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Note: This page contains sample records for the topic "voltage direct current" 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.


1

Superconducting Low Voltage Direct Current (LVDC) Networks  

Science Conference Proceedings (OSTI)

A low voltage dc superconducting distribution network is a challenging future opportunity for power distribution. This report presents a scheme for a superconducting, parallel- connected, multiterminal dc transmission system.

1994-04-27T23:59:59.000Z

2

High Voltage Direct Current (HVDC) Transmission Reference Book  

Science Conference Proceedings (OSTI)

The EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book is a state-of-the-art guidebook that provides transmission companies with a comprehensive, single source of technical information and guidance for designing, building, operating, and extending the life of HVDC transmission systems. The book joins the landmark series of EPRI power delivery reference books. These comprehensive guidebooks—each printed with a distinctive colored cover—document and distill the ...

2012-12-31T23:59:59.000Z

3

High-Voltage Direct Current Line Conductor Optimization  

Science Conference Proceedings (OSTI)

Overhead transmission lines are designed to last for 40 years. Many ac lines in service today in North America are 70 or more years old. This survival rate is a result of conservative utility design practices and detailed product specifications. This reliability record has occurred despite a wide range of conductor types and sizes. In the present transmission system, there are far fewer high-voltage direct current (HVDC) lines, but those that have been designed and built have been similarly successful in...

2011-12-21T23:59:59.000Z

4

High Voltage Direct Current Live Line and Insulator Testing  

Science Conference Proceedings (OSTI)

This report has two main parts. The focus of the first part is on live work in overhead high-voltage direct current (HVDC) lines operating above 100 kV dc. It does not address issues related to lines for electric transport that typically operate below 60 kV dc worldwide. In addition, this first part of the report is not a detailed treatise on live work but, rather, addresses the main issues related to dc live work. More detailed information on the general topic of live work can be found in the references...

2011-12-23T23:59:59.000Z

5

An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.  

SciTech Connect

References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

Litzenberger, Wayne; Lava, Val

1994-08-01T23:59:59.000Z

6

Modal analysis of multiterminal high voltage direct current transmission  

Science Conference Proceedings (OSTI)

This report describes a first phase of effort in providing the Bonneville Power Administration (BPA) with comprehensive tools for model-based analysis of interactions between the Pacific HVDC Intertie (PDCI) and the alternating current (ac) system containing it. The work builds upon the transient stability model coded by Control Technologies, Inc. (CTI) for use in the Electric Power Research Institute (EPRI) Extended Transient-Midterm Stability Package (ETMSP). The general thrust of the effort is that CM`s model be interfaced to and tested against all tools provided by EPRI`s Power System Analysis Package (PSAPAC), and that these tools be used to investigate options for PDCI use in testing and control of western system dynamics. This will require refinements to the tools, the model, and western system case data. The PSAPAC tool for eigenanalysis is the Small Signal Stability Package (SSSP), useful for performing modal analysis of the multiterminal HVDC (MTDC) system. Such analyses are necessary to design and test an expanded role of the PDCI for power system control. This study focused on testing the application of the MTDC with SSSP. Modifications were made to enable SSSP to read the MTDC model. The PSAPAC and SSSP tools and the MTDC model were evaluated for accuracy and consistency using several modal analysis techniques, including Prony analysis on ETMSP-generated data. Although SSSP appears to be useful in analyzing the PDCI modes, inconsistencies limit the overall usefulness of that approach. The modal frequencies and damping identified by SSSP are inconsistent, indicating SSSP has difficulty analyzing the MTDC representation of the dc systems. The differences between the new and existing models can be used to identify the particular modeling issues associated with SSSP which are presently resulting in inconsistent results.

Dagle, J.E.

1993-12-01T23:59:59.000Z

7

Assessment of research directions for high-voltage direct-current power systems. Final report  

Science Conference Proceedings (OSTI)

High voltage direct current (HVDC) power transmission continues to be an emerging technology nearly thirty years after its introduction into modern power systems. To date its use has been restricted to either specialized applications having identifiable economic advantages (e.g., breakeven distance) or, rarely, applications where decoupling is needed. Only recently have the operational advantages (e.g., power modulation) of HVDC been realized on operating systems. A research project whose objective was to identify hardware developments and, where appropriate, system applications which can exemplify cost and operational advantages of integrated ac/dc power systems is discussed. The three principal tasks undertaken were: assessment of equipment developments; quantification of operational advantages; and interaction with system planners. Interest in HVDC power transmission has increased markedly over the past several years, and many new systems are now being investigated. The dissemination of information about HVDC, including specifically the symposium undertaken for Task 3, is a critical factor in fostering an understanding of this important adjunct to ac power transmission.

Long, W F

1982-09-01T23:59:59.000Z

8

Energy conversion apparatus for supplying variable voltage direct current power to an electrically propelled vehicle  

SciTech Connect

A synchronous machine, operable as both a motor and a generator, is mounted on an electrically powered vehicle, such as a mine shuttle car, and includes a plurality of conductors having connections that are detachably engagable with receptacles of a stationary power bank. Engagement of the conductors with the receptacles supplies variable voltage alternating current power to the machine. The machine is drivingly connected to a flywheel on the vehicle and, operating as a motor, energizes the flywheel to store a preselected amount of mechanical energy. The electrical connection between the vehicle and the power bank is opened after the flywheel has been sufficiently charged. The stored energy in the flywheel is then available to drive the machine as a generator and produce high frequency, three phase, alternating current power. The generated power is transmitted to a full wave silicon controlled rectifier that converts the alternating current power to direct current for powering the traction motors of the vehicle. A variable voltage controller is connected to the rectifier and actuates the rectifier to supply direct current at a selected voltage level. The controller is responsive to an operator foot pedal. By manually depressing the foot pedal to a selected position, the voltage level of the rectified current is controlled. Thus, the speed of the traction motors is adjustable topropel the vehicle at a speed within a given range. After a portion of the energy stored by the flywheel is consumed, the vehicle is returned to the power bank to replenish the energy supply.

Jamison, W.B.; Burr, J.F.

1976-09-07T23:59:59.000Z

9

Environmental and Potential Health Effects of High Voltage Direct Current Transmission Lines  

Science Conference Proceedings (OSTI)

High-voltage direct current (HVDC) technology plays an important but highly selective role in the U.S. power delivery system. It is a cost-effective technology for transferring bulk power over long distances, a critical technology for asynchronous grid interconnection, and the preferred technology for long-distance underwater cable transmission. Current interest in renovating the national grid for greater loads and higher reliability as well as unique applications for renewable energy projects, including...

2012-07-31T23:59:59.000Z

10

EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book: Interim Report  

Science Conference Proceedings (OSTI)

The EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book is a state-of-the-art guidebook that provides transmission companies with a comprehensive, single source of technical information and guidance for designing, building, operating, and extending the life of HVDC transmission systems. The book joins the landmark series of EPRI power delivery reference books. These comprehensive guidebookseach printed with a distinctive colored coverdocument and distill the knowledge and experience of th...

2011-12-30T23:59:59.000Z

11

EPRI High-Voltage Direct Current (HVDC) Reference Book: Chapter 24 - Operation and Maintenance of HVDC Systems  

Science Conference Proceedings (OSTI)

This report contains descriptions of the operation and maintenance (O&M) activities of traditional high-voltage direct current (HVDC) line commutated (thyristor-based) and voltage-sourced converter (VSC) transmission systems. Both long-distance transmission schemesincluding the transmission linesand back-to-back schemes are included. The various tasks involved in the O&M of HVDC systems are described at some length, and a range of estimates is given for the staff requirements to carry out these activitie...

2010-01-19T23:59:59.000Z

12

Voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, Gregory M. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

13

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

14

High-Voltage Direct Current Corona Testing of Transmission Line Hardware and Insulator Assemblies: Development of Test Methodology  

Science Conference Proceedings (OSTI)

When specifying hardware for new high-voltage direct current (HVDC) lines or replacement hardware for existing HVDC lines utilities generally require that the hardware meet specific corona performance requirements.While standards and test methods exist for testing hardware used on HVAC systems, no such material is available for HVDC systems.HVAC tests are sometimes conducted on the hardware and the results obtained are then related to HVDC by utilizing the peak HVAC line to ...

2013-12-20T23:59:59.000Z

15

A new converter fault discrimination method for a 12-pulse high-voltage direct current system based on wavelet transform and Hidden Markov Models  

Science Conference Proceedings (OSTI)

The progressive development in high-voltage direct current (HVDC) transmission enhances the need to implement an efficient protection scheme to distinguish the minimum faulty part of the system and to relieve the stressed equipment. This paper proposes ... Keywords: Discrete Hidden Markov Models, converter faults, fault discrimination, high-voltage direct current, wavelet transform

Mohamad Tahan; Hassan Monsef; Shahrokh Farhangi

2012-06-01T23:59:59.000Z

16

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

17

Effect of Space Charge on Surface Insulation of High-Voltage Direct-Current Bushings  

Science Conference Proceedings (OSTI)

Operating data on bushings and post insulators for HVDC converter stations demonstrate that large-diameter insulators perform poorly when exposed to a combination of rain or fog and airborne contaminants. A technique that produces an intense space charge, resulting in corona at the high-voltage electrode of HVDC bushings, shows promise of improving flashover performance in some laboratory applications, but apparently has little effect under simulated service conditions.

1987-11-03T23:59:59.000Z

18

A voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoampers to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, G.M.

1990-12-21T23:59:59.000Z

19

Current-Voltage and Capacitance-Voltage characteristics of Pd ...  

Science Conference Proceedings (OSTI)

Presentation Title, Current-Voltage and Capacitance-Voltage characteristics of Pd ... Nonlocal Modeling in High Rate Deformation and Ductile Fracture of ...

20

A 4000-A HVDC (high-voltage direct-current) circuit breaker with fast fault-clearing capability: Final report  

Science Conference Proceedings (OSTI)

This project is a follow-up of the first development of a 500 kV HVDC airblast circuit breaker (EPRI project 1507-3). The objective was to increase the current interrupting capability from 2200 A to 4000 A and shorten its fault clearing time. A high current 500 kV HVDC circuit breaker has been built using the passive commutation circuit. The breaker is modular in construction and can be designed for a wide variety of system conditions. More than 400 current interruptions were carried out successfully. Tests have shown that this circuit breaker is capable of interrupting more than 4000 A dc. Practical breakers with current interrupting capability of even 5500 A dc could be built. The circuit breaker operation and the fault-clearing process can be materially speeded up if the trip signal is given as soon as the fault is detected and without waiting for the current levels to come down in response to converter control action. The new dc breakers are shown to be capable of withstanding these transient arc currents of 8000 A without affecting its ability to interrupt the direct current that follows the transient. This transient current withstand capability is greater than is likely to occur during dc faults. The fault clearing time of this HVDC circuit breaker is comparable to the fault clearing time of conventional ac breakers for ac faults. The developed HVDC circuit breaker is now commercially available and can be supplied for use in HVDC systems. Its use in such systems is expected to provide flexibility in system design and contribute to system stability. 38 refs., 52 figs., 9 tabs.

Not Available

1988-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

NREL: Measurements and Characterization - Current Versus Voltage  

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

Current Versus Voltage Current Versus Voltage The National Renewable Energy Laboratory (NREL) Device Performance group uses current versus voltage (I-V) measurement systems to assess the main performance parameters for photovoltaic (PV) cells and modules. I-V measurement systems determine the output performance of devices, including: open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF), maximum power output of the device (Pmax), voltage at maximum power (Vmax), current at maximum power (Imax), and conversion efficiency of the device (η). Some I-V systems may also be used to perform dark I-V measurements to determine diode properties and series and shunt resistances. We use three I-V systems to measure performance of individual PV cells; and four for modules - two for measurements under simulated conditions; and

22

HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH  

DOE Patents (OSTI)

A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

1962-04-17T23:59:59.000Z

23

Fiber optic current monitor for high-voltage applications  

DOE Patents (OSTI)

A current monitor which derives its power from the conductor being measured for bidirectionally measuring the magnitude of current (from DC to above 50 khz) flowing through a conductor across which a relatively high level DC voltage is applied, includes a pair of identical transmitter modules connected in opposite polarity to one another in series with the conductor being monitored, for producing from one module a first light signal having an intensity directly proportional to the magnitude of current flowing in one direction through the conductor during one period of time, and from the other module a second light signal having an intensity directly proportional to the magnitude of current flowing in the opposite direction through the conductor during another period of time, and a receiver located in a safe area remote from the high voltage area for receiving the first and second light signals, and converting the same to first and second voltage signals having levels indicative of the magnitude of current being measured at a given time. 6 figs.

Renda, G.F.

1992-04-21T23:59:59.000Z

24

Definition: Direct current | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Direct current Jump to: navigation, search Dictionary.png Direct current A type of electricity transmission and distribution by which electricity flows in one direction through the conductor, usually relatively low voltage and high current (such as from a battery). To be used for typical 120 volt or 220 volt household appliances, DC must be converted to alternating current (AC).[1][2] View on Wikipedia Wikipedia Definition Direct current (DC) is the unidirectional flow of electric charge. Direct current is produced by sources such as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow

25

Hybrid high direct current circuit interrupter  

DOE Patents (OSTI)

A device and a method are disclosed for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens. 7 figs.

Rockot, J.H.; Mikesell, H.E.; Jha, K.N.

1998-08-11T23:59:59.000Z

26

Hybrid high direct current circuit interrupter  

DOE Patents (OSTI)

A device and a method for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens.

Rockot, J.H.; Mikesell, H.E.; Jha, K.N.

1996-12-31T23:59:59.000Z

27

The Current-voltage Characteristics of Grain Boundaries in Ionic ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Current-voltage Characteristics of Grain Boundaries in Ionic ... A High-temperature Mössbauer Study of Iron-doped Ruddlesden-popper  ...

28

OMNI SMARTPUMP: DIRECT CURRENT POWERED  

E-Print Network (OSTI)

the energy savings of the variable speed DC motor over existing variable speed AC motors that couldOMNI SMARTPUMP: DIRECT CURRENT POWERED DRIP IRRIGATION SYSTEM Prepared For: California Energy Commission Energy Innovations Small Grant Program Prepared By: Omni Instruments

29

Currents' Physical Components (CPC) In Circuits with Nonsinusoidal Voltages and Currents  

E-Print Network (OSTI)

voltages and currents. It is true only for balanced loads supplied with a symmetrical voltage. However{ || || || || || || }P u u uY Y Y+ + . (20) The supply voltage is sinusoidal and symmetrical, thus RS ST TR R for energy permanent conversion in the load with power P. The remaining part of the supply current, i ­ ia

Czarnecki, Leszek S.

30

High power impulse magnetron sputtering: Current-voltage-time ...  

pauses between pulses !typically 20 ms". The nominal volt-age of the pulser was adjustable up to 1000 V. The arc threshold was set to 120 A. If the current exceeded this

31

Current isolating epitaxial buffer layers for high voltage photodiode array  

DOE Patents (OSTI)

An array of photodiodes in series on a common semi-insulating substrate has a non-conductive buffer layer between the photodiodes and the semi-insulating substrate. The buffer layer reduces current injection leakage between the photodiodes of the array and allows optical energy to be converted to high voltage electrical energy.

Morse, Jeffrey D. (Martinez, CA); Cooper, Gregory A. (Pleasant Hill, CA)

2002-01-01T23:59:59.000Z

32

Outdoor PV Module Degradation of Current-Voltage Parameters: Preprint  

DOE Green Energy (OSTI)

Photovoltaic (PV) module degradation rate analysis quantifies the loss of PV power output over time and is useful for estimating the impact of degradation on the cost of energy. An understanding of the degradation of all current-voltage (I-V) parameters helps to determine the cause of the degradation and also gives useful information for the design of the system. This study reports on data collected from 12 distinct mono- and poly-crystalline modules deployed at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. Most modules investigated showed < 0.5%/year decrease in maximum power due to short-circuit current decline.

Smith, R. M.; Jordan, D. C.; Kurtz, S. R.

2012-04-01T23:59:59.000Z

33

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

34

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

35

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

36

A new current source GTO inverter with sinusoidal output voltage and current  

SciTech Connect

A new current source inverter with sinusoidal output voltage and current is presented. Gate turn-off thyristors (GTO's) and pulsewidth modulation (PWM) control techniques are used in the current source inverter to produce the sinusoidal output voltage and current. Three capacitors are connected to the ac output terminals to absorb overvoltages which occur when the GTO current is cut off and to provide a filter function for reducing harmonics in the output current. Voltage spikes, which have been a serious problem in the practical application of this inverter, are suppressed by adding gate pulses which force the inverter into a state of shoot-through. Moreover, this inverter permits the capacitance of an ac output terminal capacitor for absorbing overvoltages to be reduced to one-tenth or less of that of a commutating capacitor in a conventional thyristor type current source inverter. A 3.7-kW induction motor is driven by the inverter. The motor efficiency and noise level are measured and compared with those obtained when the motor is driven by a conventional voltage source PWM inverter. An operating efficiency five or six percent higher and noise level 10 dB lower are obtained for the former. Therefore, this current source GTO inverter is very suitable for ac motor variable speed drives.

Hombu, M.; Matsuda, Y.; Ueda, A.; Ueda, S.

1985-09-01T23:59:59.000Z

37

An accurate continuous calibration system for high voltage current transformer  

SciTech Connect

A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

Tong Yue; Li Binhong [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province (China)

2011-02-15T23:59:59.000Z

38

Voltage holding considerations for direct-collection units  

SciTech Connect

Results have been obtained from initial experiments designed to study high-voltage breakdown under conditions of importance to the design of direct- collection units. A coaxial configuration was used to mock-up critical fields near grid wires. With appropriate heat conditioning, fields as high as 9.6 x 10/ sup 5/ V/cm were maintained at the surface of a 7-mil-diam tungsten wire. This represents an enhanced field of ~10/sup 8/V/cm at whisker'' sites. Breakdown criteria are proposed for three regimes; initial, field-emission, and ultimate, which differ by the amount of prior conditioning applied to the wire. Additional considerations of importance to direct collectors such as the effect of thermionic emission and ion bombardment are discussed. (auth)

Miley, G.H.

1973-12-01T23:59:59.000Z

39

Definition: Direct-Current Resistivity Survey | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Definition Edit with form History Facebook icon Twitter icon » Definition: Direct-Current Resistivity Survey Jump to: navigation, search Dictionary.png Direct-Current Resistivity Survey Direct-current (DC) resistivity is an active source electrical technique in which current is applied to the ground using electrodes and the earth response (voltage or potential difference) is recorded. This survey generates a geoelectric section of apparent resistivity and enables an inference of subsurface geology.[1] View on Wikipedia Wikipedia Definition References ↑ http://www.nga.com/Flyers_PDF/NGA_DC_Resistivity.pdf

40

Chronic Benzodiazepine Administration Potentiates High Voltage-Activated Calcium Currents  

E-Print Network (OSTI)

.aspetjournals.orgDownloadedfrom #12;other drugs of abuse has been reported to enhance high voltage-activated calcium channels (HVAs

Brand, Paul H.

Note: This page contains sample records for the topic "voltage direct current" 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

BB5, Nearly Ideal Current-Voltage Characteristics of Schottky Barrier ...  

Science Conference Proceedings (OSTI)

Recently, high-quality GaN free-standing substrates are available by various methods. ... Current-voltage (I-V) characteristics and capacitance-voltage (C-V) ...

42

Transformer coupling for transmitting direct current through a barrier  

DOE Patents (OSTI)

The transmission system for transmitting direct current from an energy source on one side of an electrical and mechanical barrier to a load on the other side of the barrier utilizes a transformer comprising a primary core on one side of the transformer and a secondary core on the other side of the transformer. The cores are magnetically coupled selectively by moving a magnetic ferrite coupler in and out of alignment with the poles of the cores. The direct current from the energy source is converted to a time varying current by an oscillating circuit, which oscillating circuit is optically coupled to a secondary winding on the secondary core to interrupt oscillations upon the voltage in the secondary winding exceeding a preselected level.

Brown, Ralph L. (Albuquerque, NM); Guilford, Richard P. (Albuquerque, NM); Stichman, John H. (Albuquerque, NM)

1988-01-01T23:59:59.000Z

43

Transformer coupling for transmitting direct current through a barrier  

DOE Patents (OSTI)

The transmission system for transmitting direct current from an energy source on one side of an electrical and mechanical barrier to a load on the other side of the barrier utilizes a transformer comprising a primary core on one side of the transformer and a secondary core on the other side of the transformer. The cores are magnetically coupled selectively by moving a magnetic ferrite coupler in and out of alignment with the poles of the cores. The direct current from the energy source is converted to a time varying current by an oscillating circuit, which oscillating circuit is optically coupled to a secondary winding on the secondary core to interrupt oscillations upon the voltage in the secondary winding exceeding a preselected level. 4 figs.

Brown, R.L.; Guilford, R.P.; Stichman, J.H.

