and less costly than quick-heat methods using electric or fuel-fired preheat catalysts.

Burch, S D; Potter, T F; Keyser, M A; Benson, D K

1994-11-01T23:59:59.000Z

228

Converting acoustic energy into useful other energy forms  

SciTech Connect

Sonoluminescence is an off-equilibrium phenomenon in which the energy of a resonant sound wave in a liquid is highly concentrated so as to generate flashes of light. The conversion of sound to light represents an energy amplification of eleven orders of magnitude. The flashes which occur once per cycle of the audible or ultrasonic sound fields can be comprised of over one million photons and last for less 100 picoseconds. The emission displays a clocklike synchronicity; the jitter in time between consecutive flashes is less than fifty picoseconds. The emission is blue to the eye and has a broadband spectrum increasing from 700 nanometers to 200 nanometers. The peak power is about 100 milliWatts. The initial stage of the energy focusing is effected by the nonlinear oscillations of a gas bubble trapped in the liquid. For sufficiently high drive pressures an imploding shock wave is launched into the gas by the collapsing bubble. The reflection of the shock from its focal point results in high temperatures and pressures. The sonoluminescence light emission can be sustained by sensing a characteristic of the emission and feeding back changes into the driving mechanism. The liquid is in a sealed container and the seeding of the gas bubble is effected by locally heating the liquid after sealing the container. Different energy forms than light can be obtained from the converted acoustic energy. When the gas contains deuterium and tritium there is the feasibility of the other energy form being fusion, namely including the generation of neutrons.

Putterman, Seth J. (Sherman Oaks, CA); Barber, Bradley Paul (Northridge, CA); Hiller, Robert Anthony (Los Angeles, CA); Lofstedt, Ritva Maire Johanna (Los Angeles, CA)

1997-01-01T23:59:59.000Z

229

Measured and projected performance of plasma direct converters  

DOE Green Energy (OSTI)

Test results from two plasma direct converters and their predicted cost and performance on tandem mirror fusion reactors are present. The tests were done at high power density (approx. 70 W/cm/sup 2/) in steady state to simulate the predicted conditions in a reactor. A single stage unit and a two-stage unit of the Venetian blind type were tested at up to 100 kV and 6 kW for a total time of about 80 hours. Measured efficiencies, when projected to a reactor, are typically about 50% for a single stage unit and 60 to 70% for a two-stage unit, depending on the energy distribution of the ions, the degree of subdivision of the collectors, and on the gas pressure. The high ambipolar potential in tandem mirror devices makes this good efficiency possible. When radiatively cooled grids are used, the incident power density is limited to about 100 W/cm/sup 2/ by the thermionic emission of electrons.

Barr, W.L.; Moir, R.W.

1981-10-22T23:59:59.000Z

230

Analysis of electron transport in the plasma of thermionic converters  

DOE Green Energy (OSTI)

Electron transport coefficients of a gaseous ensemble are expressed analytically as function of density, and are expressed analytically as function of temperature up to an unknown function which has to be evaluated for each specific electron-neutral atom cross section. In order to complete the analytical temperature dependence one may introduce a polynomial expansion of the function or one may derive the temperature dependence of a set of coefficients, numbering thirteen for a third approximation transport evaluation, which completely determine the transport coefficients. The latter approach is used for determining the electron transport coefficients of a cesium plasma for any ion neutral composition and any temperature between 500/sup 0/K and 3500/sup 0/K. The relation between the transport coefficients of a fully and partly ionized gas is readily available and shows that, in the classical formalism, electron-ion and electron-neutral resistivities are not additive. The present form of the transport coefficients makes possible an accurate numerical integration of transport equations eliminating lengthy computations which are frequently inaccessible. It thus provides a detailed knowledge of spatial distribution of particle and energy transport and makes possible the determination of one of the three internal voltage drops, surface barrier, sheath and plasma, which are linked together experimentally by current density versus voltage characteristics of thermionic converters.

Stoenescu, M.L.; Heinicke, P.H.

1980-03-01T23:59:59.000Z

231

A local fitting algorithm for converting planar curves to  

E-Print Network (OSTI)

In this paper we present a local fitting algorithm for converting smooth planar curves to B-splines. For a smooth planar curve a set of points together with their tangent vectors are first sampled from the curve such that the connected polygon approximates the curve with high accuracy and inflexions are detected by the sampled data efficiently. Then, a G 1 continuous Bézier spline curve is obtained by fitting the sampled data with shape preservation as well as within a prescribed accuracy. Finally, the Bézier spline is merged into a C 2 continuous B-spline curve by subdivision and control points adjustment. The merging is guaranteed to be within another error bound and with no more inflexions than the Bézier spline. In addition to shape preserving and error control, this conversion algorithm also benefits that the knots are selected automatically and adaptively according to local shape and error bound. A few experimental results are included to demonstrate the validity and efficiency of the algorithm. Keywords: curve conversion; B-spline curve; cubic Bézier curve; knot selection; shape preserving 1.

unknown authors

2007-01-01T23:59:59.000Z

232

Advanced Gate Drive for the SNS High Voltage Converter Modulator  

SciTech Connect

SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.

Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; /SLAC; Anderson, D.E.; /Oak Ridge

2009-05-07T23:59:59.000Z

233

Device to convert the energy of a fluid in motion  

SciTech Connect

A device is disclosed to convert wave energy into mechanical energy, comprises a buoyant structure whose upper portion is in the region of wave action but whose lower section is below the region of wave action, so that the water adjacent the upper and lower sections of the structure has vertical movement relative to itself. This relative movement is used to rotate a vertical shaft having radially extending horizontal axles on which panels are pivotally mounted. Ballast and/or floats are used to impose on the panels a bias tending to maintain them horizontal. The relative movement of the water is used to impel fluid vertically relative to the panels in alternatingly opposite directions; and the bias imposed by the ballast and/or floats thus causes a planing wing action of the panels which impels the shaft in rotation in one direction regardless of the direction of the movement of the impelling fluid. The floating structure can rise and fall with the waves, in which case the blade are disposed at the lower end of the device, in the still water; or the device can be stationary in the water, in which case the blades are subject to a fluid such as the water itself or air impelled by the water, at the upper end of the device.

de la Roche Kerandraon, O.; Guillaume, P.; Paroldi, D.

1983-09-27T23:59:59.000Z

234

Adaptive stabilizing control of a power system through UPFC shunt and series converters  

Science Conference Proceedings (OSTI)

The dynamic performance of a power system can be improved by using additional controls in a unified power flow controller (UPFC). Self-tuning adaptive control of the voltage magnitude of the series converter and phase angle of shunt converter for stabilization ... Keywords: UPFC, adaptive control, on-line identification, pole - shifting control, power system stabilizing control

A. H. M. A. Rahim; E. P. Nowicki

2007-07-01T23:59:59.000Z

235

A 1-GSPS CMOS Flash A/D Converter for System-on-Chip Applications  

Science Conference Proceedings (OSTI)

Abstract: This paper presents an ultrafast CMOS flash A/D converter design and performance. Although the featured A/D converter is designed in CMOS, the performance is compatible to that of GaAs technology currently available. To achieve high-speed in ...

Jincheol Yoo; Kyusun Choi; Ali Tangel

2001-04-01T23:59:59.000Z

236

Sliding Mode Control of Boost Converter: Application to energy storage system via supercapacitors  

E-Print Network (OSTI)

Sliding Mode Control of Boost Converter: Application to energy storage system via supercapacitors», «Robust control», «Supercapacitor». Abstract Sliding mode control of boost converter is studied. In order of an energy storage system based on supercapacitors technology in order to regulate the output voltage. Given

Paris-Sud XI, Université de

237

Simulation Research of Tap Change Control of Converter Transformers for HVDC Transmission System  

Science Conference Proceedings (OSTI)

High voltage direct current(HVDC) control system plays an important role for the safety of HVDC transmission system. Converter transformer tap changes control is core component of HVDC control system. Stability of HVDC transmission system operation is ... Keywords: HVDC, simulation, converter transformer, tap change control, steady process

Wang Ying; Ma Cong; Wei Wen-hui; Wang Qing-ping

2012-03-01T23:59:59.000Z

238

EPRI Power Flow to CIM Interface: Development of Power Flow to Common Information Model (CIM) Converter  

Science Conference Proceedings (OSTI)

IEEE has developed a Power Systems Application Data Dictionary (PSADD) for power system data and EPRI sponsored development of a CONVERTER program to convert PTI's PSS/E's data into this format. This project will develop the common data sources (CDSs) that translate the PSADD data to/from a Common Information Model (CIM)-structured database.

2002-11-27T23:59:59.000Z

239

Relation between verifiable random functions and convertible undeniable signatures, and new constructions  

Science Conference Proceedings (OSTI)

Verifiable random functions (VRF) and selectively convertible undeniable signature (SCUS) schemes were proposed independently in the literature. In this paper, we observe that they are tightly related. This directly yields several deterministic SCUS ... Keywords: selectively convertible undeniable signatures, standard model, verifiable random function

Kaoru Kurosawa; Ryo Nojima; Le Trieu Phong

2012-07-01T23:59:59.000Z

240

Structural And Economic Optimisation Of Bottom-Mounted Offshore Wind Energy Converters  

E-Print Network (OSTI)

A general overview is presented of the Opti-OWECS project. In several fields, support structure design, installation of the offshore wind energy converters, operation and maintenance, dynamics of the entire offshore wind energy converter, structural reliability considerations, etc., the study demonstrated new propositions which will contribute significantly to a mature offshore wind energy technology.

M. Kühn; W. A. A. M. Bierbooms; G.J.W. van Bussel; M. C. Ferguson; B. Göransson; T.T. Cockerill; R. Harrison; L.A. Harland; J. H. Vugts; R. Wiecherink; Kvaerner Turbin Ab

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Do Investment Banks' Relationships with Investors Impact Pricing? The Case of Convertible Bond Issues  

Science Conference Proceedings (OSTI)

This study examines the role of repeat interactions between placement agents (investment banks) and investors in the initial pricing of convertible bonds. Under the assumption that attracting repeat investors can reduce search frictions in primary issue ... Keywords: convertible bonds, corporate finance, securities issuance, underpricing

Brian J. Henderson; Heather Tookes

2012-12-01T23:59:59.000Z

242

Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News  

E-Print Network (OSTI)

Solar Power To Help Convert Carbon Dioxide Into Fuel : Renewable Energy News TUESDAY 25 MAY, 2010 | | Solar Power To Help Convert Carbon Dioxide Into Fuel by Energy Matters Microbiologist Derek Lovley dioxide into transportation fuels, with the help of special micro-organisms and solar power. The team

Lovley, Derek

243

Brief paper: Optimal switching instants for a switched-capacitor DC/DC power converter  

Science Conference Proceedings (OSTI)

We consider a switched-capacitor DC/DC power converter with variable switching instants. The determination of optimal switching instants giving low output ripple and strong load regulation is posed as a non-smooth dynamic optimization problem. By introducing ... Keywords: Control parametrization enhancing transform, Impulsive dynamical system, Power converter, Semi-infinite programming, Switched linear system

R. C. Loxton; K. L. Teo; V. Rehbock; W. K. Ling

2009-04-01T23:59:59.000Z

244

Association of Flyback Converters to Harvest Energy from Multiple Hydraulically Connected Biofuel Cells  

Science Conference Proceedings (OSTI)

Biofuel cells use catalysts (chemical, enzymatic or microbial) to convert chemical energy from organic substrates into electrical energy. This paper investigates energy harvesting from several low-power biofuel cells to power a load under several volts. ... Keywords: biofuel cell, energy harvesting, power management, flyback converter, low-power supply

Nicolas Degrenne, Marilyne Boileau, Florent Morel, Firas Khaled, Olivier Ondel, Francois Buret, Bruno Allard

2012-11-01T23:59:59.000Z

245

Developing and Simulation Research of the Control Model and Control Strategy of Static Frequency Converter  

Science Conference Proceedings (OSTI)

a control model and control strategy of static frequency converter (SFC) for pumped storage power plant unit is presented. Control strategy of static start-up and its mathematical model is discussed in detail. And based on the 42 poles of synchronous ... Keywords: Pumped Storage Power Plant, Static Frequency Converter, SFC, Commutation, Control

Deshun Wang; Lichun Zhang; Bo Yang; Guanjun Li; Yibin Tao; Jianzhong Fu; Jianfeng Li; Liantao Ji

2012-01-01T23:59:59.000Z

246

Observations of the mid-mantle discontinuity beneath Indonesia from S to P converted waveforms  

E-Print Network (OSTI)

Observations of the mid-mantle discontinuity beneath Indonesia from S to P converted waveforms a coherent discontinuity structure beneath Indonesia. Analysis of data recorded by three regional arrays from Indonesia from S to P converted waveforms, Geophys. Res. Lett., 33, L04302, doi:10.1029/2005GL025106. 1

Kawakatsu, Hitoshi

247

Multiport DC/DC Converter for Stand-alone Photovoltaic Lighting System with Battery Storage  

Science Conference Proceedings (OSTI)

Photovoltaic energy has nowadays an increased importance in electrical power applications. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore a multiple-input DC/DC converter ... Keywords: Multiport DC/DC Converter, photovoltaic (PV), battery, charge/discharge

Shengyong Liu; Xing Zhang; Haibin Guo; Jun Xie

2010-06-01T23:59:59.000Z

248

CMOS flash analog-to-digital converter for high speed and low voltage applications  

Science Conference Proceedings (OSTI)

A CMOS flash analog-to-digital converter (ADC) designed for high speed and low voltage is presented. Using the Threshold Inverter Quantization (TIQ) comparator technique, a flash ADC can be applied to low supply voltage. A fat tree encoder that has signal ... Keywords: TIQ comparator, analog-to-digital converter, fat tree encoder, flash ADC, high speed, low voltage

Jincheol Yoo; Kyusun Choi; Jahan Ghaznavi

2003-04-01T23:59:59.000Z

249

Emissions and Experiences with E85 Converted Cars in the BEST Project |  

Open Energy Info (EERE)

Emissions and Experiences with E85 Converted Cars in the BEST Project Emissions and Experiences with E85 Converted Cars in the BEST Project Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Emissions and Experiences with E85 Converted Cars in the BEST Project Agency/Company /Organization: BioEthanol for Sustainable Transport Focus Area: Fuels & Efficiency Topics: Best Practices Website: www.best-europe.org/upload/BEST_documents/info_documents/Best%20report The BioEthanol for Sustainable Transport (BEST) project converted vehicles from petrol to E85, exploring the possibilities, advantages, and any difficulties. Several suggestions are presented for how converted cars may be incorporated into Swedish government financial incentives. How to Use This Tool This tool is most helpful when using these strategies: Shift - Change to low-carbon modes

250

Utility-Scale Power Router: Dynamic Control of Grid Assets Using Direct AC Converter Cells  

SciTech Connect

ADEPT Project: Georgia Tech is developing a cost-effective, utility-scale power router that uses an enhanced transformer to more efficiently direct power on the grid. Existing power routing technologies are too expensive for widespread use, but the ability to route grid power to match real-time demand and power outages would significantly reduce energy costs for utilities, municipalities, and consumers. Georgia Tech is adding a power converter to an existing grid transformer to better control power flows at about 1/10th the cost of existing power routing solutions. Transformers convert the high-voltage electricity that is transmitted through the grid into the low-voltage electricity that is used by homes and businesses. The added converter uses fewer steps to convert some types of power and eliminates unnecessary power storage, among other improvements. The enhanced transformer is more efficient, and it would still work even if the converter fails, ensuring grid reliability.

None

2010-09-01T23:59:59.000Z

251

Compact self-contained electrical-to-optical converter/transmitter  

DOE Patents (OSTI)

An electrical-to-optical converter/transmitter is disclosed. A first optical receiver and a second optical receiver are provided for receiving a calibrate command and a power switching signal, respectively, from a remote processor. A third receiver is provided for receiving an analog electrical signal from a transducer. A calibrator generates a reference signal in response to the calibrate command. A combiner mixes the electrical signal with the reference signal to form a calibrated signal. A converter converts the calibrated signal to an optical signal. A transmitter transmits the optical signal to the remote processor. A primary battery supplies power to the calibrator, the combiner, the converter, and the transmitter. An optically-activated switch supplies power to the calibrator, the combiner, the converter, and the transmitter in response to the power switching signal. An auxiliary battery supplies power continuously to the switch means.

Seligmann, D.A.; Moss, W.C.; Valk, T.C.; Conder, A.D.

1992-12-31T23:59:59.000Z

252

Photo of the Week: Converting Solar Energy into Fuel | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Converting Solar Energy into Fuel Converting Solar Energy into Fuel Photo of the Week: Converting Solar Energy into Fuel May 9, 2013 - 1:13pm Addthis In this photo, Brookhaven scientist Dmitry Polyansky examines a vial containing a specialized catalyst designed to help convert solar energy into fuel. Producing clean-burning hydrogen fuel from just sunlight and water requires custom-built catalysts for water oxidation -- the part of the water-splitting process that generates oxygen atoms. A tiny amount of the solid catalyst, developed in collaboration with the University of Houston, dissolves and turns the water that lovely shade of blue. | Photo courtesy of Brookhaven National Laboratory. In this photo, Brookhaven scientist Dmitry Polyansky examines a vial containing a specialized catalyst designed to help convert solar energy

253

Effective switching frequency multiplier inverter  

SciTech Connect

A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

Su, Gui-Jia (Oak Ridge, TN); Peng, Fang Z. (Okemos, MI)

2007-08-07T23:59:59.000Z

254

Wide input range DC-DC converter with digital control scheme  

E-Print Network (OSTI)

In this thesis analysis and design of a wide input range DC-DC converter is proposed along with a robust power control scheme. The proposed converter and its control is designed to be compatible to a fuel cell power source, which exhibits 2:1 voltage variation as well as a slow transient response. The proposed approach consists of two stages: a primary three-level boost converter stage cascaded with a high frequency, isolated boost converter topology, which provides a higher voltage gain and isolation from the input source. The function of the first boost converter stage is to maintain a constant voltage at the input of the cascaded DC-DC converter to ensure optimal performance characteristics with high efficiency. At the output of the first boost converter a battery or ultracapacitor energy storage is connected to take care of the fuel cell slow transient response (200 watts/min). The robust features of the proposed control system ensure a constant output DC voltage for a variety of load fluctuations, thus limiting the power being delivered by the fuel cell during a load transient. Moreover, the proposed configuration simplifies the power control management and can interact with the fuel cell controller. The simulation results and the experimental results confirm the feasibility of the proposed system.

Harfman Todorovic, Maja

2004-12-01T23:59:59.000Z

255

A bimetal and electret-based converter for thermal energy harvesting  

E-Print Network (OSTI)

This paper presents a new device able to turn thermal gradients into electricity by using a bimetal-based heat engine coupled to an electrostatic converter. A two-steps conversion is performed: (i) a curved bimetallic strip turns the thermal gradient into a mechanical movement (thermal-to-mechanical conversion) that is (ii) then converted into electricity thanks to an electret-based electrostatic converter (mechanical-to-electrical conversion). An output power up to 5.5uW on a hot source at 50{\\deg}C has already been reached, validating this new concept.

Boisseau, S; Monfray, S; Puscasu, O; Skotnicki, T

2012-01-01T23:59:59.000Z

256

Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Announces Six Projects to Convert Captured CO2 Announces Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products July 22, 2010 - 12:00am Addthis Washington, D.C. - U.S. Energy Secretary Steven Chu announced today the selections of six projects that aim to find ways of converting captured carbon dioxide (CO2) emissions from industrial sources into useful products such as fuel, plastics, cement, and fertilizers. Funded with $106 million from the American Recovery and Reinvestment Act -matched with $156 million in private cost-share -today's selections demonstrate the potential opportunity to use CO2 as an inexpensive raw material that can help reduce carbon dioxide emissions while producing useful by-products that Americans

257

DOE-TSPP-8-2013, Converting DOE Technical Standards to Voluntary Consensus  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

-2013, Converting DOE Technical Standards to Voluntary -2013, Converting DOE Technical Standards to Voluntary Consensus Standards DOE-TSPP-8-2013, Converting DOE Technical Standards to Voluntary Consensus Standards Technical Standards Program Procedures (TSPP) - September 16, 2013 This procedure provides guidance on the conversion of DOE Technical Standards to Voluntary Consensus Standards (VCSs). This procedure applies to all Department of Energy (DOE) Headquarters and field organizations, management and operating contractors, and laboratories (hereafter referred to collectively as Technical Standards Program (TSP) participants) working to the requirements of the latest revision of DOE Order (O) 252.1A, Technical Standards Program. DOE-TSPP-8-2013, Converting DOE Technical Standards to Voluntary Consensus Standards

258

MHK Technologies/Uppsala Seabased AB Wave Energy Converter | Open Energy  

Open Energy Info (EERE)

AB Wave Energy Converter AB Wave Energy Converter < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Uppsala Seabased AB Wave Energy Converter.jpg Technology Profile Primary Organization Uppsala University Division for Electricity Technology Resource Click here Wave Technology Type Click here Point Absorber - Floating Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description The system consists of a linear permanent magnet synchronous generator located on the sea floor The generator is connected directly via a line to a buoy on the surface There are no intermediate energy conversion steps thus the generator motion is the same as the buoy motion Several generators 3 today are connected to a marine substation where the voltage is converted to grid frequency transformed to higher voltage and transmitted to shore All electrical cables throughout the system are fixed i e there are no motions that subject the cables to bending moments

259

Compact self-contained electrical-to-optical converter/transmitter  

DOE Patents (OSTI)

A first optical receiver and a second optical receiver are provided for receiving a calibrate command and a power switching signal, respectively, from a remote processor. A third receiver is provided for receiving an analog electrical signal from a transducer. A calibrator generates a reference signal in response to the calibrate command. A combiner mixes the electrical signal with the reference signal to form a calibrated signal. A converter converts the calibrated signal to an optical signal. A transmitter transmits the optical signal to the remote processor. A primary battery supplies power to the calibrator, the combiner, the converter, and the transmitter. An optically-activated switch supplies power to the calibrator, the combiner, the converter, and the transmitter in response to the power switching signal. An auxiliary battery supplies power continuously to the switch.

Seligmann, Daniel A. (Manteca, CA); Moss, William C. (San Mateo, CA); Valk, Theodore C. (Livermore, CA); Conder, Alan D. (Tracy, CA)

1995-01-01T23:59:59.000Z

260

Converting mill buildings into housing : ways of working with brick walls  

E-Print Network (OSTI)

The mill buildings of New England add a unique dimension to the heritage and identity of the region. Today some of these buildings continue to function as the site of industry, others have been converted to commercial or ...