1987-06-29T23:59:59.000Z

44

Method for exciting inductive-resistive loads with high and controllable direct current  

DOE Patents (OSTI)

Apparatus and method for transmitting dc power to a load circuit by applying a dc voltage from a standard waveform synthesizer to duration modulate a bipolar rectangular wave generator. As the amplitude of the dc voltage increases, the widths of the rectangular wave generator output pulses increase, and as the amplitude of the dc voltage decreases, the widths of the rectangular wave generator output pulses decrease. Thus, the waveform synthesizer selectively changes the durations of the rectangular wave generator bipolar output pulses so as to produce a rectangular wave ac carrier that is duration modulated in accordance with and in direct proportion to the voltage amplitude from the synthesizer. Thereupon, by transferring the carrier to the load circuit through an amplifier and a rectifier, the load current also corresponds directly to the voltage amplitude from the synthesizer. To this end, the rectified wave at less than 100% duty factor, amounts to a doubled frequency direct voltage pulse train for applying a direct current to the load, while the current ripple is minimized by a high L/R in the load circuit. In one embodiment, a power transmitting power amplifier means having a dc power supply is matched to the load circuit through a transformer for current magnification without sacrificing load current duration capability, while negative voltage and current feedback are provided in order to insure good output fidelity.

Hill, Jr., Homer M. (Princeton Junction, NJ)

1976-01-01T23:59:59.000Z

45

Biased low differential input impedance current receiver/converter device and method for low noise readout from voltage-controlled detectors  

DOE Patents (OSTI)

A first stage electronic system for receiving charge or current from voltage-controlled sensors or detectors that includes a low input impedance current receiver/converter device (for example, a transimpedance amplifier), which is directly coupled to the sensor output, a source of bias voltage, and the device's power supply (or supplies), which use the biased voltage point as a baseline.

Degtiarenko, Pavel V. (Williamsburg, VA); Popov, Vladimir E. (Newport News, VA)

2011-03-22T23:59:59.000Z

46

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

47

Ferrosilicon smelting in a direct current furnace  

DOE Patents (OSTI)

The present invention is a process for smelting ferrosilicon alloy. The process comprises adding a carbon source and tailings comprising oxides of silicon and iron to a substantially closed furnace. Heat is supplied to the furnace by striking a direct current arc between a cathode electrode and an anode functional hearth. In a preferred embodiment of the present invention, the cathode electrode is hollow and feed to the substantially closed furnace is through the hollow electrode. 1 figure.

Dosaj, V.D.; May, J.B.

1992-12-29T23:59:59.000Z

48

High-voltage direct current handbook: First edition  

Science Conference Proceedings (OSTI)

HVDC systems offer opportunities for power transfer between asynchronous systems, improved performance of the ac system in which the dc link is integrated, and possibly increased power transfer across existing lines if converted to HVDC. This handbook is intended to help planners and engineers understand the intricacies of HVDC systems.

Piwko, R.J.; Leonard, D.J.; Nolan, J.J.; Thorpe, J.B. [eds.] [GE Industrial and Power Systems, Schenectady, NY (United States)

1994-12-31T23:59:59.000Z

49

Students' Understanding of Direct Current Resistive Electrical Circuits  

E-Print Network (OSTI)

Research has shown that both high school and university students' reasoning patterns regarding direct current resistive electric circuits often differ from the currently accepted explanations. At present, there are no standard diagnostic examinations in electric circuits. Two versions of a diagnostic instrument called Determining and Interpreting Resistive Electric circuits Concepts Tests (DIRECT) were developed, each consisting of 29 questions. The information provided by the exam provides classroom instructors a means with which to evaluate the progress and conceptual difficulties of their students and their instructional methods. It can be used to evaluate curricular packages and/or other supplemental materials for their effectiveness in overcoming students' conceptual difficulties. The analyses indicate that students, especially females, tend to hold multiple misconceptions, even after instruction. During interviews, the idea that the battery is a constant source of current was used most often in answering the questions. Students tended to focus on current in solving the problems and to confuse terms, often assigning the properties of current to voltage and/or resistance. Results indicated that students do not have a clear understanding of the underlying mechanisms of electric circuit phenomena. On the other hand, students were able to translate easily from a "realistic" representation of a circuit to the corresponding schematic diagram.

Paula V. Engelhardt; Robert J. Beichner

2003-04-10T23:59:59.000Z

50

Soft-commutated direct current motor  

DOE Patents (OSTI)

A method and circuit is disclosed for soft-commutation of a direct current (DC) motor. An attenuation circuit is connected through auxiliary brushes A, A', B and B' to the commutator (16) to drain circuit from successive armature coils (15) before the main brushes (27, 28) disconnects from each of the coils (15). This prevents the spark generation that normally occurs in conventional DC motors. The attenuation circuit may also be connected before energization of the coil (15) for a soft turning on operation.

Hsu, John S. (Oak Ridge, TN)

1999-01-01T23:59:59.000Z

51

Soft-commutated direct current motor  

DOE Patents (OSTI)

A method and circuit is disclosed for soft-commutation of a direct current (DC) motor. An attenuation circuit is connected through auxiliary brushes A, A[prime], B and B[prime] to the commutator (16) to drain circuit from successive armature coils (15) before the main brushes (27, 28) disconnects from each of the coils (15). This prevents the spark generation that normally occurs in conventional DC motors. The attenuation circuit may also be connected before energization of the coil (15) for a soft turning on operation. 13 figs.

Hsu, J.S.

1999-07-27T23:59:59.000Z

52

Condition Monitoring and Diagnostics of Bushings, Current Transformers, and Voltage Transformers by Oil Analysis  

Science Conference Proceedings (OSTI)

This study was undertaken to determine the merits of oil analysis for condition monitoring and diagnostics of bushings, current, potential and voltage transformers. Oil test results and equipment information from 193 bushings, 830 current transformers, 194 potential transformers and 268 voltage transformers were analyzed. Statistical analyses was used to assigns equipment condition codes from 1 (Normal Operation) to 4 (Extreme) based on threshold limits for dissolved gas in oil results. A more recent set...

2006-12-12T23:59:59.000Z

53

Solid-state fault current limiter for voltage sag mitigation and its parameters design  

Science Conference Proceedings (OSTI)

Due to the difficulty in electric distribution network reinforcement and the interconnection of more distributed generations, fault current level has become a serious problem in system operations. The utilization of solid-state fault current limiters ... Keywords: power quality, simulation, solid-state fault current limiter, voltage sag

B. Boribun; T. Kulworawanichpong

2010-07-01T23:59:59.000Z

54

Measured Breakdown Voltage and Leakage Current of Line Worker Boots  

Science Conference Proceedings (OSTI)

Worker safety is every electric power company's number one priority. Denergized line maintenance is an important task to ensure reliable operation of a transmission line. The grounding installed during this operation must be designed to shunt any unforeseen fault current and prevent electric shock and any associated consequences. The research described in this report describes electrical characteristics of work shoes, which comprise an important part of a model for minimizing hazardous outcomes.

2009-11-02T23:59:59.000Z

55

Current-Voltage Characteristics of Bi-dithiolbenzene in Parallel Arrangement  

Science Conference Proceedings (OSTI)

The low voltage conductance of interacting two 1,4-dithiolbenzene (DTB) molecules is investigated. The simulation results show that the electron transport can be controlled either by changing the Fermi level position E{sub f} or modifying its inter-molecular spacing d. Molecular assembly system with close interaction between DTB units, affects significantly the conductance. In addition, the position of the Fermi plays an important role in determining the current flow. Moreover, it is important to note that E{sub f} affects not only the threshold voltage V{sub th}, but also the saturation voltage V{sub sat}. When E{sub f} approaches the LUMO energy level, V{sub th} decreases, while V{sub sat} increases. To conclude, the threshold voltage and the saturation voltage depend on the Fermi level position and the inter-molecular spacing.

Boudjella, Aissa [Department of Computer and Communication Technolgy, Faculty of Information and communication, Technology, University Tunku Abdul Rahman, Jalan University, Bandar Barat, 31900 Kampar, Perak (Malaysia)

2011-03-30T23:59:59.000Z

56

Watthour meter accuracy under controlled unbalanced harmonic voltage and current conditions  

SciTech Connect

This work presents the results of phase 1 of the project on the accuracy of watthour meters when subjected to closely-duplicated real-world unbalanced harmonic voltage and current conditions. Such real-world conditions involved differences in voltage and current magnitudes as well as differences in the voltage and current total harmonic distortion levels of each phase. Tests were performed on a selected sample of nine three-phase and three single-phase watthour meters. Some results showed that under a particular set of unbalanced waveforms with harmonic conditions of I{sub THD} > 80% and V{sub THD} > 2%, the percentage errors exhibited by these meters ranged from {minus}10.09% to +0.52%.

Domijan, A. Jr.; Embriz-Santander, E.; Gilani, A. [Univ. of Florida, Gainesville, FL (United States). Dept. of Electrical Engineering; Lamer, G.; Stiles, C.; Williams, C.W. Jr. [Florida Power Corp., St. Petersburg, FL (United States)

1996-01-01T23:59:59.000Z

57

Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement  

DOE Patents (OSTI)

A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet. 4 figs.

Kikta, T.J.; Mitchell, R.D.

1992-11-24T23:59:59.000Z

58

Validation of GNSS under 500,000V Direct Current (DC) transmission lines  

Science Conference Proceedings (OSTI)

The use of Global Navigation Satellite Systems (GNSS) is common among agricultural users and enables the producer to optimize crop production within soil variant fields to provide better farming practices. Many agricultural navigation systems are dependent ... Keywords: Direct Current, GNSS, High voltage transmission lines, Interference, Precision agriculture

J. B. Bancroft; A. Morrison; G. Lachapelle

2012-04-01T23:59:59.000Z

59

Different methods for direct torque control of induction motor fed from current source inverter  

Science Conference Proceedings (OSTI)

Two different methods for direct torque control (DTC) of induction motor fed from current source inverter (CSI) is analyzed in the paper. The first one is derived from well-known DTC strategy developed for voltage inverter drives. This type of control ... Keywords: CSI, DTC, constant switching, hysteresis comparator, induction motor

Aleksandar Nikolic; Borislav Jeftenic

2008-07-01T23:59:59.000Z

60

Utility Investment in Optical Voltage and Current Measurement Technology: Five Installation Case Studies  

Science Conference Proceedings (OSTI)

In late 1999, EPRI polled utility members asking them what optical sensor projects EPRI should work on in 2000 and 2001. One recommendation was to develop a series of case studies on utility experiences. This report documents five installation case studies involving optical voltage and current measurement technology.

2001-12-11T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

HIGH VOLTAGE GENERATOR  

DOE Patents (OSTI)

This patent relates to high voltage supply circuits adapted for providing operating voltages for GeigerMueller counter tubes, and is especially directed to an arrangement for maintaining uniform voltage under changing conditions of operation. In the usual power supply arrangement for counter tubes the counter voltage is taken from across the power supply output capacitor. If the count rate exceeds the current delivering capaciiy of the capacitor, the capacitor voltage will drop, decreasing the counter voltage. The present invention provides a multivibrator which has its output voltage controlled by a signal proportional to the counting rate. As the counting rate increases beyond the current delivering capacity of the capacitor, the rectified voltage output from the multivibrator is increased to maintain uniform counter voltage.

Zito, G.V.

1959-04-21T23:59:59.000Z

62

Proceedings: High Voltage Current Transformers and Bushings: Failure Prediction and Prevention Symposium  

Science Conference Proceedings (OSTI)

EPRI-sponsored research has identified key parameters indicative of condition and impending failure of oil-filled, high-voltage current transformers (HVCTs) and bushings. These findings will assist utilities to improve the monitoring of HVCTs and bushings, and to develop mitigation techniques to reduce the risk of catastrophic transformer failure. These proceedings present the results of this research and the experiences of other researchers worldwide.

1999-12-01T23:59:59.000Z

63

Direct-Current Resistivity At Dixie Valley Geothermal Field Area...  

Open Energy Info (EERE)

Home Exploration Activity: Direct-Current Resistivity At Dixie Valley Geothermal Field Area (Laney, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field...

64

Direct-Current Resistivity Survey At Beowawe Hot Springs Area...  

Open Energy Info (EERE)

Activity Details Location Beowawe Hot Springs Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown References Sabodh...

65

Direct-Current Resistivity Survey At Mauna Loa Northeast Rift...  

Open Energy Info (EERE)

Details Location Mauna Loa Northeast Rift Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The vertical...

66

Utility Direct Medium Voltage DC Fast Charger Update: DC Fast Charger Characterization  

Science Conference Proceedings (OSTI)

EPRI developed a fact charging technology for electric vehicles based on a solid state transformer technology known as the Intelligent Universal Transformer (IUT). The IUT technology replaces both the independent power conversion units as well as the conventional transformer with a single interface system which can be used for fast charging of electric vehicles. The versatility of the IUT provides an intermediate DC bus voltage at the 400-V level that can be directly used for a DC distribution ...

2012-12-31T23:59:59.000Z

67

Current-Voltage Characteristics and non-Gaussian fluctuations in two different protein light receptors  

E-Print Network (OSTI)

We investigate conductance and conductance fluctuations of two transmembrane proteins, bacteriorhodopsin and proteorhodopsin, belonging to the family of protein light receptors. These proteins are widely diffused in aqueous environments, are sensitive to visible light and are promising biomaterials for the realization of novel photodevices. The conductance exhibits a rapid increase at increasing applied voltages, over a threshold value. Around the threshold value the variance of conductance fluctuations shows a dramatic jump of about 5 orders of magnitude: conductance and variance behaviours trace a second order phase transition. Furthermore, the conductance fluctuations evidence a non-Gaussian behaviour with a probability density function (PDF) which follows a generalized Gumbel distribution, typical of extreme-value statistics. The theoretical model is validated on existing current-voltage measurements and the interpretation of the PDF of conductance fluctuations is proven to be in line with the microscopic mechanisms responsible of charge transport.

E. Alfinito; J. Pousset; L. Reggiani

2013-05-24T23:59:59.000Z

68

Category:Direct-Current Resistivity Survey | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Edit History Facebook icon Twitter icon » Category:Direct-Current Resistivity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Direct-Current Resistivity Survey page? For detailed information on Direct-Current Resistivity Survey as exploration techniques, click here. Category:Direct-Current Resistivity Survey Add.png Add a new Direct-Current Resistivity Survey Technique Subcategories This category has the following 2 subcategories, out of 2 total. E [×] Electrical Profiling Configurations‎ 3 pages V [×] Vertical Electrical Sounding Configurations‎ 2 pages

69

Dark current-voltage measurements on photovoltaic modules as a diagnostic or manufacturing tool  

DOE Green Energy (OSTI)

Dark current-voltage (dark I-V) measurements are commonly used to analyze the electrical characteristics of solar cells, providing an effective way to determine fundamental performance parameters without the need for a solar simulator. The dark I-V measurement procedure does not provide information regarding short-circuit current, but is more sensitive than light I-V measurements in determining the other parameters (series resistance, shunt resistance, diode factor, and diode saturation currents) that dictate the electrical performance of a photovoltaic device. The work documented here extends the use of dark I-V measurements to photovoltaic modules, illustrates their use in diagnosing module performance losses, and proposes their use for process monitoring during manufacturing.

King, D.L.; Hansen, B.R.; Quintana, M.A.; Kratochvil, J.A.

1997-10-01T23:59:59.000Z

70

Voltage-current curves for a planar symmetrical diode with reverse bias  

Science Conference Proceedings (OSTI)

We have examined thermionic emission for the (110) crystallographic plane (face) in W and have examined the voltage-current curves in the retarding-potential range. The diode had cathode and anode composed of identical (100) and (111) faces of tungsten single crystals having 99.999 wt. % purity. The back-bias curves measured with a tungsten single crystal are described for T > /Theta//sub te/ by an expression derived for a recombination-emission model. These curves and the temperature dependence of the intensity for the recombination-emission spectra have been used to determine the electron excitation energy.

Azizov, E.E.; Babaev, V.G.; Mashtakova, V.A.

1988-07-01T23:59:59.000Z

71

Improved current saturation and shifted switching threshold voltage in In2O3 nanowire based, fully transparent NMOS inverters via femtosecond laser annealing  

E-Print Network (OSTI)

Transistors based on various types of non-silicon nanowires have shown great potential for a variety of applications, especially for those require transparency and low-temperature substrates. However, critical requirements for circuit functionality such as saturated source-drain current, and matched threshold voltages of individual nanowire transistors in a way that is compatible with low temperature substrates, have not been achieved. Here we show that femtosecond laser pulses can anneal individual transistors based on In2O3 nanowires, improve the saturation of the source-drain current, and permanently shift the threshold voltage to the positive direction. We applied this technique and successfully shifted the switching threshold voltages of NMOS based inverters and improved their noise margin, in both depletion and enhancement modes. Our demonstration provides a method to trim the parameters of individual nanowire transistors, and suggests potential for large-scale integration of nanowire-based circuit bloc...

Lee, Chunghun; Srisungsitthisunti, Pornsak; Kim, Seongmin; Zhou, Chongwu; Janes, David B; Xu, Xianfan; Roy, Kaushik; Ju, Sanghyun; Qi, Minghao

2010-01-01T23:59:59.000Z

72

Direct-Current Resistivity Survey | Open Energy Information  

Open Energy Info (EERE)

Direct-Current Resistivity Survey Direct-Current Resistivity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Direct-Current Resistivity Survey Details Activities (65) Areas (34) Regions (4) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electrical Techniques Information Provided by Technique Lithology: Rock type, mineral and clay content may be inferred. Stratigraphic/Structural: Determination of fracture zones, faults, depth to groundwater aquifers. Hydrological: Resistivity influenced by porosity, permeability, fluid saturation, fluid type and phase state of the pore water. Thermal: Resistivity influenced by temperature.[1] Cost Information

73

Voltage- and time-dependent action of histrionicotoxin on the endplate current of the frog muscle.J. Gen  

E-Print Network (OSTI)

arrow poison frog, Dendrobates histrionicus, decreased the amplitude and timecourse of the endplate current, and altered the voltage dependence of the halfdecay time. In addition, the toxin produced a characteristic nonlinearity in the current-voltage relationship of the endplate current when 3-s voltage conditioning steps were used. Reduction in time of the conditioning steps to 10 ms made the current-voltage relationship linear. The decrease in peak amplitude of the endplate current (epc) produced by histrionicotoxin measured during long hyperpolarizing conditioning steps was fitted by a single exponential function. The calculated rate constants ranged from 0.03 to 0.14 s-1 and varied with membrane potential at hyperpolarizing levels. The voltage- and time-dependent action of histrionicotoxin does not require an initial activation of receptors by acetylcholine (ACh). The characteristic of the current-voltage relationship can be accounted for by the observed voltage and time dependency of the attenuation of the endplate current amplitude in the presence of histrionicotoxin during long conditioning steps. These effects of histrionicotoxin on the peak amplitude, and on the voltage and time dependence of the epc were concentration-dependent and slowly reversible upon washing out the toxin. Thus, the voltage- and time-dependent action of histrionicotoxin at the endplate is related to an increase in the affinity between the toxin and the ACh receptor-ionic channel complex. This increase in affinity is postulated to be due to a conformational change of the macromolecule in the presence of histrionicotoxin which is demonstrated to be relatively slow, i.e., on the order of tens of seconds.

Leona M. Masukawa; Edson X. Albuquerque

1978-01-01T23:59:59.000Z

74

Direct-Current Resistivity At Blue Mountain Area (Fairbank Engineering,  

Open Energy Info (EERE)

Direct-Current Resistivity At Blue Mountain Area (Fairbank Engineering, Direct-Current Resistivity At Blue Mountain Area (Fairbank Engineering, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Blue Mountain Area (Fairbank Engineering, 2005) Exploration Activity Details Location Blue Mountain Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Geophysical surveys that have been conducted specifically for the geothermal program at Blue Mountain include a self-potential (SP) survey, and additional IP/electrical resistivity traversing. These surveys were conducted under a cooperative program between Noramex Corporation and the Energy and Geosciences Institute (EGI), University of Utah, with funding

75

Harmonics from SVC transformer saturation with direct current offset  

SciTech Connect

Circulation of direct current in transformer windings can cause significant transformer saturation and harmonic generation. This problem may be experienced by static var compensators with anti-parallel thyristor arrangement. This paper presents a technique to analyze the harmonic distortions caused by transformer saturation with direct current offset. The technique is used to investigate the harmonic generation from the transformer of a static var compensator to be installed in the B.C. Hydro system.

Xu, W.; Martinich, T.G.; Sawada, J.H.; Mansour, Y. (British Columbia Hydro, Burnaby, British Columbia (Canada))

1994-07-01T23:59:59.000Z

76

Soft commutated direct current motor [summary of proposed paper  

SciTech Connect

A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

Hsu, John S.