Pressman, Paul

1981-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Research Projects to Convert Captured CO2 Emissions to Useful Products |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Projects to Convert Captured CO2 Emissions to Useful Projects to Convert Captured CO2 Emissions to Useful Products Research Projects to Convert Captured CO2 Emissions to Useful Products July 6, 2010 - 1:00pm Addthis Washington, DC - Research to help find ways of converting into useful products CO2 captured from emissions of power plants and industrial facilities will be conducted by six projects announced today by the U.S. Department of Energy (DOE). The projects are located in North Carolina, New Jersey, Massachusetts, Rhode Island, Georgia, and Quebec, Canada (through collaboration with a company based in Lexington, Ky.) and have a total value of approximately $5.9 million over two-to-three years, with $4.4 million of DOE funding and $1.5 million of non-Federal cost sharing. The work will be managed by the

262

Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Six Projects to Convert Captured CO2 Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products July 22, 2010 - 1:00pm Addthis Washington, DC - U.S. Energy Secretary Steven Chu announced today the selections of six projects that aim to find ways of converting captured carbon dioxide (CO2) emissions from industrial sources into useful products such as fuel, plastics, cement, and fertilizers. Funded with $106 million from the American Recovery and Reinvestment Act -matched with $156 million in private cost-share -today's selections demonstrate the potential opportunity to use CO2 as an inexpensive raw material that can help reduce carbon dioxide emissions while producing useful by-products that Americans

263

Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Six Projects to Convert Captured CO2 Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products Secretary Chu Announces Six Projects to Convert Captured CO2 Emissions from Industrial Sources into Useful Products July 22, 2010 - 12:00am Addthis Washington, D.C. - U.S. Energy Secretary Steven Chu announced today the selections of six projects that aim to find ways of converting captured carbon dioxide (CO2) emissions from industrial sources into useful products such as fuel, plastics, cement, and fertilizers. Funded with $106 million from the American Recovery and Reinvestment Act -matched with $156 million in private cost-share -today's selections demonstrate the potential opportunity to use CO2 as an inexpensive raw material that can help reduce carbon dioxide emissions while producing useful by-products that Americans

264

DOE Will Convert Northeast Home Heating Oil Reserve to Ultra Low Sulfur  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE Will Convert Northeast Home Heating Oil Reserve to Ultra Low DOE Will Convert Northeast Home Heating Oil Reserve to Ultra Low Sulfur Distillate DOE Will Convert Northeast Home Heating Oil Reserve to Ultra Low Sulfur Distillate February 1, 2011 - 12:00pm Addthis Washington, DC - The current inventory of the Northeast Home Heating Oil Reserve will be converted to cleaner burning ultra low sulfur distillate to comply with new, more stringent fuel standards by some Northeastern states, the U.S. Department of Energy (DOE) said today. The State of New York and other Northeastern states are implementing more stringent fuel standards that require replacement of high sulfur (2,000 parts per million) heating oil to ultra low sulfur fuel (15 parts per million). As a result, DOE will sell the current inventory of the Northeast

265

Two U.S. University Research Reactors to be Converted From Highly Enriched  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

U.S. University Research Reactors to be Converted From Highly U.S. University Research Reactors to be Converted From Highly Enriched Uranium to Low-Enriched Uranium Two U.S. University Research Reactors to be Converted From Highly Enriched Uranium to Low-Enriched Uranium April 11, 2005 - 11:34am Addthis WASHINGTON, D.C. - As part of the Bush administration's aggressive effort to reduce the amount of weapons-grade nuclear material worldwide, Secretary of Energy Samuel W. Bodman announced today that the Department of Energy (DOE) has begun to convert research reactors from using highly-enriched uranium (HEU) to low-enriched uranium fuel (LEU) at the University of Florida and Texas A&M University. This effort, by DOE's National Nuclear Security Administration (NNSA) and the Office of Nuclear Energy, Science and Technology, are the latest steps

266

Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions, and  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions, Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions, and Eco-Driving Weekly Wrap-Up: Testing Wind Blades, Converting Carbon Emissions, and Eco-Driving July 23, 2010 - 5:17pm Addthis Elizabeth Meckes Elizabeth Meckes Director of User Experience & Digital Technologies, Office of Public Affairs On Thursday, Secretary Chu announced six projects that aim to find ways of convert captured carbon dioxide (CO2) emissions from industrial sources into useful products. The innovative projects - funded with $106 million from the American Recovery and Reinvestment Act and matched with $156 million in private cost-share - will seek to use CO2 emissions from industrial sources to create useful products such as fuel, plastics, cement, and fertilizers. Find out more here.

267

DOE Will Convert Northeast Home Heating Oil Reserve to Ultra Low Sulfur  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Will Convert Northeast Home Heating Oil Reserve to Ultra Low Will Convert Northeast Home Heating Oil Reserve to Ultra Low Sulfur Distillate DOE Will Convert Northeast Home Heating Oil Reserve to Ultra Low Sulfur Distillate February 1, 2011 - 12:00pm Addthis Washington, DC - The current inventory of the Northeast Home Heating Oil Reserve will be converted to cleaner burning ultra low sulfur distillate to comply with new, more stringent fuel standards by some Northeastern states, the U.S. Department of Energy (DOE) said today. The State of New York and other Northeastern states are implementing more stringent fuel standards that require replacement of high sulfur (2,000 parts per million) heating oil to ultra low sulfur fuel (15 parts per million). As a result, DOE will sell the current inventory of the Northeast Home Heating Oil Reserve, a total of approximately 2 million barrels, and

268

Progress on Converting a NIF Quad to Eight, Petawatt Beams for Advanced Radiography  

Science Conference Proceedings (OSTI)

We are converting a quad of NIF beamlines into eight, short-pulse (1-50 ps), petawatt-class beams for advanced radiography and fast ignition experiments. This paper describes progress toward completing this project.

Crane, J K

2009-10-19T23:59:59.000Z

269

High efficiency resonant dc/dc converter for solar power applications  

E-Print Network (OSTI)

This thesis presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across ...

Inam, Wardah

2013-01-01T23:59:59.000Z

270

Single-phase Converter-less Excitation Synchronous Stand-along Wind Power Generator System.  

E-Print Network (OSTI)

??In this thesis, a single-phase converter-less excitation synchronous stand-along wind power generator system is proposed. In order to simplify the system and improve the system… (more)

Lin, Chin-wei

2013-01-01T23:59:59.000Z

271

Radio frequency dc-dc converters : device characterization, topology evaluation, and design  

E-Print Network (OSTI)

High frequency power conversion is attractive for the opportunities it affords for improved performance. Dc-dc converters operating at high frequencies use smaller-valued energy storage elements, which tend to be physically ...

Leitermann, Olivia

2008-01-01T23:59:59.000Z

272

Design of ultra low power analog-to-digital converter for ambulatory EEG recording  

E-Print Network (OSTI)

Portable acquisition of biopotential signals requires the design of compact, energy efficient circuits and systems. Such systems typically include analog-to-digital converter for digitizing signals from AFE and feeding it ...

El-Damak, Dina Reda

2012-01-01T23:59:59.000Z

273

Design of a low-voltage low-power dc-dc HF converter  

E-Print Network (OSTI)

Many portable electronic applications could benefit from a power converter able to achieve high efficiency across wide input and output voltage ranges at a small size. However, it is difficult for many conventional power ...

Hu, Jingying, Ph. D. Massachusetts Institute of Technology.

2008-01-01T23:59:59.000Z

274

Design and evaluation of a very high frequency dc/dc converter  

E-Print Network (OSTI)

This thesis presents a resonant boost topology suitable for very high frequency (VHF, 30-300 MHz) dc-dc power conversion. The proposed design is a fixed frequency, fixed duty ratio resonant converter featuring low device ...

Pilawa-Podgurski, Robert C. N

2007-01-01T23:59:59.000Z

275

Single-inductor, multiple-output buck converter with parallel source transient recovery  

E-Print Network (OSTI)

To address the need for multiple regulated voltage supplies in electronic devices, this thesis presents a modeling and design study of a single-inductor, multiple-output (SIMO) DC-DC buck converter with parallel source ...

King, Charles Jackson, III

2009-01-01T23:59:59.000Z

276

A zero-crossing based pipelined analog-to-digital converter with supply voltage scalibility  

E-Print Network (OSTI)

A zero-crossing based pipelined analog-to-digital converter (ADC) has been designed and is fabricated in a 65nm CMOS process. The highly digital implementation characteristic of the zero-crossing detection technique enables ...

Lee, Sunghyuk

2010-01-01T23:59:59.000Z

277

High Voltage Thermal Battery Reliability Required to Equal Inverter-Converter Systems  

SciTech Connect

MC-583 and XMC-650 circuits, including associated pulse transformers, are compare with the inverter-converter system typical of present fuses. The required probabilities of thermal battery shorts and opens are determined.

1955-06-14T23:59:59.000Z

278

A single inductor dual input dual output DC-DC converter with hybrid supplies for solar energy harvesting applications  

Science Conference Proceedings (OSTI)

A single inductor dual input dual output (SIDIDO) DC-DC converter is proposed for solar energy harvesting applications. The converter supports hybrid power supplies from both the photovoltaic (PV) cells and the rechargeable battery. Apart from the conventional ... Keywords: DC-DC converter, MPPT, PV cells, dual-input-dual-output, energy harvesting, single inductor

Hui Shao; Chi-Ying Tsui; Wing-Hung Ki

2009-08-01T23:59:59.000Z

279

Direct connection of series self-excited generators and HVDC converters  

Science Conference Proceedings (OSTI)

An alternative and simpler solution is proposed for the direct connection of generators to HVdc converters. The generator exciter windings are connected in series with the output of the HVdc converter and take the place of the conventional smoothing reactor. Existing steady state and time domain simulation programs are modified to represent the behavior of the series direct connection scheme. It is shown that series excitation extends naturally the power transmission capability and permits fast fault clearances.

Arrillaga, J.; Macdonald, S.J.; Watson, N.R.; Watson, S. (Univ. Canterbury, Christchurch (New Zealand))

1993-10-01T23:59:59.000Z

280

Design considerations for DC-DC converters in fuel cell systems  

E-Print Network (OSTI)

Rapidly rising fossil fuel costs along with increased environmental awareness has encouraged the development of alternative energy sources. Such sources include fuel cells, wind, solar and ocean tide power. Among them, fuel cells have received increased interest in the recent years. This is mainly due to their high efficiency, modularity, and simple construction. However, due to their low output voltage and wide variation from no load to full load, a power electronics converter is required to interface the fuel cell with its loads. This dissertation focuses on developing a set of considerations that will assist designers of the power electronics converter in the design and optimization of the system. These design considerations are obtained analytically and verified experimentally and allow obtaining an efficient and stable fuel cell – power converter system. In addition to the design guidelines this dissertation presents new power converter topologies that do not require the use of transformers to achieve a large voltage gain. Further a new modular fuel cell power converter system that divides the fuel cell stack to optimize power generation is proposed. It is shown by means of mathematical analysis and experimental prototypes that the proposed solutions contribute to the reduction of size and cost of the power converter as well to increase the efficiency of the system.

Palma Fanjul, Leonardo Manuel

2006-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

100kW Energy Transfer Multiplexer Power Converter Prototype Development Project  

DOE Green Energy (OSTI)

Project Final Report for "100kW Energy Transfer Multiplexer Power Converter Prototype Development Project" prepared under DOE grant number DE-FG36-03GO13138. This project relates to the further development and prototype construction/evaluation for the Energy Transfer Multiplexer (ETM) power converter topology concept. The ETM uses a series resonant link to transfer energy from any phase of a multiphase input to any phase of a multiphase output, converting any input voltage and frequency to any output voltage and frequency. The basic form of the ETM converter consists of an eight (8)-switch matrix (six phase power switches and two ground power switches) and a series L-C resonant circuit. Electronic control of the switches allows energy to be transferred in the proper amount from any phase to any other phase. Depending upon the final circuit application, the switches may be either SCRs or IGBTs. The inherent characteristics of the ETM converter include the following: Power processing in either direction (bidirectional); Large voltage gain without the need of low frequency magnetics; High efficiency independent of output load and frequency; Wide bandwidth with fast transient response and; Operation as a current source. The ETM is able to synthesize true sinusoidal waveforms with low harmonic distortions. For a low power PM wind generation system, the ETM has the following characteristics and advantages: It provides voltage gain without the need of low frequency magnetics (DC inductors) and; It has constant high efficiency independent of the load. The ETM converter can be implemented into a PM wind power system with smaller size, reduced weight and lower cost. As a result of our analyses, the ETM offers wind power generation technology for the reduction of the cost and size as well as the increase in performance of low power, low wind speed power generation. This project is the further theoretical/analytical exploration of the ETM converter concept in relationship to PM wind power generator applications in the 100kW and under power range. The theoretical/analytical and bench scale work focuses on simplifying the basic ETM converter topology (in terms of parts count and complexity) for the specific application of the low power PM system. The project goals and objectives were for Spellman HV will develop a 100kW prototype ETM power converter based on paralleled lower ratings converters. The proposed configuration of this prototype is a 100kW rated converter comprised of four (4) 34kW rated modules connected in parallel (the fourth converter is included to demonstrate N+1 fault tolerance). This approach is more viable as there is lower technological risk involved in developing a 34kW-rated converter than a single 100kW unit. The modular system approach should have a lower deployment and service cost over a single unit system, because of the economics of scale (smaller units at a higher volume means lower manufacturing cost) and because of improved serviceability (a non-redundant power system with one failed module will still operate at a lower power level). There is also the added benefit that greater commercial application and acceptance should be achieved by having a modular system available in which fault tolerance (N+1 or 2N) is a feature. This modular approach would allow the output power to be increased by adding more paralleled converters. Thus, the maximum output power of the overall power system is a function of the interconnection medium (the hot swap connection subsystem), rather than the ratings of a single module. The project was implemented with Spellman HV acting as the program management and production assembly and test facility; The Baker Company acting as a technical consultant and resource when required; and dtm Associates acting as the design/development resource for the hardware development of the 100kW ETM converter prototype.

S. Merrill Skeist; Richard H. (Dick) Baker; Anthony G.P. Marini; DOE Project Officer - Keith Bennett

2006-03-21T23:59:59.000Z

282

FINAL REPORT OF RESEARCH ON CuxS/ (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79  

E-Print Network (OSTI)

Cu X S/(Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 -of Research on Photovoltaic Solar Energy Converters CuxSI(Cd

Chin, B.L.

2013-01-01T23:59:59.000Z

283

On proton CT reconstruction using MVCT-converted virtual proton projections  

Science Conference Proceedings (OSTI)

Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of {+-}0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of {+-}0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of {+-}1.1% compared with that reconstructed from theoretical projections. If these images are used for treatment planning, the average proton range uncertainty is estimated to be less than 1.5% for an imaging dose in the milligray range. Conclusions: The proposed method can be used to convert x-ray projections into virtual proton projections. The converted proton projections can be blended with existing proton projections or can be used solely for pCT reconstruction, addressing the range limit problem of pCT using current therapeutic proton machines.

Wang Dongxu; Mackie, T. Rockwell; Tome, Wolfgang A. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Morgridge Institute of Research, University of Wisconsin, Madison, Wisconsin 53715 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Oncophysics Institute, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461 (United States)

2012-06-15T23:59:59.000Z

284

Glass material oxidation and dissolution system: Converting miscellaneous fissile materials to glass  

SciTech Connect

The cold war and the development of nuclear energy have resulted in significant inventories of miscellaneous fissile materials (MFMs). MFMs include (1) plutonium scrap and residue, (2) miscellaneous spent nuclear fuel (SNF), (3) certain hot cell wastes, and (4) many one-of-a-kind materials. Major concerns associated with the long-term management of these materials include: safeguards and nonproliferation issues; health, environment, and safety concerns. waste management requirements; and high storage costs. These issues can be addressed by converting the MFMs to glass for secure, long-term storage or repository disposal; however, conventional glass-making processes require oxide-like feed materials. Converting MFMs to oxide-like materials with subsequent vitrification is a complex and expensive process. A new vitrification process has been invented, the Glass Material Oxidation and Dissolution System (GMODS), which directly converts metals, ceramics, and amorphous solids to glass; oxidizes organics with the residue converted to glass; and converts chlorides to borosilicate glass and a secondary sodium chloride (NaCl) stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium, Zircaloy, stainless steel, multiple oxides, and other materials to glass. However, significant work is required to develop GMODS further for applications at an industrial scale. If implemented, GMODS will provide a new approach to manage these materials.

Forsberg, C.W.; Ferrada, J.J.

1996-03-19T23:59:59.000Z

285

Digital multimode buck converter control with loss-minimizing synchronous rectifier adaptation  

E-Print Network (OSTI)

Abstract—This paper develops a multimode control strategy which allows for efficient operation of the buck converter over a wide load range. A method for control of synchronous rectifiers as a direct function of the load current is introduced [1]. The function relating the synchronous-rectifier timing to the load current is optimized on-line with a gradient power-loss-minimizing algorithm. Only low-bandwidth measurements of the load current and a power-loss-related quantity are required, making the technique suitable for digital controller implementations. Compared to alternative loss-minimizing approaches, this method has superior adjustment speed and robustness to disturbances, and can simultaneously optimize multiple parameters. The proposed synchronous-rectifier control also accomplishes an automatic, optimal transition to discontinuous-conduction mode at light load. Further, by imposing a minimum duty-ratio, the converter automatically enters pulse-skipping mode at very light load. Thus, the same controller structure can be used in both fixed-frequency pulsewidth modulation and variable-frequency pulse-skipping modes. These techniques are demonstrated on a digitally-controlled 100-W buck converter. Index Terms—Adaptive control, dead-time, digital control, gradient methods, multimode control, optimization methods, pulse skipping, pulsewidth modulated (PWM) power converters, pulsewidth modulation (PWM), synchronous rectifier (SR), variable frequency control. Fig. 1. Buck converter with SR (M), and the corresponding MOSFET control signals.

Angel V. Peterchev; Seth R. S

2006-01-01T23:59:59.000Z

286

MHK Technologies/Multi Absorbing Wave Energy Converter MAWEC | Open Energy  

Open Energy Info (EERE)

Absorbing Wave Energy Converter MAWEC Absorbing Wave Energy Converter MAWEC < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Multi Absorbing Wave Energy Converter MAWEC.jpg Technology Profile Primary Organization Leancon Wave Energy Project(s) where this technology is utilized *MHK Projects/Leancon Real Sea Test Technology Resource Click here Wave Technology Type Click here Oscillating Wave Surge Converter Technology Readiness Level Click here TRL 1-3: Discovery / Concept Definition / Early Stage Development & Design & Engineering Technology Description MAWEC is an OWC wave energy converter that works differently from other OWCs in that it concurrently utilizes pressure and suck. This gives the wanted effect that the vertical force on the WEC is zero when the WEC stretches over more than one wave length. The device is V-shaped and oriented perpendicular to wave direction. The device consists of a number of vertical air tubes, and when a wave passes, air is pushed into a pressure channel that sucks air out of the suck channel. During one wave period each tube (120 in total) goes through a sequence where air is first pushed into a pressure channel when the wave is rising and is later sucked from the pressure channel when the wave is falling. In this situation there is constant pressure in the pressure channel and the air flow through the turbines is constant.

287

Scientists Discover how Bacteria Convert Mercury to Toxic Form | U.S. DOE  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists Discover how Bacteria Convert Mercury to Toxic Form Scientists Discover how Bacteria Convert Mercury to Toxic Form Biological and Environmental Research (BER) BER Home About Research Facilities Science Highlights Searchable Archive of BER Highlights External link Benefits of BER Funding Opportunities Biological & Environmental Research Advisory Committee (BERAC) News & Resources Contact Information Biological and Environmental Research U.S. Department of Energy SC-23/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3251 F: (301) 903-5051 E: sc.ber@science.doe.gov More Information » April 2013 Scientists Discover how Bacteria Convert Mercury to Toxic Form Two genes responsible for mercury methylation identified. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo

288

DC to DC power converters and methods of controlling the same  

DOE Patents (OSTI)

A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

2012-12-11T23:59:59.000Z

289

Design considerations for a thermophotovoltaic energy converter using heat pipe radiators  

DOE Green Energy (OSTI)

The purpose of this paper is to discuss concepts for using high temperature heat pipes to transport energy from a heat source to a thermophotovoltaic (TPV) converter. Within the converter, the condenser portion of each heat pipe acts as a photon radiator, providing a radiant flux to adjacent TPV cells, which in turn create electricity. Using heat pipes in this way could help to increase the power output and the power density of TPV systems. TPV systems with radiator temperatures in the range of 1,500 K are expected to produce as much as 3.6 W/cm{sup 3} of heat exchanger volume at an efficiency of 20% or greater. Four different arrangements of heat pipe-TPV energy converters are considered. Performance and sizing calculations for each of the concepts are presented. Finally, concerns with this concept and issues which remain to be considered are discussed.

Ashcroft, J.; DePoy, D. [Lockheed Martin Corp., Schenectady, NY (United States)

1997-06-01T23:59:59.000Z

290

Experience in the installation of a microprocessor system for controlling converter units of the Vyborg substation  

SciTech Connect

The experience in the installation of modern digital systems for controlling converter units at the Vyborg converter substation on the basis of advanced microprocessor devices is considered. It is shown that debugging of a control and protection system on mathematical and physical models does not guarantee optimum control of actual converter devices. Examples of advancing the control and protection system are described, the necessity for which has become obvious in tests of actual equipment. Comparison of oscillograms of processes before optimization of the control system and after its optimization and adjustment shows that the digital control system makes it possible to improve substantially the algorithms of control and protection in the short term and without changing the hardware component.

Gusakovskii, K. B.; Zmaznov, E. Yu.; Katantsev, S. V.; Mazurenko, A. K.; Mestergazi, V. A.; Prochan, G. G.; Funtikova, S. F. [High Voltage Direct Current Power Transmission Research Institute (NIIPT) (Russian Federation)

2006-01-15T23:59:59.000Z

291

SUBCONTRACT REPORT: DC-DC Converter for Fuel Cell and Hybrid Vehicles  

DOE Green Energy (OSTI)

The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.

Marlino, Laura D [ORNL; Zhu, Lizhi [Ballard Power Systems/Siemens VDO

2007-07-01T23:59:59.000Z

292

An 8-bit current mode ripple folding analog to digital converter  

E-Print Network (OSTI)

Design of an 8-bit current mode, ripple-folding analog to digital (A/D) converter is discussed. The ripple folding technique and the possible implementations in different process technologies are summarized. To have an A/D converter compatible with the standard CMOS processes, the switched current technique is used for the implementation. The architecture is a cascade of 8 minimum and maximum detectors pipelined by 7 current memories. The A/D converter, which is designed in TSMC 0.35 []m CMOS technology, achieves 8 bits of resolution at a conversion rate of 100 MHz with an SFDR of 62 dB. The total power consumption by the analog circuitry is 120mW, more than half of which is dissipated by the 8 current comparators. The achieved INL and DNL values are less than 0.4 LSB.

Dinc, Huseyin

2002-01-01T23:59:59.000Z

293

Chemical reactor for converting a first material into a second material  

Science Conference Proceedings (OSTI)

A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

Kong, Peter C

2012-10-16T23:59:59.000Z

294

Evolution of the CERN Power Converter Function Generator/Controller for Operation in Fast Cycling Accelerators  

E-Print Network (OSTI)

Power converters in the LHC are controlled by the second generation of an embedded computer known as a Function Generator/Controller (FGC2). Following the success of this control system, new power converter installations at CERN will be based around an evolution of the design – a third generation called FGC3. The FGC3 will initially be used in the PS Booster and Linac4. This paper compares the hardware of the two generations of FGC and details the decisions made during the design of the FGC3.

Calcoen, D; Semanaz, PF

2011-01-01T23:59:59.000Z

295

Development of a New Multilevel Converter-Based Intelligent Universal Transformer: Design Analysis  

Science Conference Proceedings (OSTI)

This report provides a comprehensive design analysis of a high-voltage multilevel converter-based intelligent universal transformer (IUT). The proposed IUT design includes back-to-back, interconnected, multi-level converters coupled to a switched inverter circuit via a high-frequency transformer. The input of the universal transformer can be coupled to a high-voltage distribution system such as 4.16-kV with the use of existing high-voltage silicon insulated-gate bipolar transistor (IGBT) devices, and the...

2004-03-29T23:59:59.000Z

296

Chemical reactor and method for chemically converting a first material into a second material  

DOE Patents (OSTI)

A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

Kong, Peter C. (Idaho Falls, ID)

2008-04-08T23:59:59.000Z

297

System Integration Issues of DC to DC converters in the sLHC Trackers  

E-Print Network (OSTI)

The upgrade of the trackers at the sLHC experiments requires implementing new powering schemes that will provide an increased power density with reduced losses and material budget. A scheme based on buck and switched capacitors DC to DC converters has been proposed as an optimal solution. The buck converter is based on a power ASIC, connected to a custom made air core inductor. The arrangement of the parts and the board layout of the power module are designed to minimize the emissions of EMI in a compact volume, enabling its integration on the tracker modules and staves.

Allongue, B; Faccio, F; Fuentes, c; Michelisa, S; Orlandia, S

2009-01-01T23:59:59.000Z

298

Converter Program: PSADD Dictionary for Dynamics Model, Version 2.0  

Science Conference Proceedings (OSTI)

This manual contains a listing of the PSADD dictionary for PSS/E dynamics models. The format of this dictionary is the same as that used for the "main" PSADD. Wherever possible, dictionary names and data types are the same as those used in the "main" PSADD. Please note that not all of the PSS/E dynamics models have been included in this dictionary and are convertible by the CONVERTER program. EPRI advisors and PTI engineers selected the models for inclusion based on the perceived "usefulness" of the mode...

2000-07-13T23:59:59.000Z

299

Evaluation of the effectiveness of shielding and filtering of HVDC converter stations  

Science Conference Proceedings (OSTI)

The electromagnetic interference (EMI) generated by the periodic turn-on and turn-off of the valves is an important consideration in the design of HVDC converter stations. Remedial measures such as shielding the valve hall and filtering have been used in order to reduce the interference levels to acceptable values. The application of recently-developed Numerical Electromagnetic Code (NEC) to the problem of EMI from HVDC converter stations is investigated in this paper, with particular emphasis on evaluating the effectiveness of valve hall shielding and filtering.

Dallaire, R.D.; Maruvada, P.S.

1989-04-01T23:59:59.000Z

300

SoC Energy Savings = Reduce+Reuse+Recycle: A Case Study Using a 660MHz DC-DC Converter with Integrated Output Filter  

E-Print Network (OSTI)

SoC Energy Savings = Reduce+Reuse+Recycle: A Case Study Using a 660MHz DC-DC Converter will use all 3 of these techniques in the DC-DC buck converter shown in Fig. 1. Energy reduction of the DC-DC converter front-end drivers. Power Converter supplied energy reused energy recycled energy

Lemieux, Guy

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

GAMMA-RAY DETECTION WITH PbO GLASS CONVERTERS IN MWPC: ELECTRON CONVERSION EFFICIENCY AND TIME RESOLUTION  

E-Print Network (OSTI)

Converters in MWPC: Electron Conversion Efficiency and Timeimprove on the electron conversion efficiency and electronconverter the electron conversion efficiency E was measured

Lum, G.K.

2013-01-01T23:59:59.000Z

302

Calculation of HVDC-converter harmonics in frequency domain with regard to asymmetries and comparison with time domain simulations  

SciTech Connect

In order to study the effects of large HVDC converters to the feeding ac networks, it is of importance to explain and to calculate harmonic phenomena which are a result of converter operation. During commissioning of real HVDC converters it could be seen, that harmonics resulting from unsymmetries in the system voltages or from unsymmetries in converter operation led to significant difficulties concerning the system design. For this reason, not only the effects of characteristic but also the effects of noncharacteristic converter harmonics must be taken into account. The aim is to describe the steady state harmonic behavior of the converter. The harmonic spectra are not determined by time domain analysis but instead the solution is found by frequency domain calculations. This can result in reduced calculation time in comparison to conventional fourier analysis of the time functions. The converter is interpreted as an amplitude modulator with voltage and current converter functions which describe the coupling of the dc circuit and the ac network through the converter. To verify the theory, comparison of frequency domain with time domain calculations were carried out.

Rittiger, J. [Siemens AG, Erlangen (Germany); Kulicke, B. [Technische Univ. Berlin (Germany)

1995-10-01T23:59:59.000Z

303

A High Frequency Isolated Current-fed Bidirectional DC/AC Converter For Grid-Tied Energy Storage System  

E-Print Network (OSTI)

AC Converter for Grid-tied Energy Storage System Xiaolei Hu,resources, grid-tied energy storage systems voltage to abe increasingly incorporated. Energy storage devices allows

King Jet, Tseng

2013-01-01T23:59:59.000Z

304

GAMMA-RAY DETECTION WITH PbO GLASS CONVERTERS IN MWPC: ELECTRON CONVERSION EFFICIENCY AND TIME RESOLUTION  

E-Print Network (OSTI)

1.5 factor. and T and the projection of these results on thethe converter, and the projection of these results on the

Lum, G.K.

2013-01-01T23:59:59.000Z

305

Under U.S.-Russia Partnership, Final Shipment of Fuel Converted From 20,000  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Under U.S.-Russia Partnership, Final Shipment of Fuel Converted Under U.S.-Russia Partnership, Final Shipment of Fuel Converted From 20,000 Russian Nuclear Warheads Arrives in United States and Will Be Used for U.S. Electricity Under U.S.-Russia Partnership, Final Shipment of Fuel Converted From 20,000 Russian Nuclear Warheads Arrives in United States and Will Be Used for U.S. Electricity December 10, 2013 - 2:50pm Addthis News Media Contact (202) 586-4940 WASHINGTON, D.C. - The United States and Russia are today commemorating the completion of the 1993 U.S.-Russia HEU Purchase Agreement, commonly known as the Megatons to Megawatts Program, with this week's off-loading of the final shipment of low enriched uranium (LEU) at the Port of Baltimore in Baltimore, Maryland, from Russia. The shipment was the last of the LEU converted from more than 500 metric tons of weapons-origin highly enriched

306

Regenerative Braking for an Electric Vehicle Using Ultracapacitors and a Buck-Boost Converter  

E-Print Network (OSTI)

-mail: jdixon@ing.puc.cl *University of Concepción Abstract An ultracapacitor bank control system and decelerations of the vehicle with minimal loss of energy, and minimal degradation of the main battery pack. The system uses an IGBT Buck-Boost converter, which is connected to the ultracapacitor bank at the Boost side

Rudnick, Hugh

307

Integration of planar transformer and/or planar inductor with power switches in power converter  

DOE Patents (OSTI)

A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.

Chen, Kanghua (Canton, MI); Ahmed, Sayeed (Canton, MI); Zhu, Lizhi (Canton, MI)

2007-10-30T23:59:59.000Z

308

Integrated Power Adapter: Isolated Converter with Integrated Passives and Low Material Stress  

SciTech Connect

ADEPT Project: CPES at Virginia Tech is developing an extremely efficient power converter that could be used in power adapters for small, lightweight laptops and other types of mobile electronic devices. Power adapters convert electrical energy into useable power for an electronic device, and they currently waste a lot of energy when they are plugged into an outlet to power up. CPES at Virginia Tech is integrating high-density capacitors, new magnetic materials, high-frequency integrated circuits, and a constant-flux transformer to create its efficient power converter. The high-density capacitors enable the power adapter to store more energy. The new magnetic materials also increase energy storage, and they can be precisely dispensed using a low-cost ink-jet printer which keeps costs down. The high-frequency integrated circuits can handle more power, and they can handle it more efficiently. And, the constant-flux transformer processes a consistent flow of electrical current, which makes the converter more efficient.

None

2010-09-01T23:59:59.000Z

309

MHK Technologies/Ocean Wave Energy Converter OWEC | Open Energy Information  

Open Energy Info (EERE)

Converter OWEC Converter OWEC < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Ocean Wave Energy Converter OWEC.jpg Technology Profile Primary Organization Ocean Wave Energy Company Technology Resource Click here Wave Technology Type Click here Point Absorber - Submerged Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description Neutrally suspended and positively buoyant modules are quick connected into open frame networks Submerged portions are stabilized by variable ballast buoyancy chambers and optional damper sheets situated at a relatively calm depth Frame members carry shaft components of linear rotary converters associated with large point absorber buoys Both directions of reciprocal wave motion i e vertical and horizontal motion directly drive components of counter rotating electrical generators Compared to standard generators wherein one is associated with upstroke and another of smaller proportion with downstroke this configuration increases relative speed with fewer parts Electromechanical loads are real time adjustable with respect to wave sensor web resulting in optimal energy conversion from near fully submerged wave following buoys Electrical conductors are series connected and further quick connected with those of other modules via upper frame members Through implementation of rep

310

Asynchronous Sigma-Delta analog-to digital converter based on the charge pump integrator  

Science Conference Proceedings (OSTI)

The concept of the asynchronous Sigma-Delta analog-to-digital converter (ASD-ADC) based on the charge pump integrator is discussed in the paper. A two-level conversion scheme is utilized. The first level is accomplished by amplitude-to-pulse-width mapping ... Keywords: Asynchronous Sigma-Delta modulation, Asynchronous circuits, Charge pump, Time quantization, Time-to-digital conversion

Dariusz Ko?cielnik; Marek Mi?kowicz

2008-06-01T23:59:59.000Z

311

Steady State Performance Analysis of a VSC-Based HVDC Converter Stations Using PSCAD/EMTDC  

Science Conference Proceedings (OSTI)

This paper presents a steady state performance analysis carried out to study the behavior of a two VSC-based operating as a single-input single output HVDC link. The digital model of the HVDC link has been implemented and evaluated using PSCAD/EMTDC©. ... Keywords: Voltage source converter, HVDC Stations, pulse width modulation, harmonic spectra

Eduardo Vásquez-Mortera; Edgar L. Moreno-Goytia

2008-09-01T23:59:59.000Z

312

Predictive Power Control of Doubly-Fed Induction Generator for Wave Energy Converters  

E-Print Network (OSTI)

the Doubly- fed induction generator (DFIG). This paper deals then with a model-based predictive power control of a DFIG-based Wave Energy Converter (WEC). In the proposed control approach, the predicted output power was calculated using a DFIG linearized state-space model. The DFIG-based WEC power tracking performances further

Paris-Sud XI, Université de

313

Relation between Verifiable Random Functions and Convertible Undeniable Signatures, and New Constructions  

E-Print Network (OSTI)

. Verifiable random functions (VRF) and selectively-convertible undeniable signature (SCUS) schemes were. This directly yields several deterministic SCUS schemes based on existing VRF constructions. In addition, we transaction escrow schemes [14]. 1.2 Our contributions We first show VRF implies deterministic SCUS

314

A novel time-based low-power pipeline analog to digital converter  

Science Conference Proceedings (OSTI)

A new power reduction technique for analog-to-digital converters is proposed in this paper. A novel current-mode algorithm which uses time to perform analog-to-digital conversion has been described and a 12 bit 100-ksample/s time-based pipeline analog ... Keywords: Bottom plate sampling, Continues-time comparator, Digital correction, Pipeline ADC

Mohammad Hossein Zarifi; Javad Frounchi; Shahin Farshchi; Jack W. Judy

2010-03-01T23:59:59.000Z

315

A Hybrid Energy System Using Cascaded H-bridge Converter , Zhong Du2  

E-Print Network (OSTI)

energy system, cascaded multilevel converter, single dc source I. INTRODUCTION As different energy generation, storage, and transmission. The power from hybrid energy systems can be combined on the dc side of Energy Source 1 and Energy Source 2. To analyze mode I, a dc source is assumed to be connected

Tolbert, Leon M.

316

A time-based energy-efficient analog-to-digital converter  

E-Print Network (OSTI)

Dual-slope converters use time to perform analog-to-digital conversion but require 2N+1 clock cycles to achieve N bits of precision. We describe a novel algorithm that also uses time to perform analog-to-digital conversion ...

Yang, Heemin Yi, 1976-

2006-01-01T23:59:59.000Z

317

Modeling and controller design of a wind energy conversion system with matrix converter  

Science Conference Proceedings (OSTI)

In order to meet increasing power demand, taking into account economical and environmental factors, wind energy conversion is gradually gaining interest as a suitable source of renewable energy. In this paper, The modeling of the Wind Energy Conversion ... Keywords: FCC, PWM, SPVM, WECS, induction generator, matrix converter CSCF, power control, variable speed, wind turbine

Y. S. Rao; A. J. laxmi; K. M. S. N. Krishna

2011-02-01T23:59:59.000Z

318

Convertibility of Function Points into COSMIC Function Points: A study using Piecewise Linear Regression  

Science Conference Proceedings (OSTI)

Background: COSMIC Function Points and traditional Function Points (i.e., IFPUG Function Points and more recent variation of Function Points, such as NESMA and FISMA) are probably the best known and most widely used Functional Size Measurement methods. ... Keywords: COSMIC Function Points, Data analysis, Function Point analysis, Functional Size Measurement, Functional size measure convertibility, Outliers

Luigi Lavazza; Sandro Morasca

2011-08-01T23:59:59.000Z

319

EPRI HVDC Reference Book: Chapter 13 - DC Transmission with Voltage Sourced Converters  

Science Conference Proceedings (OSTI)

DC Transmission with voltage sourced converters (VSC) is a relatively new development in DC transmission. This report covers circuits, theory and capabilities of this new development in HVDC transmission. The report will be a Chapter in the comprehensive HVDC reference guide that EPRI is preparing.

2009-12-21T23:59:59.000Z

320

A Dual-Supply Buck Converter with Improved Light-Load Efficiency  

E-Print Network (OSTI)

Power consumption and device size have been placed at the primary concerns for battery-operated portable applications. Switching converters gain popularity in powering portable devices due to their high efficiency, compact sizes and high current delivery capability. However portable devices usually operate at light loads most of the time and are only required to deliver high current in very short periods, while conventional buck converter suffers from low efficiency at light load due to the switching losses that do not scale with load current. In this research, a novel technique for buck converter is proposed to reduce the switching loss by reducing the effective voltage supply at light load. This buck converter, implemented in TSMC 0.18 micrometers CMOS technology, operates with a input voltage of 3.3V and generates an output voltage of 0.9V, delivers a load current from 1mA to 400mA, and achieves 54 percent ~ 91 percent power efficiency. It is designed to work with a constant switching frequency of 3MHz. Without sacrificing output frequency spectrum or output ripple, an efficiency improvement of up to 20 percent is obtained at light load.

Zhang, Chao

2011-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Fully monolithic cellular buck converter design for 3-D power delivery  

E-Print Network (OSTI)

A fully monolithic interleaved buck dc-dc point-of-load (PoL) converter has been designed and fabricated in a 0.18-mm SiGe BiCMOS process. Target application of the design is 3-D power delivery for future microprocessors, ...

Sun, Jian

322

System analysis of a negative impedance converter receiver for ultra low frequencies  

Science Conference Proceedings (OSTI)

Monitoring electromagnetic waves in the Ultra Low Frequency (ULF) range between 1 mHz and 1 Hz is essential for an understanding of the processes in the earths magnetosphere. Also earthquake prone areas are under suspect to emit precursor ULF signals. ... Keywords: magnetosphere, negative impedance convert, system analysis, ultra low frequency

Ernst D. Schmitter

2008-07-01T23:59:59.000Z

323

The Effects of Wave Energy Converters on a Monochromatic Wave Climate  

E-Print Network (OSTI)

in wave energy converters as a possible means of providing renewable energy, the effects of a wave energy The interest in renewable energies is currently increasing due to the reported rise in global temperature is that of wave energy. The research is multifaceted and includes research on the efficiency of wave energy

Fox-Kemper, Baylor

324

Generator set, 100kW frequency converter. Final technical report  

SciTech Connect

The Contractor shall furnish all engineering labor, tools, services, supplies, materials, equipment, and facilities necessary to perform an investigation and study of means to extend the capability of the contractor's existing Power Center Inverter System to the 100 kW level. This 100 kW Inverter System shall meet the basic performance parameters of the frequency converter.

Corry, T.

1975-07-01T23:59:59.000Z

325

Cesium-plasma-conductivity enhancement in the advanced thermionic energy converter. Final report  

DOE Green Energy (OSTI)

Two methods of plasma conductivity enhancement in a cesium vapor thermionic energy converter have been studied. The first involved resonance photoabsorption of several cesium lines and the second utilized cesium plasma sustenance by application of microwave power. An extensive study of ionization processes in a cesium discharge in the presence of resonance ionization was made. Calculations were made of expected percentage excitation levels for several cesium resonance transitions for different values of neutral density and temperature as well as incident radiation power levels. The results of some of these computations were tabulated. Several ionization schemes were considered. A number of cesium transitions were investigated in the range of 799 to 870 nanometers for four different cesium reservoir temperatures, 467, 511, 550 and 591 K. The related absorption coefficients of the radiation lines in the plasma were deduced and tabulated. The resulting plasma conductivity increase was recorded and the associated ionization enhancement was deduced. A microwave cavity was built where the emitter and collector of a simple thermionic converter made up two of the cavity walls and resonant microwave power was externally applied. The I-V characteristics of the thermionic converter were studied under several microwave power levels in the range of 0 to 2 watts. Significant shifts to higher currents were observed as the microwave power levels were raised. In conclusion, both methods show promise as auxiliary ionization mechanisms for the thermionic energy converter, especially at low emitter temperatures.

Manikopoulos, C.N.

326

Introduction of the Renewable Micro-Grid Test-Bed Dr. Wenxin Liu  

E-Print Network (OSTI)

Turbine: PMSM, 3kW, 8.3A Wind Generator: PMSM, 3kW, 8.3A 3 AC/DC Converter & DC/AC Inverter Wind Wind Turbine #1 3kW, 8.3A Wind Turbine #2 3kW Wind Generator #2 3kW RS232 Communication Renewable-bed Wind Turbine Generator Simulators ES Simulator AC Load M/G Set 1 Overview of the Micro-grid Test

Johnson, Eric E.

327

New one-phase dual converter for superconducting inductive energy storage and transfer applications: the one-phase inductor-converter bridge  

DOE Green Energy (OSTI)

This report presents the results of theoretical and experimental development of the one-phase Inductor-Converter Bridge (ICB). The basic operating principles of the circuit are described followed by a theoretical treatment of the dynamics and control of the system. The successful results of the first experimental operation and control of the one-phase ICB are presented and explained. Finally, a discussion of some of the interesting transient and steady state behavior of the circuit, along with some of its unique features, is given.

Ehsani, M.; Kustom, R.L.

1984-03-01T23:59:59.000Z

328

Thermoelectric converter  

DOE Patents (OSTI)

This invention relates in general to thermoelectric units and more particularly to a tubular thermoelectric unit which includes an array of tandemly arranged radially tapered annular thermoelectric pellets having insulation material of a lower density than the thermoelectric pellets positioned between each pellet. (Official Gazette)

Kim, C.K.

1974-02-26T23:59:59.000Z

329

High Efficiency Thermionics (HET-IV) and Converter Advancement (CAP) programs. Final reports  

DOE Green Energy (OSTI)

This report contains the final report of the High Efficiency Thermionics (HET-IV) Program, Attachment A, performed at Rasor Associates, Inc. (RAI); and the final report of the Converter Advancement Program (CAP), performed at the Bettis Atomic Power Laboratory, Attachment B. The phenomenology of cesium-oxygen thermionic converters was elucidated in these programs, and the factors that had prevented the achievement of stable, enhanced cesium-oxygen converter performance for the previous thirty years were identified. Based on these discoveries, cesium-oxygen vapor sources were developed that achieved stable performance with factor-of-two improvements in power density and thermal efficiency, relative to conventional, cesium-only ignited mode thermionic converters. Key achievements of the HET-IV/CAP programs are as follows: a new technique for measuring minute traces of oxygen in cesium atmospheres; the determination of the proper range of oxygen partial pressures for optimum converter performance--10{sup {minus}7} to 10{sup {minus}9} torr; the discovery, and analysis of the cesium-oxygen liquid migration and compositional segregation phenomena; the successful use of capillary forces to contain the migration phenomenon; the use of differential heating to control compositional segregation, and induce vapor circulation; the development of mechanically and chemically stable, porous reservoir structures; the development of precise, in situ oxygen charging methods; stable improvements in emitter performance, up to effective emitter bare work functions of 5.4 eV; stable improvements in barrier index, to value below 1.8 Volts; the development of detailed microscopic models for cesium-oxygen reservoir dynamics and collector work function behavior; and the discovery of new relationships between electrode geometry and Schock Instability.

Geller, C.B.; Murray, C.S.; Riley, D.R. [Bettis Atomic Power Lab., West Mifflin, PA (United States)] [Bettis Atomic Power Lab., West Mifflin, PA (United States); Desplat, J.L.; Hansen, L.K.; Hatch, G.L.; McVey, J.B.; Rasor, N.S. [Rasor Associates, Inc., Sunnyvale, CA (United States)] [Rasor Associates, Inc., Sunnyvale, CA (United States)

1996-04-01T23:59:59.000Z

330

Neutronic design of a fission converter-based epithermal neutron beam for neutron capture therapy  

SciTech Connect

To meet the needs for neutron capture theory (NCT) irradiations, a high-intensity, high-quality fusion converter-based epithermal neutron beam has been designed for the MITR-II research reactor. This epithermal neutron beam, capable of delivering treatments in a few minutes with negligible background contamination from fast neutrons and photons, will be installed in the present thermal column and hohlraum of the 5-MW MITR-II research reactor. Spent or fresh MITR-II fuel elements will be used to fuel the converter. With a fission converter power of {approximately}80 kW using spent fuel, epithermal fluxes (1 eV < E < 10 keV) in excess of 10{sup 10} n/cm{sup 2} {center_dot} s are achievable at the target position with negligible photon and fast neutron contamination, i.e., <2 {times} 10{sup {minus}11}cGy-cm{sup 2}/n. With the currently available {sup 10}B delivery compound boronophenylalanine-fructose, average therapeutic ratios of {approximately}5 can be achieved using this beam for brain irradiations with deep effective penetration ({approximately}9.5 cm) and high dose rates of up to 400 to 600 RBE cGy/min. If NCT becomes an accepted therapy, fission converter-based beams constructed at existing reactors could meet a large fraction of the projected requirements for intense, low-background epithermal neutron beams at a relatively low cost. The results of an extensive set of neutronic design studies investigating all components of the beam are presented. These detailed studies can be useful as guidance for others who may wish to use the fission converter approach to develop epithermal beams for NCT.

Kiger, W.S. III; Sakamoto, S.; Harling, O.K. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1999-01-01T23:59:59.000Z

331

Design and analysis of modern three-phase AC/AC power converters for AC drives and utility interface  

E-Print Network (OSTI)

Significant advances in modern ac/ac power converter technologies and demands of industries have reached beyond standard ac/ac power converters with voltage-source inverters fed from diode rectifiers. Power electronics converters have been matured to stages toward compact realization, increased high-power handling capability, and improving utility interface. Modern ac/ac power converter topologies with various control strategies have been introduced for the further improvements, such as matrix converters, current-fed converters, PWM rectifiers, and active power filters. In this dissertation, several new converter topologies are proposed in conjunction with developed control schemes based on the modern ac/ac converters which enhance performance and solve the drawbacks of conventional converters. In this study, a new fault-tolerant PWM strategy is first proposed for matrix converters. The added fault-tolerant scheme would strengthen the matrix converter technology for aerospace and military applications. A modulation strategy is developed to reshape output currents for continuous operation, against fault occurrence in matrix converter drives. This study designs a hybrid, high-performance ac/ac power converter for high power applications, based on a high-power load commutated inverter and a mediumpower voltage source inverter. Natural commutation of the load commutated inverter is actively controlled by the voltage source inverter. In addition, the developed hybrid system ensures sinusoidal output current/voltage waveforms and fast dynamic response in high power areas. A new topology and control scheme for a six-step current source inverter is proposed. The proposed topology utilizes a small voltage source inverter, to turn off main thyristor switches, transfer reactive load energy, and limit peak voltages across loads. The proposed topology maximizes benefits of the constituent converters: highpower handling capability of large thyristor-based current source inverters as well as fast and easy control of small voltage source inverters. This study analyzes, compares, and evaluates two topologies for unity power factor and multiple ac/ac power conversions. Theoretical analyses and comparisons of the two topologies, grounded on mathematical approaches, are presented from the standpoint of converter kVA ratings, dc-link voltage requirements, switch ratings, semiconductor losses, and reactive component sizes. Analysis, simulation, and experimental results are detailed for each proposed topology.

Kwak, Sangshin

2006-05-01T23:59:59.000Z

332

Performance Evaluation of a Multi-Port DC-DC Current Source Converter for High Power Applications  

E-Print Network (OSTI)

With the ever-growing developments of sustainable energy sources such as fuel cells, photovoltaics, and other distributed generation, the need for a reliable power conversion system that interfaces these sources is in great demand. In order to provide the highest degree of flexibility in a truly distributed network, it is desired to not only interface multiple sources, but to also interface multiple loads. Modern multi-port converters use high frequency transformers to deliver the different power levels, which add to the size and complexity of the system. The different topological variations of the proposed multi-port dc-dc converter have the potential to solve these problems. This thesis proposes a unique dc-dc current source converter for multi-port power conversion. The presented work will explain the proposed multi-port dc-dc converter's operating characteristics, control algorithms, design and a proof of application. The converter will be evaluated to determine its functionality and applicability. Also, it will be shown that our converter has advantages over modern multi-port converters in its ease of scalability from kW to MW, low cost, high power density and adaption to countless combinations of multiple sources. Finally we will present modeling and simulation of the proposed converter using the PSIM software. This research will show that this new converter topology is unstable without feedback control. If the operating point is moved, one of the source ports of the multiport converter becomes unstable and dies off supplying very little or no power to the load while the remaining source port supplies all of the power the load demands. In order to prevent this and add stability to the converter a simple yet unique control method was implemented. This control method allowed for the load power demanded to be shared between the two sources as well as regulate the load voltage about its desired value.