1998-10-22T23:59:59.000Z

77

Harmonic voltages and currents on two Greek islands with photovoltaic stations: Study and field measurements  

Science Conference Proceedings (OSTI)

The purpose of this paper is to investigate the harmonic distortion present to the electric grid of two small Greek islands (Arki and Antikythera) where Photovoltaic Stations are installed, to study their inverters harmonic behavior and to present the measurements of the harmonic voltages and currents obtained at field tests on these two islands. It is shown that the harmonics injected by the Photovoltaic Stations to the electric grid are not very high and at most cases they can not cause significant problems to the appliances to he customers. On the other had, a theoretical analysis of the installed inverters technology is also presented, showing that the results from the measurements and those of the presented analysis are quite identical. From both measurements and theoretical analysis remarkable conclusions concerning the problem of harmonics are drawn.

Vokas, G.A.; Machias, A.V. [National Technical Univ., Athens (Greece). Electric Power Div.

1995-06-01T23:59:59.000Z

78

Direct-Current Resistivity Survey At Blue Mountain Area (Fairbank  

Open Energy Info (EERE)

5) 5) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Blue Mountain Area (Fairbank Engineering, 2005) Exploration Activity Details Location Blue Mountain Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Geophysical surveys that have been conducted specifically for the geothermal program at Blue Mountain include a self-potential (SP) survey, and additional IP/electrical resistivity traversing. These surveys were conducted under a cooperative program between Noramex Corporation and the Energy and Geosciences Institute (EGI), University of Utah, with funding support from the DOE's Office of Geothermal Technology (DOE/OGT).

79

Validity of approximations applied in calculations of single-wall metallic carbon nanotube current-voltage characteristics  

Science Conference Proceedings (OSTI)

The calculation results of dependencies of electric current in the infinitely long single-wall metallic carbon nanotubes of armchair type with different diameter values on the strength of constant and uniform longitudinal electric field applied to them ... Keywords: Boltzmann equation, Current---voltage characteristic, Electron---phonon transport, Single-wall carbon nanotube

Dmitry Pozdnyakov

2012-12-01T23:59:59.000Z

80

Effect of natural convection on the current-voltage characteristic of a DC discharge in neon at intermediate pressures  

SciTech Connect

The parameters of the positive column of a glow discharge in neon are calculated with allowance for the induced hydrodynamic motion. It is shown that natural convection in the pressure range of {approx}0.1 atm significantly affects the profiles of the parameters of the positive column and its current-voltage characteristic. The convection arising at large deposited energies improves heat removal, due to which the temperature in the central region of the discharge becomes lower than that calculated from the heat conduction equation. As a result, the current-voltage characteristic is shifted. With allowance for convection, the current-voltage characteristic changes at currents much lower than the critical current at which a transition into the constricted state is observed. This change is uniquely related to the Rayleigh number in the discharge. Thus, a simplified analysis of thermal conduction and diffusion, even with detailed account of kinetic processes occurring in the positive column, does not allow one to accurately calculate the current-voltage characteristic and other discharge parameters at intermediate gas pressures.

Uvarov, A. V. [Moscow State University, Faculty of Physics (Russian Federation); Sakharova, N. A. [Russian Academy of Sciences, Semenov Institute of Chemical Physics (Russian Federation); Vinnichenko, N. A. [Moscow State University, Faculty of Physics (Russian Federation)

2011-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Current status of CMOS low voltage and low power wireless IC designs  

Science Conference Proceedings (OSTI)

This paper surveys recent research on CMOS low voltage and low power IC designs for wireless applications. Advancements and challenges in using nanometer IC processes are addressed, and the impacts of device scaling on wireless systems are discussed. ... Keywords: CMOS, Integrated Circuits (IC), Low-Power, Low-Voltage, Nanometer, Radio Frequency (RF), Sub-1V, Wireless

Tommy K. Tsang; Mourad N. El-Gamal; Krzysztof Iniewski; Kenneth A. Townsend; James W. Haslett; Yanjie Wang

2007-10-01T23:59:59.000Z

82

Utility-Scale Solar Power Converter: Agile Direct Grid Connect Medium Voltage 4.7-13.8 kV Power Converter for PV Applications Utilizing Wide Band Gap Devices  

SciTech Connect

Solar ADEPT Project: Satcon is developing a compact, lightweight power conversion device that is capable of taking utility-scale solar power and outputting it directly into the electric utility grid at distribution voltage levels—eliminating the need for large transformers. Transformers “step up” the voltage of the power that is generated by a solar power system so it can be efficiently transported through transmission lines and eventually “stepped down” to usable voltages before it enters homes and businesses. Power companies step up the voltage because less electricity is lost along transmission lines when the voltage is high and current is low. Satcon’s new power conversion devices will eliminate these heavy transformers and connect a utility-scale solar power system directly to the grid. Satcon’s modular devices are designed to ensure reliability—if one device fails it can be bypassed and the system can continue to run.

None

2012-01-25T23:59:59.000Z

83

Connecting Renewables Directly to the Grid: Resilient Multi-Terminal HVDC Networks with High-Voltage High-Frequency Electronics  

SciTech Connect

GENI Project: GE is developing electricity transmission hardware that could connect distributed renewable energy sources, like wind farms, directly to the grid—eliminating the need to feed the energy generated through intermediate power conversion stations before they enter the grid. GE is using the advanced semiconductor material silicon carbide (SiC) to conduct electricity through its transmission hardware because SiC can operate at higher voltage levels than semiconductors made out of other materials. This high-voltage capability is important because electricity must be converted to high-voltage levels before it can be sent along the grid’s network of transmission lines. Power companies do this because less electricity is lost along the lines when the voltage is high.

None

2012-01-23T23:59:59.000Z

84

CMOS Open Defect Detection Based on Supply Current in Time-Variable Electric Field and Supply Voltage Application  

Science Conference Proceedings (OSTI)

In this paper, a new test method is proposed for detecting open defects in CMOS ICs. The method is based on supply current of ICs generated by applying time-variable supply voltage and electric field from the outside of the ICs. The feasibility of the ...

Masaki Hashizume; Masahiro Ichimiya; Hiroyuki Yotsuyanagi; Takeomi Tamesada

2001-11-01T23:59:59.000Z

85

Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Savaghebi, Mehdi; Guerro, Josep M.; Jalilian, Alireza ; Quintero, Juan Carlos Vasquez  

E-Print Network (OSTI)

Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Savaghebi, Mehdi; Guerro-Connected Microgrids. In Proceedings of the 21st IEEE International Symposium on Industrial Electronics (ISIE), 2012;Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Mehdi Savaghebi1 , Josep M. Guerrero

Vasquez, Juan Carlos

86

Direct-Current Resistivity At Central Nevada Seismic Zone Region  

Open Energy Info (EERE)

At Central Nevada Seismic At Central Nevada Seismic Zone Region (Pritchett, 2004) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best way to find "hidden" basin and range geothermal resources of this general type is to carry out simultaneous SP and low-frequency MT surveys, and then

87

Advanced Faraday cage measurements of charge, short-circuit current and open-circuit voltage  

E-Print Network (OSTI)

(cont.) above atmospheric pressure caused both positive current and negative current pulses with the negative pulse larger than the positive pulse. A pressure decrease of more than 10psi below atmospheric pressure also ...

Amin, M. Shahrooz, 1981-

2004-01-01T23:59:59.000Z

88

Static current-voltage characteristics of Au/CaF{sub 2}/n-Si(111) MIS tunneling structures  

SciTech Connect

Using molecular-beam epitaxy, Au/CaF{sub 2}/n-Si(111) structures were fabricated that exhibit lower currents at a given fluoride film thickness (1.5-2 nm) than those of all similar structures studied. At a positive voltage at the metal, the current is in agreement with that calculated within the model with conservation of the transverse component of the wave vector during tunneling transport. Relative contributions of electron and hole components were analyzed for forward and reverse biases. The effect of the nonuniform distribution of the insulator thickness over the area on measured currents was estimated. The thin CaF{sub 2} layers that were grown are potentially applicable as barrier layers in various devices of functional electronics.

Suturin, S. M., E-mail: suturin@mail.ioffe.ru; Banshchikov, A. G.; Sokolov, N. S.; Tyaginov, S. E.; Vexler, M. I. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

2008-11-15T23:59:59.000Z

89

Design issues in low-voltage high-speed current-mode logic buffers  

Science Conference Proceedings (OSTI)

A current-mode logic (CML) buffer is based on a simple differential circuit. This paper investigates important problems involved in the design of a CML buffer as well as a chain of tapered CML buffers. A new design procedure to systematically design ... Keywords: VLSI, current-mode logic, high-speed, integrated circuit, noise

Payam Heydari

2003-04-01T23:59:59.000Z

90

DIRECT-DRIVE AND EDDY-CURRENT SEPTUM MAGNETS  

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

laminations and leakage fields are summarized in Appendices A and B, respectively. 2. Direct-Drive Septum For the upper half of the 2-D direct-drive septum magnet in Fig. 1 the...

91

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

92

Analysis and design of a high-current, high-voltage accurate power supply for the APS storage ring  

SciTech Connect

There are 81 dipole magnets contained in the storage ring at the Advanced Photon Source (APS). These magnets are connected in series and are energized by only one 12-phase power supply. The eighty-first magnet is located in a temperature-controlled room with an NMR probe to monitor the magnetic field in the magnet and provide a reference signal for correction of the field drift due to aging of the components. The current in the magnets will be held at 497 A. The required current stability of the power supply is {plus_minus}30 ppM, the current reproducibility is {plus_minus}50 ppM, and the current ripple is {plus_minus}400 ppM. The voltage required to maintain such a current in the magnets is about 1700 V. Different schemes for regulating current in the magnets are studied. Pspice software is used to simulate the behavior and the design of such a power supply under different conditions. The pros and cons of each scheme will be given and the proper power and regulating scheme will be selected.

Fathizadeh, M.

1993-08-01T23:59:59.000Z

93

EIS-0450: TransWest Express 600 kV Direct Current Transmission...  

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

50: TransWest Express 600 kV Direct Current Transmission Project in Wyoming, Colorado, Utah, and Nevada EIS-0450: TransWest Express 600 kV Direct Current Transmission Project in...

94

Generator Stator Core Condition Monitoring by Tracking Shaft Voltage and Grounding Current  

Science Conference Proceedings (OSTI)

In order to identify repairable problems early, generator core monitoring must be improved. The primary risks to core integrity are 1) deterioration of core lamination insulation, which results in electrical currents circulating through the core material, causing it to severely overheat and melt, and 2) relaxation of core pressure, which results in fatigue cracking of core laminations. Generator core condition monitors provide strong indicators of severe overheating of the core insulation. The indication...

2010-02-23T23:59:59.000Z

95

Pulsed current wave shaping with a transmission line by utilizing superposition of a forward and a backward voltage wave for fast capillary Z-pinch discharge  

Science Conference Proceedings (OSTI)

By using a water transmission line, current wave shaping was demonstrated for a fast capillary Z-pinch discharge recombination soft x-ray laser study. The pulsed power system consists of a water capacitor, a gap switch, a transmission line, and a capillary plasma load. A voltage wave initiated at the water capacitor propagates toward the capillary load through the transmission line. Control of the pulse delay that occurred in the transmission line provides the superposition of the forward and the backward voltage waves effectively in order to perform current wave shaping with higher current amplitude and rapid current decay.

Sakai, Y.; Takahashi, S.; Watanabe, M.; Hotta, E. [Department of Energy Sciences, Tokyo Institute of Technology, Nagatsuta, Midoriku, Yokohama, Kanagawa 226-8502 (Japan); Kim, G.-H. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2010-04-15T23:59:59.000Z

96

Direct current sputtering of boron from boron/coron mixtures  

DOE Patents (OSTI)

A method for coating a substrate with boron by sputtering includes lowering the electrical resistance of a boron-containing rod to allow electrical conduction in the rod; placing the boron-containing rod inside a vacuum chamber containing substrate material to be coated; applying an electrical potential between the boron target material and the vacuum chamber; countering a current avalanche that commences when the conduction heating rate exceeds the cooling rate, and until a steady equilibrium heating current is reached; and, coating the substrate material with boron by sputtering from the boron-containing rod.

Timberlake, John R. (Allentown, NJ); Manos, Dennis (Williamsburg, VA); Nartowitz, Ed (Edison, NJ)

1994-01-01T23:59:59.000Z

97

Direct current sputtering of boron from boron/carbon mixtures  

DOE Patents (OSTI)

A method for coating a substrate with boron by sputtering includes lowering the electrical resistance of a boron-containing rod to allow electrical conduction in the rod; placing the boron-containing rod inside a vacuum chamber containing substrate material to be coated; applying an electrical potential between the boron target material and the vacuum chamber; countering a current avalanche that commences when the conduction heating rate exceeds the cooling rate, and until a steady equilibrium heating current is reached and coating the substrate material with boron by sputtering from the boron-containing rod.

Timberlake, J.R.; Manos, D.; Nartowitz, E.

1993-12-31T23:59:59.000Z

98

Direct current sputtering of boron from boron/boron mixtures  

DOE Patents (OSTI)

A method for coating a substrate with boron by sputtering includes lowering the electrical resistance of a boron-containing rod to allow electrical conduction in the rod; placing the boron-containing rod inside a vacuum chamber containing substrate material to be coated; applying an electrical potential between the boron target material and the vacuum chamber; countering a current avalanche that commences when the conduction heating rate exceeds the cooling rate, and until a steady equilibrium heating current is reached; and, coating the substrate material with boron by sputtering from the boron-containing rod. 2 figures.

Timberlake, J.R.; Manos, D.; Nartowitz, E.

1994-12-13T23:59:59.000Z

99

Field Trial of impressed current, sacrificial anode, constant voltage and intermittent cathodic protection on a steel reinforced coastal bridge  

Science Conference Proceedings (OSTI)

Equipment has been designed and installed for a field trial being conducted on a coastal reinforced concrete bridge with a newly installed cathodic protection (CP) system. The purpose of the field trial is to determine the optimum form of intermittent CP for protecting coastal bridges. The forms of CP that were considered for the field trial are: (1) impressed current CP as the control; (2) currentinterrupted ICCP; (3) corrosion rate monitoring device controlled ICCP; (4) constant voltage CP; and (5) sacrificial anode CP. Once the test is initiated, the performance of these four forms of CP on a coastal RC bridge and their effectiveness in providing protection to reinforcing steel will be is compared with that achieved by present Oregon Department of Transportation ICCP practices. Details are presented on the set up of the experiment and the logic used to control CP intermittently. The field trial is scheduled to be started early 2007.

Bullard, S.J.; Covino, B.S., Jr.; Williamson, K.M.; Holcomb, G.R.; Ziomek-Moroz, M.; Eden, D.A. (Intercorr International Inc.); Cryer, C.B. (ODOT); Tran, H. (ODOT)

2007-03-01T23:59:59.000Z

100

Eddy Variability and Energetics from Direct Current Measurements in the Antarctic Circumpolar Current South of Australia  

Science Conference Proceedings (OSTI)

Two-year time series measurements of current velocity and temperature in the Subantarctic Front (SAF) south of Australia from 1993 to 1995 provide estimates of eddy fluxes of heat and momentum across the Antarctic Circumpolar Current (ACC) and ...

Helen E. Phillips; Stephen R. Rintoul

2000-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Current LDRD Schedule, Laboratory Directed Research and Development (LDRD)  

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

Homepage BNL Home Homepage BNL Home BNL: Departments | Science | ESS&H | Newsroom | Administration | Visitors | Directory search Go Find People Site Details LDRD Home Current Schedule Proposal Submission Subject Area DOE Order O413.2B DOE-SC Roles & Responsibilities Guidance dated 6/13/06 (pdf) LDRD Reports (PDFs) View Reports Other Information BNL Site Index Can't View PDFs? LDRD Schedule for Fiscal Year 2013 October 1, 2012 FY 2013 Approval of Funding Ceiling from DOE - SC October 1 FY 2013 Individual Project Approvals by DOE - BHSO October 15 Call for FY2012 Individual Project Annual Reports October 31 Information Due to the OMBE/CFO Database November 15 Complex-wide Data from HQ Due to Congress November 20 FY 2012 Individual Project Annual Reports Due

102

High-Resolution Directional Wave Spectra from Horizontally Mounted Acoustic Doppler Current Meters  

Science Conference Proceedings (OSTI)

The paper discusses the estimation of directional wave spectra by the Iterative Maximum Likelihood Method. The performance of the estimate is illustrated using data obtained by an Acoustic Doppler Current Meter in the CUrrent Measurement ...

Harald E. Krogstad; R. Lee Gordon; Martin C. Miller

1988-04-01T23:59:59.000Z

103

Direct-Current Resistivity Survey At Soda Lake Area (Combs 2006...  

Open Energy Info (EERE)

Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes "EM sounding, MT, CSAMT, dipole-dipole resistivity; reservoir...

104

Oscillation modes of direct current microdischarges with parallel-plate geometry  

SciTech Connect

Two different oscillation modes in microdischarge with parallel-plate geometry have been observed: relaxation oscillations with frequency range between 1.23 and 2.1 kHz and free-running oscillations with 7 kHz frequency. The oscillation modes are induced by increasing power supply voltage or discharge current. For a given power supply voltage, there is a spontaneous transition from one to other oscillation mode and vice versa. Before the transition from relaxation to free-running oscillations, the spontaneous increase of oscillation frequency of relaxation oscillations form 1.3 kHz to 2.1 kHz is measured. Fourier transform spectra of relaxation oscillations reveal chaotic behavior of microdischarges. Volt-ampere (V-A) characteristics associated with relaxation oscillations describes periodical transition between low current, diffuse discharge, and normal glow. However, free-running oscillations appear in subnormal glow only.

Stefanovic, Ilija; Kuschel, Thomas; Winter, Joerg [Institut fuer Experimentalphysik II, Ruhr-Universitaet Bochum, 44781 Bochum (Germany); Skoro, Nikola; Maric, Dragana; Petrovic, Zoran Lj [Institute of Physics, University of Belgrade, POB 68, 11080 Belgrade (Serbia)

2011-10-15T23:59:59.000Z

105

Students' understanding of direct current resistive electrical circuits Paula Vetter Engelhardta)  

E-Print Network (OSTI)

for the answer key as well as for the objectives. Both open- ended questions during the early development stagesStudents' understanding of direct current resistive electrical circuits Paula Vetter Engelhardta regarding direct current resistive electric circuits often differ from the accepted explanations. At present

Zollman, Dean

106

Direct-Current Resistivity Survey At Roosevelt Hot Springs Area (Combs  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Roosevelt Hot Springs Area (Combs Direct-Current Resistivity Survey At Roosevelt Hot Springs Area (Combs 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Roosevelt Hot Springs Area (Combs 2006) Exploration Activity Details Location Roosevelt Hot Springs Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes "SP, MT, dipole-dipole resistivity, CSAMT; sufficient electrical data may be available" References Jim Combs (1 January 2006) Historical Exploration And Drilling Data From Geothermal Prospects And Power Generation Projects In The Western United States Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Roosevelt_Hot_Springs_Area_(Combs_2006)&oldid=510548"

107

Direct-Current Resistivity At Cove Fort Area - Liquid (Combs 2006) | Open  

Open Energy Info (EERE)

Direct-Current Resistivity At Cove Fort Area - Liquid (Combs 2006) Direct-Current Resistivity At Cove Fort Area - Liquid (Combs 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Cove Fort Area (Combs 2006) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes "SP, dipole-dipole resistivity, CSAMT; sufficient electrical data are available. Reservoir model?" References Jim Combs (1 January 2006) Historical Exploration And Drilling Data From Geothermal Prospects And Power Generation Projects In The Western United States Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_At_Cove_Fort_Area_-_Liquid_(Combs_2006)&oldid=598123

108

Direct-Current Resistivity Survey At Cove Fort Area - Vapor (Warpinski, Et  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Cove Fort Area - Vapor (Warpinski, Et Direct-Current Resistivity Survey At Cove Fort Area - Vapor (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Cove Fort Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal Resource Exploration And Definition Projects Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Cove_Fort_Area_-_Vapor_(Warpinski,_Et_Al.,_2004)&oldid=598134"

109

Direct-Current Resistivity At Cove Fort Area - Liquid (Warpinski, Et Al.,  

Open Energy Info (EERE)

Direct-Current Resistivity At Cove Fort Area - Liquid (Warpinski, Et Al., Direct-Current Resistivity At Cove Fort Area - Liquid (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal Resource Exploration And Definition Projects Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_At_Cove_Fort_Area_-_Liquid_(Warpinski,_Et_Al.,_2004)&oldid=598125" Categories: Exploration Activities

110

Direct-Current Resistivity Survey At Marysville Mt Area (Blackwell) | Open  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Marysville Mt Area (Blackwell) Direct-Current Resistivity Survey At Marysville Mt Area (Blackwell) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Marysville Mt Area (Blackwell) Exploration Activity Details Location Marysville Mt Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes A dipole-dipole resistivity survey of the area was carried out with estimated penetration up to 700 meters and no indication of low values of resistivity were found associated with the thermal anomaly. References D. D. Blackwell (Unknown) Exploration In A Blind Geothermal Area Near Marysville, Montana, Usa Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Marysville_Mt_Area_(Blackwell)&oldid=510539

111

Direct-Current Resistivity At Brady Hot Springs Area (Combs 2006) | Open  

Open Energy Info (EERE)

Direct-Current Resistivity At Brady Hot Springs Area (Combs 2006) Direct-Current Resistivity At Brady Hot Springs Area (Combs 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Brady Hot Springs Area (Combs 2006) Exploration Activity Details Location Brady Hot Springs Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes "sufficient geophysical data are not available" References Jim Combs (1 January 2006) Historical Exploration And Drilling Data From Geothermal Prospects And Power Generation Projects In The Western United States Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_At_Brady_Hot_Springs_Area_(Combs_2006)&oldid=594379"

112

Direct-Current Resistivity Survey At Cove Fort Area - Liquid (Combs 2006) |  

Open Energy Info (EERE)

- Liquid (Combs 2006) - Liquid (Combs 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Cove Fort Area (Combs 2006) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes "SP, dipole-dipole resistivity, CSAMT; sufficient electrical data are available. Reservoir model?" References Jim Combs (1 January 2006) Historical Exploration And Drilling Data From Geothermal Prospects And Power Generation Projects In The Western United States Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Cove_Fort_Area_-_Liquid_(Combs_2006)&oldid=598127"

113

Direct-Current Resistivity Survey At Hualalai Northwest Rift Area (Thomas,  

Open Energy Info (EERE)

Hualalai Northwest Rift Area (Thomas, Hualalai Northwest Rift Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Hualalai Northwest Rift Area (Thomas, 1986) Exploration Activity Details Location Hualalai Northwest Rift Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes A total of seven Schlumberger soundings were performed on Hualalai. References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In Hawaii Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Hualalai_Northwest_Rift_Area_(Thomas,_1986)&oldid=510528" Category: Exploration Activities What links here Related changes

114

Direct-Current Resistivity Survey At Cove Fort Area - Vapor (Warpinski, Et  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Cove Fort Area - Vapor (Warpinski, Et Direct-Current Resistivity Survey At Cove Fort Area - Vapor (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Cove Fort Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location.