Yancey, Billy Ferrall

2010-05-01T23:59:59.000Z

333

Original article: Adaptive sliding mode control of interleaved parallel boost converter for fuel cell energy generation system  

Science Conference Proceedings (OSTI)

This paper deals with the problem of controlling energy generation systems including fuel cells (FCs) and interleaved boost power converters. The proposed nonlinear adaptive controller is designed using sliding mode control (SMC) technique based on the ... Keywords: Adaptive control, Fuel cell, Interleaved boost converter, Sliding mode control

H. El Fadil, F. Giri, Josep M. Guerrero

2013-05-01T23:59:59.000Z

334

Study on Tubular Busbar Corona Design Optimization of ±660kV HVDC Converter Substation in Qingdao  

Science Conference Proceedings (OSTI)

The HVDC busbar corona characteristic is the main factor taken into account for choosing busbar of HVDC converter substation. By establishing the calculation models of electric field strength along the busbar surface, ground total electric field strength ... Keywords: ±660 kV HVDC, converter substation, corona characteristics, electromagnetic, tubular busbar optimization

Xu Mingming; Li Kejun; Tan Zhenyu; Niu Lin

2010-06-01T23:59:59.000Z

335

Operating space of a bidirectional PWM ac-to-dc converter applied in active line-conditioning  

Science Conference Proceedings (OSTI)

The paper presents the operating space of a bidirectional PWM ac-to-dc converter which can act also as a line conditioner. This analysis of the operating space will prove the secondary line conditioning functionality of the PWM dc converters. Starting ...

R. Paku; R. Marschalko

2008-05-01T23:59:59.000Z

336

Phase-Shifted Full Bridge DC-DC Converter with Energy Recovery Clamp and Reduced Circulating Current  

E-Print Network (OSTI)

Phase-Shifted Full Bridge DC-DC Converter with Energy Recovery Clamp and Reduced Circulating an improved PSFB DC-DC converter using only a modified energy recovery clamp circuit attached at the secondary and/or output voltage changes. Section II describes the PSFB DC-DC circuit with the proposed energy

337

A three-level buck converter to regulate a high-voltage DC-to-AC inverter  

E-Print Network (OSTI)

A three-level buck converter is designed and analyzed, and shown to be suitable as a high-voltage down converter as a pre-regulation stage for a 600 watt DC-to-AC power inverter. Topology selection for the inverter is ...

Schrock, Kenneth C

2008-01-01T23:59:59.000Z

338

HVDC converter stations for voltages above 600 kV: R and D needs and priorities: Final report  

Science Conference Proceedings (OSTI)

A study of the R and D needed to build converter stations for HVDC transmission lines with pole-to-ground voltages between 800 and 1200 kV confirmed that economical designs for more than 800 kV will require long-term R and D. Converter stations for 800 kV appear possible with existing technology.

Krishnayya, P.C.S.; Maruvada, P.S.; Lambeth, P.J.; Desilets, G.; Trinh, N.G.

1986-12-01T23:59:59.000Z

339

Boost Converters for Gas Electric and Fuel Cell Hybrid Electric Vehicles  

DOE Green Energy (OSTI)

Hybrid electric vehicles (HEVs) are driven by at least two prime energy sources, such as an internal combustion engine (ICE) and propulsion battery. For a series HEV configuration, the ICE drives only a generator, which maintains the state-of-charge (SOC) of propulsion and accessory batteries and drives the electric traction motor. For a parallel HEV configuration, the ICE is mechanically connected to directly drive the wheels as well as the generator, which likewise maintains the SOC of propulsion and accessory batteries and drives the electric traction motor. Today the prime energy source is an ICE; tomorrow it will very likely be a fuel cell (FC). Use of the FC eliminates a direct drive capability accentuating the importance of the battery charge and discharge systems. In both systems, the electric traction motor may use the voltage directly from the batteries or from a boost converter that raises the voltage. If low battery voltage is used directly, some special control circuitry, such as dual mode inverter control (DMIC) which adds a small cost, is necessary to drive the electric motor above base speed. If high voltage is chosen for more efficient motor operation or for high speed operation, the propulsion battery voltage must be raised, which would require some type of two-quadrant bidirectional chopper with an additional cost. Two common direct current (dc)-to-dc converters are: (1) the transformer-based boost or buck converter, which inverts a dc voltage, feeds the resulting alternating current (ac) into a transformer to raise or lower the voltage, and rectifies it to complete the conversion; and (2) the inductor-based switch mode boost or buck converter [1]. The switch-mode boost and buck features are discussed in this report as they operate in a bi-directional chopper. A benefit of the transformer-based boost converter is that it isolates the high voltage from the low voltage. Usually the transformer is large, further increasing the cost. A useful feature of the switch mode boost converter is its simplicity. Its inductor must handle the entire current, which is responsible for its main cost. The new Z-source inverter technology [2,3] boosts voltage directly by actively using the zero state time to boost the voltage. In the traditional pulse width modulated (PWM) inverter, this time is used only to control the average voltage by disconnecting the supply voltage from the motor. The purpose of this study is to examine the Z-source's potential for reducing the cost and improving the reliability of HEVs.

McKeever, JW

2005-06-16T23:59:59.000Z

340

Boost Converters for Gas Electric and Fuel Cell Hybrid Electric Vehicles  

SciTech Connect

Hybrid electric vehicles (HEVs) are driven by at least two prime energy sources, such as an internal combustion engine (ICE) and propulsion battery. For a series HEV configuration, the ICE drives only a generator, which maintains the state-of-charge (SOC) of propulsion and accessory batteries and drives the electric traction motor. For a parallel HEV configuration, the ICE is mechanically connected to directly drive the wheels as well as the generator, which likewise maintains the SOC of propulsion and accessory batteries and drives the electric traction motor. Today the prime energy source is an ICE; tomorrow it will very likely be a fuel cell (FC). Use of the FC eliminates a direct drive capability accentuating the importance of the battery charge and discharge systems. In both systems, the electric traction motor may use the voltage directly from the batteries or from a boost converter that raises the voltage. If low battery voltage is used directly, some special control circuitry, such as dual mode inverter control (DMIC) which adds a small cost, is necessary to drive the electric motor above base speed. If high voltage is chosen for more efficient motor operation or for high speed operation, the propulsion battery voltage must be raised, which would require some type of two-quadrant bidirectional chopper with an additional cost. Two common direct current (dc)-to-dc converters are: (1) the transformer-based boost or buck converter, which inverts a dc voltage, feeds the resulting alternating current (ac) into a transformer to raise or lower the voltage, and rectifies it to complete the conversion; and (2) the inductor-based switch mode boost or buck converter [1]. The switch-mode boost and buck features are discussed in this report as they operate in a bi-directional chopper. A benefit of the transformer-based boost converter is that it isolates the high voltage from the low voltage. Usually the transformer is large, further increasing the cost. A useful feature of the switch mode boost converter is its simplicity. Its inductor must handle the entire current, which is responsible for its main cost. The new Z-source inverter technology [2,3] boosts voltage directly by actively using the zero state time to boost the voltage. In the traditional pulse width modulated (PWM) inverter, this time is used only to control the average voltage by disconnecting the supply voltage from the motor. The purpose of this study is to examine the Z-source's potential for reducing the cost and improving the reliability of HEVs.

McKeever, JW

2005-06-16T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Optimization of DC-DC Converters for Improved Electromagnetic Compatibility With High Energy Physics Front-End Electronics  

E-Print Network (OSTI)

The upgrade of the Large Hadron Collider (LHC) experiments at CERN sets new challenges for the powering of the detectors. One of the powering schemes under study is based on DC-DC buck converters mounted on the front-end modules. The hard environmental conditions impose strict restrictions to the converters in terms of low volume, radiation and magnetic field tolerance. Furthermore, the noise emission of the switching converters must not affect the performance of the powered systems. A study of the sources and paths of noise of a synchronous buck converter has been made for identifying the critical parameters to reduce their emissions. As proof of principle, a converter was designed following the PCB layout considerations proposed and then used for powering a silicon strip module prototype for the ATLAS upgrade, in order to evaluate their compatibility.

Fuentes, C; Michelis, S; Blanchot, G; Allongue, B; Faccio, F; Orlandi, S; Kayal, M; Pontt, J

2011-01-01T23:59:59.000Z

342

Electrical performance characteristics of high power converters for space power applications. Final report, 1 January 1988-30 September 1989  

SciTech Connect

The first goal of this project was to investigate various converters that would be suitable for processing electric power derived from a nuclear reactor. The implementation is indicated of a 20 kHz system that includes a source converter, a ballast converter, and a fixed frequency converter for generating the 20 kHz output. This system can be converted to dc simply by removing the fixed frequency converter. This present study emphasized the design and testing of the source and ballast converters. A push-pull current-fed (PPCF) design was selected for the source converter, and a 2.7 kW version of this was implemented using three 900 watt modules in parallel. The characteristic equation for two converters in parallel was derived, but this analysis did not yield any experimental methods for measuring relative stability. The three source modules were first tested individually and then in parallel as a 2.7 kW system. All tests proved to be satisfactory; the system was stable; efficiency and regulation were acceptable; and the system was fault tolerant. The design of a ballast-load converter, which was operated as a shunt regulator, was investigated. The proposed power circuit is suitable for use with BJTs because proportional base drive is easily implemented. A control circuit which minimizes switching frequency ripple and automatically bypasses a faulty shunt section was developed. A nonlinear state-space-averaged model of the shunt regulator was developed and shown to produce an accurate incremental (small-signal) dynamic model, even though the usual state-space-averaging assumptions were not met. The nonlinear model was also shown to be useful for large-signal dynamic simulation using PSpice.

Stuart, T.A.; King, R.J.

1989-09-01T23:59:59.000Z

343

U.S.-Russia Twenty-Year Partnership Completes Final Milestone in Converting  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

U.S.-Russia Twenty-Year Partnership Completes Final Milestone in U.S.-Russia Twenty-Year Partnership Completes Final Milestone in Converting 20,000 Russian Nuclear Warheads into Fuel for U.S. Electricity U.S.-Russia Twenty-Year Partnership Completes Final Milestone in Converting 20,000 Russian Nuclear Warheads into Fuel for U.S. Electricity November 14, 2013 - 11:26am Addthis NEWS MEDIA CONTACT National Nuclear Security Administration (NNSA) Public Affairs: (202) 586-7371 WASHINGTON - U.S. Energy Secretary Ernest Moniz today announced the final shipment of low enriched uranium (LEU) derived from Russian weapons-origin highly enriched uranium (HEU) under the 1993 U.S.-Russia HEU Purchase Agreement, commonly known as the Megatons to Megawatts Program. Under this Agreement, Russia downblended 500 metric tons of HEU, equivalent to 20,000

344

Propulsion system for a motor vehicle using a bidirectional energy converter  

DOE Patents (OSTI)

A motor vehicle propulsion system includes an electrical energy source and a traction motor coupled to receive electrical energy from the electrical energy source. The system also has a first bus provided electrical energy by the electrical energy source and a second bus of relatively lower voltage than the first bus. In addition, the system includes an electrically-driven source of reaction gas for the electrical energy source, the source of reaction gas coupled to receive electrical energy from the first bus. Also, the system has an electrical storage device coupled to the second bus for storing electrical energy at the lower voltage. The system also includes a bidirectional energy converter coupled to convert electrical energy from the first bus to the second bus and from the second bus to the first bus.

Tamor, Michael Alan (Toledo, OH); Gale, Allan Roy (Livonia, MI)

1999-01-01T23:59:59.000Z

345

FISSION TARGET DESIGN AND INTEGRATION OF NEUTRON CONVERTER FOR EURISOL-DS PROJECT  

E-Print Network (OSTI)

A study of a new fission target for EURISOL-DS is presented with a detailed description of the target. Calculations of several configurations were done using Monte Carlo code FLUKA aimed to obtaining 1015 fissions/s on single target. In Eurisol, neutrons inducing the fission reactions are produced by a proton beam 1GeV-4mA interacting with a mercury converter. The target configuration was customized to gain fission yield from the large amount of low energy neutrons produced by the Hg converter. To this purpose, the fissile material is composed by discs of 238-Uranium carbide enriched with 15 g of 235-U. Studies of several geometries were done in order to define the shape and composition of uranium target, taking into account the mechanical and space constraints

J. Bermudez, O. Alyakrinskiy, M. Barbui, F. Negoita, L. Serbina, L.B. Tecchio, E. Udup

346

Calculation of HVDC converter noncharacteristic harmonics using digital time-domain simulation method  

Science Conference Proceedings (OSTI)

In this paper, noncharacteristic harmonics of an HVdc converter station are calculated based on the use of digital time-domain simulation methods. An enhanced version of the Electromagnetic Transients Program (EMTP) is used for the studies. The noncharacteristic harmonics of interest are (1) the dc side triplen harmonics, and (2) the ac side second harmonic. Impacts of loading conditions, neutral filter, and converter firing angle on the dc side triplen harmonics are discussed. Effects of ac side network parameters, static VAR compensator (SVC), transformer half-cycle saturation, and Geomagnetically Induced Current (GIC) on the ac side second harmonic instability are also presented. This paper concludes that the digital time-domain simulation method provides significant flexibility for accurate prediction of (1) generation mechanism, and (2) adverse impacts of HVdc noncharacteristic harmonics.

Sarshar, A. [Trench Electric, Scarborough, Ontario (Canada); Iravani, M.R.; Li, J. [Univ. of Toronto, Ontario (Canada). Dept. of Electrical and Computer Engineering

1996-01-01T23:59:59.000Z

347

Efficient Power Converters for PV Arrays : Scalable Submodule Power Conversion for Utility-Scale Photovoltaics  

Science Conference Proceedings (OSTI)

Solar ADEPT Project: SolarBridge is developing a new power conversion technique to improve the energy output of PV power plants. This new technique is specifically aimed at large plants where many solar panels are connected together. SolarBridge is correcting for the inefficiencies that occur when two solar panels that encounter different amounts of sun are connected together. In most conventional PV system, the weakest panel limits the energy production of the entire system. That’s because all of the energy collected by the PV system feeds into a single collection point where a central inverter then converts it into useable energy for the grid. SolarBridge has found a more efficient and cost-effective way to convert solar energy, correcting these power differences before they reach the grid.

None

2012-02-23T23:59:59.000Z

348

Thermionic converter with differentially heated cesium-oxygen source and method of operation  

DOE Green Energy (OSTI)

A thermionic converter having an emitter, a collector, and a source of cesium vapor is provided, wherein the source of cesium vapor is differentially heated so that said source has a hotter end and a cooler end, with cesium vapor evaporating from said hotter end into the space between the emitter and the collector and with cesium vapor condensing at said cooler end. The condensed cesium vapor migrates through a porous element from the cooler end to the hotter end.

Rasor, N.S.; Riley, D.R.; Murray, C.S.; Geller, C.B.

1998-12-01T23:59:59.000Z

349

Marcy Convertible Static Compensator (CSC) Performance Analysis, Availability, and Response to System Disturbances: Technical Update  

Science Conference Proceedings (OSTI)

The development and installation of the Convertible Static Compensator (CSC) system at the New York Power Authority's (NYPA's) Marcy substation is the latest in a series of projects sponsored by EPRI's Flexible AC Transmission System (FACTS) initiative. The CSC is a power electronics-based controller that provides multiple compensating modes, which are needed to securely increase power transfer capability limits of existing transmission systems. The CSC provides flexible dynamic voltage control (to avoid...

2003-03-10T23:59:59.000Z

350

RPM-SIM-Based Analysis of Power Converter Applications in Renewable Energy Systems: Preprint  

DOE Green Energy (OSTI)

This paper briefly presents the RPM-SIM simulator and, in particular, its abilities to simulate and analyze renewable energy systems with power converters. This modular simulation system is used to study applications and cost-effective performance of renewable energy systems, analyze both static and dynamic performance, develop control strategies, and simulate autonomous renewable energy systems under different generation and load conditions (such as different wind speeds, temperature, insolation conditions, and load profiles).

Bialasiewicz, J. T.; Muljadi, E.; Nix, R. G.

2001-11-01T23:59:59.000Z

351

A three-phase converter model for harmonic analysis of HVDC systems  

Science Conference Proceedings (OSTI)

An equivalent circuit model is presented to model bridge converters for three-phase HVDC harmonic power flow analysis. The validity and accuracy of the model are verified by comparing simulation results against field test results. The model is interfaced with a multiphase harmonic load flow program to investigate the generation of non-characteristic harmonics from HVDC links and the flow of HVDC harmonics in a real system.

Xu, W.; Drakos, J.E.; Mansour, Y.; Chang, A. (B.C. Hydro, Burnaby, British Columbia (Canada))

1994-07-01T23:59:59.000Z

352

Catalyst and process for converting synthesis gas to liquid motor fuels  

DOE Patents (OSTI)

The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

Coughlin, Peter K. (Yorktown Heights, NY)

1987-01-01T23:59:59.000Z

353

High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters  

DOE Patents (OSTI)

A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.

Wanlass, Mark W. (Golden, CO)

2011-11-29T23:59:59.000Z

354

System Tests with DC-DC Converters for the CMS Silicon Strip Tracker at SLHC  

E-Print Network (OSTI)

The delivery of power is considered to be one of the major challenges for the upgrade of the CMS silicon strip tracker for SLHC. The inevitable increase in granularity and complexity of the device is expected to result in a power consumption comparable or even higher than the power consumption of todays' strip tracker. However, the space available for cables will remain the same. In addition, a further increase of the tracker material budget due to cables and cooling is considered inacceptable, as the performance of the CMS detector must not be compromised for the upgrade. Novel powering schemes such as serial powering or usage of DC-DC converters have been proposed to solve the problem. To test the second option, substructures of the current CMS silicon strip tracker have been operated for the first time with off-the-shelf DC-DC buck converters as well as with first prototypes of custom-designed DC-DC converters. The tests are described and the results are discussed.

Klein, K; Karpinski, W; Merz, J; Sammet, J

2008-01-01T23:59:59.000Z

355

Programmatic status of NASA`s CSTI high capacity power Stirling Space Power Converter Program  

DOE Green Energy (OSTI)

An overview is presented of the NASA Lewis Research Center Free-Piston Stirling Space Power Converter Technology Development Program. This work is being conducted under NASA`s Civil Space Technology Initiative (CSTI). The goal of the CSTI High Capacity Power element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space initiatives. Efforts are focused upon increasing system thermal and electric energy conversion efficiency at least fivefold over current SP-100 technology, and on achieving systems that are compatible with space nuclear reactors. This paper will discuss the status of test activities with the Space Power Research Engine (SPRE). Design deficiencies are gradually being corrected and the power converter is now outputting 11.5 kWe at a temperature ratio of 2 (design output is 12.5 kWe). Detail designs have been completed for the 1050 K Component Test Power Converter (CTPC). The success of these and future designs is dependent upon supporting research and technology efforts including heat pipes, gas bearings, superalloy joining technologies and high efficiency alternators. This paper also provides an update of progress in these technologies.

Dudenhoefer, J.E.

1994-09-01T23:59:59.000Z

356

PERFORMANCE AND ENERGY-TRANSFER MEASUREMENTS ON CYLINDRICAL CESIUM THERMIONIC CONVERTERS  

SciTech Connect

Detailed measurements of performance and energy transfer were made on two highly instrumented cylindrical cesium thermionic converters with electrically heated tungsten emitters. The first converter, OC-4, which had a niobium collector, operated with an initial electrical output of 6.9 watts/cm/sup 2/. This output gradually degraded to a value of 4.6 watts/cm/sup 2/ after 1351 hr. These power values were measured at the electrodes for an average emitter temperature of 1 750 deg C, Converter OC-5, which had a molybdenum collector, has operated 260 hr to date, with a power output and efficiency of 11.1 watts/cm/sup 2/ and 16%, respectively, at an average emitter temperature of 1800 deg C. These operating data are compared with those for lower emitter temperatures below. Temperature Density Efficiency Energy values of the emitter electron cooling, collector electron heating, thermal radiation, and cesium conduction were calorimetrically determined as a function of emitter temperature, collector temperature, cesium pressure, and current. For all the data obtained, the emitter temperature profile was measured by thermocouples. From the calorimeter measurements, correlations were found for the prediction of emitter electron cooling DELTA Q/sub E/ and collector electron heating DELTA Q/sub C/: DELTA Q/sub E/ = I (2.6 + V), and DELTA Q/sub C/ = I (2. The correlation is valid within 4% accuracy over the operating variable range: emitter temperature of 1200 to 1800 deg C; cesium reservoir temperature of 300 to 400 deg C;, collector temperature of 600 to 700 deg C; and current of zero to 15 amp/cm/sup 2/ . Through measurements of emitterstructure heat losses, of the cesium-vapor thermal conduction, and of the electrode radiation heat transfer, it was found that all the zero-current energy-transfer quantities can be accurately predicted with RAT, a two-dimensional digital-computer heat-transfer code. The electron cooling correlation, together with the ability to calculate all of the power-loss values in a thermionic converter, makes it possible to compute the efficiency of a converter when the I-V characteristics and materials properties are known This is of special interest to thermionic reactor analysis, since the input to the reactor problem is the amount of fission produced in each of a very large number of cells within the reactor. Apart from the utility of the correlation discovered, the determination of the value of 2.6 volts in the current-heating terms is of fundamental interest and invites further study. (auth)

Holland, J.W.

1963-11-13T23:59:59.000Z

357

THE POWER OUTPUT AND EFFICIENCY OF THERMIONIC CONVERTERS CONNECTED IN SERIES AND PARALLEL CIRCUITS--PART I  

SciTech Connect

Optimum and off-optimum performance is experimentally obtained for one of the 10 mil spaced, 7 cm/sup 2/ emitter area, cylindrical geometry thermionic converters to be used in the series and parallel connected thermionic converter experiment. The results are presented as graphs of output voltage vs power input, and power output vs power input. The current is the major parameter in both cases. The data in these forms are used to compute the power output of twin converter circults having unequal power inputs. The optimum load conditions for operation are then determined. The results are valuable in guiding thermionic power plant design. (auth)

Holland, J.W.

1962-04-10T23:59:59.000Z

358

Investigation of Multi-Frequency Power Transmission and System  

E-Print Network (OSTI)

This dissertation presents a new power system transmission concept based on frequency selectivity named Multi-Frequency Power System (MFPS). This system allows for selective power transmission among terminals in an interconnected system, and is enabled by power electronic technology. The dissertation starts with a presentation of some of the challenges faced by modern power systems, and includes a description of various power system technologies developed in an attempt to solve them. Then, our proposed solution is presented as an alternative to electric power transmission, and the fundamental concepts are explained. A version of the MFPS is developed, which has relevance to the problem of renewable sources integration. This AC DC Power System is further explored, and the topology of the system and the converters is presented, as well as the control techniques used in its operation. The dissertation also presents a performance study of the AC DC system, which was done in Simulink, and it demonstrates the robustness of the system under various dynamic and fault conditions. Finally, a summary of the work is given in the last section of the dissertation. The contributions of our research to the state of technology are discussed. These contributions include: the demonstration of power selectivity based on frequency identification, the development of a novel transmission system and a AC DC integrated implementation of it, and the development of a control and converter that enables selective power transmission. Also, some of the most relevant future research initiatives related to this topic are presented.