115

Direct-Current Resistivity At Kilauea Southwest Rift And South Flank Area  

Open Energy Info (EERE)

Direct-Current Resistivity At Kilauea Southwest Rift And South Flank Area Direct-Current Resistivity At Kilauea Southwest Rift And South Flank Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Kilauea Southwest Rift And South Flank Area (Thomas, 1986) Exploration Activity Details Location Kilauea Southwest Rift And South Flank Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The electrical resistivity data acquired on the southwest rift delineated two distinct basement resistivity structures northwest of the rift zone: a high-resistivity basement at approximately 60 m a.s.l, and located north of a prehistoric fissure, and a low-resistivity deep basement (20 m a.s.1.) to the south and east of this fissure (Figs 48, 49). These data suggest that a

116

Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2002) |  

Open Energy Info (EERE)

Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2002) Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location. References N. R. Warpinski, A. R. Sattlerl, D. A. Sanchez (2002) Geothermal

117

Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2002) |  

Open Energy Info (EERE)

(Redirected from Direct-Current Resistivity At Cove Fort Area - Vapor (Redirected from Direct-Current Resistivity At Cove Fort Area - Vapor (Warpinski, Et Al., 2002)) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location.

118

Direct-Current Resistivity Survey At Lightning Dock Area (Cunniff & Bowers,  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Lightning Dock Area (Cunniff & Bowers, Direct-Current Resistivity Survey At Lightning Dock Area (Cunniff & Bowers, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Lightning Dock Area (Cunniff & Bowers, 2005) Exploration Activity Details Location Lightning Dock Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Two electrical resistivity survey lines were run in the project area: a southern east-west line along Caliche Road, and a northern east-west line in the south half Section 6, T25S, R19W (figure 5). The Caliche Road line is located south of the greenhouse complex and was run along the road, which was also used for a gravity traverse. The northern line, named

119

Direct-Current Resistivity Survey At Coso Geothermal Area (1977) | Open  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Coso Geothermal Area (1977) Direct-Current Resistivity Survey At Coso Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Coso Geothermal Area (1977) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date 1977 Usefulness useful regional reconnaissance DOE-funding Unknown Exploration Basis To investigate electrical properties of rocks associated with thermal phenomena of the Devil's Kitchen-Coso Hot Springs area Notes DC resistivity geophysical surveys determined that the secondary low in the geothermal area, best defined by the 7.5-Hz AMT map and dc soundings, is caused by a shallow conductive zone (5--30 ohm m) interpreted to be

120

EIS-0450: TransWest Express 600 kV Direct Current Transmission Project in  

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

0: TransWest Express 600 kV Direct Current Transmission 0: TransWest Express 600 kV Direct Current Transmission Project in Wyoming, Colorado, Utah, and Nevada EIS-0450: TransWest Express 600 kV Direct Current Transmission Project in Wyoming, Colorado, Utah, and Nevada Summary This EIS, being prepared jointly by DOE's Western Area Power Administration and the Department of the Interior's Bureau of Land Management (Wyoming State Office), evaluates the environmental impacts of granting a right-of-way for the TransWest Express 600-kilovolt Direct Current Transmission Project and amending a land use plan. The project consists of an overhead transmission line that would extend approximately 725 miles from south-central Wyoming, through Colorado and Utah. Western proposes to be a joint owner of the project. Public Comment Opportunities

Note: This page contains sample records for the topic "voltage direct current" 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

Direct-Current Resistivity Survey At Kilauea Southwest Rift And South Flank  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Kilauea Southwest Rift And South Flank Direct-Current Resistivity Survey At Kilauea Southwest Rift And South Flank Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Kilauea Southwest Rift And South Flank Area (Thomas, 1986) Exploration Activity Details Location Kilauea Southwest Rift And South Flank Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The electrical resistivity data acquired on the southwest rift delineated two distinct basement resistivity structures northwest of the rift zone: a high-resistivity basement at approximately 60 m a.s.l, and located north of a prehistoric fissure, and a low-resistivity deep basement (20 m a.s.1.) to

122

Key elements for a sensitive 77 K direct current superconducting quantum interference device magnetometer  

E-Print Network (OSTI)

B is the applied field and sq is the flux coupled to the SQUID. Aeff is determined by the design determined by the smaller inductance, but flux linking the pickup loop induces a current which couples fluxKey elements for a sensitive 77 K direct current superconducting quantum interference device

Lee, Luke P.

123

THE DEVELOPMENT OF A DIRECT COUPLED, TRANSISTORIZED, SUB-MILLIMICROAMPERE CURRENT AMPLIFIER  

SciTech Connect

Development of a direct coupled, transistorized current amplifler is reported with sensitivities extending below the millimicroampere region of input currents. The amplifier employs a shunt feedback and exhibits reproducible characteristics. Discovery of this special effect and the design and testing employed in the incorporation of transistors into the amplifier are described. (J.R.D.)

May, F.T.

1961-08-11T23:59:59.000Z

124

Device for monitoring cell voltage  

SciTech Connect

A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.

Doepke, Matthias (Garbsen, DE); Eisermann, Henning (Edermissen, DE)

2012-08-21T23:59:59.000Z

125

Feasibility Study for the Development of High-Voltage, Low-Current Power Semiconductor Devices: 2003 Strategic Science and Technolog y Project  

Science Conference Proceedings (OSTI)

The intelligent universal transformer (IUT) will be an advanced power-electronics replacement for conventional distribution transformers that adds significant new functional capabilities to those available from conventional copper and iron transformers. This report assesses the state of the art and development options for obtaining high-voltage, low-current power semiconductors (both switches and diodes) needed in the circuit topology being developed for the IUT.

2004-03-29T23:59:59.000Z

126

High voltage DC power supply  

DOE Patents (OSTI)

A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.

Droege, T.F.

1989-12-19T23:59:59.000Z

127

Direct-Current Resistivity Survey At Mauna Loa Northeast Rift Area (Thomas,  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Mauna Loa Direct-Current Resistivity Survey At Mauna Loa Northeast Rift Area (Thomas, 1986) Exploration Activity Details Location Mauna Loa Northeast Rift Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The vertical electrical sounding surveys encountered few difficulties and were able to resolve basement resistivities in all locations. The resistivity sections derived indicated a 3000- 20,000 ohm.m surface layer underlain by a 500- 900 ohm-m cold freshwatersaturated layer and a basement layer of less than 100 ohm.m (Kauahikaua and Mattice, 1981). The depth of penetration of these soundings was estimated to be about 800 m to 900 m b.s.1. and thus the basement resistivities probably correspond to basalts

128

Direct-Current Resistivity Survey At Clear Lake Area (Skokan, 1993) | Open  

Open Energy Info (EERE)

Area (Skokan, 1993) Area (Skokan, 1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Clear Lake Area (Skokan, 1993) Exploration Activity Details Location Clear Lake Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Several direct-current, bipole-dipole surveys were carried out in the area. These field measurements (Rapolla and Keller, 1984) were combined by spatially averaging apparent resistivities on a one kilometer grid ( Fig. 6 ). The authors felt that local geologic noise could be reduced and large-scale features would be emphasized by this averaging. The most significant feature which resulted was a clear electrical signature of the

129

Direct-Current Resistivity Survey At Nw Basin & Range Region (Pritchett,  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity Survey At Nw Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Nw Basin & Range Region (Pritchett, 2004) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The

130

Direct-Current Resistivity Survey At Haleakala Volcano Area (Thomas, 1986)  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Haleakala Direct-Current Resistivity Survey At Haleakala Volcano Area (Thomas, 1986) Exploration Activity Details Location Haleakala Volcano Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The field survey program on the northwest rift zone consisted of soil mercury and radon emanometry surveys, groundwater temperature and chemistry studies, Schlumberger resistivity soundings and self-potential profiles. Geophysical and geochemical surveys along this rift (southwest) were limited by difficult field conditions and access limitations. The geophysical program consisted of one Schlumberger sounding, one self-potential profile and one controlled-source electromagnetic sounding. The geochemical data collected included a reconnaissance soil mercury and

131

Direct-Current Resistivity Survey At Mt Princeton Hot Springs Area  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity Survey At Mt Princeton Hot Springs Area (Richards, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Mt Princeton Hot Springs Area (Richards, Et Al., 2010) Exploration Activity Details Location Mt Princeton Hot Springs Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Used to map fracture and fluid flow patterns. References K. Richards, A. Revil, A. Jardani, F. Henderson, M. Batzle, A. Haas (2010) Pattern Of Shallow Ground Water Flow At Mount Princeton Hot Springs,

132

Direct-Current Resistivity Survey At Mokapu Penninsula Area (Thomas, 1986)  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Mokapu Direct-Current Resistivity Survey At Mokapu Penninsula Area (Thomas, 1986) Exploration Activity Details Location Mokapu Penninsula Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Geophysical surveys on Mokapu were restricted to three Schlumberger soundings (Fig. 17). The results of these soundings appeared to indicate a highly resistive surface section underlain by one or more layers of intermediate to low resistivity (Fig. 18). Basement resistivities in all cases were less than 3 ohm.m and were interpreted to correspond to alluvial layers saturated with cold seawater (Lienert, 1982). --- A separate geophysical analysis performed on the Koolau caldera area (Kauahikaua, 1981 a) synthesized existing self-potential, gravity, seismic and aeromagnetic

133

Direct-Current Resistivity At Long Valley Caldera Area (Pribnow, Et Al.,  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity At Long Valley Caldera Area (Pribnow, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Long Valley Caldera Area (Pribnow, Et Al., 2003) Exploration Activity Details Location Long Valley Caldera Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes DC electrical sounding measurements provide a 2-D image of the resistivity distribution beneath Long Valley Caldera. Conductive zones and SP anomalies correlate with the location of known faults in agreement with previous

134

Direct-Current Resistivity Survey At Dixie Valley Geothermal Field Area  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Dixie Valley Direct-Current Resistivity Survey At Dixie Valley Geothermal Field Area (Laney, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Structural Controls, Alteration, Permeability and Thermal Regime of Dixie Valley from New-Generation Mt/Galvanic Array Profiling, Phillip Wannamaker. A new-generation MT/DC array resistivity measurement system was applied at the Dixie Valley thermal area. Basic goals of the survey are 1), resolve a fundamental structural ambiguity at the Dixie Valley thermal area (single rangefront fault versus shallower, stepped pediment; 2), delineate fault zones which have experienced fluid flux as indicated by low resistivity;

135

Direct-Current Resistivity Survey At Kilauea Summit Area (Keller, Et Al.,  

Open Energy Info (EERE)

1979) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Kilauea Summit Area (Keller, Et Al., 1979) Exploration Activity Details Location Kilauea Summit Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes An electromagnetic sounding survey by Jackson and Keller (1972) defined a strong resistivity anomaly above the center of inflation associated with volcanic activity during the early 1960's. References George V. Keller, L. Trowbridge Grose, John C. Murray, Catherine K. Skokan (1979) Results Of An Experimental Drill Hole At The Summit Of Kilauea Volcano, Hawaii Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Kilauea_Summit_Area_(Keller,_Et_Al.,_1979)&oldid=510532

136

Direct-Current Resistivity Survey At Cove Fort Area (Warpinski, Et Al.,  

Open Energy Info (EERE)

(Warpinski, Et Al., (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Cove Fort Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal Resource Exploration And Definition Projects Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Cove_Fort_Area_(Warpinski,_Et_Al.,_2004)&oldid=598126" Categories: Exploration Activities DOE Funded Activities What links here

137

Direct-Current Resistivity At Haleakala Volcano Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity At Haleakala Volcano Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Haleakala Volcano Area (Thomas, 1986) Exploration Activity Details Location Haleakala Volcano Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The field survey program on the northwest rift zone consisted of soil mercury and radon emanometry surveys, groundwater temperature and chemistry studies, Schlumberger resistivity soundings and self-potential profiles.

138

Direct-Current Resistivity Survey At Long Valley Caldera Area (Pribnow, Et  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity Survey At Long Valley Caldera Area (Pribnow, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Long Valley Caldera Area (Pribnow, Et Al., 2003) Exploration Activity Details Location Long Valley Caldera Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes DC electrical sounding measurements provide a 2-D image of the resistivity distribution beneath Long Valley Caldera. Conductive zones and SP anomalies

139

Direct-Current Resistivity At Kilauea Summit Area (Keller, Et Al., 1979) |  

Open Energy Info (EERE)

Summit Area (Keller, Et Al., 1979) Summit Area (Keller, Et Al., 1979) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Kilauea Summit Area (Keller, Et Al., 1979) Exploration Activity Details Location Kilauea Summit Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes An electromagnetic sounding survey by Jackson and Keller (1972) defined a strong resistivity anomaly above the center of inflation associated with volcanic activity during the early 1960's. References George V. Keller, L. Trowbridge Grose, John C. Murray, Catherine K. Skokan (1979) Results Of An Experimental Drill Hole At The Summit Of Kilauea Volcano, Hawaii Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_At_Kilauea_Summit_Area_(Keller,_Et_Al.,_1979)&oldid=594370"

140

Direct-Current Resistivity At Clear Lake Area (Skokan, 1993) | Open Energy  

Open Energy Info (EERE)

Clear Lake Area (Skokan, 1993) Clear Lake Area (Skokan, 1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Clear Lake Area (Skokan, 1993) Exploration Activity Details Location Clear Lake Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Several direct-current, bipole-dipole surveys were carried out in the area. These field measurements (Rapolla and Keller, 1984) were combined by spatially averaging apparent resistivities on a one kilometer grid ( Fig. 6 ). The authors felt that local geologic noise could be reduced and large-scale features would be emphasized by this averaging. The most significant feature which resulted was a clear electrical signature of the

Note: This page contains sample records for the topic "voltage direct current" 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

Direct-Current Resistivity Survey At Mauna Loa Southwest Rift Area (Thomas,  

Open Energy Info (EERE)

Area (Thomas, Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Mauna Loa Southwest Rift Area (Thomas, 1986) Exploration Activity Details Location Mauna Loa Southwest Rift Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Field surveys in the South Point area were limited to a series of Schlumberger soundings and a self-potential traverse across the rift zone. The absence of groundwater wells and time and funding constraints precluded any geochemical field surveys. References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In Hawaii Retrieved from "http://en.openei.org/w/index.php?title=Direct-Current_Resistivity_Survey_At_Mauna_Loa_Southwest_Rift_Area_(Thomas,_1986)&oldid=510541"

142

Direct-Current Resistivity Survey At Kawaihae Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity Survey At Kawaihae Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Kawaihae Area (Thomas, 1986) Exploration Activity Details Location Kawaihae Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes In addition to the aeromagnetic data, the field survey program in Kawaihae included six Schlumberger resistivity soundings between Kawaihae and Waimea (Kauahikaua and Mattice, 1981). The results of these sounding (Fig. 35)

143

Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2004) |  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Cove Fort Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal Resource Exploration And Definition Projects

144

Direct-Current Resistivity At Lualualei Valley Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

Lualualei Valley Area (Thomas, 1986) Lualualei Valley Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Lualualei Valley Area (Thomas, 1986) Exploration Activity Details Location Lualualei Valley Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Three Schlumberger resistivity soundings were performed in Lualualei Valley (Mattice and Kauahikaua, 1979). K840 Interpretation of the resistivity soundings suggests that the source of the warm water layer within the valley was the dense dike complex associated with the ancient magma chamber of Waianae volcano. References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In Hawaii Retrieved from

145

Direct-Current Resistivity Survey At Lightning Dock Area (Warpinski, Et  

Open Energy Info (EERE)

Et Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Lightning Dock Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Lightning Dock Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes As a foundation for successful siting and drilling a deep test well, additional geophysical work has been completed including gravity, resistivity, and airborne magnetic surveys. Several new seismic profiles are planned to provide more focused siting and drilling plans. These new geophysical surveys are being integrated into the combined thermal, hydrologic, and subsurface stratigraphic information data sets to provide a

146

Direct-Current Resistivity Survey At Walker-Lane Transitional Zone Region  

Open Energy Info (EERE)

Pritchett, 2004) Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Walker-Lane Transitional Zone Region (Pritchett, 2004) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best

147

Combination, a model vehicle engine and a direct-current generator  

SciTech Connect

This patent describes an engine for a model vehicle and a direct-current generator, comprising: an internal-combustion engine; and a direct-current generator operatively coupled to the engine; wherein the generator comprises an armature, and a drive coupling member drivingly engaged with the armature; the armature has three poles; each of the poles has not less than six hundred turns of magnetic wire; the engine having first means comprising a crankshaft, and second means comprising a connecting rod; and one of the first a second means has means for drivingly engaging the drive coupling for imparting rotation to the generator from the engine.

Williams, G.A.

1987-01-20T23:59:59.000Z

148

Direct-Current Resistivity At Lightning Dock Area (Warpinski, Et Al., 2002)  

Open Energy Info (EERE)

2) 2) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Lightning Dock Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Lightning Dock Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes As a foundation for successful siting and drilling a deep test well, additional geophysical work has been completed including gravity, resistivity, and airborne magnetic surveys. Several new seismic profiles are planned to provide more focused siting and drilling plans. These new geophysical surveys are being integrated into the combined thermal, hydrologic, and subsurface stratigraphic information data sets to provide a

149

Direct-Current Resistivity Survey At Lualualei Valley Area (Thomas, 1986) |  

Open Energy Info (EERE)

Lualualei Valley Area (Thomas, 1986) Lualualei Valley Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Lualualei Valley Area (Thomas, 1986) Exploration Activity Details Location Lualualei Valley Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Three Schlumberger resistivity soundings were performed in Lualualei Valley (Mattice and Kauahikaua, 1979). K840 Interpretation of the resistivity soundings suggests that the source of the warm water layer within the valley was the dense dike complex associated with the ancient magma chamber of Waianae volcano. References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In Hawaii

150

Direct-Current Resistivity Survey At Northern Basin & Range Region  

Open Energy Info (EERE)

Region Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Northern Basin & Range Region (Pritchett, 2004) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best

151

Stray current interference control for HVDC earth currents  

SciTech Connect

High-voltage direct current (HVDC) transmission lines exist around the world, with several in the US. When one conductor must be taken out of operation (in case of emergency), the earth may be used as an alternate conductor. The earth current may be accumulated on and discharged from underground metallic structures that cross the voltage gradient created by the current. Test results on two lines showed that stray current interference is not a major problem if mitigated properly.