Barazarte Conte, Ronald

2011-08-01T23:59:59.000Z

359

Design and testing of an internal mode converter for a 1.5 MW, 110 GHz gyrotron with a depressed collector  

E-Print Network (OSTI)

We report experimental results on a 1.5 MW, 110 GHz, 3 microsecond pulsed gyrotron with a single-stage depressed collector. A simplified mode converter with smooth mirror surfaces has been installed in the tube. The converter ...

Tax, David Samuel

360

Verktyg för lönsamhetsberäkningar vid bränslekonvertering av spetslastpannor från olja till pellets; Tool for estimating the profitability of converting a peak-load oil-fired boiler to pellets.  

E-Print Network (OSTI)

?? This report summarizes the development of a calculation program estimating the profitability of converting a peak-load oil-fired boiler to pellets. To convert an oil-fired… (more)

Sorby, Jonathan

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
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361

Design, status and first operations of the spallation neutron source polyphase resonant converter modulator system  

DOE Green Energy (OSTI)

The Spallation Neutron Source (SNS) is a new 1.4 MW average power beam, 1 GeV accelerator being built at Oak Ridge National Laboratory. The accelerator requires 15 converter-modulator stations each providing between 9 and 11 MW pulses with up to a 1 .I MW average power. The converter-modulator can be described as a resonant 20 kHz polyphase boost inverter. Each converter modulator derives its buss voltage from a standard substation cast-core transformer. Each substation is followed by an SCR pre-regulator to accommodate voltage changes from no load to full load, in addition to providing a soft-start function. Energy storage is provided by self-clearing metallized hazy polypropylene traction capacitors. These capacitors do not fail short, but clear any internal anomaly. Three 'H-Bridge' IGBT transistor networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are time-gated to generate the desired klystron pulse width. Pulse width modulation of the individual 20 lcHz pulses is utilized to provide regulated output waveforms with DSP based adaptive feedforward and feedback techniques. The boost transformer design utilizes nanocrystalline alloy that provides low core loss at design flux levels and switching frequencies. Capacitors are used on the transformer secondary networks to resonate the leakage inductance. The transformers are wound for a specific leakage inductance, not turns ratio. This design technique generates multiple secondary volts per turn as compared to the primary. With the appropriate tuning conditions, switching losses are minimized. The resonant topology has the added benefit of being deQed in a klystron fault condition, with little energy deposited in the arc. This obviates the need of crowbars or other related networks. A review of these design parameters, operational performance, production status, and OWL installation and performance to date will be presented.

Reass, W. A. (William A.); Apgar, S. E. (Sean E.); Baca, D. M. (David M.); Doss, James D.; Gonzales, J. (Jacqueline); Gribble, R. F. (Robert F.); Hardek, T. W. (Thomas W.); Lynch, M. T. (Michael T.); Rees, D. E. (Daniel E.); Tallerico, P. J. (Paul J.); Trujillo, P. B. (Pete B.); Anderson, D. E. (David E.); Heidenreich, D. A. (Dale A.); Hicks, J. D. (Jim D.); Leontiev, V. N.

2003-01-01T23:59:59.000Z

362

Experimental and numerical study of the behavior of three-way catalytic converters under different engine operation conditions  

E-Print Network (OSTI)

The thesis reports the studies on how the three-way catalytic converters behave under different operation conditions. The main focus of the work is in the oxygen storage capacity of the three-way catalyst. Rich-to-lean ...

Zhang, Yuetao

2005-01-01T23:59:59.000Z

363

Design and testing of a 13. 75-MW converter for a superconducting magnetic-energy-storage system  

DOE Green Energy (OSTI)

A 30 MJ superconducting magnetic energy storage system will be installed in 1982 in Tacoma, WA, to act as a transmission line stabilizer. Two 6 MVA transformers and a 5.5 kA, + 2.5 kV converter will connect the superconducting coil to the 13.8 kV bus and regulate the power flow between the coil and the three phase system. The design philosophy for the converter including its control and protection system is given in the paper. The converter has been tested with 10% overvoltage at no load, with 10% overcurrent at zero output voltage and with a watercooled resistive load of about 1 MW. These test results show that the converter will meet the expected full load operating conditions.

Boenig, H.J.; Turner, R.D.; Neft, C.L.; Sueker, K.H.

1981-01-01T23:59:59.000Z

364

Systems and methods for commutating inductor current using a matrix converter  

DOE Patents (OSTI)

Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

Ransom, Ray M; Kajouke, Lateef A; Perisic, Milun

2012-10-16T23:59:59.000Z

365

Ultracold neutron accumulation in a superfluid-helium converter with magnetic multipole reflector  

E-Print Network (OSTI)

We analyze accumulation of ultracold neutrons (UCN) in a superfluid-helium converter vessel surrounded by a magnetic multipole reflector. Employing formulas valid for trapped UCN in mechanical equilibrium we solved the rate equation and obtained results for the saturation density of low field seeking UCN for any field strength of the multipolar field. The addition of magnetic storage can increase the density and energy of the UCN produced and serves to mitigate the effects of wall losses on the source performance. This work was performed in preparation of the UCN source project SuperSUN at the ILL.

O. Zimmer; R. Golub

2013-03-08T23:59:59.000Z

366

Process for converting heavy oil deposited on coal to distillable oil in a low severity process  

DOE Patents (OSTI)

A process for removing oil from coal fines that have been agglomerated or blended with heavy oil comprises the steps of heating the coal fines to temperatures over 350.degree. C. up to 450.degree. C. in an inert atmosphere, such as steam or nitrogen, to convert some of the heavy oil to lighter, and distilling and collecting the lighter oils. The pressure at which the process is carried out can be from atmospheric to 100 atmospheres. A hydrogen donor can be added to the oil prior to deposition on the coal surface to increase the yield of distillable oil.

Ignasiak, Teresa (417 Heffernan Drive, Edmonton, Alberta, CA); Strausz, Otto (13119 Grand View Drive, Edmonton, Alberta, CA); Ignasiak, Boleslaw (417 heffernan Drive, Edmonton, Alberta, CA); Janiak, Jerzy (17820 - 76 Ave., Edmonton, Alberta, CA); Pawlak, Wanda (3046 - 11465 - 41 Avenue, Edmonton, Alberta, CA); Szymocha, Kazimierz (3125 - 109 Street, Edmonton, Alberta, CA); Turak, Ali A. (Edmonton, CA)

1994-01-01T23:59:59.000Z

367

Design Optimisation Of An Offshore Wind Energy Converter By Means Of Tailored Dynamics  

E-Print Network (OSTI)

Tailoring the dynamics of an offshore wind energy converter can offer an effective design optimisation during the successive stages of the design process. Concerning the particular problem of fatigue due to combined wind and wave loading two simplified approaches are proposed and demonstrated which are well suited for the early design stages when integrated, non-linear time domain simulations are too cumbersome. This enables the use of standard design tools from the wind energy and offshore technology communities by superposition of separate analyses of hydrodynamic fatigue in the frequency domain and aerodynamic fatigue in the time domain.

M. Kühn

1999-01-01T23:59:59.000Z

368

Functionally gradient material for membrane reactors to convert methane gas into value-added products  

DOE Patents (OSTI)

A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials. 7 figs.

Balachandran, U.; Dusek, J.T.; Kleefisch, M.S.; Kobylinski, T.P.

1996-11-12T23:59:59.000Z

369

Functionally gradient material for membrane reactors to convert methane gas into value-added products  

DOE Patents (OSTI)

A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials.

Balachandran, Uthamalingam (Hinsdale, IL); Dusek, Joseph T. (Lombard, IL); Kleefisch, Mark S. (Napersville, IL); Kobylinski, Thadeus P. (Lisle, IL)

1996-01-01T23:59:59.000Z

370

Method of converting an existing vehicle powertrain to a hybrid powertrain system  

DOE Patents (OSTI)

A method of converting an existing vehicle powertrain including a manual transmission to a hybrid powertrain system with an automated powertrain transmission. The first step in the method of attaching a gear train housing to a housing of said manual transmission, said gear train housing receiving as end of drive shaft of said transmission and rotatably supporting a gear train assembly. Secondly, mounting an electric motor/generator to said gear train housing and attaching a motor/generator drive shaft of said electric motor/generator to said gear train assembly. Lastly, connecting an electro-mechanical clutch actuator to a friction clutch mechanism of said manual transmission.

Reed, Jr., Richard G. (Royal Oak, MI); Boberg, Evan S. (Hazel Park, MI); Lawrie, Robert E. (Whitmore Lake, MI); Castaing, Francois J. (Bloomfield Township, MI)

2001-12-25T23:59:59.000Z

371

2 MW Active Bouncer Converter Design for Long Pulse Klystron Modulators  

E-Print Network (OSTI)

This paper presents some design issues of a 2 MW interleaved buck converter which is used as an active bouncer droop compensator for a 5.5MW long pulse klystron modulator. This novel design concept presents many challenges in terms of voltage ripple versus pulse rise-time. Issues related to the voltage ripple specification versus output filter design are discussed in detail. The design study is analyzed analytically, simulated numerically and is validated by experimental results obtained from a full power prototype.

Aguglia, D

2012-01-01T23:59:59.000Z

372

A Fusing Switch for Fault Suppression in the SNS High Voltage Converter Modulators  

DOE Green Energy (OSTI)

The High Voltage Converter Modulators (HVCMs) at the Spallation Neutron Source (SNS) have operated in excess of a combined 250,000 hours. Performance and reliability improvements to the HVCM are ongoing to increase modulator availability as accelerator system demands increase. There is a relatively large amount of energy storage in the HVCMs, {approx}180 kJ. This energy has the potential to dump into unsuppressed faults, cause damage, and increase the time to repair. The 'fusing switch' concept involves isolation of this stored energy from the location of the most common faults. This paper introduces this concept and its application to the HVCMs.

Kemp, Mark A.; Burkhart, Craig; Nguyen, Minh N.; /SLAC; Anderson, David E.; /Oak Ridge

2009-08-03T23:59:59.000Z

373

Chemical vapor deposition techniques and related methods for manufacturing microminiature thermionic converters  

DOE Patents (OSTI)

Methods of manufacturing microminiature thermionic converters (MTCs) having high energy-conversion efficiencies and variable operating temperatures using MEMS manufacturing techniques including chemical vapor deposition. The MTCs made using the methods of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. The MTCs also exhibit maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

King, Donald B. (Albuquerque, NM); Sadwick, Laurence P. (Salt Lake City, UT); Wernsman, Bernard R. (Clairton, PA)

2002-06-25T23:59:59.000Z

374

The worldwide demand for green energy systems is evident. In this context, wind energy converters will play a paramount role. Extending the service life of a  

E-Print Network (OSTI)

ABSTRACT The worldwide demand for green energy systems is evident. In this context, wind energy converters will play a paramount role. Extending the service life of a wind energy converter translates and operation of the wind energy converters make it beneficial to know the structural condition

Stanford University

375

Capability of the MIMAS process to convert the stockpiles of separated plutonium into MOX fuel for use in LWRs  

Science Conference Proceedings (OSTI)

Long-term storage of plutonium separated from fission products is not a good solution according to the current non-proliferation criteria as well as from an economic point of view. This material has thus to be converted to the equivalent of the “spent fuel standard.” Only one technique has so far reached the industrial maturity necessary to convert the important existing plutonium stockpiles: it is the use of plutonium to manufacture and irradiate mixed-oxide (MOX) fuel.

Paul Deramaix; Yvon Vanderborck; Werner Couwenbergh

2000-01-01T23:59:59.000Z

376

Improving the low voltage ride through of doubly fed induction generator during intermittent voltage source converter faults  

Science Conference Proceedings (OSTI)

The impact of different voltage source converter (VSC) faults on the low voltage ride through (LVRT) capability of the doubly fed induction generator (DFIG) is also investigated. Faults such as fire-through of the VSC switches and short circuit across the DC-link capacitor are considered in this paper. The impact of internal VSC faults when they occur within the grid side converter (GSC)

2013-01-01T23:59:59.000Z

377

A fully integrated switched-capacitor DC-DC converter with dual output for low power application  

Science Conference Proceedings (OSTI)

This paper presents a fully integrated on-chip switched-capacitor (SC) DC-DC converter that supports two regulated power supply voltages of 2.2V and 3.2V from 5V input supply and delivers the maximum load currents up to 8mA at both of the outputs. The ... Keywords: dc-dc converter, dual output, switched-capacitor

Heungjun Jeon; Yong-Bin Kim

2012-05-01T23:59:59.000Z

378

Design, improvement, and testing of a thermal-electrical analysis application of a multiple beta-tube AMTEC converter  

E-Print Network (OSTI)

A new design AMTEC converter model was developed, and its effectiveness as a design tool was evaluated. To develop the model, requirements of the model were defined, several new design models were successively developed, and finally an optimal new design model was developed. The model was created within Sinda/Fluint, with its graphical interface, Thermal Desktop, a software package that can be used to conduct complex thermal and fluid analyses. Performance predictions were then correlated and compared with actual performance data from the Road Runner II AMTEC converter. Predicted performance results were within 10% of actual performance data for all operating conditions analyzed. This accuracy tended to increase within operating ranges that would be more likely encountered in AMTEC applications. Performance predictions and parametric design studies were then performed on a proposed new design converter model with a variety of annular condenser heights and with potassium as a working fluid to evaluate the effects of various design modifications. Results clearly indicated the effects of the converter design modifications on the converter's power and efficiency, thus simplifying the design optimization process. With the close correlation to actual data and the design information obtained from parametric studies, it was determined that the model could serve as an effective tool for the design of AMTEC converters.

Pavlenko, Ilia V.

2003-12-01T23:59:59.000Z

379

Startup of the Fission Converter Epithermal Neutron Irradiation Facility at the MIT Reactor  

Science Conference Proceedings (OSTI)

A new epithermal neutron irradiation facility, based on a fission converter assembly placed in the thermal column outside the reactor core, has been put into operation at the Massachusetts Institute of Technology Research Reactor (MITR). This facility was constructed to provide a high-intensity, forward-directed beam for use in neutron capture therapy with an epithermal flux of [approximately equal to]10{sup 10} n/cm{sup 2}.s at the medical room entrance with negligible fast neutron and gamma-ray contamination. The fission converter assembly consists of 10 or 11 MITR fuel elements placed in an aluminum tank and cooled with D{sub 2}O. Thermal-hydraulic criteria were established based on heat deposition calculations. Various startup tests were performed to verify expected neutronic and thermal-hydraulic behavior. Flow testing showed an almost flat flow distribution across the fuel elements with <5% bypass flow. The total reactivity change caused by operation of the facility was measured at 0.014 {+-} 0.002% {delta}K/K. Thermal power produced by the facility was measured to be 83.1 {+-} 4.2 kW. All of these test results satisfied the thermal-hydraulic safety criteria. In addition, radiation shielding design measurements were made that verified design calculations for the neutronic performance.

Newton, Thomas H. Jr.; Riley, Kent J.; Binns, Peter J.; Kohse, Gordon E.; Hu Linwen; Harling, Otto K. [Massachusetts Institute of Technology (United States)

2002-08-15T23:59:59.000Z

380

A 1 MEGAWATT POLYPHASE BOOST CONVERTER-MODULATOR FOR KLYSTRON PULSE APPLICATION  

SciTech Connect

This paper describes electrical design criteria and first operational results a 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching 20 kHz polyphase bridge, boost converter/modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2300 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. PWM (pulse width modulation) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt-peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. A review of these design parameters and the first results of the performance characteristics will be presented.

W.A. REASS; J.D. DOSS; R.F. GRIBBLE

2001-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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381

Progress in converting {sup 99}Mo production from high- to low-enriched uranium--1999.  

SciTech Connect

Over this past year, extraordinary progress has been made in executing our charter to assist in converting Mo-99 production worldwide from HEU to LEU. Building on the successful development of the experimental LEU-foil target, we have designed a new, economical irradiation target. We have also successfully demonstrated, in collaboration with BATAN in Indonesia, that LEU can be substituted for HEU in the Cintichem target without loss of product yield or purity; in fact, conversion may make economic sense. We are interacting with a number of commercial producers--we have begun active collaborations with the CNEA and ANSTO; we are working to define the scope of collaborations with MDS Nordion and Mallinckrodt; and IRE has offered its services to irradiate and test a target at the appropriate time. Conversion of the CNEA process is on schedule. Other papers presented at this meeting will present specific results on the demonstration of the LEU-modified Cintichem process, the development of the new target, and progress in converting the CNEA process.

Snelgrove, J. L.; Vandegrift, G. F.; Conner, C.; Wiencek, T. C.; Hofman, G. L.

1999-09-29T23:59:59.000Z

382

Adaptive feedforward and feedback control schemes for sliding mode controlled power converters  

E-Print Network (OSTI)

Abstract—A major disadvantage of applying sliding mode control to dc/dc converters is that the steady-state switching frequency is affected by line and load variations. This is undesirable as it complicates the design of the input and output filters. To reduce switching frequency deviation in the events of line and load variations, an adaptive feedforward control scheme that varies the hysteresis band according to the change of line input voltage and an adaptive feedback control scheme that varies the control parameter (i.e., sliding coefficient) according to the change of the output load are proposed. This paper presents a thorough investigation into the problem and the effectiveness of the proposed solutions. In addition, methods of implementing the proposed adaptive control strategies are discussed. Experimental results confirm that the adaptive control schemes are capable of reducing the switching frequency variations caused by both line and load variations. Index Terms—Adaptive feedback control, adaptive feedforward control, buck converter, hysteresis modulation, pulse-width-modulation (PWM), sliding mode (SM)control. I.

Siew-chong Tan; Y. M. Lai; Chi K. Tse; Martin K. H. Cheung; Student Member

2006-01-01T23:59:59.000Z

383

Options for converting excess plutonium to feed for the MOX fuel fabrication facility  

SciTech Connect

The storage and safekeeping of excess plutonium in the United States represents a multibillion-dollar lifecycle cost to the taxpayers and poses challenges to National Security and Nuclear Non-Proliferation. Los Alamos National Laboratory is considering options for converting some portion of the 13 metric tons of excess plutonium that was previously destined for long-term waste disposition into feed for the MOX Fuel Fabrication Facility (MFFF). This approach could reduce storage costs and security ri sks, and produce fuel for nuclear energy at the same time. Over the course of 30 years of weapons related plutonium production, Los Alamos has developed a number of flow sheets aimed at separation and purification of plutonium. Flow sheets for converting metal to oxide and for removing chloride and fluoride from plutonium residues have been developed and withstood the test oftime. This presentation will address some potential options for utilizing processes and infrastructure developed by Defense Programs to transform a large variety of highly impure plutonium into feedstock for the MFFF.

Watts, Joe A [Los Alamos National Laboratory; Smith, Paul H [Los Alamos National Laboratory; Psaras, John D [Los Alamos National Laboratory; Jarvinen, Gordon D [Los Alamos National Laboratory; Costa, David A [Los Alamos National Laboratory; Joyce, Jr., Edward L [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

384

Methods of chemically converting first materials to second materials utilizing hybrid-plasma systems  

DOE Green Energy (OSTI)

In one aspect, the invention encompasses a method of chemically converting a first material to a second material. A first plasma and a second plasma are formed, and the first plasma is in fluid communication with the second plasma. The second plasma comprises activated hydrogen and oxygen, and is formed from a water vapor. A first material is flowed into the first plasma to at least partially ionize at least a portion of the first material. The at least partially ionized first material is flowed into the second plasma to react at least some components of the first material with at least one of the activated hydrogen and activated oxygen. Such converts at least some of the first material to a second material. In another aspect, the invention encompasses a method of forming a synthetic gas by flowing a hydrocarbon-containing material into a hybrid-plasma system. In yet another aspect, the invention encompasses a method of degrading a hydrocarbon-containing material by flowing such material into a hybrid-plasma system. In yet another aspect, the invention encompasses a method of releasing an inorganic component of a complex comprising the inorganic component and an other component, wherein the complex is flowed through a hybrid-plasma system.

Kong, Peter C. (Idaho Falls, ID); Grandy, Jon D. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

385

First results of the Los Alamos polyphase boost converter-modulator  

DOE Green Energy (OSTI)

This paper describes the first full-scale electrical test results of the Los Alamos polyphase boost converter-modulator being developed for the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The convertrr-modulator provides 140 kV, 1.2 mS, 60 Hz pulses to a 5 MW, 805 MHz klystron. The system, which has 1 MW average power, derives its +/- 1250 Volt DC buss link voltages from a standard 3-phase utility 13.8 kV to 2100 volt transformer. An SCR pre-regulator provides a soft-start function in addition to correction of line and load variations, from no-load to full-load. Energy storage is provided by low inductance self-clearing metallized hazy polypropylene traction capacitors. Each of the 3-phase H-bridge Insulated Gate Bipolar Transistor (IGBT) Pulse-Width Modulation (PWM) drivers are resonated with the amorphous nanocrystalline boost transformer and associated peaking circuits to provide zero-voltage-switching characteristics for the IGBT's. This design feature minimizes IGBT switching losses. By PWM of individual IGBT conduction angles, output pulse regulation with adaptive feedforward and feedback techniques is used to improve the klystron voltage pulse shape. In addition to the first operational results, this paper will discuss the relevant design techniques associated with the boost converter-modulator topology.

Doss, James D.; Gribble, R. F. (Robert F.); Lynch, M. T. (Michael T.); Rees, D. E. (Daniel E.); Tallerico, P. J. (Paul J.); Reass, W. A. (William A.)

2001-01-01T23:59:59.000Z

386

Advanced converter technology. Technical progress report, May 23, 1979-May 22, 1980  

DOE Green Energy (OSTI)

The overall objective of this program is to define an advanced converter system employing 1980's technology in all subsystem and component areas for use in electrochemical energy storage systems. Additional experimental effort will validate elements of the advanced commutation circuitry on a full-scale breadboard basis. Improved models of battery electrical characteristics are beng defined and experimental apparatus is being designed to measure these characteristics and to enable better definition of the battery-power conditioner interface. Improvement of energy-storage system performance through modification of battery converter characteristics will also be investigated. During this first year of the contract, a new more advanced concept for power conditioning based on a concept defined by United Technologies Corporation for fuel cell use was evaluated. This high switching frequency concept has the potential for significantly reducing the size and cost of battery plant power conditioners. As a result, the Department of Energy authorized redirection of the program to first evaluate this new concept and then to reorient the program to adopt this concept as the primary one. Progress is reported. (WHK)

Banic, C. V.; Eckhouse, S. A.; Kornbrust, F. J.; Lipman, K.; Peterson, J. L.; Rosati, R. W.

1980-01-01T23:59:59.000Z

387

A Low-Cost Soft-Switched DC/DC Converter for Solid-Oxide Fuel Cells  

DOE Green Energy (OSTI)

A highly efficient DC to DC converter has been developed for low-voltage high-current solid oxide fuel cells. The newly developed 'V6' converter resembles what has been done in internal combustion engine that split into multiple cylinders to increase the output capacity without having to increase individual cell size and to smooth out the torque with interleaving operation. The development was started with topology overview to ensure that all the DC to DC converter circuits were included in the study. Efficiency models for different circuit topologies were established, and computer simulations were performed to determine the best candidate converter circuit. Through design optimization including topology selection, device selection, magnetic component design, thermal design, and digital controller design, a bench prototype rated 5-kW, with 20 to 50V input and 200/400V output was fabricated and tested. Efficiency goal of 97% was proven achievable through hardware experiment. This DC to DC converter was then modified in the later stage to converter 35 to 63 V input and 13.8 V output for automotive charging applications. The complete prototype was tested at Delphi with their solid oxide fuel cell test stand to verify the performance of the modified DC to DC converter. The output was tested up to 3-kW level, and the efficiency exceeded 97.5%. Multiple-phase interleaving operation design was proved to be reliable and ripple free at the output, which is desirable for the battery charging. Overall this is a very successful collaboration project between the SECA Core Technology Team and Industrial Team.