Fitzgerald, J.H. III [PSG Corrosion Engineering/Corrpro Cos., Detroit, MI (United States); Kroon, D.H. [Corrpro Companies Inc., Spring, TX (United States)

1995-06-01T23:59:59.000Z

152

Direct-Current Resistivity Survey At Raft River Geothermal Area (1983) |  

Open Energy Info (EERE)

Raft River Geothermal Area (1983) Raft River Geothermal Area (1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Raft River Geothermal Area (1983) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date 1983 Usefulness not indicated DOE-funding Unknown Notes The objectives of the resistivity measurements were to determine if measureable changes could be observed and whether they could be used to infer the direction of fluid flow. Most of the apparent resistivity changes observed after the injection phase of Test 5 are smaller than the estimated standard deviation of the measurements. However, the contour map of the changes suggest an anomalous trend to the northeast which is similar to the

153

Experimental and theoretical studies of a high temperature cesium-barium tacitron, with application to low voltage-high current inversion. Final report, April 1, 1993--February 28, 1994  

SciTech Connect

A low voltage/high current switch refer-red as ``Cs-Ba tacitron`` is studied for use as a dc to ac inverter in high temperature and/or ionizing radiation environments. The operational characteristics of the Cs-Ba tacitron as a switch were investigated experimentally in three modes: (a) breakdown mode, (b) I-V mode, and (c) current modulation mode. Operation parameters measured include switching frequencies up to 20 kHz, hold-off voltages up to 200 V, current densities in excess of 15 A/CM{sup 2}, switch power density of 1 kW/cm{sup 2}, and a switching efficiency in excess of 90 % at collector voltages greater than 30 V. Also, if the discharge current is circuit limited to a value below the maximum thermal emission current density, the voltage drop is constant and below 3 V.

Murray, C.S.; El-Genk, M.S.

1994-02-01T23:59:59.000Z

154

Fluid modeling of radio frequency and direct currents in a biased magnetized plasma  

SciTech Connect

This model aims at simulating a magnetized plasma column connected on one side to a probe and on the other side to an ICRH (Ion Cyclotron Resonant Heating) antenna. This is a double probe modeling of a plasma flux tube exchanging perpendicular currents: rf polarization current and dc currents (inertia, viscous, and friction) perpendicular to the magnetic field. A self consistent solution for the rectified potential and the density is obtained under the assumptions of flute hypothesis, inertialess electrons, and no collision in parallel direction. The main effect of rf biasing on the antenna side is to shift the IV characteristic so that the floating potential can be increased up to ln(I{sub 0}(eV{sub rf}/(k{sub B}T{sub e}))), with I{sub 0} the modified Bessel function of the first kind. On the contrary, the effect of dc currents is to decrease the plasma potential and the sheath potential which can be lower than 3k{sub B}T{sub e}/e or even be negative. Experimental characteristics are well matched by the 1D fluid code and exhibit very high negative currents (more than 30 j{sub i} the ion saturation current) for high positive biasing of the probe and for long flux tube (10 m). The non-saturation of the electron current is here due to high transverse transport enhanced by convective fluxes and dc currents able to bring an amount of density around the biased flux tube. During comparisons with experiments, the floating potential measured by a reciprocating probe is recovered by the code revealing that for a 120 V measured peak potential on the probe, the rf potential on the ICRH antenna is twice this value. Finally, the density profile can be flattened or steepened as a function of the transverse dc current direction.

Faudot, E.; Heuraux, S. [IJL-P2M UMR 7198 CNRS, F-54506 Vandoeuvre les Nancy, IJL, P2M-Faculte des Sciences, Vandoeuvre les Nancy 54506 (France); Kubic, M.; Gunn, J.; Colas, L. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

2013-04-15T23:59:59.000Z

155

TRANSISTOR HIGH VOLTAGE POWER SUPPLY  

DOE Patents (OSTI)

High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

Driver, G.E.

1958-07-15T23:59:59.000Z

156

Direct-Current Resistivity Survey At Valles Caldera - Redondo Area (Wilt &  

Open Energy Info (EERE)

Wilt & Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Valles Caldera - Redondo Area (Wilt & Haar, 1986) Exploration Activity Details Location Valles Caldera - Redondo Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Telluric profiles, magnetotelluric sounding, dc resistivity, and electromagnetic sounding surveys were all performed over the caldera in hopes of outlining deep drilling targets (Group 7 Inc., 1972; McPhar, 1973; Geonomics Inc., 1976). These data are used to help define the electrical structure in the reservoir region. Some of the data were reinterpreted using computer models, and interpretations from the various surveys were

157

Direct-Current Resistivity Survey At Valles Caldera - Sulphur Springs Area  

Open Energy Info (EERE)

Wilt & Haar, 1986) Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Valles Caldera - Sulphur Springs Area (Wilt & Haar, 1986) Exploration Activity Details Location Valles Caldera - Sulphur Springs Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Telluric profiles, magnetotelluric sounding, dc resistivity, and electromagnetic sounding surveys were all performed over the caldera in hopes of outlining deep drilling targets (Group 7 Inc., 1972; McPhar, 1973; Geonomics Inc., 1976). These data are used to help define the electrical structure in the reservoir region. Some of the data were reinterpreted using computer models, and interpretations from the various surveys were

158

Direct-Current Resistivity At Kilauea East Rift Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

Kilauea East Rift Area (Thomas, 1986) Kilauea East Rift Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Kilauea East Rift Area (Thomas, 1986) Exploration Activity Details Location Kilauea East Rift Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Electrical resistivity studies performed on the Kilauea East Rift Zone have employed a variety of techniques. Bipole mapping was conducted by Keller et al. (1977a) as part of the Hawaii Geothermal Project (HGP) geoscience program and was able to provide data on the regional resistivity structure of the summit and eastern flank of Kilauea. The model developed indicated several different types of resistivity sections depending on the location

159

Direct-Current Resistivity At Kawaihae Area (Thomas, 1986) | Open Energy  

Open Energy Info (EERE)

Kawaihae Area (Thomas, 1986) Kawaihae Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Kawaihae Area (Thomas, 1986) Exploration Activity Details Location Kawaihae Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes In addition to the aeromagnetic data, the field survey program in Kawaihae included six Schlumberger resistivity soundings between Kawaihae and Waimea (Kauahikaua and Mattice, 1981). The results of these sounding (Fig. 35) detected apparent resistivity differences in the surface rock depending on whether the soundings were done on Kohala or Mauna Kea lavas (Figs 36, 37), whereas uniform resistivities of 650- 850 ohm.m were found at depths of

160

Direct-Current Resistivity At Dixie Valley Geothermal Field Area (Laney,  

Open Energy Info (EERE)

2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Dixie Valley Geothermal Field Area (Laney, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Structural Controls, Alteration, Permeability and Thermal Regime of Dixie Valley from New-Generation Mt/Galvanic Array Profiling, Phillip Wannamaker. A new-generation MT/DC array resistivity measurement system was applied at the Dixie Valley thermal area. Basic goals of the survey are 1), resolve a fundamental structural ambiguity at the Dixie Valley thermal area (single rangefront fault versus shallower, stepped pediment; 2), delineate fault

Note: This page contains sample records for the topic "voltage direct current" 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

Direct-Current Resistivity Survey At Cove Fort Area (Warpinski, Et Al.,  

Open Energy Info (EERE)

Cove Fort Area (Warpinski, Et Al., Cove Fort Area (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Cove Fort Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location. References N. R. Warpinski, A. R. Sattlerl, D. A. Sanchez (2002) Geothermal

162

Direct-Current Resistivity At Lightning Dock Area (Cunniff & Bowers, 2005)  

Open Energy Info (EERE)

Lightning Dock Area (Cunniff & Bowers, 2005) Lightning Dock Area (Cunniff & Bowers, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Lightning Dock Area (Cunniff & Bowers, 2005) Exploration Activity Details Location Lightning Dock Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Two electrical resistivity survey lines were run in the project area: a southern east-west line along Caliche Road, and a northern east-west line in the south half Section 6, T25S, R19W (figure 5). The Caliche Road line is located south of the greenhouse complex and was run along the road, which was also used for a gravity traverse. The northern line, named "Church Road,"+K846 was parallel to the east-west road and gravity

163

Direct-Current Resistivity Survey At Kilauea East Rift Area (Thomas, 1986)  

Open Energy Info (EERE)

Kilauea East Rift Area (Thomas, 1986) Kilauea East Rift Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Kilauea East Rift Area (Thomas, 1986) Exploration Activity Details Location Kilauea East Rift Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Electrical resistivity studies performed on the Kilauea East Rift Zone have employed a variety of techniques. Bipole mapping was conducted by Keller et al. (1977a) as part of the Hawaii Geothermal Project (HGP) geoscience program and was able to provide data on the regional resistivity structure of the summit and eastern flank of Kilauea. The model developed indicated several different types of resistivity sections depending on the location

164

Direct-Current Resistivity At Honokowai Area (Thomas, 1986) | Open Energy  

Open Energy Info (EERE)

Honokowai Area (Thomas, 1986) Honokowai Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Honokowai Area (Thomas, 1986) Exploration Activity Details Location Honokowai Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not useful DOE-funding Unknown Notes Three Schlumberger resistivity surveys were attempted on the alluvial plain around Honokowai (Fig. 22). Two of the soundings penetrated to a moderate-resistivity basement, interpreted to be seawater-saturated basalt, whereas the other sounding encountered a high-resistivity intermediate layer which could not be adequately penetrated to allow resolution of the basement resistivity (Mattice, 1981). References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In

165

Direct-Current Resistivity Survey At Honokowai Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

Honokowai Area (Thomas, 1986) Honokowai Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Honokowai Area (Thomas, 1986) Exploration Activity Details Location Honokowai Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not useful DOE-funding Unknown Notes Three Schlumberger resistivity surveys were attempted on the alluvial plain around Honokowai (Fig. 22). Two of the soundings penetrated to a moderate-resistivity basement, interpreted to be seawater-saturated basalt, whereas the other sounding encountered a high-resistivity intermediate layer which could not be adequately penetrated to allow resolution of the basement resistivity (Mattice, 1981). References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In

166

Direct-Current Resistivity Survey At Stillwater Area (Laney, 2005) | Open  

Open Energy Info (EERE)

Stillwater Area (Laney, 2005) Stillwater Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Stillwater Area (Laney, 2005) Exploration Activity Details Location Stillwater Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Structural Controls, Alteration, Permeability and Thermal Regime of Dixie Valley from New-Generation Mt/Galvanic Array Profiling, Phillip Wannamaker. A new-generation MT/DC array resistivity measurement system was applied at the Dixie Valley thermal area. Basic goals of the survey are 1), resolve a fundamental structural ambiguity at the Dixie Valley thermal area (single rangefront fault versus shallower, stepped pediment; 2), delineate fault

167

The importance of an external circuit in a particle-in-cell/Monte Carlo collisions model for a direct current planar magnetron  

SciTech Connect

In modeling direct current (dc) discharges, such as dc magnetrons, a current-limiting device is often neglected. In this study, it is shown that an external circuit consisting of a voltage source and a resistor is inevitable in calculating the correct cathode current. Avoiding the external circuit can cause the current to converge (if at all) to a wrong volt-ampere regime. The importance of this external circuit is studied by comparing the results with those of a model without current-limiting device. For this purpose, a 2d3v particle-in-cell/Monte Carlo collisions model was applied to calculate discharge characteristics, such as cathode potential and current, particle fluxes and densities, and potential distribution in the plasma. It is shown that the calculated cathode current is several orders of magnitude lower when an external circuit is omitted, leading to lower charged particle fluxes and densities, and a wider plasma sheath. Also, it was shown, that only simulations with external circuit can bring the cathode current into a certain plasma regime, which has its own typical properties. In this work, the normal and abnormal regimes were studied.

Bultinck, E.; Kolev, I.; Bogaerts, A. [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Antwerp (Belgium); Depla, D. [Department of Solid State Sciences, Ghent University, Krijgslaan 281 (S1), 9000 Ghent (Belgium)

2008-01-01T23:59:59.000Z

168

Structure formation upon reactive direct current magnetron sputtering of transition metal oxide films  

Science Conference Proceedings (OSTI)

A comparative study of reactive direct current magnetron sputtering for different transition metal oxides reveals crystalline films at room temperature for group 4 and amorphous films for groups 5 and 6. This observation cannot be explained by the known growth laws and is attributed to the impact of energetic particles, originating from the oxidized target, on the growing film. This scenario is supported by measured target characteristics, the evolution of deposition stress of the films, and the observed backsputtering.

Ngaruiya, J.M.; Kappertz, O.; Mohamed, S.H.; Wuttig, M. [I. Physikalisches Institut der RWTH Aachen, D-52056 Aachen, Germany and Jomo Kenyatta University of Agriculture and Technology, Box 62000 Nairobi (Kenya); I. Physikalisches Institut der RWTH Aachen, D-52056 Aachen (Germany)

2004-08-02T23:59:59.000Z

169

Mefenamic acid bi-directionally modulates the transient outward K{sup +} current in rat cerebellar granule cells  

Science Conference Proceedings (OSTI)

The effect of non-steroidal anti-inflammatory drugs (NSAIDs) on ion channels has been widely studied in several cell models, but less is known about their modulatory mechanisms. In this report, the effect of mefenamic acid on voltage-activated transient outward K{sup +} current (I{sub A}) in cultured rat cerebellar granule cells was investigated. At a concentration of 5 {mu}M to 100 {mu}M, mefenamic acid reversibly inhibited I{sub A} in a dose-dependent manner. However, mefenamic acid at a concentration of 1 {mu}M significantly increased the amplitude of I{sub A} to 113 {+-} 1.5% of the control. At more than 10 {mu}M, mefenamic acid inhibited the amplitude of I{sub A} without any effect on activation or inactivation. In addition, a higher concentration of mefenamic acid induced a significant acceleration of recovery from inactivation with an increase of the peak amplitude elicited by the second test pulse. Intracellular application of mefenamic acid could significantly increase the amplitude of I{sub A}, but had no effect on the inhibition induced by extracellular mefenamic acid, implying that mefenamic acid may exert its effect from both inside and outside the ion channel. Furthermore, the activation of current induced by intracellular application of mefenamic acid was mimicked by other cyclooxygenase inhibitors and arachidonic acid. Our data demonstrate that mefenamic acid is able to bi-directionally modulate I{sub A} channels in neurons at different concentrations and by different methods of application, and two different mechanisms may be involved.

Zhang Man; Shi Wenjie; Fei Xiaowei; Liu Yarong; Zeng Ximin [Institute of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200433 (China); Mei Yanai [Institute of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200433 (China)], E-mail: yamei@fudan.edu.cn

2008-02-01T23:59:59.000Z

170

Optical voltage reference  

DOE Patents (OSTI)

An optical voltage reference for providing an alternative to a battery source is described. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function. 2 figures.

Rankin, R.; Kotter, D.

1994-04-26T23:59:59.000Z

171

Optical voltage reference  

DOE Patents (OSTI)

An optical voltage reference for providing an alternative to a battery source. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function.

Rankin, R.; Kotter, D.

1992-12-31T23:59:59.000Z

172

High voltage photovoltaic power converter  

DOE Patents (OSTI)

An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

Haigh, Ronald E. (Arvada, CO); Wojtczuk, Steve (Cambridge, MA); Jacobson, Gerard F. (Livermore, CA); Hagans, Karla G. (Livermore, CA)

2001-01-01T23:59:59.000Z

173

Direct Current Fast Charger System Characterization: Standards, Penetration Potential, Testing, and Performance Evaluation  

Science Conference Proceedings (OSTI)

The importance of direct current (dc) fast charging of plug-in electric vehicles (PEVs) is expected to grow in the near future. This report presents a brief overview of the various standards and protocols in use and in development along with a market assessment of various dc fast chargers and compatible vehicles planned. Modeling and analysis were performed to evaluate the penetration of dc fast chargers based on vehicle driving patterns, region, and charger power. A 200-V, three-phase fast charger was i...

2011-12-14T23:59:59.000Z

174

Note: Direct measurement of the point-to-point resolution for microns-thick specimens in the ultrahigh-voltage electron microscope  

SciTech Connect

We report on a direct measurement method and results of the point-to-point resolution for microns-thick amorphous specimens in the ultrahigh-voltage electron microscope (ultra-HVEM). We first obtain the ultra-HVEM images of nanometer gold particles with different sizes on the top surfaces of the thick epoxy-resin specimens. Based on the Rayleigh criterion, the point-to-point resolution is then determined as the minimum distance between centers of two resolvable tangent gold particles. Some values of resolution are accordingly acquired for the specimens with different thicknesses at the accelerating voltage of 2 MV, for example, 18.5 nm and 28.4 nm for the 5 {mu}m and 8 {mu}m thick epoxy-resin specimens, respectively. The presented method and results provide a reliable and useful approach to quantifying and comparing the achievable spatial resolution for the thick specimens imaged in the mode of transmission electron including the scanning transmission electron microscope.

Wang Fang; Cao Meng; Zhang Haibo [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049 (China); Nishi, Ryuji; Takaoka, Akio [Research Center for Ultrahigh-Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

2011-06-15T23:59:59.000Z

175

Lagrangian Modeling at Sandia National Laboratories: Current Status and Future Directions  

National Nuclear Security Administration (NNSA)

Lagrangian Modeling at Sandia National Laboratories: Lagrangian Modeling at Sandia National Laboratories: Current Status and Future Directions A. C. Robinson, * Martin W. Heinstein, * Guglielmo Scovazzi * * Sandia National Laboratories, New Mexico, 87185 Efficient Lagrangian methodologies for quadrilaterals and hexahedral meshes have been available for a number of years. Mesh generation issues for complex three-dimensional geometries can, however, be a severe limiting factor. Mesh generation for triangular and tetrahedral meshes is readily available, but solid mechanics discretizations on these meshes are not so well established because of problems with locking. We review a relatively new node-based uniform strain element as well as an SUPG stabilized formulation that hold promise for effective simulations

176

Direct-Current Resistivity Survey At Lahaina-Kaanapali Area (Thomas, 1986)  

Open Energy Info (EERE)

Survey At Survey At Lahaina-Kaanapali Area (Thomas, 1986) Exploration Activity Details Location Lahaina-Kaanapali Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Four Schlumberger soundings were performed along the coastal strip adjacent to Lahaina town (Fig. 22). Three of the four soundings were able to detect a moderate to low-resistivity basement that was interpreted to be basalt saturated with seawater at 20degrees C (Mattice, 1981). None of the resistivity sounding data in this area indicated subsurface resistivities lower than could be accounted for by local ambient temperatures (Mattice and Lienert, 1980). References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In

177

Direct-Current Resistivity Survey At Central Nevada Seismic Zone Region  

Open Energy Info (EERE)

Survey At Central Nevada Survey At Central Nevada Seismic Zone Region (Pritchett, 2004) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best way to find "hidden" basin and range geothermal resources of this general type is to carry out simultaneous SP and low-frequency MT surveys, and then

178

Direct-Current Resistivity At Lahaina-Kaanapali Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

At Lahaina-Kaanapali Area At Lahaina-Kaanapali Area (Thomas, 1986) Exploration Activity Details Location Lahaina-Kaanapali Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Four Schlumberger soundings were performed along the coastal strip adjacent to Lahaina town (Fig. 22). Three of the four soundings were able to detect a moderate to low-resistivity basement that was interpreted to be basalt saturated with seawater at 20degrees C (Mattice, 1981). None of the resistivity sounding data in this area indicated subsurface resistivities lower than could be accounted for by local ambient temperatures (Mattice and Lienert, 1980). References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In Hawaii

179

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

180

Assessment of research directions for high voltage direct current power systems. Quarterly technical progress report, October 1, 1980-December 31, 1980  

SciTech Connect

Activities during this quarterly period on proposed HVDC systems research are reported. These activities include studies of HVDC converters, computerized simulation of HVDC systems, circuit breakers, and long-range planning of HVDC projects. (LCL)

Long, W F

1981-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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.


181

? Adjustable Output Voltage  

E-Print Network (OSTI)

The LM25010 features all the functions needed to implement a low cost, efficient, buck regulator capable of supplying in excess of 1A load current. This high voltage regulator integrates an N-Channel Buck Switch, and is available in thermally enhanced LLP-10 and TSSOP-14EP packages. The constant on-time regulation scheme requires no loop compensation resulting in fast load transient response and simplified circuit implementation. The operating frequency remains constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The valley current limit detection is set at 1.25A. Additional features include: VCC under-voltage lock-out, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limiter.

Lmq Is Aec-q Grade

2008-01-01T23:59:59.000Z

182

Current Status and Future Directions: A Matrix that Outlines the Direction of Incentive Regulation for US Electrics: An Approach to Recognizing Value in Retail Energy Businesses  

Science Conference Proceedings (OSTI)

This report describes research into the current status and direction of incentive regulation for electric distribution companies across the United States. Researchers included interviews with the staff of the National Association of Regulatory Utility Commissioners (NARUC), as well as reviews of the NARUC database and other databases. The report explores where states are in their current implementation of performance-based regulation (PBR) / incentive regulation, and the extent to which states are aggres...

2000-11-06T23:59:59.000Z

183

Data fusion analysis of a surface direct-current resistivity and well pick data set  

SciTech Connect

Pacific Northwest Laboratory (PNL) has been tasked with testing, debugging, and refining the Hanford Site data fusion workstation (DFW), with the assistance of Coleman Research Corporation (CRC), before delivering the DFW to the environmental restoration client at the Hanford Site. Data fusion is the mathematical combination (or fusion) of disparate data sets into a single interpretation. The data fusion software used in this study was developed by CRC. This report discusses the results of evaluating a surface direct-current (dc) resistivity and well-pick data set using two methods: data fusion technology and commercially available software (i.e., RESIX Plus from Interpex Ltd., Golden, Colorado), the conventional method of analysis. The report compares the two technologies; describes the survey, procedures, and results; and includes conclusions and recommendations. The surface dc resistivity and well-pick data set had been acquired by PNL from a study performed in May 1993 at Eielson Air Force Base near Fairbanks, Alaska. The resistivity survey data were acquired to map the top of permafrost in support of a hydrogeologic study. This data set provided an excellent opportunity to test and refine the dc resistivity capabilities of the DFW; previously, the data fusion software was untested on dc resistivity data. The DFW was used to evaluate the dc resistivity survey data and to produce a 3-dimensional earth model of the study area.

Clayton, E.A.; Lewis, R.E.

1995-09-01T23:59:59.000Z

184

The case for a directional dark matter detector and the status of current experimental efforts  

E-Print Network (OSTI)

We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and ...

Battat, James

185

Assessment and Evaluation of Next Generation High-Voltage DC Technologies—Phase 2  

Science Conference Proceedings (OSTI)

As an established technology for bulk power transmission, high-voltage direct current (HVDC) power transmission is being used worldwide, and more than 100 schemes are operating at present. Advances in voltage sourced converter (VSC) technologies and power electronic devices with use of insulated-gate bipolar transistors (IGBTs) will provide improved system performance and reliability. Also, the present highest operating voltage is +/- 800 kV as China and India are building +/- 800-kV lines. Anticipating ...

2009-12-17T23:59:59.000Z

186

A Direct Calculation of Current Drive in Toroidal Geometry J. C. Wright and C. K. Phillips  

E-Print Network (OSTI)

field in the quasilinear flux are used to evaluate the current in a specified toroidal geometry. PACS­induced quasilinear flux in a toroidal geometry and a Green's function for the current. An expression calculation of the current using a quasilinear flux model for a spectrum of parallel wavenum­ bers, k k j k

187

Direct observation of the current distribution in thin superconducting strips using magneto-optic imaging  

E-Print Network (OSTI)

study of the flux and current distribution of a long thin strip of YBa2Cu3O7 placed in a perpendicular to the magneto-optically found field map we find on a model-independent basis the current distribution across critical field is negli- gible, they obtained explicit expressions for the field and current distributions

Johansen, Tom Henning

188

Electron launching voltage monitor  

DOE Patents (OSTI)

An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors.

Mendel, Clifford W. (Albuquerque, NM); Savage, Mark E. (Albuquerque, NM)

1992-01-01T23:59:59.000Z

189

Three dimensional complex plasma structures in a combined radio frequency and direct current discharge  

E-Print Network (OSTI)

We report on the first detailed analysis of large three dimensional (3D) complex plasma structures in experiments performed in pure rf and combined rf+dc discharge modes. Inductively coupled plasma (ICP) is generated by an rf coil wrapped around the vertically positioned cylindrical glass tube at a pressure of 0.3 mbar. In addition, dc plasma can be generated by applying voltage to the electrodes at the ends of the tube far from the rf coil. The injected monodisperse particles are levitated in the plasma below the coil. A scanning laser sheet and a high resolution camera are used to determine the 3D positions of about $10^5$ particles. The observed bowl-shaped particle clouds reveal coexistence of various structures, including well-distinguished solid-like, less ordered liquid-like, and pronounced string-like phases. New criteria to identify string-like structures are proposed.

S. Mitic; B. A. Klumov; S. A. Khrapak; G. E. Morfill

2013-04-03T23:59:59.000Z

190

A Direct Calculation of Current Drive in Toroidal Geometry J. C. Wright and C. K. Phillips  

E-Print Network (OSTI)

field in the quasilinear flux are used to evaluate the current in a specified toroidal geometry. PACS-induced quasilinear flux in a toroidal geometry and a Green's function for the current. An expression, , was parameter- ized by combining a ray­tracing solution for the wave fields with the quasilinear flux, ql

191

Current:  

Office of Legacy Management (LM)

OWNE3 (55) OWNE3 (55) -------- past: _--_-------------------- Current: Owner contacted I-J yes ,Fqna; ------------_------------- if yes, date contacted TYPE OF OPEF(ATION ---__-------_____ c] Research & Development -4 Facility Type ci Production scale testing 0 Pilbt Scale 0 Bench Scale Process 0 Theoretical Studies 0 Sample & Analysis C Productian E Disposal/Storage TYPE OF CONTRACi _------_-------_ tlanuf acturi ng University Research Organizaticn q Prime --. _' cl Other information (i.e., cost price, + fixed fee, unit time % material, qtr) ------- ~----~---~~------__--------- YuncOntractor Purchase Order Contract/Purkhase Order # cc-km ----_----~~-----___--------- --------------------------------- OWNEKSHIP: AEC/ME3 AEC/MED GOVT GOUT CONTRACTOR CCNTRACTOR

192

Current:  

Office of Legacy Management (LM)

Qwner contacted n yes Qwner contacted n yes Current: ---------------------L---- if yes, date contacted Research & Development cl Facility Type 0 . Productioff 0 Di 3pcsal /Storage TYPE OF CONTRACT ---------------- q Prime q Subcontractor 0 Purchase Order 0 Other information (i.e. q cast + fixed fee, unit piice, time & material, etr) ------- ------_-----_--------------- 0 Production scale testing 0 Pilot Scale 0 Bench Scale Process a Theoretical Studies Sample & Analysis rcc t O' L~1 q Manufacturing 0 University 0 Research Organization 0 Government Sponsored Facility 0 Other ~--~~---_--__-____--- ' Contract/Purchase Order # __-u~-rc,~~--___~~I_IzI__zpI------------ CONTRACTING PE3IOD: lW/ ------------------ _----__--~-~~--~~_-----~~~~~~~~~~~~~~ ClWNERSHIP:

193

Low-voltage gyrotrons  

SciTech Connect

For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5-10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%-2% in the submillimeter wavelength region).

Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S. [Institute of Applied Physics RAS, N. Novgorod 603600 (Russian Federation); Nusinovich, G. S. [IREAP, University of Maryland, College Park, Maryland 20742-3511 (United States)

2013-03-15T23:59:59.000Z

194

Problems with the Current Definitions of the Standard Deviation of Wind Direction  

Science Conference Proceedings (OSTI)

Much of the ongoing debate about how to define the standard deviation of wind direction can be attributed to the widespread implementation of a faulty method of defining it in wind-measuring instrumentation in the previous decade. In this paper, ...

N. I. Fisher

1987-11-01T23:59:59.000Z

195

Strain-optic voltage monitor  

DOE Patents (OSTI)

A voltage monitor which uses the shift in absorption edge of crystalline material to measure strain resulting from electric field-induced deformation of piezoelectric or electrostrictive material, providing a simple and accurate means for measuring voltage applied either by direct contact with the crystalline material or by subjecting the material to an electric field.

Weiss, J.D.

1995-12-31T23:59:59.000Z

196

Method and apparatus for monitoring armature position in direct-current solenoids  

DOE Patents (OSTI)

A method for determining the position of an armature of a dc-powered solenoid. Electrical circuitry is provided to introduce a small alternating current flow through the coil. As a result, the impedance and resistance of the solenoid coil can be measured to provide information indicative of the armature's position.

Moyers, John C. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN)

1996-12-10T23:59:59.000Z

197

Current Practice and a Direction Forward in Checkpoint/Restart Implementations for Fault Tolerance  

Science Conference Proceedings (OSTI)

Checkpoint/restart is a general idea for which particular implementations enable various functionalities in computer systems, including process migration, gang scheduling, hibernation, and fault tolerance. For fault tolerance, in current practice, implementations ... Keywords: Fault tolerance, checkpoint/restart, autonomic computing, Linux

Jose Carlos Sancho; Fabrizio Petrini; Kei Davis; Roberto Gioiosa; Song Jiang

2005-04-01T23:59:59.000Z

198

Direct imaging of neural currents using ultra-low field magnetic resonance techniques  

DOE Patents (OSTI)

Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

Volegov, Petr L. (Los Alamos, NM); Matlashov, Andrei N. (Los Alamos, NM); Mosher, John C. (Los Alamos, NM); Espy, Michelle A. (Los Alamos, NM); Kraus, Jr., Robert H. (Los Alamos, NM)

2009-08-11T23:59:59.000Z

199

Advanced intake technology for cooling-water intakes: current status and future direction  

SciTech Connect

A synthesis of a meeting on research and developments related to cooling water intake structures and a critical analysis of the current status of the screening technology are presented. Among the conclusions and recommendations of this workshop were the following: there is a very definite shift towards fine mesh screening for the protection of larval forms; because of the biological variability and site related factors, a single screening technology cannot be expected to solve entrainment/impingement problems at all sites; variations are highly likely in the degree of success in safely screening organisms under laboratory conditions or in prototype and full scale testing, therefore tests conducted under field conditions should have more weight than lab tests in final decision making; selection of the intake design should be based on a comprehensive total system optimization including cost, plant reliability, importance of species to be screened, ecological impacts, demonstrated necessity for larval exclusion etc.; and tests should be standardized as much as possible in order to obtain comparable results at various sites. (LCL)

Sharma, R.K.; Fritz, E.S.; Murarka, I.P.

1981-01-01T23:59:59.000Z

200

HIGH VOLTAGE GENERATOR  

DOE Patents (OSTI)

A generator is presented for producing relatively large currents at high voltages. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.

Schwemin, A.J.

1959-03-17T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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.


201

HIGH VOLTAGE GENERATOR  

DOE Patents (OSTI)

A generator for producing relatively large currents at high voltages is described. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The above-noted circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.

Schwemin, A.J.

1959-03-17T23:59:59.000Z

202

Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal  

E-Print Network (OSTI)

is too low to be used directly for many practical applications. For example, a single light emitting diode (LED) requires a minimum voltage of 2 V.2 Thus, effective methods of boosting MFC voltages

203

EIS-0450: TransWest Express 600 kV Direct Current Transmission Project in Wyoming, Colorado, Utah, and Nevada  

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

Draft Environmental Impact Statement: Public Comment Period Ends 09/25/13This EIS, being prepared jointly by DOE’s Western Area Power Administration and the Department of the Interior’s Bureau of Land Management (Wyoming State Office), evaluates the environmental impacts of granting a right-of-way for the TransWest Express 600-kilovolt Direct Current Transmission Project and amending a land use plan. The project consists of an overhead transmission line that would extend approximately 725 miles from south-central Wyoming, through Colorado and Utah. Western proposes to be a joint owner of the project.

204

An Electronic Voltage Transformer Based on WLAN Technology  

Science Conference Proceedings (OSTI)

An electronic voltage transformer based on WLAN technology is developed for adapting to the development trends of substations’ synthesis automation. The transformer is composed of voltage-to-current conversion unit, signal processing unit and data ... Keywords: electronic voltage transformer, voltage-to-current conversion, WLAN technology, digital interface, wireless communication

Jianqin Feng; Qingming Wang; Fen Niu; Guangzhao Cui; Anping Zheng

2010-03-01T23:59:59.000Z

205

Direct current slice imaging  

Science Conference Proceedings (OSTI)

We report a new variation of the velocity map ion imaging method that allows the central section of the photofragment ion cloud to be recorded exclusively. The relevant speed and angular distributions for a molecular photodissociation or scattering event may therefore be obtained without need to utilize inversion methods such as the inverse Abel transform. In contrast to the recently reported “slicing” technique of Kitsopoulos and co-workers [C. R. Gebhardt et al.

Dave Townsend; Michael P. Minitti; Arthur G. Suits

2003-01-01T23:59:59.000Z

206

Current–voltage and capacitance–voltage studies of nanocrystalline ...  

Science Conference Proceedings (OSTI)

characteristics of ZnS nanocrystals/polymer composite doped with tetraphenylbenzidine single layer structure light-emitting diode. Appl Phys Lett 69

207

Modular high voltage power supply for chemical analysis  

DOE Patents (OSTI)

A high voltage power supply for use in a system such as a microfluidics system, uses a DC--DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC--DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

2007-01-09T23:59:59.000Z

208

Modular high voltage power supply for chemical analysis  

DOE Patents (OSTI)

A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

2008-07-15T23:59:59.000Z

209

RF current sensor  

DOE Patents (OSTI)

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1998-11-10T23:59:59.000Z

210

Definition: Alternating current | Open Energy Information  

Open Energy Info (EERE)

Alternating current Alternating current Jump to: navigation, search Dictionary.png Alternating current An electric current that reverses its direction at regularly recurring intervals. In the United States, the standard is 120 reversals or 60 cycles per second. Electricity transmission networks use AC.[1][2] View on Wikipedia Wikipedia Definition In alternating current (AC, also ac), the flow of electric charge periodically reverses direction. In direct current (DC, also dc), the flow of electric charge is only in one direction. The abbreviations AC and DC are often used to mean simply alternating and direct, as when they modify current or voltage. AC is the form in which electric power is delivered to businesses and residences. The usual waveform of an AC power circuit is a

211

Alternating and direct current electrochemical studies of a wool wax-based corrosion preventive coating on aluminum alloy 2024  

SciTech Connect

The corrosion behavior of Al 2024-T3 treated with a wool wax (lanolin)-based corrosion preventive coating in aqueous 0.5 M sodium chloride was studied using electrochemical impedance spectroscopy (EIS) and direct current electrode polarization. DC measurements were modeled by three reactions: oxidation of aluminum, reduction of oxygen, and reduction of hydrogen. Alternating current behavior of untreated specimens was modeled using the Randles circuit, and that of inhibited specimens was modeled using parallel resistance-capacitance circuits representing the coating and the charge-transfer process. AC and DC estimates of the polarization resistance of coated specimens were 50 M{Omega}-cm{sup 2} and 32 M{Omega}-cm{sup 2}, respectively. AC and DC values for bare control specimens were of the order of 3 k{Omega}-cm{sup 2} and 15 k{Omega}-cm{sup 2}, respectively. The wool wax coating was found to be a very effective corrosion preventative for this alloy in the aqueous saline environment whether applied to freshly prepared surfaces or to corroded specimens removed from simulated service.

Su, P.C.; Devereux, O.F. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Metallurgy and Materials Engineering

1998-06-01T23:59:59.000Z

212

HIGH VOLTAGE ION SOURCE  

DOE Patents (OSTI)

A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.

Luce, J.S.

1960-04-19T23:59:59.000Z

213

PQ Encyclopedia: Understanding Voltage Unbalance  

Science Conference Proceedings (OSTI)

This PQ Encyclopedia examines voltage unbalance, methods to calculate line voltages and the degree of voltage unbalance, and mitigation techniques.

2009-12-11T23:59:59.000Z

214

Electronic circuit for measuring series connected electrochemical cell voltages  

DOE Patents (OSTI)

An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The electronic circuit includes a plurality of energy storage cells forming the energy storage device. A voltage divider circuit is connected to at least one of the energy storage cells. A current regulating circuit is provided for regulating the current through the voltage divider circuit. A voltage measurement node is associated with the voltage divider circuit for producing a voltage signal which is proportional to the voltage across the energy storage cell.

Ashtiani, Cyrus N. (West Bloomfield, MI); Stuart, Thomas A. (Toledo, OH)

2000-01-01T23:59:59.000Z

215

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

Kuchnir, M.; Mills, F.E.

1984-09-28T23:59:59.000Z

216

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

Kuchnir, Moyses (Elmhurst, IL); Mills, Frederick E. (Elburn, IL)

1987-01-01T23:59:59.000Z

217

Cooperative frequency control with a multi-terminal high-voltage DC network  

Science Conference Proceedings (OSTI)

We consider frequency control in power systems made of several non-synchronous AC areas connected by a multi-terminal high-voltage direct current (HVDC) grid. We propose two HVDC control schemes to make the areas collectively react to power imbalances, ... Keywords: Decentralized control, Frequency control, HVDC systems, Power system control

Alain Sarlette; Jing Dai; Yannick Phulpin; Damien Ernst

2012-12-01T23:59:59.000Z

218

Low power, scalable multichannel high voltage controller  

DOE Patents (OSTI)

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2006-03-14T23:59:59.000Z

219

Low power, scalable multichannel high voltage controller  

DOE Patents (OSTI)

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2008-03-25T23:59:59.000Z

220

Current balancing for battery strings  

SciTech Connect

A battery plant is described which features magnetic circuit means for balancing the electrical current flow through a pluraliircuitbattery strings which are connected electrically in parallel. The magnetic circuit means is associated with the battery strings such that the conductors carrying the electrical current flow through each of the battery strings pass through the magnetic circuit means in directions which cause the electromagnetic fields of at least one predetermined pair of the conductors to oppose each other. In an alternative embodiment, a low voltage converter is associated with each of the battery strings for balancing the electrical current flow through the battery strings.

Galloway, James H. (New Baltimore, MI)

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Ancillary service details: Voltage control  

SciTech Connect

Voltage control is accomplished by managing reactive power on an alternating-current power system. Reactive power can be produced and absorbed by both generation and transmission equipment. Reactive-power devices differ substantially in the magnitude and speed of response and in their capital costs. System operators, transmission owners, generators, customers, power marketers, and government regulators need to pay close attention to voltage control as they restructure the U.S. electricity industry. Voltage control can affect reliability and commerce in three ways: (1) Voltages must be maintained within an acceptable range for both customer and power-system equipment to function properly. (2) The movement of reactive power consumes transmission resources, which limits the ability to move real power and worsens congestion. (3) The movement of reactive power results in real-power losses. When generators are required to supply excessive amounts of reactive power, their real-power production must be curtailed. These opportunity costs are not currently compensated for in most regions. Current tariffs are based on embedded costs. These embedded-cost tariffs average about $0.51/MWh, equivalent to $1.5 billion annually for the United States as a whole. Although this cost is low when compared with the cost of energy, it still aggregates to a significant amount of money. This report takes a basic look at why the power system requires reactive power (an appendix explains the fundamentals of real and reactive power). The report then examines the various types of generation and transmission resources used to supply reactive power and to control voltage. Finally it discusses how these resources are deployed and paid for in several reliability regions around the country. As the U.S. electricity industry is restructured, the generation, transmission, and system-control equipment and functions that maintain voltages within the appropriate ranges are being deintegrated.

Kirby, B.; Hirst, E.

1997-12-01T23:59:59.000Z

222

Capacitively coupled RF voltage probe having optimized flux linkage  

DOE Patents (OSTI)

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1999-02-02T23:59:59.000Z

223

Mitigation of different type voltage sags in low voltage distribution systems using dynamic voltage restorer  

Science Conference Proceedings (OSTI)

The main problems of the voltage sag in low voltage distribution systems due to sensitive loads. Voltage sags can caused malfunction in the distribution system. In order to protect voltage sags in the network a device which called Dynamic Voltage Restorer ... Keywords: custom device, dynamic voltage restorer (DVR), low voltage, power injected, voltage sag

Rosli Omar

2010-03-01T23:59:59.000Z

224

Analog Integrated Circuits and Signal Processing, 42, 231–238, 2005 c ? 2005 Springer Science + Business Media, Inc. Manufactured in The Netherlands. Cascode Monolithic DC-DC Converter for Reliable Operation at High Input Voltages  

E-Print Network (OSTI)

Abstract. A cascode bridge circuit for monolithic switching DC-DC converters operating at high input voltages is proposed in this paper. The proposed circuit can also be used as an I/O buffer to interface circuits operating at significantly different voltages. The circuit technique permits the full integration of the active and passive devices of a switching DC-DC converter with a high voltage conversion ratio in a standard low voltage CMOS technology. The cascode bridge structure guarantees the reliable operation of deep submicrometer MOSFETs without exposure to high voltage stress while operating at high input and output voltages. With the proposed circuit technique, steady-state voltage differences between the terminals of all of the MOSFETs in a switching DC-DC converter are maintained within a range imposed by a target low voltage CMOS technology. High-to-low DC-DC converters operating at input voltages up to three times as high as the maximum voltage that can be directly applied across the terminals of a MOSFET are described. An efficiency of 79.6 % is achieved for 5.4 volts to 0.9 volts conversion assuming a 0.18 µm CMOS technology. The DC-DC converter operates at a switching frequency of 97 MHz while supplying a DC current of 250 mA to the load. Key Words: low voltage DC-DC converters, monolithic voltage regulators, low voltage CMOS technology, MOSFET reliability issues, high voltage stress 1.