Jason Lai

2009-03-03T23:59:59.000Z

388

Categorical Exclusion Determination Form Proposed Action Title: (0474-1528) Ideal Power Converters Inc. -  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

rgy rgy ·Submitby£-mail Categorical Exclusion Determination Form Proposed Action Title: (0474-1528) Ideal Power Converters Inc. - Dual Bi-Directional Silicon IGBTs Modules Enables Breakthrough PV Inverter Using Current-Modulation Topology Program or Field Office: Advanced Research Projects Agency - Energy LocationCs) CCitY/County/State): California, New York, Virginia, Texas Proposed Action Description: Funding will support development of a low-cost, high-efficiency 100 kW power inverter to connect photovoltaic (PV) solar panels to the grid, using revolutionary bi-directiona linsulated gate bipolar transistor (BD-IGBT) switches and dual chip modules. Proposed work consists of indoor laboratory-based research and development (R&D) and semiconductor fabrication, including (1) device

389

A 8 bits Pipeline Analog to Digital Converter Design for High Speed Camera Application  

E-Print Network (OSTI)

- This paper describes a pipeline analog-to-digital converter is implemented for high speed camera. In the pipeline ADC design, prime factor is designing operational amplifier with high gain so ADC have been high speed. The other advantage of pipeline is simple on concept, easy to implement in layout and have flexibility to increase speed. We made design and simulation using Mentor Graphics Software with 0.6 \\mu m CMOS technology with a total power dissipation of 75.47 mW. Circuit techniques used include a precise comparator, operational amplifier and clock management. A switched capacitor is used to sample and multiplying at each stage. Simulation a worst case DNL and INL of 0.75 LSB. The design operates at 5 V dc. The ADC achieves a SNDR of 44.86 dB. keywords: pipeline, switched capacitor, clock management

Prasetyo, Eri; Ginhac, Nurul Huda Dominique; Paindavoine, Michel

2008-01-01T23:59:59.000Z

390

Optimal Driving Force for Converting Excitons into Free Carriers in Excitonic Solar Cells  

DOE Green Energy (OSTI)

A general but limiting characteristic in excitonic photovoltaics is that a portion of the incident photon energy appears necessary for converting excitons into electrical charges, resulting in a loss of efficiency. Currently, the mechanism underlying this process is unclear. Here, we describe the development of an experimental method for measuring charge creation yields in organic solar cell materials. We use this method to examine a series of conjugated polymer:fullerene blend films and observe two unexpected features: the existence of an optimal driving force and a loss in conversion efficiency if this force is exceeded. These observations have implications for the design of excitonic photovoltaic devices and can be explained by a simple Marcus formulation that introduces the importance of reorganization energy.

Coffey, D. C.; Larson, B. W.; Hains, A. W.; Whitaker, J. B.; Kopidakis, N.; Boltalina, O. V.; Strauss, S. H.; Rumbles, G.

2012-04-26T23:59:59.000Z

391

Active filters for high-voltage direct-current (HVDC) converter terminals: Final report  

SciTech Connect

This report evaluates the technical and economic feasibility for active filtering of dc-side voltage harmonics and the ac-side current harmonics produced by a HVDC converter. The following designs for the active filter concepts are compared with the existing ac-side and dc-side passive filters used at the Dickinson terminal of the CU HVDC transmission line project: the dc-side active filter consisting of a capacitor coupled current injection source to actively ''neutralize'' the 12th, 24th and the 36th harmonics and, the ac-side active filter designed to provide the same fundamental frequency reactive VARs as the existing passive filters. Controlled currents are injected to actively filter the 11th and the 13th harmonic currents. A cost comparison is made between these active filter designs and existing passive filters supplied by the United Power Association (UPA). 22 figs., 11 tabs.

Mohan, N.; Wong, C.

1988-08-01T23:59:59.000Z

392

Feasibility study of AC- and DC-side active filters for HVDC converter terminals  

SciTech Connect

This paper evaluates the technical and economic feasibility for active filtering of dc-side voltage harmonics and the ac-side current harmonics produced by a HVDC converter. The following designs for the active filter concepts are compared with the existing ac-side and dc-side passive filters used at the Dickinson terminal of the CU HVDC transmission line project: the dc-side active filter consisting of a capacitor coupled current injection source to actively neutralize the 12th, 24th and the 36th harmonics, and the ac-side active filter designed to provide the same fundamental frequency reactive VARs as the existing passive filters. Controlled currents are injected to actively filter the 11th and 13th harmonic currents. A cost comparison is made between these active filter designs and the cost of the existing passive filters supplied by the United Power Association (UPA).

Wong, C.; Mohan, N. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Electrical Engineering); Wright, S.E. (Electric Power Research Inst., Palo Alto, CA (USA)); Mortenson, K.N. (United Power Association, Elk River, MN (USA))

1989-10-01T23:59:59.000Z

393

System and method for converting wellhead gas to liquefied petroleum gases (LPG)  

SciTech Connect

A method of converting natural wellhead gas to liquefied petroleum gases (LPG) may comprise the steps of: separating natural gas from petroleum fluids exiting a well-head; compressing the natural gas; refrigerating the natural gas, liquefying at least a portion thereof; and separating LPG from gas vapors of the refrigerated natural gas. A system for performing the method may comprise: a two-stage gas compressor connected to the wellhead; a refrigeration unit downstream of the gas compressor for cooling the compressed gases therefrom; and a product separator downstream of the refrigeration unit for receiving cooled and compressed gases discharged from the refrigeration unit and separating LPG therein from gases remaining in vapor form.

May, R.L.; Snow, N.J. Jr.

1983-12-06T23:59:59.000Z

394

An ultra low-power digitally-controlled buck converter IC for cellular phone applications  

E-Print Network (OSTI)

Abstract — This paper describes a dual-mode digitallycontrolled buck converter IC for cellular phone applications. An architecture employing internal power management is introduced to ensure voltage compatibility between a singlecell lithium-ion battery voltage and a low voltage integrated circuit technology. Special purpose analog and digital interface elements are developed. These include a ring-oscillator based ADC (ring-ADC), which is nearly entirely synthesizable, robust against switching noise, and has flexible resolution control, and a very low power ring oscillator-multiplexer based Digital PWM generation module (ring-MUX DPWM). The chip, which includes an output power stage rated for 400 mA, occupies 2mm 2 active area in 0.25-µm CMOS. Very high efficiencies are achieved over a load range of 0.1 to 400 mA. Measured quiescent current in PFM mode is 4 µA. I.

Jinwen Xiao; Angel Peterchev; Jianhui Zhang; Seth Sanders

2004-01-01T23:59:59.000Z

395

Kinetic studies of competitive adsorption processes related to automobile catalytic converters  

DOE Green Energy (OSTI)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this project was to study the microscopic details for the adsorption of CO, NO, and O{sub 2} on transition metal surfaces under conditions resembling those present in automobile catalytic converters. Initial sticking coefficients were measured as a function of temperature on transition metal single crystals by using a method originally developed by King and Wells. These measurements were performed under conditions emulating those typical of competitive adsorption, namely, where the substrate is exposed to a mixture of two or more gases simultaneously, or where one molecule is adsorbed on the surface prior to exposure to the second gas. The experimental results were then analyzed by using Monte Carlo computer simulation algorithm in an attempt to better understand the relevant aspects of the adsorption process.

Zaera, F. [Univ. of California, Riverside, CA (United States). Dept. of Chemistry; Paffett, M.T. [Los Alamos National Lab., NM (United States)

1998-12-31T23:59:59.000Z

396

Converting Boundary Representation Solid Models to Half-Space Representation Models for Monte Carlo Analysis  

SciTech Connect

Solid modeling computer software systems provide for the design of three-dimensional solid models used in the design and analysis of physical components. The current state-of-the-art in solid modeling representation uses a boundary representation format in which geometry and topology are used to form three-dimensional boundaries of the solid. The geometry representation used in these systems is cubic B-spline curves and surfaces--a network of cubic B-spline functions in three-dimensional Cartesian coordinate space. Many Monte Carlo codes, however, use a geometry representation in which geometry units are specified by intersections and unions of half-spaces. This paper describes an algorithm for converting from a boundary representation to a half-space representation.

Davis JE, Eddy MJ, Sutton TM, Altomari TJ

2007-03-01T23:59:59.000Z

397

Quantum interface between frequency-uncorrelated down-converted entanglement and atomic-ensemble quantum memory  

E-Print Network (OSTI)

Photonic entanglement source and quantum memory are two basic building blocks of linear-optical quantum computation and long-distance quantum communication. In the past decades, intensive researches have been carried out, and remarkable progress, particularly based on the spontaneous parametric down-converted (SPDC) entanglement source and atomic ensembles, has been achieved. Currently, an important task towards scalable quantum information processing (QIP) is to efficiently write and read entanglement generated from a SPDC source into and out of an atomic quantum memory. Here we report the first experimental realization of a quantum interface by building a 5 MHz frequency-uncorrelated SPDC source and reversibly mapping the generated entangled photons into and out of a remote optically thick cold atomic memory using electromagnetically induced transparency. The frequency correlation between the entangled photons is almost fully eliminated with a suitable pump pulse. The storage of a triggered single photon wi...

Jin, Xian-Min; Zhang, Han; Dai, Han-Ning; Yang, Sheng-Jun; Zhao, Tian-Ming; Rui, Jun; He, Yu; Jiang, Xiao; Yang, Fan; Pan, Ge-Sheng; Yuan, Zhen-Sheng; Deng, Youjin; Chen, Zeng-Bing; Bao, Xiao-Hui; Zhao, Bo; Chen, Shuai; Pan, Jian-Wei

2010-01-01T23:59:59.000Z

398

Case Study: Lessons Learned From Converting Electric Chillers to Steam Chillers in a Electric Deregulated Market.  

E-Print Network (OSTI)

This paper will examine an example of converting two electric centrifugal chillers, which needed to be replaced, to use steam turbine driven centrifugal chillers at a large commercial office building consisting of approximately 700,000 square feet in Center City Philadelphia. The existing 2,000 ton plant was replaced by 2,400 tons of cooling, in the 1997 time frame along with new cooling towers, and the required auxiliaries for the new plant. The paper will look at the impact of steam cooling on the facility's electric load profile both prior to the conversion, as well as after the conversion. This is of particular interest due to the fact that Pennsylvania is deregulated for electric service. One of the benefits in deciding to do the conversion was that a flatter load profile due to steam cooling should allow better electric pricing from energy suppliers.

Wohl, J.

2001-05-01T23:59:59.000Z

399

Process for Converting Waste Glass Fiber into Value Added Products, Final Report  

Science Conference Proceedings (OSTI)

Nature of the Event: Technology demonstration. The project successfully met all of its technical objectives. Albacem has signed an exclusive licensing agreement with Vitro Minerals Inc., a specialty minerals company, to commercialize the Albacem technology (website: www.vitrominerals.com). Location: The basic research for the project was conducted in Peoria, Illinois, and Atlanta, Georgia, with third-party laboratory verification carried out in Ontario, Canada. Pilot-scale trials (multi-ton) were conducted at a facility in South Carolina. Full-scale manufacturing facilities have been designed and are scheduled for construction by Vitro Minerals during 2006 at a location in the Georgia, North Carolina, and South Carolina tri-state area. The Technology: This technology consists of a process to eliminate solid wastes generated at glass fiber manufacturing facilities by converting them to value-added materials (VCAS Pozzolans) suitable for use in cement and concrete applications. This technology will help divert up to 250,000 tpy of discarded glass fiber manufacturing wastes into beneficial use applications in the concrete construction industry. This technology can also be used for processing glass fiber waste materials reclaimed from monofills at manufacturing facilities. The addition of take-back materials and reclamation from landfills can help supply over 500,000 tpy of glass fiber waste for processing into value added products. In the Albacem process, waste glass fiber is ground to a fine powder that effectively functions as a reactive pozzolanic admixture for use in portland ce¬ment-based building materials and products, such as concrete, mortars, terrazzo, tile, and grouts. Because the waste fiber from the glass manufacturing industry is vitreous, clean, and low in iron and alkalis, the resulting pozzolan is white in color and highly consistent in chemical composition. This white pozzolan, termed VCAS Pozzolan (for Vitreous Calcium-Alumino-Silicate). is especially suited for white concrete applications where it imparts desirable benefits such as increased long-term strength and improved long-term durability of concrete products. Two U.S. patents entitled have been issued to Albacem covering the technology. Third-party validation testing has confirmed that the pozzolanic product is an excellent, high performance material that conforms to a ASTM standards and improves the strength and durability of concrete. Currently, there are no known significant competing technologies to process glass fiber manufacturing by-products and con¬vert them into value-added products. Most glass fiber-forming and fabrication wastes continue to be disposed in landfills at significant costs and with associated negative environmental impact. It is estimated that in a typical glass fiber manufactur¬ing facility, 10-20% by weight of the processed glass material is sent for dis¬posal to a landfill. Today, supplementary ce¬menting materials or mineral admixtures are key to achieving strong and durable concrete. Recovered materials such as coal fly ash, ground granulated blast furnace slag and silica fume are widely accepted and used in concrete all over the world, espe¬cially in the construction of “high performance” structures such as massive dams, bridges, subway tunnels, etc. These min¬eral admixtures are not suitable for white concrete and light-colored architectural concrete applications. Converting waste glass fibers into a high performance white pozzolan would allow white concrete producers to gain from the same durability benefits currently realized by gray concrete producers. Description of the Benefit: Albacem’s technology will enable the glass fiber industry to eliminate nearly 100% of its glass fiber produc¬tion waste streams by converting them into viable value-added products. With this technology, the glass industry can prevent the landfilling of about 250,000 tons of waste glass fiber annually. Glass manufacturers will realize improved production efficiency by reducing process costs through the elimination of solid was

Hemmings, Raymond T.

2005-12-31T23:59:59.000Z

400

Photovoltaic power converter system with a controller configured to actively compensate load harmonics  

DOE Patents (OSTI)

Photovoltaic power converter system including a controller configured to reduce load harmonics is provided. The system comprises a photovoltaic array and an inverter electrically coupled to the array to generate an output current for energizing a load connected to the inverter and to a mains grid supply voltage. The system further comprises a controller including a first circuit coupled to receive a load current to measure a harmonic current in the load current. The controller includes a second circuit to generate a fundamental reference drawn by the load. The controller further includes a third circuit for combining the measured harmonic current and the fundamental reference to generate a command output signal for generating the output current for energizing the load connected to the inverter. The photovoltaic system may be configured to compensate harmonic currents that may be drawn by the load.

de Rooij, Michael Andrew (Clifton Park, NY); Steigerwald, Robert Louis (Burnt Hills, NY); Delgado, Eladio Clemente (Burnt Hills, NY)

2008-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

The Utilization and Recovery of Energy from Blast Furnaces and Converters  

E-Print Network (OSTI)

The Bischoff Blast Furnace Top Gas Process for high pressure blast furnaces is presented as an example of a modern gas treatment process in the iron and steel industry: the work potential of the high pressure top gas is utilized in a plant comprising a gas cleaning unit for dust removal and a turbine for converting the recoverable thermal energy into mechanical and electrical energy. The adjustable annular gap scrubber for separating fine dust also serves as an element for regulating the gas pressure at the blast furnace top so that pressure control by the turbine and its control gear is no longer necessary. Moreover, in the event of a turbine outage the annular gap scrubber can be used as a low noise, pressure-throttling element. The economic use of a turbine for recovering energy from top gas depends on many parameters, such as top pressure, top gas rate, clean gas temperature, local cost of electric power, etc. A profitability analysis for a specific installation shows a remarkably short payback period. The process incorporates a new concept in blast air compression. Mechanical energy from the turbine is transferred directly to the axial flow compressor so that the prior conversion of energy via the power generating cycle is dispensed with. Coupled to the turbine is the compressor motor which, while rated to cover the full power requirement, uses about 40% less electrical power from the power supply system. Finally, as an example of the future potential of this process, a new continuous steelmaking process is presented which employs a closed top converter. The gas, held under pressure during refining, is subsequently cleaned and expanded as the blast furnace process described above. This gas is cleaned without any entrainment of air to furnish a gaseous fuel of high calorific value. Since the steelmaking process is continuous, the gas is constantly available and can be fed into the distribution system without any intermediate storage.

Hegemann, K. R.; Niess, T.; Baare, R. D.

1979-01-01T23:59:59.000Z

402

Development of mixed-conducting ceramic membranes for converting methane to syngas  

DOE Green Energy (OSTI)

The abundantly available natural gas (mostly methane) discovered in remote areas has stimulated considerable research on upgrading this gas to high-value-added clean-burning fuels such as dimethyl ether and alcohols and to pollution-fighting additives. Of the two routes to convert methane to valuable products direct and indirect, the direct route involving partial oxidation of methane to syngas (CO + H{sub 2}) by air is preferred. Syngas is the key intermediate product used to form a variety of petrochemicals and transportation fuels. This paper is concerned with the selective transport of oxygen from air for converting methane to syngas by means of a mixed-conducting ceramic oxide membrane prepared from Sr-Fe-Co-O oxide. While both perovskite and nonperovskite type Sr-Fe-Co-O oxides permeate large amounts of oxygen when the membrane tube is subjected to oxygen pressure gradients, the work shows that the nonperovskite SrFeCo{sub 0.5}O{sub x} exhibits remarkable stability during oxygen permeation. More particularly, extruded and sintered tubes from SrFeCo{sub 0.5}O{sub x} have been evaluated in a reactor operating at {approx} 850 C for conversion of methane into syngas in the presence of a reforming catalyst. Methane conversion efficiencies of {approx} 99% were observed. In addition, oxygen permeability of SrFeCo{sub 0.5}O{sub x} was measured as a function of oxygen partial pressure gradient and temperature in a gas-tight electrochemical cell. Oxygen permeability has also been calculated from conductivity data and the results are compared and discussed.

Balachandran, U.; Maiya, P.S.; Ma, B.; Dusek, J.T.; Mieville, R.L.; Picciolo, J.J.

1997-04-01T23:59:59.000Z

403

Conceptual design of electrical balance of plant for advanced battery energy storage facility. Annual report, March 1979. [20-MW, 100 MWh  

SciTech Connect

Large-scale efforts are in progress to develop advanced batteries for utility energy storage systems. Realization of the full benefits available from those systems requires development, not only of the batteries themselves, but also the ac/dc power converter, the bulk power interconnecting equipment, and the peripheral electric balance of plant equipment that integrate the battery/converter into a properly controlled and protected energy system. This study addresses these overall system aspects; although tailored to a 20-MW, 100-MWh lithium/sulfide battery system, the technology and concepts are applicable to any battery energy storage system. 42 figures, 14 tables. (RWR)

1980-01-01T23:59:59.000Z

404

Tests with a line-commutated converter as a variable inductive load on the Bonneville Power Administration transmission system  

DOE Green Energy (OSTI)

A twelve-pulse, line-commutated converter, with a steady-state rating of 2.5 kV and 5.5 kA, formerly used for charging and discharging a superconducting magnet, was reconfigured as a static reactive power load. Tests staged at the Tacoma, WA, substation of the Bonneville Power Administration (BPA) revealed that the converter could be used as a variable inductive load, provided a stable current controller was installed. The unit was modulated as a variable VAR load following a sinusoidal VAR demand signal with an amplitude up to 14.8 MVAR. The total losses at maximum VAR output were 370 kW. This paper explains the necessary modifications of the converter to operate as a variable reactive load. Measured current waveshapes are analyzed. The effects of such a load on the BPA transmission system are presented.

Boenig, H.J.; Hauer, J.F.; Nielsen, R.G.

1986-01-01T23:59:59.000Z

405

New approaches for the reduction of plasma arc drop in second-generation thermionic converters. Final report  

DOE Green Energy (OSTI)

Investigations of ion generation and recombination mechanisms in the cesium plasma as they pertain to the advanced mode thermionic energy converter are described. The changes in plasma density and temperature within the converter have been studied under the influence of several promising auxiliary ionization candidate sources. Three novel approaches of external cesium ion generation have been investigated in some detail, namely vibrationally excited N/sub 2/ as an energy source of ionization of Cs ions in a DC discharge, microwave power as a means of resonant sustenance of the cesium plasma, and ion generation in a pulse N/sub 2/-Cs mixture. The experimental data obtained and discussed show that all three techniques - i.e. the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave power - have considerable promise as schemes in auxiliary ion generation applicable to the advanced thermionic energy converter.

Hatziprokopiou, M.E.; Shaw, D.T.

1981-03-31T23:59:59.000Z

406

Process for converting sodium nitrate-containing, caustic liquid radioactive wastes to solid insoluble products  

DOE Patents (OSTI)

A method for converting sodium nitrate-containing, caustic, radioactive wastes to a solid, relatively insoluble, thermally stable form is provided and comprises the steps of reacting powdered aluminum silicate clay, e.g., kaolin, bentonite, dickite, halloysite, pyrophyllite, etc., with the sodium nitrate-containing radioactive wastes which have a caustic concentration of about 3 to 7 M at a temperature of 30.degree. C to 100.degree. C to thereby entrap the dissolved radioactive salts in the aluminosilicate matrix. In one embodiment the sodium nitrate-containing, caustic, radioactive liquid waste, such as neutralized Purex-type waste, or salts or oxide produced by evaporation or calcination of these liquid wastes (e.g., anhydrous salt cake) is converted at a temperature within the range of 30.degree. C to 100.degree. C to the solid mineral form-cancrinite having an approximate chemical formula 2(NaAlSiO.sub.4) .sup.. xSalt.sup.. y H.sub.2 O with x = 0.52 and y = 0.68 when the entrapped salt is NaNO.sub.3. In another embodiment the sodium nitrate-containing, caustic, radioactive liquid is reacted with the powdered aluminum silicate clay at a temperature within the range of 30.degree. C to 100.degree. C, the resulting reaction product is air dried eitheras loose powder or molded shapes (e.g., bricks) and then fired at a temperature of at least 600.degree. C to form the solid mineral form-nepheline which has the approximate chemical formula of NaAlSiO.sub.4. The leach rate of the entrapped radioactive salts with distilled water is reduced essentially to that of the aluminosilicate lattice which is very low, e.g., in the range of 10.sup.-.sup.2 to 10.sup.-.sup.4 g/cm.sup.2 -- day for cancrinite and 10.sup.-.sup.3 to 10.sup.-.sup.5 g/cm.sup.2 -- day for nepheline.

Barney, Gary S. (Richland, WA); Brownell, Lloyd E. (Richland, WA)

1977-01-01T23:59:59.000Z

407

Contribution of nano-scale effects to the total efficiency of converters of thermal neutrons on the basis of gadolinium foils  

E-Print Network (OSTI)

We study the influence of nano-scale layers of converters made from natural gadolinium and its 157 isotope into the total efficiency of registration of thermal neutrons. Our estimations show that contribution of low-energy Auger electrons with the runs about nanometers in gadolinium, to the total efficiency of neutron converters in this case is essential and results in growth of the total efficiency of converters. The received results are in good consent to the experimental data.

D. A. Abdushukurov; D. V. Bondarenko; Kh. Kh. Muminov; D. Yu. Chistyakov

2008-02-04T23:59:59.000Z

408

D)Ig,Ital Pred'icti've n-Line Energy t*imi4zat4ioon cheme for D-DC Converters  

E-Print Network (OSTI)

D)Ig,Ital Pred'icti've n-Line Energy t*imi4zat4ioon cheme for D-DC Converters Olivier Trescases1 energy conservation technique based on predicting the load current of a DC-DC converter that may feed-time and applied as feed-forward to the DC-DC converter in order to reduce the total energy drawn from the battery

Prodiæ, Aleksandar

409

422 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 18, NO. 2, MAY 2003 Converting System Limits to Market Signals  

E-Print Network (OSTI)

422 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 18, NO. 2, MAY 2003 Converting System Limits to Market of flow limits on interfaces as surrogates for stability limits. These transformed limits are often, or transformer. Often system limits are enforced on all credible contingencies. FGR Flowgate rights, the right

410

Study of a Family of Buck-Boost Converter with Tapped Inductor for Grid-Connected Photovoltaic Systems  

Science Conference Proceedings (OSTI)

Among the photovoltaic (PV) systems, the ones interconnected to the electric system have presented a greater growth in the developed countries. In order to transform the generated DC energy in AC energy ready to be delivered to a grid, the concept of ... Keywords: Buck boost converter, ac module, tapped inductor

Juan C. Yris; Jorge H. Calleja; Abraham C. Sanchez; Leobardo H. Gonzalez

2010-09-01T23:59:59.000Z

411

Summary of PhD Thesis: Supercapacitor energy storage systems and power converters for the reduction of energy consumption  

E-Print Network (OSTI)

Summary of PhD Thesis: Supercapacitor energy storage systems and power converters for the reduction savings that could be achieved in the public transport sector by using supercapacitor based energy of a conventional line with that of a tram/metro line benefiting from supercapacitors (or other ESS technologies

Glineur, François

412

Creating systems that effectively convert energy, such as efficient solar cells and electrochemical batteries, has been a  

E-Print Network (OSTI)

SEMTE abstract Creating systems that effectively convert energy, such as efficient solar cells stimuli, the solar energy from sunlight, and the mechanical motion is commonplace, indeed fundamental and electrochemical batteries, has been a longstanding scientific pursuit, especially given the global energy

Reisslein, Martin

413

Efficiency Analysis of a High Frequency Buck Converter for On-Chip Integration with a Dual-VDD  

E-Print Network (OSTI)

An analysis of the power characteristics of a buck converter is presented in this paper. A high switching frequency is the key design parameter that simultaneously permits monolithic integration and high efficiency. A parasitic model of the buck converter is developed. With this model, a design space is determined that allows integration of active and passive devices on the same die for a target technology. An efficiency of 88.4 % at a switching frequency of 477 MHz is demonstrated for a voltage conversion from 1.2 volts to 0.9 volts while supplying 9.5 amperes average current assuming an 80 nm CMOS technology. The area occupied by the buck converter is 12.6 mm 2. An analytic estimate of the efficiency is shown to be within 2.4 % of simulation at the target design point. Full integration of a high efficiency buck converter on the same die with a dual-VDD microprocessor is shown to be feasible. 1.

Volkan Kursun; Siva G. Narendra; Vivek K. De; Eby G. Friedman

2002-01-01T23:59:59.000Z

414

Discrete-Time Poles and Dynamics of Discontinuous Mode Boost and Buck Converters Under Various Control Schemes  

E-Print Network (OSTI)

Nonlinear systems, such as switching DC-DC boost or buck converters, have rich dynamics. A simple one-dimensional discrete-time model is used to analyze the boost or buck converter in discontinuous conduction mode. Seven different control schemes (open-loop power stage, voltage mode control, current mode control, constant power load, constant current load, constant-on-time control, and boundary conduction mode) are analyzed systematically. The linearized dynamics is obtained simply by taking partial derivatives with respect to dynamic variables. In the discrete-time model, there is only a single pole and no zero. The single closed-loop pole is a linear combination of three terms: the open-loop pole, a term due to the control scheme, and a term due to the non-resistive load. Even with a single pole, the phase response of the discrete-time model can go beyond -90 degrees as in the two-pole average models. In the boost converter with a resistive load under current mode control, adding the compensating ramp has no effect on the pole location. Increasing the ramp slope decreases the DC gain of control-to-output transfer function and increases the audio-susceptibility. Similar analysis is applied to the buck converter with a non-resistive load or variable switching frequency. The derived dynamics agrees closely with the exact switching model and the past research results.

Chung-Chieh Fang

2012-11-19T23:59:59.000Z

415

Design optimization methodology for power converters based on global energy requirement criteria. Application to a DC-DC flyback structure  

E-Print Network (OSTI)

produce direct current, and most existing electric loads could be powered with direct currents [4», « Life Cycle Analysis (LCA)», «Device modeling». Abstract This paper discusses a design methodology consumption profile. Introduction Nowadays, converters are currently designed to present the best cost and

Paris-Sud XI, Université de

416

Simulation of an ammonia plant accident using rigorous heterogeneous models: Effect of shift converters disturbances on the methanator  

Science Conference Proceedings (OSTI)

Disturbance introduced into the shift converters section of the ammonia production line may lead to problems in the ammonia production line which manifest themselves in other units of the production line. A real accident that took place in an ammonia ... Keywords: Accident, Ammonia, Catalytic reactors, Heterogeneous models, Modelling, Simulation

F. M. Alhabdan; S. S. E. H. Elnashaie

1995-02-01T23:59:59.000Z

417

New Power Electronics Converter Interfacing a Hybrid Dc/Ac Microgrid M. Alibeik, E. C. dos Santos Jr.  

E-Print Network (OSTI)

New Power Electronics Converter Interfacing a Hybrid Dc/Ac Microgrid M. Alibeik, E. C. dos Santos possible to combine ac and dc subgrids to form the hybrid microgrid. The main advantage of the hybrid microgrid is that it has higher efficiency and lesser power conversion. In this work is proposed a new

Zhou, Yaoqi

418

Intentional Islanded Operation of Converter Fed Microgrids Charles K. Sao, Student Member, IEEE, and Peter W. Lehn, Member, IEEE  

E-Print Network (OSTI)

1 Intentional Islanded Operation of Converter Fed Microgrids Charles K. Sao, Student Member, IEEE microgrid and proposes a control scheme to regulate its voltage and frequency. The model, which is formulated in an instantaneously synchro- nized reference frame, shows that the microgrid voltage depends

Lehn, Peter W.

419

A Multiphase, Modular, Bidirectional, Triple-Voltage DC-DC Converter Power Systems  

Science Conference Proceedings (OSTI)

Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage [14 V, 42 V, and high voltage (HV)] nets. These will be necessary to accommodate existing 14-V loads as well as efficiently handle new heavy loads at the 42-V net and a traction drive on the HV bus. A low-cost DC-DC converter was proposed for connecting the three voltage nets. It minimizes the number of switches and their associated gate driver components by using two half-bridges and a high-frequency transformer. Another salient feature is that the half bridge on the 42-V bus is also utilized to provide the 14-V bus by operating at duty ratios around an atypical value of 1/3. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft switching. The use of half bridges makes the topology well suited for interleaved multiphase modular configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with an atypical duty ratio on the transformer and a preferred multiphase configuration to minimize capacitor ripple currents.

Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

2008-01-01T23:59:59.000Z

420

New generation polyphase resonant converter-modulators for the Korean atomic energy research institute  

SciTech Connect

This paper will present operational data and performance parameters of the newest generation polyphase resonant high voltage converter modulator (HVCM) as developed and delivered to the KAERI 100 MeV ''PEFP'' accelerator [1]. The KAERI design realizes improvements from the SNS and SLAC designs [2]. To improve the IGBT switching performance at 20 kHz for the KAERI system, the HVCM utilizes the typical zero-voltage-switching (ZVS) at turn on and as well as artificial zero-current-switching (ZCS) at turn-off. The new technique of artificial ZCS technique should result in a 6 fold reduction of IGBT switching losses (3). This improves the HCVM conversion efficiency to better than 95% at full average power, which is 500 kW for the KAERI two klystron 105 kV, 50 A application. The artificial ZCS is accomplished by placing a resonant RLC circuit across the input busswork to the resonant boost transformer. This secondary resonant circuit provides a damped ''kick-back'' to assist in IGBT commutation. As the transformer input busswork is extremely low inductance (< 10 nH), the single RLC network acts like it is across each of the four IGBT collector-emitter terminals of the H-bridge switching network. We will review these topological improvements and the overall system as delivered to the KAERI accelerator and provide details of the operational results.

Reass, William A [Los Alamos National Laboratory; Baca, David M [Los Alamos National Laboratory; Gribble, Robert F [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

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421

Process of converting starch to glucose and glucose to lactic acid  

DOE Green Energy (OSTI)

This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

1990-12-31T23:59:59.000Z

422

Characterization of Sputter Deposited Thin Film Scandate Cathodes for Miniaturized Thermionic Converter Applications  

DOE Green Energy (OSTI)

We have successfully developed a method for fabricating scandate-based thermionic emitters in thin film form. The primary goal of our effort is to develop thin film emitters that exhibit low work fimction, high intrinsic electron emissivity, minimum thermal activation properties and that can be readily incorporated into a microgap converter. Our approach has been to incorporate BaSrO into a SqOq matrix using rf sputtering to produce thin films. Diode testing has shown the resulting films to be electron emissive at temperatures as low as 900 K with current densities of 0.1 mA.cm-2 at 1100 K and saturation voltages. We calculate an approximate maximum work function of 1.8 eV and an apparent emission constant (Richardson's constant, A*) of 36 mA.cm-2.K-2. Film compositional and structural analysis shows that a significant surface and subsurface alkaline earth hydroxide phase can form and probably explains the limited utilization and stability of Ba and its surface complexes. The flexibility inherent in sputter deposition suggests alternate strategies for eliminating undesirable phases and optimizing thin film emitter properties.

King, D.B.; Ruffner, J.H.; Zavadil, K.R.

1998-12-14T23:59:59.000Z

423

(Assessment of the potential of Yunnan Province, China to grow and convert biomass to electricity)  

DOE Green Energy (OSTI)

The purpose of the trip was to conduct a preliminary evaluation of biomass energy development in Yunnan Province, China. The evaluation included an assessment of the potential to grow and convert biomass to electricity, and an evaluation of the institutional relationships, which would be critical to the establishment of a collaborative biomass energy development project. This site visit was undertaken to evaluate the potential of an integrated biomass energy project, including the growing and handling of biomass feedstocks and its conversion to electricity. Based on this site visit, it was concluded that biomass production risks are real and further research on species screening and experiments is necessary before proceeding to the conversion phase of this project. The location of potential sites inspected and the logistics required for handling and transporting biomass may also be a concern. The commitment of support (labor and land) and leadership to this project by the Chinese is overwhelming exceeding all pre-site visit expectations. In sum, there is a definite opportunity in Yunnan for an integrated biomass energy project and a potential market for US technology.

Perlack, R.D.

1990-10-15T23:59:59.000Z

424

LDRD final report: photonic analog-to-digital converter (ADC) technology  

Science Conference Proceedings (OSTI)

We report on an LDRD seed program of novel technology development (started by an FY98 Engineering Tech-base project) that will enable extremely high-fidelity analog-to-digital converters for a variety of national security missions. High speed (l0+ GS/s ), high precision (l0+ bits) ADC technology requires extremely short aperture times ({approx}1ps ) with very low jitter requirements (sub 10fs ). These fundamental requirements, along with other technological barriers, are difficult to realize with electronics: However, we outline here, a way to achieve these timing apertures using a novel multi-wavelength optoelectronic short-pulse optical source. Our approach uses an optoelectronic feedback scheme with high optical Q to produce an optical pulse train with ultra-low jitter ( sub 5fs) and high amplitude stability (<10{sup 10}). This approach requires low power and can be integrated into an optoelectronic integrated circuit to minimize the size. Under this seed program we have demonstrated that the optical feedback mechanism can be used to generate a high Q resonator. This has reduced the technical risk for further development, making it an attractive candidate for outside funding.

Bowers, M; Deri, B; Haigh, R; Lowry, M; Sargis, P; Stafford, R; Tong, T

1999-02-18T23:59:59.000Z

425

A high converter concept for fuel management with blanket fuel assemblies in boiling water reactors  

SciTech Connect

Studies on the natural Uranium saving and waste reduction potential of a multiple-plant BWR system were performed. The BWR High Converter system should enable a multiple recycling of MOX fuel in current BWR plants by introducing blanket fuel assemblies and burning Uranium and MOX fuel separately. The feasibility of Uranium cores with blankets and full-MOX cores with Plutonium qualities as low as 40% were studied. The power concentration due to blanket insertion is manageable with modern fuel and acceptable values for the thermal limits and reactivity coefficients were obtained. While challenges remain, full-MOX cores also complied with the main design criteria. The combination of Uranium and Plutonium burners in appropriate proportions could enable obtaining as much as 40% more energy out of Uranium ore. Moreover, a proper adjustment of blanket average stay and Plutonium qualities could lead to a system with nearly no Plutonium left for final disposal. The achievement of such goals with current light water technology makes the BWR HC concept an attractive option to improve the fuel cycle until Gen-IV designs are mature. (authors)

Martinez-Frances, N.; Timm, W.; Rossbach, D. [AREVA, AREVA NP, Erlangen (Germany)

2012-07-01T23:59:59.000Z

426

Thermally induced evolution of morphology on ceramic surfaces in a thermionic converter  

DOE Green Energy (OSTI)

The morphology of alumina and scandia ceramics exposed to controlled vacuum and diffusion modes in a thermionic converter has been studied. Evidence for vaporization at a temperature of 1,770 K is manifest in the resulting surface morphologies of both ceramics, consistent with reported sample mass loss. Alumina shows intergranular relief with the formation of terrace--step structure on the grain surfaces. Terrace formation is not directly observed on scandia, however the development of vertical structure and maintenance of voids indicates that vaporization is initiated by structure at the grain edges. Extensive Sc{sub 2}O{sub 3} re-deposition occurs on the scandia surface, possibly mediated by the presence of molybdenum and tungsten. Evidence exists for refractory metal secondary phase formation in this deposit in the form of Sc{sub 6}MO{sub 12} (M = W or Mo). Alumina also shows evidence for materials` interactions in the form of tantalum assisted vaporization which significantly alters the terrace structure.

Zavadil, K.R. [Sandia National Labs., Albuquerque, NM (United States); Olson, D.L. [Team Specialty Services, Albuquerque, NM (United States); Klinkov, A.E. [JS Intertek, Kurchatov (Russian Federation)

1996-12-01T23:59:59.000Z

427

Development of a Novel Bi-Directional Isolated Multiple-Input DC-DC Converter  

DOE Green Energy (OSTI)

There is vital need for a compact, lightweight, and efficient energy-storage system that is both affordable and has an acceptable cycle life for the large-scale production of electric vehicles (EVs) and hybrid electric vehicles (HEVs). Most of the current research employs a battery-storage unit (BU) combined with a fuel cell (FC) stack in order to achieve the operating voltage-current point of maximum efficiency for the FC system. A system block diagram is shown in Fig.1.1. In such a conventional arrangement, the battery is sized to deliver the difference between the energy required by the traction drive and the energy supplied by the FC system. Energy requirements can increase depending on the drive cycle over which the vehicle is expected to operate. Peak-power transients result in an increase of losses and elevated temperatures which result in a decrease in the lifetime of the battery. This research will propose a novel two-input direct current (dc) dc to dc converter to interface an additional energy-storage element, an ultracapacitor (UC), which is shown in Fig.1.2. It will assist the battery during transients to reduce the peak-power requirements of the battery.

Li, H.

2005-10-24T23:59:59.000Z

428

System and method for converting wellhead gas to liquefied petroleum gases (LPG)  

SciTech Connect

A method of converting natural wellhead gas to liquefied petroleum gases (LPG) may comprise the steps of: separating natural gas from petroleum fluids exiting a wellhead; compressing the natural gas; refrigerating the natural gas, liquefying at least a portion thereof; separating LPG from gas vapors of the refrigerated natural gas; storing the separated LPG in a storage tank with a vapor space therein; and recirculating a portion of the LPG vapors in the storage tank with the natural gas exiting the wellhead to enhance recovery of LPG. A system for performing the method may comprise: a two-stage gas compressor connected to the wellhead; a refrigeration unit downstream of the gas compressor for refrigerating the compressed gases therefrom; at least one product separator downstream of the refrigerator unit for receiving refrigerated and compressed gases discharged from the refrigerator unit and separating LPG therein from gases remaining in vapor form; and a storage tank for receiving and storing the separated LPG therein, the storage tank having a vapor space therein connected upstream of the gas compressor through a pressure regulator allowing recirculation of some LPG vapors with the natural gases through said system.

May, R.L.; Sinclair, B.W.

1984-07-31T23:59:59.000Z

429

Process of converting starch to glucose and glucose to lactic acid  

DOE Patents (OSTI)

This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

1990-01-01T23:59:59.000Z

430

Angiotensin receptors and angiotensin I-converting enzyme in rat intestine  

SciTech Connect

The purpose of this study was to map the distribution of angiotensin II (ANG II) receptors and ANG I-converting enzyme (ACE) in rat intestine. ANG II binding sites were visualized by in vitro autoradiography using iodinated (Sar1, Ile8)ANG II. The distribution of ACE was mapped using an iodinated derivative of lisinopril. Male Sprague-Dawley rats were killed and the interior of the whole intestine washed with ice-cold saline. Segments of duodenum, jejunum, ileum, and colon were quickly frozen in a mixture of isopentane and dry ice. Twenty-micron frozen sections were thaw-mounted onto gelatin-coated slides, incubated with either ligand, and exposed to X-ray film. After exposure and subsequent development, the films were quantitated by computerized densitometry. ANG II receptors were most dense in the colon, followed by the ileum, duodenum, and jejunum. Within each segment of intestine, specific ANG II binding sites were localized exclusively to the muscularis. In contrast, ACE was present in both the mucosa and the muscularis. The colocalization of ANG II receptors and ACE may suggest a role for locally generated ANG II in the control of intestinal function. The luminal orientation of ACE in the mucosa of the small intestine may suggest that at this site ACE serves primarily to hydrolyze dietary peptides.

Duggan, K.A.; Mendelsohn, F.A.; Levens, N.R. (Austin Hospital, Melbourne, Victoria (Australia))

1989-10-01T23:59:59.000Z

431

Behavioral modeling and digital calibration of pipeline analog to digital converters  

E-Print Network (OSTI)

This research focuses on digital calibration of pipeline analog to digital converters (ADCs) and also modeling of error sources and design parameters of pipeline ADCs. Modern applications such as communications systems require high resolution ADCs at high rates of conversion speed. Pipeline ADCs show great potential for high-speed high-resolution applications. But limited matching property of available process technologies does not permit implementation of high-resolution pipeline ADCs unless a calibration scheme is used. There are two major methods of calibration. The first uses some redundant analog components implemented during the design of the ADC to adjust some of the analog components. These redundant analog components also have limited accuracy and cause some additional problems such as loading and area consumption. Laser trimming of analog components cannot solve the problem due to difficulty of accurate trimming beyond 12-bit. Correcting the component's matching error in digital domain is the second method of calibration. This thesis presents detailed analyses for the possibility of digital correction of the errors due to analog circuitry. As a result an efficient method for the digital calibration method is proposed. This method has the advantage of measuring the required calibration coefficients by sweeping the input voltage through the whole dynamic range.

Bilhan, Erkan

2001-01-01T23:59:59.000Z

432

Guide for Identifying and Converting High-Potential Petroleum Brownfield Sites to Alternative Fuel Stations  

DOE Green Energy (OSTI)

Former gasoline stations that are now classified as brownfields can be good sites to sell alternative fuels because they are in locations that are convenient to vehicles and they may be seeking a new source of income. However, their success as alternative fueling stations is highly dependent on location-specific criteria. First, this report outlines what these criteria are, how to prioritize them, and then applies that assessment framework to five of the most popular alternative fuels--electricity, natural gas, hydrogen, ethanol, and biodiesel. The second part of this report delves into the criteria and tools used to assess an alternative fuel retail site at the local level. It does this through two case studies of converting former gasoline stations in the Seattle-Eugene area into electric charge stations. The third part of this report addresses steps to be taken after the specific site has been selected. This includes choosing and installing the recharging equipment, which includes steps to take in the permitting process and key players to include.

Johnson, C.; Hettinger, D.; Mosey, G.

2011-05-01T23:59:59.000Z

433

Questions and Answers - If the energy could be directly converted to  

NLE Websites -- All DOE Office Websites (Extended Search)

Why does the U.S. useFahrenheit instead of Celsius? Why does the U.S. use<br>Fahrenheit instead of Celsius? Previous Question (Why does the U.S. use Fahrenheit instead of Celsius?) Questions and Answers Main Index Next Question (Is there a way to tell how many atoms are in an object?) Is there a way to tell how manyatoms are in an object? If the energy could be directly converted to matter, how long would it take a person on a bicycle-type generator to create a single atom? That's an interesting question. First, how much energy per second can a person produce? Power is the name we use for the time rate of energy production. A person can easily generate about 1/10 of a horsepower. In other units, 1/10 of a horsepower is about 75 watts of power which is 75 joules/second. Watts and joules are named after famous scientists. Can you

434

Evaluation of battery converters based on 4. 8-MW fuel cell demonstrator inverter. Final report. [Contains brief glossary  

DOE Green Energy (OSTI)

Electrical power conditioning is a critical element in the development of advanced electrochemical energy storage systems. This program evaluates the use of existing self-commutated converter technology (as developed by the Power Systems Division of United Technologies for the 4.8-MW Fuel Cell Demonstrator) with modification for use in battery energy storage systems. The program consists of three parts: evaluation of the cost and performance of a self-commutated converter modified to maintain production commonality between battery and fuel cell power conditioners, demonstration of the principal characteristics required for the battery application in MW-scale hardware, and investigation of the technical requirements of operation isolated from the utility system. A power-conditioning system consisting of a self-commutated converter augmented with a phase-controlled rectifier was selected and a preliminary design, prepared. A principal factor in this selection was production commonality with the fuel cell inverter system. Additional types of augmentation, and the use of a self-commutated converter system without augmentation, were also considered. A survey of advanced battery manufacturers was used to establish the dc interface characteristics. The principal characteristics of self-commutated converter operation required for battery application were demonstrated with the aid of an available 0.5-MW development system. A survey of five REA and municipal utilities and three A and E firms was conducted to determine technical requirements for operation in a mode isolated from the utility. Definitive requirements for this application were not established because of the limited scope of this study. 63 figures, 37 tables.

Not Available

1980-10-01T23:59:59.000Z

435

Characterization of B2H6 Plasma Doping for Converted p+ Poly-Si Gate  

SciTech Connect

We have investigated the characteristics of B2H6 plasma doping (PLAD) process used to convert the n+ doped poly-Si gate to the p+ poly-Si gate for pMOS. The throughput of the PLAD process is much higher than a conventional beam line implantation process at low energy and high dose ranges. The B2H6 plasma counter-doping on the n+ poly-Si were performed in the energy range of 5kV {approx} 9kV and dose of {approx}E16 number sign /cm2. The B2H6 Plasma doped poly-Si layers were characterized by TDS, SIMS, AFM, and TEM.The TDS analysis showed hydrogen desorption from the B2H6 plasma doped p+ poly-Si layer at a low temperature. The surface concentration of PLAD doped boron was much higher compared to the conventional beam line implantation. However, a serious loss of surface dopant was also observed during photoresist strip and post cleaning. The surface dopant loss could be suppressed by 10% with optimization of the cleaning condition, leading to improve characteristics of PLAD doped p+ poly-Si pMOS, compared to the beam line implantation. Moreover, flat band voltage (VFB) shift was not observed in the C-V curves and there was no significant difference in I-V characteristics between PLAD and the conventional ion implantation. Deeper and higher dopant profile will be helpful to decrease required dose gap between PLAD and beam line implantation.

Oh, Jae-Geun; Lee, J. K.; Hwang, S. H.; Cho, H. J.; Sohn, Y. S.; Sheen, D. S.; Pyi, S. H. [Hynix Semiconductor Inc., San 136-1 Ami-ri, Bubal-eub, Ichon-si, Kyoungki-do, 467-701 (Korea, Republic of); Lee, S. W.; Hahn, S. H. [Varian Korea Ltd., 433-1 Mogok-dong Pyeongtaek-si Kyoungki-do 459-040 (Korea, Republic of); Jeon, Y. B.; Fang, Z.; Singh, V. [Varian Semiconductor Equipment Associates Incorporate, 35 Dory Road, Gloucester, MA 01930 (United States)

2006-11-13T23:59:59.000Z

436

Converting a commercial electric direct-drive robot to operate from joint torque commands  

SciTech Connect

Many robot control algorithms for high performance in-contact operations including hybrid force/position, stiffness control and impedance control approaches require the command the joint torques. However, most commercially available robots do not provide joint torque command capabilities. The joint command at the user level is typically position or velocity and at the control developer level is voltage, current, or pulse-width, and the torque generated is a nonlinear function of the command and joint position. To enable the application of high performance in-contact control algorithms to commercially available robots, and thereby facilitate technology transfer from the robot control research community to commercial applications, an methodology has been developed to linearize the torque characteristics of electric motor-amplifier combinations. A four degree of freedom Adept 2 robot, having pulse-width modulation amplifiers and both variable reluctance and brushless DC motors, is converted to operate from joint torque commands to demonstrate the methodology. The commercial robot controller is replaced by a VME-based system incorporating special purpose hardware and firmware programmed from experimental data. The performance improvement is experimentally measured and graphically displayed using three-dimensional plots of torque vs command vs position. The average percentage torque deviation over the command and position ranges is reduced from as much as 76% to below 5% for the direct-drive joints 1, 2 and 4 and is cut by one half in the remaining ball-screw driven joint 3. Further, the torque deviation of the direct-drive joints drops below 2.5% if only the upper 90% of the torque range is considered. 23 refs., 20 figs., 2 tabs.