Volkan Kursun; Siva G. Narendra; Vivek K. De; Eby G. Friedman

2004-01-01T23:59:59.000Z

225

Automatic voltage imbalance detector  

DOE Patents (OSTI)

A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, Ronald E. (Los Alamos, NM); McCormick, J. Byron (Los Alamos, NM); Kerwin, William J. (Tucson, AZ)

1984-01-01T23:59:59.000Z

226

Analytical modeling of eddy-current losses caused by pulse-width-modulation switching in permanent-magnet brushless direct-current motors  

Science Conference Proceedings (OSTI)

Because of their high efficiency and power density the PM brushless dc motor is a strong candidate for electric and hybrid vehicle propulsion systems. An analytical approach is developed to predict the inverter high frequency pulse width modulation (PWM) switching caused eddy-current losses in a permanent magnet brushless dc motor. The model uses polar coordinates to take curvature effects into account, and is also capable of including the space harmonic effect of the stator magnetic field and the stator lamination effect on the losses. The model was applied to an existing motor design and was verified with the finite element method. Good agreement was achieved between the two approaches. Hence, the model is expected to be very helpful in predicting PWM switching losses in permanent magnet machine design.

Deng, F. [General Motors Corp., Flint, MI (United States). Delphi-Energy and Engine Management Systems] [General Motors Corp., Flint, MI (United States). Delphi-Energy and Engine Management Systems; Nehl, T.W. [General Motors Corp., Warren, MI (United States). Research and Development Center] [General Motors Corp., Warren, MI (United States). Research and Development Center

1998-09-01T23:59:59.000Z

227

Characterisation of the VELO High Voltage System  

E-Print Network (OSTI)

The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence that the high voltage system can be safely used and demonstrate that low noise is produced by the power supplies. LHCb Public Note, LHCb-2008-009Contents 1

Barinjaka Rakotomiaramanana; Chris Parkes; Lars Eklund

2008-01-01T23:59:59.000Z

228

Constant voltage ultracapacitor  

Science Conference Proceedings (OSTI)

Ultracapacitors have attracted lots of attention recently due to their growing use in hybrid vehicles and in energy storage applications for the smart grid. A very undesirable feature of ultracapacitors is the fact that the voltage drops as the capacitor is discharged. DC-DC converters are employed at present to convert the voltage of the ultracapacitor to constant voltage; however

Ezzat G. Bakhoum

2012-01-01T23:59:59.000Z

229

Corona and Motor Voltage Interim Report  

SciTech Connect

It has been suggested that to meet the FreedomCAR objectives for cost, size, weight, efficiency, and reliability higher buss voltages be utilized in HEV and FC automotive applications. The reasoning is that since electric power is equal to the product of voltage and current for a given power a higher voltage and lower current would result in smaller cable and inverter switching components. Consequently, the system can be lighter and smaller. On the other hand, higher voltages are known to require better and thicker electrical insulation that reduce the available slot area for motor windings. One cause of slow insulation breakdown is corona that gradually erodes the insulation and shortens the life expectancy of the motor. This study reports on the results of a study on corona initiating voltages for mush-wound and bobbin-wound stators. A unique testing method is illustrated.

Hsu, J.S.

2005-05-06T23:59:59.000Z

230

Zinc and Health: Current Status and Future Directions Zinc Transport in the Brain: Routes of Zinc Influx and Efflux in Neurons1,2  

E-Print Network (OSTI)

Zinc and Health: Current Status and Future Directions Zinc Transport in the Brain: Routes of Zinc and that mediate extracellular zinc toxicity and (3) a plasma membrane transporter potentially present in all of mechanism, is the transporter pathway. The kinetics of zinc uptake in cultured neurons under resting

231

Experimental observation of the behaviour of cogenerated dusty plasma using a bipolar pulsed direct current power supply  

SciTech Connect

We have experimentally observed the behaviour of cogenerated dusts in unmagnetized plasma produced using a bipolar pulsed dc power supply. In this experiment, the dust particles have been generated through sputtering of graphite cathode and were stratified between two electrodes. This stratification of dust clouds has obtained at a typical range of plasma parameters, namely, 650 V (peak-to-peak) with 0.2 mbar pressure. In above condition, we detected the Taylor-like instability at the interface of two dusty clouds with different densities. A very less dust density (void like) region inside the lesser dust density portion is also noted. Again, it has been observed that a self excited dust density wave propagates towards the higher density dust fluid inside the system as well as a stationary band structure of thin multiple layers of dust particles when we apply a higher voltage (750 V peak-to-peak). The wavelength, phase velocity, and frequency of the excited wave have also been estimated.

Sarkar, Sanjib; Bose, M. [Department of Physics, Jadavpur University, Kolkata 700032 (India); Pramanik, J. [Kharagpur College, Kharagpur 721305, West Bengal (India); Mukherjee, S. [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India)

2013-02-15T23:59:59.000Z

232

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

233

Principles of Stray Current  

Science Conference Proceedings (OSTI)

...current ( Ref 5 , 11 ) High voltage ac (HVAC) power lines ( Ref 12 , Ref 13 , Ref 14 ) Any current source that may use the earth as a path, either intentionally

234

Omni-directional railguns  

DOE Patents (OSTI)

This invention is comprised of a device for electromagetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire.

Shahinpoor, M.

1994-12-31T23:59:59.000Z

235

Low voltage operation of plasma focus  

SciTech Connect

Plasma foci of compact sizes and operating with low energies (from tens of joules to few hundred joules) have found application in recent years and have attracted plasma-physics scientists and engineers for research in this direction. We are presenting a low energy and miniature plasma focus which operates from a capacitor bank of 8.4 {mu}F capacity, charged at 4.2-4.3 kV and delivering approximately 52 kA peak current at approximately 60 nH calculated circuit inductance. The total circuit inductance includes the plasma focus inductance. The reported plasma focus operates at the lowest voltage among all reported plasma foci so far. Moreover the cost of capacitor bank used for plasma focus is nearly 20 U.S. dollars making it very cheap. At low voltage operation of plasma focus, the initial breakdown mechanism becomes important for operation of plasma focus. The quartz glass tube is used as insulator and breakdown initiation is done on its surface. The total energy of the plasma focus is approximately 75 J. The plasma focus system is made compact and the switching of capacitor bank energy is done by manual operating switch. The focus is operated with hydrogen and deuterium filled at 1-2 mbar.

Shukla, Rohit; Sharma, S. K.; Banerjee, P.; Das, R.; Deb, P.; Prabahar, T.; Das, B. K.; Adhikary, B.; Shyam, A. [Energetics and Electromagnetics Division, Facility for Electromagnetic Systems, Bhabha Atomic Research Center, Visakhapatanam, A.P. 530012 (India)

2010-08-15T23:59:59.000Z

236

Characterisation of the VELO High Voltage System  

E-Print Network (OSTI)

The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; vercation of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence th...

Rakotomiaramanana, B; Eklund, L

2008-01-01T23:59:59.000Z

237

Characterisation of the VELO High Voltage System  

E-Print Network (OSTI)

The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence...

Rakotomiaramanana, B; Eklund, L

2008-01-01T23:59:59.000Z

238

Direct Measurements of Current Shear in the Tropical Pacific Ocean and Its Effect on Drift Buoy Performance  

Science Conference Proceedings (OSTI)

Measurements of ocean surface currents derived from drift buoy trajectories are subject to errors caused by slippage of the buoy relative to the surrounding water. This slippage error is caused by a number of forces acting on the buoy and drogue ...

David S. Bitterman; Donald V. Hansen

1989-04-01T23:59:59.000Z

239

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. Cańizares

1991-01-01T23:59:59.000Z

240

Voltage stability/security assessment and on-line control  

SciTech Connect

Project RP3040-1 was initiated in 1989, and concluded with the release of the Voltage Stability analysis program, VSTAB, in 1992. VSTAB is a production grade program for voltage stability assessment of large complex power systems. During the course of the RP3040-1, much effort was spent in developing a clear understanding of voltage stability and in defining the special modeling and analytical techniques required to accurately capture the phenomenon through simulation. The result was the development of new steady state methods which can complement the dynamic simulation methods currently available with EPRI's Extended Transient/Midterm Stability Program (ETMSP). VSTAB uses an enhanced powerflow combined with a specially developed modal analysis algorithm to provide information regarding both the proximity to, and mechanism of, voltage instability. The program is fast, easy to use, and comprehensive in both modeling and analysis features. This Programmer's Manual documents the structure and code details of VSTAB. It is intended as a reference document for those required to maintain or enhance the VSTAB program. For details on analytical techniques used in the program, readers are directed to the VSTAB Application Guide and Final Report for project RP3040-1.

Morison, G.K.; Gao, B.; Hamadanizadeh, H. (Ontario Hydro, Toronto, ON (Canada))

1993-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Automated Voltage Standard Ready  

Science Conference Proceedings (OSTI)

... “We wanted a standard that was ... as envisioned, then within our lifetimes there will no longer be a need for voltage transfer standards that have to be ...

2013-04-08T23:59:59.000Z

242

Transformer current sensor for superconducting magnetic coils  

DOE Patents (OSTI)

A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

Shen, Stewart S. (Oak Ridge, TN); Wilson, C. Thomas (Norris, TN)

1988-01-01T23:59:59.000Z

243

Lightweight PV Inverters: Dual Bi-Directional IGBTs Modules Enables Breakthrough PV Inverter Using Current Modulation Topology  

Science Conference Proceedings (OSTI)

Solar ADEPT Project: PV inverters convert DC power generated by modules into usable AC power. IPC’s initial 30kW 94lb. PV inverter reduces the weight of comparable 30kW PV inverters by 90%—reducing the cost of materials, manufacturing, shipping, and installation. With ARPA-E support, new bi-directional silicon power switches will be developed, commercialized, and utilized in IPC’s next-generation PV inverter. With these components, IPC will produce 100kW inverters that weight less than 100lb., reducing the weight of conventional 3,000lb. 100kW inverters by more than 95%. The new power switches will cut IPC’s $/W manufacturing cost in half, as well as further reduce indirect shipping and installation costs.

None

2012-01-30T23:59:59.000Z

244

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

245

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

246

Voltage Quality Improvement Using DVR  

Science Conference Proceedings (OSTI)

The problem of voltage sags and Swells and its severe impact on sensitive loads is well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is one of the most efficient and effective ... Keywords: Dynamic Voltage Restorer (DVR), Voltage sags, Voltage swells, Custom power, Power Quality

M. Arun Bhaskar; S. S. Dash; C. Subramani; M. Jagadeesh Kumar; P. R. Giresh; M. Varun Kumar

2010-03-01T23:59:59.000Z

247

Substation voltage upgrading  

SciTech Connect

Substation voltage uprating, i.e., conversion of a substation from a lower rated voltage to a higher rated voltage without a complete substation rebuild, can lead to excellent economic benefits. Utilization of the old substation layout and/or the existing equipment, to some extent, is the practical objective of such an uprating. The objective of this project was to assess the opportunities for substation uprating in the industry, to establish feasibility for such uprating and to study methods for accomplishing it. The final aim of the project was to provide guidance to utilities interested in uprating. 56 refs., 41 figs., 18 tabs.

Panek, J.; Elahi, H.; Sublich, M. (General Electric Co., Schenectady, NY (USA). Systems Development and Engineering Dept.)

1989-08-01T23:59:59.000Z

248

A Superconducting transformer system for high current cable testing  

Science Conference Proceedings (OSTI)

This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10 464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples.

Godeke, A.; Dietderich, D. R.; Joseph, J. M.; Lizarazo, J.; Prestemon, S. O.; Miller, G.; Weijers, H. W.

2010-02-15T23:59:59.000Z

249

Method of determining the open circuit voltage of a battery in a closed circuit  

SciTech Connect

The open circuit voltage of a battery which is connected in a closed circuit is determined without breaking the circuit or causing voltage upsets therein. The closed circuit voltage across the battery and the current flowing through it are determined under normal load and then a fractional change is made in the load and the new current and voltage values determined. The open circuit voltage is then calculated, according to known principles, from the two sets of values.

Brown, William E. (Walnut Creek, CA)

1980-01-01T23:59:59.000Z

250

High voltage RF feedthrough bushing  

DOE Patents (OSTI)

Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

Grotz, Glenn F. (Huntington Station, NY)

1984-01-01T23:59:59.000Z

251

High-voltage-compatible, fully depleted CCDs  

SciTech Connect

We describe charge-coupled device (CCD) developmentactivities at the Lawrence Berkeley National Laboratory (LBNL).Back-illuminated CCDs fabricated on 200-300 mu m thick, fully depleted,high-resistivity silicon substrates are produced in partnership with acommercial CCD foundry.The CCDs are fully depleted by the application ofa substrate bias voltage. Spatial resolution considerations requireoperation of thick, fully depleted CCDs at high substrate bias voltages.We have developed CCDs that are compatible with substrate bias voltagesof at least 200V. This improves spatial resolution for a given thickness,and allows for full depletion of thicker CCDs than previously considered.We have demonstrated full depletion of 650-675 mu m thick CCDs, withpotential applications in direct x-ray detection. In this work we discussthe issues related to high-voltage operation of fully depleted CCDs, aswell as experimental results on high-voltage-compatible CCDs.

Holland, Stephen E.; Bebek, Chris J.; Dawson, Kyle S.; Emes, JohnE.; Fabricius, Max H.; Fairfield, Jessaym A.; Groom, Don E.; Karcher, A.; Kolbe, William F.; Palaio, Nick P.; Roe, Natalie A.; Wang, Guobin

2006-05-15T23:59:59.000Z

252

Comparative High Voltage Impulse Measurement  

Science Conference Proceedings (OSTI)

... substrate and surrounded by insulating oil; the low ... the amplitudes of the voltage peaks that are ... The uncertainties in the peak output voltages for the ...

2013-04-19T23:59:59.000Z

253

Low voltage arc formation in railguns  

DOE Patents (OSTI)

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Hawke, R.S.

1985-08-05T23:59:59.000Z

254

Low voltage arc formation in railguns  

DOE Patents (OSTI)

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Hawke, Ronald S. (Livermore, CA)

1987-01-01T23:59:59.000Z

255

Low voltage arc formation in railguns  

DOE Patents (OSTI)

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

Hawke, R.S.

1987-11-17T23:59:59.000Z

256

Research on Low-Voltage Ride-Through Technology of Doubly-Fed VSCF Wind Power Generation System  

Science Conference Proceedings (OSTI)

Currently, some of the variable speed wind turbine on market have some low-voltage through capacity?LVRT?, but do not have dynamic reactive power support capacity under fault. DFIG can’t provide dynamic voltage support, in addition, ... Keywords: wind power, voltage dip, low voltage ride-through (LVRT), transient voltage control, rotor-side converter

Bao Wei; Yin Zhongdong

2009-10-01T23:59:59.000Z

257

Radio-frequency powered glow discharge device and method with high voltage interface  

DOE Patents (OSTI)

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28T23:59:59.000Z

258

Radio-frequency powered glow discharge device and method with high voltage interface  

DOE Patents (OSTI)

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

259

CIRCUITS FOR CURRENT MEASUREMENTS  

DOE Patents (OSTI)

Circuits are presented for measurement of a logarithmic scale of current flowing in a high impedance. In one form of the invention the disclosed circuit is in combination with an ionization chamber to measure lonization current. The particular circuit arrangement lncludes a vacuum tube having at least one grid, an ionization chamber connected in series with a high voltage source and the grid of the vacuum tube, and a d-c amplifier feedback circuit. As the ionization chamber current passes between the grid and cathode of the tube, the feedback circuit acts to stabilize the anode current, and the feedback voltage is a measure of the logaritbm of the ionization current.

Cox, R.J.

1958-11-01T23:59:59.000Z

260

HIGH VOLTAGE ELECTRODES  

DOE Patents (OSTI)

S>This patent relates to electrode structure for creating an intense direct current electric field which may have a field strength of the order of two to three times that heretofore obtained, with automatic suppression of arcing. The positive electrode is a conventional conductive material such as copper while the negative electrode is made from a special material having a resistivity greater than that of good conductors and less than that of good insulators. When an incipient arc occurs, the moderate resistivity of the negative electrode causes a momentary, localized decrease in the electric field intensity, thus suppressing the flow of electrons and avoiding arcing. Heated glass may be utilized for the negative electrode, since it provides the desired combination of resistivity, capacity, dielectric strength, mechani-cal strength, and thermal stability. (AEC)

Murray, J.J.

1963-04-23T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1996-01-01T23:59:59.000Z

262

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 figs.

Shimer, D.W.; Lange, A.C.

1996-10-15T23:59:59.000Z

263

High frequency breakdown voltage  

SciTech Connect

This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O{degrees}C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f{sub c}, the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f{sub ce}, is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions` concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance.

Chu, Thanh Duy

1992-03-01T23:59:59.000Z

264

High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1995-01-01T23:59:59.000Z

265

High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

Shimer, D.W.; Lange, A.C.

1995-05-23T23:59:59.000Z

266

A high-voltage low-power DC-DC buck regulator for automotive applications  

Science Conference Proceedings (OSTI)

This work presents a High-Voltage Low-Power CMOS DC-DC buck regulator for automotive applications. The overall system, including the high and low voltage analog devices, the power MOS and the low voltage digital devices, was realized in the Austriamicrosystems ... Keywords: DC-DC regulator, buck converter, current control, low quiscent current, pulse frequency modulation

G. Pasetti; L. Fanucci; R. Serventi

2010-03-01T23:59:59.000Z

267

Monitoring Volume Transport through Measurement of Cable Voltage across the Korea Strait  

Science Conference Proceedings (OSTI)

Voltage induced by the Tsushima Current on an abandoned submarine telephone cable between Pusan, Korea, and Hamada, Japan, has been measured since March 1998 in order to monitor the volume transport through the Korea Strait. Voltage has a good ...

Kuh Kim; Sang Jin Lyu; Young-Gyu Kim; Byung Ho Choi; Keisuke Taira; Henry T. Perkins; William J. Teague; Jeffrey W. Book

2004-04-01T23:59:59.000Z

268

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Stringfield, R.M.; Wheat, R.M. Jr.

1989-02-21T23:59:59.000Z

269

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

270

High voltage variable diameter insulator  

DOE Patents (OSTI)

A high voltage feedthrough assembly (10) having a tubular insulator (15) extending between the ground plane ring (16) and the high voltage ring (30). The insulator (15) is made of Pyrex and decreases in diameter from the ground plane ring (16) to the high voltage ring (30), producing equipotential lines almost perpendicular to the wall (27) of the insulator (15) to optimize the voltage-holding capability of the feedthrough assembly (10).

Vanecek, David L. (Martinez, CA); Pike, Chester D. (Pinole, CA)

1984-01-01T23:59:59.000Z

271

Automatic voltage-imbalance detector  

DOE Patents (OSTI)

A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, R.E.; McCormick, J.B.; Kerwin, W.J.

1981-05-20T23:59:59.000Z

272

3430 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 61, NO. 8, OCTOBER 2012 Experimental Validation of High-Voltage-Ratio  

E-Print Network (OSTI)

Validation of High-Voltage-Ratio Low-Input-Current-Ripple Converters for Hybrid Fuel Cell Supercapacitor

Simões, Marcelo Godoy

273

SECONDARY ELECTRON TRAJECTORIES IN HIGH-GRADIENT VACUUM INSULATORS WITH FAST HIGH-VOLTAGE PULSES  

Science Conference Proceedings (OSTI)

Vacuum insulators composed of alternating layers of metal and dielectric, known as high-gradient insulators (HGIs), have been shown to withstand higher electric fields than conventional insulators. Primary or secondary electrons (emitted from the insulator surface) can be deflected by magnetic fields from external sources, the high-current electron beam, the conduction current in the transmission line, or the displacement current in the insulator. These electrons are deflected either toward or away from the insulator surface and this affects the performance of the vacuum insulator. This paper shows the effects of displacement current from short voltage pulses on the performance of high gradient insulators. Generally, vacuum insulator failure is due to surface flashover, initiated by electrons emitted from a triple junction. These electrons strike the insulator surface thus producing secondary electrons, and can lead to a subsequent electron cascade along the surface. The displacement current in the insulator can deflect electrons either toward or away from the insulator surface, and affects the performance of the vacuum insulator when the insulator is subjected to a fast high-voltage pulse. Vacuum insulators composed of alternating layers of metal and dielectric, known as high-gradient insulators (HGIs), have been shown to withstand higher electric fields than conventional insulators. HGIs, being tolerant of the direct view of high-current electron and ion beams, and having desirable RF properties for accelerators, are a key enabling technology for the dielectric-wall accelerators (DWA) being developed at Lawrence Livermore National Laboratory (LLNL). Characteristically, insulator surface breakdown thresholds go up as the applied voltage pulse width decreases. To attain the highest accelerating gradient in the DWA, short accelerating voltage pulses are only applied locally, along the HGI accelerator tube, in sync with the charged particle bunch, and the effects of displacement current on trajectories of electrons emitted from HGI surface are particularly interesting. This paper presents simulated electron trajectories experiencing either constant or short-duration applied voltage pulses. Comparisons of these trajectories clearly indicate the importance of the voltage pulse shape, especially the rise time, in the flashover initiation process for HGIs.