Muir, P.F.

1991-07-01T23:59:59.000Z

437

Multi-port DC-DC Power Converter for Renewable Energy Application  

E-Print Network (OSTI)

In recent years, there has been lots of emphasis put on the development of renewable energy. While considerable improvement on renewable energy has been made, there are some inherent limitations for these renewable energies. For example, for solar and wind power, there is an intermittent nature. For the fuel cell, the dynamics of electro-chemical reaction is quite slow compared to the electric load. This will not be acceptable for modern electric application, which requires constant voltage of constant frequency. This work proposed and evaluated a new power circuit that can deal with the problem of the intermittent nature and slow response of the renewable energy. The proposed circuit integrates different renewable energy sources as well as energy storage. By integrating renewable energy sources with statistical tendency to compensate each other, the effect of the intermittent nature can be greatly reduced. This integration will increase the reliability and utilization of the overall system. Moreover, the integration of energy storage solves the problem of the slow response of renewable energy. It can provide the extra energy required by load or absorb the excessive energy provided by the energy sources, greatly improving the dynamics of overall system. To better understand the proposed circuit, "Dual Active Bridge" and "Triple Active Bridge" were reviewed first. The operation principles and the modeling were presented. Analysis and design of the overall system were discussed. Controller design and stability issues were investigated. Furthermore, the function of the central controller was explained. In the end, different simulations were made and discussed. Results from the simulations showed that the proposed multi-port DC-DC power converter had satisfactory performance under different scenarios encountered in practical renewable energy application. The proposed circuit is an effective solution to the problem due to the intermittent nature and slow response of the renewable energy.

Chou, Hung-Ming

2009-08-01T23:59:59.000Z

438

G I A. J. Brcslill, Director halt:: Protection Ci&ieerirG Divisio...  

Office of Legacy Management (LM)

axd NY. F. Msce of the &scac..zetts Institute of Teci:;iolozy, Occupational Medical Service, Mr. R. Hoxell, Massac::usetIs Insti.t.ule of Tec:fioloGy, Btlilding...

439

International economic effects of halting the voyage of CSAV RIO PUELO  

E-Print Network (OSTI)

On July 31, 2004, the United States Coast Guard stopped the container ship CSAV RIO PUELO off of the Port of New York and New Jersey. The intervention occurred after the United States Department of Agriculture received ...

Jones, Eric C. (Eric Cooper)

2005-01-01T23:59:59.000Z

440

Energy Recovery from High-frequency Clocks using DC-DC Converters M. Alimadadi, S. Sheikhaei, G. Lemieux, S. Mirabbasi, W. Dunford, P. Palmer.  

E-Print Network (OSTI)

Energy Recovery from High-frequency Clocks using DC-DC Converters M. Alimadadi, S. Sheikhaei, G Power Supply) PWM Controller PWM clock Rload Figure 1. Recycling clock energy with a DC-DC converter a significant amount of energy to distribute a multi-GHz clock. By discharging the clock network to ground every

Lemieux, Guy

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441

Original article: Design of a medium voltage power converter-storage devices embedded in a hybrid emergency network for more electrical aircraft  

Science Conference Proceedings (OSTI)

The purpose of this paper is to present and describe a hybrid electrical network for an aircraft in emergency operation. The principle of this network is to hybridize, through a bidirectional DC/DC converter, a high speed turbine (Ram Air turbine - RAT) ... Keywords: Electrical network, Electrochemical storage, Energy management, Hybridization, Power converter design

R. Rigo Mariani, F. Lacressonniere, G. Fontes, X. Roboam

2013-05-01T23:59:59.000Z

442

Comparison on control strategies of the grid-side converter of variable speed constant frequency doubly-fed wind power generation system  

Science Conference Proceedings (OSTI)

Direct power control, vector control based on d-q synchronous rotating reference frame and ?-? static reference frame for the grid-side converter of variable speed constant frequency doubly-fed wind turbines are analyzed. System simulation ... Keywords: ?-? static reference frame, d-q rotating reference frame, direct power control, doubly-fed wind power generation system, grid-side converter

Xian-Ming Zhou; Ting-Long Pan; Zhi-Cheng Ji

2009-06-01T23:59:59.000Z

443

Optimization of the design of DC-DC converters for improving the electromagnetic compatibility with the Front-End electronic for the super Large Hadron Collider Trackers  

E-Print Network (OSTI)

The upgrade of the Large Hadron Collider (LHC) experiments at CERN sets new challenges for the powering of the detectors. One of the powering schemes under study is based on DC-DC buck converters mounted on the front-end modules. The hard environmental conditions impose strict restrictions to the converters in terms of low volume, radiation and magnetic field tolerance. Furthermore, the noise emission of the switching converters must not affect the performance of the powered systems. A study of the sources and paths of noise of a synchronous buck converter has been made for identifying the critical parameters to reduce their emissions. As proof of principle, a converter was designed following the PCB layout considerations proposed and then used for powering a silicon strip module prototype for the ATLAS upgrade, in order to evaluate their compatibility.

Fuentes Rojas, Cristian Alejandro; Blanchot, G

2011-01-01T23:59:59.000Z

444

Economic Feasibility of Converting Landfill Gas to Natural Gas for Use as a Transportation Fuel in Refuse Trucks  

E-Print Network (OSTI)

Approximately 136,000 refuse trucks were in operation in the United States in 2007. These trucks burn approximately 1.2 billion gallons of diesel fuel a year, releasing almost 27 billion pounds of greenhouse gases. In addition to contributing to global climate change, diesel-fueled refuse trucks are one of the most concentrated sources of health-threatening air pollution in most cities. The landfills that they ultimately place their waste in are the second largest source of human-related methane emissions in the United States, accounting for approximately 23 percent of these emissions in 2007. At the same time, methane emissions from landfills represent a lost opportunity to capture and use a significant energy resource. Many landfill-gas-to-energy (LFGTE) projects are underway in an attempt to curb emissions and make better use of this energy. The methane that is extracted from these landfills can be converted into a transportation fuel, sold as a pipeline-quality natural gas, operate turbines for electricity, or be flared. The unique relationship that occurs between refuse trucks' constant visits to the landfill and the ability of the landfill itself to produce a transportation fuel creates an ability to accomplish emissions reduction in two sectors with the implementation of using landfill gas to fuel refuse trucks. Landfill owners and operators are very reluctant to invest in large capital LFGTE projects without knowing their long-term feasibility. The costs and benefits associated with each LFGTE project have been presented in such a way that owners/operators can make informed decisions based on economics while also implementing clean energy technology. Owners/operators benefit from larger economic returns, and the citizens of the surrounding cities benefit from better air quality. This research focused on six scenarios: converting landfill gas (LFG) to liquefied natural gas (LNG) for use as a transportation fuel, converting LFG to compressed natural gas (CNG) for use as a transportation fuel, converting LFG to pipeline-quality natural gas, converting LFG to electricity, flaring LFG, and doing nothing. For the test case of a 280-acre landfill, the option of converting LFG to CNG for use as a transportation fuel provided the best benefit-cost ratio at 5.63. Other significant benefit-cost findings involved the LFG-to-LNG option, providing a 5.51 benefit-cost ratio. Currently, the most commonly used LFGTE option of converting LFG to electricity provides only a 1.35 benefit-cost ratio while flaring which is the most common mitigation strategy provides a 1.21, further providing evidence that converting LFG to LNG/CNG for use as a transportation fuel provides greater economic benefits than the most common LFGTE option or mitigation strategy.

Sprague, Stephen M.

2009-12-01T23:59:59.000Z

445

Monolithic, multi-bandgap, tandem, ultra-thin, strain-counterbalanced, photovoltaic energy converters with optimal subcell bandgaps  

SciTech Connect

Modeling a monolithic, multi-bandgap, tandem, solar photovoltaic converter or thermophotovoltaic converter by constraining the bandgap value for the bottom subcell to no less than a particular value produces an optimum combination of subcell bandgaps that provide theoretical energy conversion efficiencies nearly as good as unconstrained maximum theoretical conversion efficiency models, but which are more conducive to actual fabrication to achieve such conversion efficiencies than unconstrained model optimum bandgap combinations. Achieving such constrained or unconstrained optimum bandgap combinations includes growth of a graded layer transition from larger lattice constant on the parent substrate to a smaller lattice constant to accommodate higher bandgap upper subcells and at least one graded layer that transitions back to a larger lattice constant to accommodate lower bandgap lower subcells and to counter-strain the epistructure to mitigate epistructure bowing.

Wanlass, Mark W. (Golden, CO); Mascarenhas, Angelo (Lakewood, CO)

2012-05-08T23:59:59.000Z

446

Rf phase measurement at PHERMEX (Pulsed High Energy Radiographic Machine Emitting X-Rays) using time-to-digital converters  

Science Conference Proceedings (OSTI)

Recent advances in time-to-digital converters (TDCs) have made 50-MHz rf phase measurement possible without the use of double-balanced mixers. These advances allow zero crossing discriminators to be used in conjunction with fast CAMAC TDCs to make amplitude-independent phase measurements. This method uses a time interval proportional to the phase angle, thus eliminating any of the calculations and calibration required with double-balanced mixers. 4 refs., 1 fig., 1 tab.

Watson, S.A.; Jennings, G.R.; Moir, D.C.

1989-01-01T23:59:59.000Z

447

A high efficiency, soft switching dc-dc converter with adaptive current-ripple control for portable applications  

E-Print Network (OSTI)

Abstract—A novel control scheme for improving the power efficiency of low-voltage dc–dc converters for battery-powered, portable applications is presented. In such applications, light-load efficiency is crucial for extending battery life, since mobile devices operate in stand-by mode for most of the time. The proposed technique adaptively reduces the inductor current ripple with decreasing load current while soft switching the converter to also reduce switching losses, thereby significantly improving light-load efficiency and therefore extending the operation life of battery-powered devices. A load-dependent, mode-hopping strategy is employed to maintain high efficiency over a wide load range. Hysteretic (sliding-mode) control with user programmable hysteresis is implemented to adaptively regulate the current ripple and therefore optimize conduction and switching losses. Experimental results show that for a 1-A, 5- to 1.8-V buck regulator, the proposed technique achieved 5 % power efficiency improvement (from 72 % to 77%) at 100 mA of load current and a 1.5% improvement (from 84 % to 85.5%) at 300 mA, which constitute light-load efficiency improvements, when compared to the best reported, state-of-the-art techniques. As a result, the battery life in a typical digital signalr processing microprocessor application is improved by 7%, which demonstrates the effectiveness of the proposed solution. Index Terms—Battery life, buck converter, dc–dc converter, efficiency, hysteretic control, sliding-mode control, soft switching, switching regulator.

Siyuan Zhou; Student Member; Gabriel A. Rincón-mora; Senior Member

2006-01-01T23:59:59.000Z

448

The Fission Converter-Based Epithermal Neutron Irradiation Facility at the Massachusetts Institute of Technology Reactor  

SciTech Connect

A new type of epithermal neutron irradiation facility for use in neutron capture therapy has been designed, constructed, and put into operation at the Massachusetts Institute of Technology Research Reactor (MITR). A fission converter, using plate-type fuel and driven by the MITR, is used as the source of neutrons. After partial moderation and filtration of the fission neutrons, a high-intensity forward directed beam is available with epithermal neutron flux [approximately equal to]10{sup 10} n/cm{sup 2}.s, 1 eV {<=} E {<=} 10 keV, at the entrance to the medical irradiation room, and epithermal neutron flux = 3 to 5 x 10{sup 9} n/cm{sup 2}.s at the end of the patient collimator. This is currently the highest-intensity epithermal neutron beam. Furthermore, the system is designed and licensed to operate at three times higher power and flux should this be desired. Beam contamination from unwanted fast neutrons and gamma rays in the aluminum, polytetrafluoroethylene, cadmium and lead-filtered beam is negligible with a specific fast neutron and gamma dose, D{sub {gamma}}{sub ,fn}/{phi}{sub epi} [less than or approximately equal] 2 x 10{sup -13} Gy cm{sup 2}/n{sub epi}. With a currently approved neutron capture compound, boronophenylalanine, the therapeutically advantageous depth of penetration is >9 cm for a unilateral beam placement. Single fraction irradiations to tolerance can be completed in 5 to 10 min. An irradiation control system based on beam monitors and redundant, high-reliability programmable logic controllers is used to control the three beam shutters and to ensure that the prescribed neutron fluence is accurately delivered to the patient. A patient collimator with variable beam sizes facilitates patient irradiations in any desired orientation. A shielded medical room with a large window provides direct viewing of the patient, as well as remote viewing by television. Rapid access through a shielded and automatically operated door is provided. The D{sub 2}O cooling system for the fuel has been conservatively designed with excess capacity and is fully instrumented to ensure detection and control of off-normal conditions. A wide range of possible abnormal events or accident scenarios has been analyzed to show that even in the worst cases, there should be no fission product release through fuel damage. This facility has been licensed to operate by the U.S. Nuclear Regulatory Commission, and initial operation commenced in June 2000.

Harling, O.K. [Massachusetts Institute of Technology (United States); Riley, K.J. [Massachusetts Institute of Technology (United States); Newton, T.H. [Massachusetts Institute of Technology (United States); Wilson, B.A. [Massachusetts Institute of Technology (United States); Bernard, J.A. [Massachusetts Institute of Technology (United States); Hu, L-W. [Massachusetts Institute of Technology (United States); Fonteneau, E.J. [Massachusetts Institute of Technology (United States); Menadier, P.T. [Massachusetts Institute of Technology (United States); Ali, S.J. [Massachusetts Institute of Technology (United States); Sutharshan, B. [Massachusetts Institute of Technology (United States); Kohse, G.E. [Massachusetts Institute of Technology (United States); Ostrovsky, Y. [Massachusetts Institute of Technology (United States); Stahle, P.W. [Massachusetts Institute of Technology (United States); Binns, P.J. [Massachusetts Institute of Technology (United States); Kiger, W.S. III [Massachusetts Institute of Technology (United States); Busse, P.M. [Beth-Israel Deaconess Medical Center (Israel)

2002-03-15T23:59:59.000Z

449

Hybrid Electric Vehicle Power Management Solutions Based on Isolated and Non-Isolated Configurations of MMCCC Converter  

Science Conference Proceedings (OSTI)

This paper presents the various configurations of a multilevel modular capacitor-clamped converter (MMCCC), and it reveals many useful and new formations of the original MMCCC for transferring power in either an isolated or nonisolated manner. The various features of the original MMCCC circuit are best suited for a multibus system in future plug-in hybrid or fuel-cell-powered vehicles' drive train. The original MMCCC is capable of bidirectional power transfer using multilevel modular structure with capacitor-clamped topology. It has a nonisolated structure, and it offers very high efficiency even at partial loads. This circuit was modified to integrate single or multiple high-frequency transformers by using the intermediate voltage nodes of the converter. On the other hand, a special formation of the MMCCC can exhibit dc outputs offering limited isolation without using any isolation transformer. This modified version can produce a high conversion ratio from a limited number of components and has several useful applications in providing power to multiple low-voltage loads in a hybrid or electric automobile. This paper will investigate the origin of generating ac outputs from the MMCCC and shows how the transformer-free version can be modified to create limited isolation from the circuit. In addition, this paper will compare various modified forms of the MMCCC topology with existing dc-dc converter circuits from compactness and component utilization perspectives.

Khan, Faisal H [ORNL; Tolbert, Leon M [ORNL; Webb, William E [Oak Ridge National Laboratory (ORNL)

2009-01-01T23:59:59.000Z

450

A Bidirectional, Triple-Voltage DC-DC Converter for Hybrid and Fuel Cell Vehicle Power Systems  

Science Conference Proceedings (OSTI)

Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage (14V, 42V and high voltage (HV)) nets. These will be necessary to accommodate existing 14V loads as well as efficiently handle new heavy loads at the 42V net and an electrical traction drive on the HV bus. A low-cost bi-directional dc-dc converter was proposed in (10) for connecting the three voltage nets. The converter consists of two half-bridges and a high-frequency transformer; thus minimizing the number of switching devices and their associated gate driver components. One salient feature is that the half-bridge on the 42V bus is also utilized to provide the 14V bus by operating its duty ratio around an atypical value of 1/3. This eliminates the need for an additional 14V/42V converter. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft-switching; no extra active switches or passive resonant components are required. The use of half-bridges makes the topology suitable for interleaved multi-phase configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with the atypical duty ratio on the transformer and a preferred multi-phase configuration to minimize capacitor ripple currents.

Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

2007-01-01T23:59:59.000Z

451

Synthetic Metagenomics: Converting digital information back to Biology (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)  

SciTech Connect

Sam Deutsch of the DOE JGI on "Synthetic Metagenomics: Converting digital information back to Biology" at the 8th Annual Genomics of Energy & Environment Meeting in Walnut Creek, Calif.

Deutsch, Sam [DOE Joint Genome Institute

2013-03-01T23:59:59.000Z

452

Measurements of ion cyclotron range of frequencies mode converted wave intensity with phase contrast imaging in Alcator C-Mod and comparison with full-wave simulations  

E-Print Network (OSTI)

Radio frequency waves in the ion cyclotron range of frequencies (ICRF) are widely used to heat tokamak plasmas. In ICRF heating schemes involving multiple ion species, the launched fast waves convert to ion cyclotron waves ...

Jaeger, E. F.

453

Recommended practice for fire protection for electric generating plants and high voltage direct current converter stations. 2005 ed.  

Science Conference Proceedings (OSTI)

The standard outlines fire safety recommendations for gas, oil, coal, and alternative fuel electric generating plants including high voltage direct current converter stations and combustion turbine units greater than 7500 hp used for electric generation. Provisions apply to both new and existing plants. The document provides fire prevention and fire protection recommendations for the: safety of construction and operating personnel; physical integrity of plant components; and continuity of plant operations. The 2005 edition includes revisions and new art that clarify existing provisions. 5 annexes.

NONE

2005-07-01T23:59:59.000Z

454

Analysis and experimental results of a single-stage high-power-factor electronic ballast based on flyback converter  

SciTech Connect

A new single-stage high-power-factor electronic ballast based on a flyback converter is presented in this paper. The ballast is able to supply a fluorescent lamp assuring a high-input power factor for the utility line. Other features are lamp power regulation against line voltage variations and low lamp current crest factor, both assuring long lamp life. The ballast is analyzed at steady-state operation, and design equations and characteristics are obtained. Also, a procedure for the ballast design is presented. Finally, simulation and experimental results from a laboratory prototype are shown.

Calleja, A.J.; Alonso, J.M.; Lopez, E.; Ribas, J.; Martinez, J.A.; Rico-Secades, M.

1999-11-01T23:59:59.000Z

455

Unbalanced-grid-fault ride-through control for a doubly fed induction generator wind turbine with series grid-side converter  

Science Conference Proceedings (OSTI)

The grid codes now require doubly fed induction generator (DFIG) wind turbines having the "low voltage ride-through (LVRT)" capability. However, a traditional DFIG with a partially rated back-to-back converter has inherent difficulties to ride through ... Keywords: doubly fed induction generator (DFIG), low voltage ride-through (LVRT), series grid-side converter (SGSC), unbalanced grid fault, voltage dips, voltage sags, wind power generation, wind turbine

Yong Liao; Hui Li; Jun Yao

2011-02-01T23:59:59.000Z

456

OBSERVATION Microbial Electrosynthesis: Feeding Microbes Electricity To Convert Carbon Dioxide and Water to Multicarbon Extracellular Organic Compounds  

E-Print Network (OSTI)

ABSTRACT The possibility of providing the acetogenic microorganism Sporomusa ovata with electrons delivered directly to the cells with a graphite electrode for the reduction of carbon dioxide to organic compounds was investigated. Biofilms of S. ovata growing on graphite cathode surfaces consumed electrons with the reduction of carbon dioxide to acetate and small amounts of 2-oxobutyrate. Electrons appearing in these products accounted for over 85 % of the electrons consumed. These results demonstrate that microbial production of multicarbon organic compounds from carbon dioxide and water with electricity as the energy source is feasible. IMPORTANCE Reducing carbon dioxide to multicarbon organic chemicals and fuels with electricity has been identified as an attractive strategy to convert solar energy that is harvested intermittently with photovoltaic technology and store it as covalent chemical bonds. The organic compounds produced can then be distributed via existing infrastructure. Nonbiological electrochemical reduction of carbon dioxide has proven problematic. The results presented here suggest that microbiological catalysts may be a robust alternative, and when coupled with photovoltaics, current-driven microbial carbon dioxide reduction represents a new form of photosynthesis that might convert solar energy to organic products more effectively than traditional biomass-based strategies.

Kelly P. Nevin; Trevor L. Woodard; Ashley E. Franks; Zarath M. Summers; Derek R. Lovley

2010-01-01T23:59:59.000Z

457

OPERATIONAL RESULTS OF THE SPALLATION NEUTRON SOURCE (SNS) POLYPHASE CONVERTER-MODULATOR FOR THE 140 KV KLYSTRON RF SYSTEMS  

SciTech Connect

This paper describes the first operational results of the 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching, 20 kHz polyphase bridge, boost converter-modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2100 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. Pulse-Width Modulation (PWM) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. Reviews of these design parameters and an examination of the first operational results will be performed.

W.A. REASS; J.D. DOSS; ET AL

2001-06-01T23:59:59.000Z

458

Operational results of the spallation neutron source (SNS) polyphase converter-modulator for the 140 KV klystron RF system  

SciTech Connect

This paper describes the first operational results of the 140 kV, 1 MW average, 11 MW peak, zero-voltageswitching, 20 kHz polyphase bridge, boost converter-modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2100 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three 'H-Bridge' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. Pulse-Width Modulation (PWM) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. Reviews of these design parameters and an examination of the first operational results will be performed.

Reass, W. A. (William A.); Doss, James D.; Gribble, R. F. (Robert F.); Lynch, M. T. (Michael T.); Rees, D. E. (Daniel E.); Tallerico, P. J. (Paul J.); Borovina, D. L.

2001-01-01T23:59:59.000Z

459

Operational results of the spallation neutron source (SNS) polyphase converter-modulator for the 140 KV klystron RF system  

DOE Green Energy (OSTI)

This paper describes the first operational results of the 140 kV, 1 MW average, 11 MW peak, zero-voltageswitching, 20 kHz polyphase bridge, boost converter-modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2100 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three 'H-Bridge' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. Pulse-Width Modulation (PWM) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. Reviews of these design parameters and an examination of the first operational results will be performed.

Reass, W. A. (William A.); Doss, James D.; Gribble, R. F. (Robert F.); Lynch, M. T. (Michael T.); Rees, D. E. (Daniel E.); Tallerico, P. J. (Paul J.); Borovina, D. L.

2001-01-01T23:59:59.000Z

460

OPERATIONAL RESULTS OF THE SPALLATION NEUTRON SOURCE (SNS) POLYPHASE CONVERTER-MODULATOR FOR THE 140 KV KLYSTRON RF SYSTEMS  

SciTech Connect

This paper describes the first operational results of the 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching, 20 kHz polyphase bridge, boost converter-modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2100 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. Pulse-Width Modulation (PWM) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. Reviews of these design parameters and an examination of the first operational results will be performed.

W.A. REASS; J.D. DOSS; ET AL

2001-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "ac-dc converters halt" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461