Chen, Y; Blackfield, D; Nelson, S D; Poole, B

2010-04-21T23:59:59.000Z

274

Model of ionic currents through microtubule nanopores and the lumen  

E-Print Network (OSTI)

It has been suggested that microtubules and other cytoskeletal filaments may act as electrical transmission lines. An electrical circuit model of the microtubule is constructed incorporating features of its cylindrical structure with nanopores in its walls and is used to test whether such features might contribute to the proposed role of the microtubule as a mediator in intracellular signaling. Based on the results of Brownian dynamics simulations, the nanopores were found to have asymmetric inner and outer conductances, manifested as nonlinear IV curves. Our simulations indicate that a combination of this asymmetry and an internal voltage source arising from the motion of the C-terminal tails can allow a current to be pumped across the microtubule wall and propagate down the microtubule through the lumen. This current is demonstrated to add directly to the longitudinal current resulting from an external voltage source, and could be significant in amplifying low-intensity endogenous currents within the cellul...

Freedman, Holly; Priel, Avner; Carpenter, Eric; Noskovd, Sergei Y; Tuszynski, Jack A

2009-01-01T23:59:59.000Z

275

High Voltage MOSFET Gate/Bulk Driver Controller for a Microbattery Switch Matrix in a 0.35 µm Microwave SOI Technology  

Science Conference Proceedings (OSTI)

Integrated microbatteries are being currently developed to act as a "micropower" source in microsatellites. The current and voltage rating of the microbattery is fixed. Certain highly miniaturized systems require higher voltages and currents. A switching ... Keywords: LDMOSFET, SOI, microbattery, micropower

Vinesh Sukumar; Mahmoud Alahmad; Kevin Buck; Herbert Hess; Harry Li; Dave Cox; Fadi Nessir Zghoul; Jeremy Jackson; Stephen Terry; Ben Blalock; M. M. Mojarradi; W. C. West; J. F. Whitacre

2005-09-01T23:59:59.000Z

276

High PRF high current switch  

DOE Green Energy (OSTI)

A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

Moran, Stuart L. (Fredericksburg, VA); Hutcherson, R. Kenneth (College Park, MD)

1990-03-27T23:59:59.000Z

277

Evaluation of the electromagnetic effects due to direct lighting to nuclear explosive areas at Pantex. Final report  

Science Conference Proceedings (OSTI)

This report summarizes the effort to quantify the electromagnetic environments in the nuclear explosive areas at Pantex due to direct lightning. The fundamental measure of the threat to nuclear safety is assumed to be the maximum voltage between any two points in an assembly area, which is then available for producing arcing or for driving current into critical subsystems of a nuclear weapon. This maximum voltage has been computed with simple analytical models and with three-dimensional finite-difference computer codes.

Merewether, K.O.; Chen, K.C.

1993-11-01T23:59:59.000Z

278

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

279

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

280

Time varying voltage combustion control and diagnostics sensor  

DOE Patents (OSTI)

A time-varying voltage is applied to an electrode, or a pair of electrodes, of a sensor installed in a fuel nozzle disposed adjacent the combustion zone of a continuous combustion system, such as of the gas turbine engine type. The time-varying voltage induces a time-varying current in the flame which is measured and used to determine flame capacitance using AC electrical circuit analysis. Flame capacitance is used to accurately determine the position of the flame from the sensor and the fuel/air ratio. The fuel and/or air flow rate (s) is/are then adjusted to provide reduced flame instability problems such as flashback, combustion dynamics and lean blowout, as well as reduced emissions. The time-varying voltage may be an alternating voltage and the time-varying current may be an alternating current.

Chorpening, Benjamin T. (Morgantown, WV); Thornton, Jimmy D. (Morgantown, WV); Huckaby, E. David (Morgantown, WV); Fincham, William (Fairmont, WV)

2011-04-19T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Low-Voltage Cable Aging Management Guidance  

Science Conference Proceedings (OSTI)

This report, intended for use by power plant engineers and craft and administrative personnel who are responsible for cable system aging management, provides guidance on the effective and efficient application of current information and techniques related to aging and condition monitoring (CM) of low-voltage cables. The identification of cables that are prone to early aging and the timely replacement or repair of cables that are degraded will minimize unnecessary power losses, unplanned shutdowns, ...

2013-12-23T23:59:59.000Z

282

A compact high voltage pulse generator  

SciTech Connect

A compact, easily transportable, pulse generator has been developed for a variety of applications that require a pulse duration in the range of 1 {mu} sec., voltages from 150 to 300 KV and current levels from 2,000 to 3,000 amps. The generator has a simple cylindrical configuration and modular construction to facilitate assembly and service. The generator may be operated single-pulse or repetitively at pulse repetition rates to 50 Hz in a burst mode.

Rohwein, G.J.; Babcock, S.R.

1994-07-01T23:59:59.000Z

283

Planning of distribution networks for medium voltage and low voltage.  

E-Print Network (OSTI)

??Determination of the placement and rating of transformers and feeders are the main objective of the basic distribution network planning. The bus voltage and the… (more)

Ziari, Iman

2011-01-01T23:59:59.000Z

284

High voltage feedthrough bushing  

DOE Patents (OSTI)

A feedthrough bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.

Brucker, J.P.

1991-12-31T23:59:59.000Z

285

Substation voltage upgrading  

SciTech Connect

This report addresses specific issues to support sound yet not unduly conservative uprating practices for substations. The main parts of the report cover the insulation withstand and overvoltage protection aspects, environmental measurements, reliability criteria, and industry experience. First the insulation design concerns are addressed. Substation stress by a backflashover of the line insulation due to lightning in the vicinity of the substation is recognized as a critical stress. A representative part of a 550 kV BIL substation was erected at the EPRI High Voltage Transmission Research Center, where also a special test circuit was assembled to produce a fast front, slow tail (0.2/200 {mu}s) wave. The substation as well as some special configurations were tested for line-to-ground and line-to-line withstand. Computer studies were performed to complement the test results. A number of important conclusions was reached. The most prominent result in that the high frequency oscillations, as caused by reflections within the substation, do not effect the Critical Flashover Voltage (CFO). The present practice, based on the highest peak is therefore very conservative. The slow tail of the wave appears to dictate the CFO. An arrester model for computer studies to represent very fast as well as slow phenomena was derived. It is based on full scale arrester test data, made available in this project. The computer program to calculate arrester model parameters is also a part of the report. The electric environmental measurements are reported for the tested substation at the HVTRC and for the uprated substation of Public Service Company of Colorado, both before and after the uprating. The performance is satisfactory when corona free hardware is used. Insulation design criteria are analyzed based on substation reliability, the system viewpoint and consequences of the failure. Utility experience with uprated substations is reviewed.

Panek, J.; Elahi, H.; Lux, A.; Imece, A.F. (General Electric Co., Schenectady, NY (United States). Power Systems Engineering Dept.); LaPanse, R.A.; Stewart, J.R. (Public Service Co. of Colorado, Denver, CO (United States))

1992-04-01T23:59:59.000Z

286

Voltage Vehicles | Open Energy Information  

Open Energy Info (EERE)

Sector Vehicles Product Voltage Vehicles is a nascent, full-service alternative fuel vehicle distributor specializing in the full spectrum of electric vehicles (EV) and...

287

Humidity, Temperature, and Voltage (Presentation)  

SciTech Connect

An update is given on the work of the PV Quality Assurance Task Force; Group 3: studying the effects of humidity, temperature, and voltage bias.

Wohlgemuth, J.

2012-03-01T23:59:59.000Z

288

A Hybrid Framework for Voltage Security Assessment Integrating Simulation and Measurement Based Approaches  

Science Conference Proceedings (OSTI)

Voltage stability is the ability of a power system to maintain adequate voltage magnitudes at buses, which is a major concern in daily power system operations and a leading factor to limit power transfers in a prevailing open-access environment. Currently, simulation-based voltage security assessment (VSA) tools are applied widely by electric utilities to analyze either steady-state or transient voltage stability issues. Those VSA tools can help operators foresee the next critical ...

2012-12-31T23:59:59.000Z

289

Alternative Energy Development and China's Energy Future  

E-Print Network (OSTI)

high voltage direct current (HVDC) transmission which canhigh voltage direct current (HVDC) transmission, an increase

Zheng, Nina

2012-01-01T23:59:59.000Z

290

Design & Fabrication of a High-Voltage Photovoltaic Cell  

DOE Green Energy (OSTI)

Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.

Felder, Jennifer; /North Carolina State U. /SLAC

2012-09-05T23:59:59.000Z

291

Skill Assessment of Resolving Ocean Surface Current Structure Using Compact-Antenna-Style HF Radar and the MUSIC Direction-Finding Algorithm  

Science Conference Proceedings (OSTI)

A skill analysis of the Multiple Signal Characterization (MUSIC) algorithm used in compact-antenna-style HF radar ocean current radial velocity/bearing determination is performed using simulation. The simulation is based upon three collocated ...

Tony de Paolo; Eric Terrill

2007-07-01T23:59:59.000Z

292

LOW VOLTAGE 14 Mev NEUTRON SOURCE  

DOE Patents (OSTI)

An apparatus yielding high-energy neutrons at the rate of 10/sup 8/ or more per second by the D,T or D,D reactions is described. The deuterium gas filling is ionized by electrons emitted from a filament, and the resulting ions are focused into a beam and accelerated against a fixed target. The apparatus is built in accordance with the relationship V/sub s/ = A--B log pd, where V/sub s/ is the sparking voltage, p the gas pressure, and d the gap length between the high voltage electrodes. Typical parameters to obtain the high neutron yields are 55 to 80 kv, 0.5 to 7.0 ma beam current, 5 to 12 microns D/sub 2/, and a gap length of 1 centimeter.

Little, R.N. Jr.; Graves, E.R.

1959-09-29T23:59:59.000Z

293

Low Swing Dual Threshold Voltage Domino Logic  

E-Print Network (OSTI)

A low swing domino logic technique is proposed to decrease power consumption without sacrificing noise immunity. With the proposed low swing domino logic circuit technique, active power consumption is reduced by up to 9.4% while improving the noise immunity by 2.6% as compared to standard domino logic circuits. It is also shown that by applying a low swing contention reduction technique, the power savings can be further increased by 6.7% while the delay can be improved by 8.6%. A simple and efficient dual threshold voltage (dual-V t ) circuit technique that incorporates low swing signals is also proposed. It is shown that the proposed dual-V technique reduces the standby leakage current by approximately 235 times while offering enhanced delay characteristics as compared to a standard low threshold voltage implementation.

Volkan Kursun; Eby G. Friedman

2002-01-01T23:59:59.000Z

294

Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz  

Science Conference Proceedings (OSTI)

A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux locked operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect {sup 27}Al NQR signals in ruby (Al{sub 2}O{sub 3}[Cr{sup 3+}]) at 359 and 714 kHz. {copyright} {ital 1996 American Institute of Physics.}

TonThat, D.M.; Clarke, J. [Department of Physics, University of , California (United States)]|[Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1996-08-01T23:59:59.000Z

295

Prediction of DC current return flow in northern Namibia Share et al. SAGA Biennial Technical Meeting and Exhibition Short Paper  

E-Print Network (OSTI)

. ABB Power Technologies AB - HVDC, Sweden, jan.wasborg@se.abb.com 12. Other members of the SAMTEX in the Otjiwarongo and Katima Mulilo regions, where in future the installation of high-voltage direct current (HVDC is needed for the optimal placement of HVDC earth electrodes in the future. An interesting challenge is now

Jones, Alan G.

296

Integrated Technology for Distribution Systems Applications: Survey and Testing of Voltage Detecting/Indicating Devices for AC Power Lines  

Science Conference Proceedings (OSTI)

This report summarizes product reviews and testing commercially available voltage-sensing devices used to detect energized electric distribution lines, with particular focus on minimum detection and indication performance. To adequately detect line energization across the entire spectrum of possible voltage levels on a power line (from 40 Vac to full line voltage), multiple devices are currently necessary. The ideal improvement to address current gaps in voltage sensing would be the development of a ...

2013-12-17T23:59:59.000Z

297

Magnetic Method to Characterize the Current Densities in Breaker Arc  

Science Conference Proceedings (OSTI)

The purpose of this research was to use magnetic induction measurements from a low voltage breaker arc, to reconstruct the arc's current density. The measurements were made using Hall effect sensors, which were placed close to, but outside the breaking device. The arc was modelled as a rectangular current sheet, composed of a mix of threadlike current segments and with a current density varying across the propagation direction. We found the magnetic induction of the arc is a convolution product of the current density, and a function depending on the breaker geometry and arc model. Using deconvolution methods, the current density in the electric arc was determined.The method is used to study the arc behavior into the breaker device. Notably, position, arc size, and electric conductivity could all be determined, and then used to characterize the arc mode, diffuse or concentrated, and study the condition of its mode changing.

Machkour, Nadia [National Institute of Standards and Technology (United States)

2005-04-15T23:59:59.000Z

298

Two terminal line voltage thermostat  

Science Conference Proceedings (OSTI)

A two terminal line voltage thermostat includes a switch which effectively connects line voltage to a heater load. The entire process is controlled by an integrated circuit microcontroller which is powered by a rectified voltage from a transformer secondary connected to a primary which is in series with the heater load. Backup battery power is provided to maintain limited functions of the microcontroller in the event of overall power loss. The microcontroller is programmed to meet the temperature sensing and control requirements specific to a two terminal electric baseboard heating installation. 7 figs.

Stalsberg, K.J.; Ingalls, J.E.; Hoglund, S.R.

1995-10-10T23:59:59.000Z

299

Measurements of Voltage and Current Surges on the AC ...  

Science Conference Proceedings (OSTI)

... Environments R. Odenberg Transtector Systems. Inc. Hayden Lake, Idaho 83835 Abstract - Speci a1 computerized instrumentation ...

2013-05-17T23:59:59.000Z

300

Current-voltage Characteristics of Metal-Carbon Nanotube Contacts  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Advances in Dielectric Materials and Electronic Devices. Presentation Title ...

Note: This page contains sample records for the topic "voltage direct current" 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

X10, Effect of Aluminum Composition on Current-Voltage ...  

Science Conference Proceedings (OSTI)

L6, PECVD-SiN, Si or Si/Al2O3-Capped ED-Mode AlN/GaN Inverters · Hide details for [

302

Chapter 4 - Understanding Voltage Sags  

Science Conference Proceedings (OSTI)

This chapter of the EPRI Solutions PQ Encyclopedia provides information for understanding the voltage sag, which is the single most potent cause of end user power quality (PQ) problems.

2005-12-31T23:59:59.000Z

303

Definition: Automated Voltage Regulators | Open Energy Information  

Open Energy Info (EERE)

Regulators Regulators Jump to: navigation, search Dictionary.png Automated Voltage Regulators Voltage regulators are transformers that can increase or decrease the voltage on a distribution circuit to help keep the voltage within a pre-determined band. Unlike capacitor banks, voltage regulators cannot adjust power factor. These devices typically monitor the voltage at the location where they are connected, and compare it to a programmed set point. If the voltage deviates too far from the set point, the voltage regulator can increase or decrease its output voltage by moving the tap on the secondary side up or down. An automated voltage regulator can operate with remote control signals, or in concert with other area voltage control devices, to help regulate distribution voltage in a coordinated fashion.

304

High-voltage-compatible, fully depleted CCDs  

E-Print Network (OSTI)

result of this high-voltage requirement, we have taken a di?voltage is necessary in order to meet the PSF requirementsrequirements for SNAP have resulted in a need to operate at substrate bias voltages

2006-01-01T23:59:59.000Z

305

High Voltage GaN Schottky Rectifiers  

SciTech Connect

Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.

CAO,X.A.; CHO,H.; CHU,S.N.G.; CHUO,C.-C.; CHYI,J.-I.; DANG,G.T.; HAN,JUNG; LEE,C.-M.; PEARTON,S.J.; REN,F.; WILSON,R.G.; ZHANG,A.P.

1999-10-25T23:59:59.000Z

306

Performance of Dynamic Voltage Restorer (DVR) against Voltage Sags and Swells Using Space Vector PWM Technique  

Science Conference Proceedings (OSTI)

Due to increasing complexity in the power system, voltage sags are now becoming one of the most significant power quality problems. Voltage sag is a short reduction voltage from nominal voltage, occurs in a short time. Short-lived voltage sags may not ... Keywords: Custom power, power quality, voltage sag, SPWM, SVPWM, DVR, PSCAD/EMTDC.

Palaparthi Ananthababu; Burle Trinadha; K. Ram Charan

2009-12-01T23:59:59.000Z

307

A CMOS threshold voltage reference source for very-low-voltage applications  

Science Conference Proceedings (OSTI)

This paper describes a CMOS voltage reference that makes use of weak inversion CMOS transistors and linear resistors, without the need for bipolar transistors. Its operation is analogous to the bandgap reference voltage, but the reference voltage is ... Keywords: Threshold voltage, Ultra-low-power, Very-low-voltage, Voltage reference

Luis H. C. Ferreira; Tales C. Pimenta; Robson L. Moreno

2008-12-01T23:59:59.000Z

308

High voltage electrical amplifier having a short rise time  

DOE Patents (OSTI)

A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and the voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage. 8 figs.

Christie, D.J.; Dallum, G.E.

1989-12-07T23:59:59.000Z

309

High voltage electrical amplifier having a short rise time  

DOE Patents (OSTI)

A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)

1991-01-01T23:59:59.000Z

310

Surge voltage suppression in residential power circuits  

Science Conference Proceedings (OSTI)

... Tran- sients in Low Voltage Supply Systems,'' The ... a high-voltage transformer for an oil furnace ... of service entrance SPD of 1960-1970 vintage were ...

2013-05-17T23:59:59.000Z

311

Available Technologies: Direct Electron Detector for Low Voltage ...  

... such as biology and polymer chemistry, where the samples of interest are susceptible to damage from high energy electrons.

312

Unlikely Combination of Experiments with a Novel High-Voltage CIGS Photovoltaic Array (Presentation)  

DOE Green Energy (OSTI)

The goals of this study are to: (1) parameterize current-voltage (I-V) performance over a wide range of illumination and temperatures: (a) 50-1150 W/m{sup 2} irradiance, 5-65 C; (b) obtain array temperature coefficients; and (c) quantify energy production; (2) investigate high-voltage leakage currents from the CIS modules in a high-voltage array: determine dependence on moisture, temperature, and voltage bias and ascertain corrosion problems if any; and (3) study long-term power and energy production stability.

del Cueto, J. A.; Sekulic, B. R.

2006-05-01T23:59:59.000Z

313

Automated Voltage Control in LHCb  

E-Print Network (OSTI)

LHCb is one of the 4 LHC experiments. In order to ensure the safety of the detector and to maximize efficiency, LHCb needs to coordinate its own operations, in particular the voltage configuration of the different subdetectors, according to the accelerator status. A control software has been developed for this purpose, based on the Finite State Machine toolkit and the SCADA system used for control throughout LHCb (and the other LHC experiments). This software permits to efficiently drive both the Low Voltage (LV) and High Voltage (HV) systems of the 10 different sub-detectors that constitute LHCb, setting each sub-system to the required voltage (easily configurable at run-time) based on the accelerator state. The control software is also responsible for monitoring the state of the Sub-detector voltages and adding it to the event data in the form of status-bits. Safe and yet flexible operation of the LHCb detector has been obtained and automatic actions, triggered by the state changes of the ...

Granado Cardoso, L; Jacobsson, R

2011-01-01T23:59:59.000Z

314

Current status and future directions for the U.S. Department of Energy`s short-rotation woody crop research  

DOE Green Energy (OSTI)

The US Department of Energy (DOE) initiated the Biofuels Feedstock Development Program (BFDP) at Oak Ridge National Laboratory (ORNL) in 1978. The program`s goal is to provide leadership in the development, demonstration and implementation of environmentally acceptable and commercially viable biomass supply systems. Three model short-rotation woody crop (SRWC) species, i.e. Populus spp., Acer saccharinum and Salix spp., have been selected for further development based on their productivity, adaptability, and suitability as biomass feedstocks. Of these three, Populus is the primary candidate for SRWC in the United States. For Populus the prescribed management system involves the use of intensive site preparation of agricultural quality lands, improved clonal plant materials at ca. 1,000 trees/ac, mechanical and chemical weed control for the first 2 years, and rotation length of 6--8 years, followed by replanting. Currently, due to the wider spacings and larger tree sizes, traditional, start-stop, one-piece harvesting techniques are being applied to SRWC; this includes the use of feller-bunchers, skidding to a common landing, and on-site chipping. Under the above silvicultural system, harvesting and transportation expenditures account for 50 to 60% of the total production costs. The productivity goals for SRWC are 8--12 t/ac/yr, with the current average across all sites and clones at ca. 4 t/ac/yr. Productivity rates on large-scale plantings have been documented at 11 t/ac/yr. To increase the average productivity rates, silvicultural enrichments [e.g., spacing variances, fertilization once per rotation (ca. 70 lbs/ac N), and irrigation], genetic improvement, and molecular genetics techniques are being applied to all model species. This research is being managed under the concept of regional, integrated Crop Development Centers. There are presently 3 Populus crop development centers.

Tuskan, G.A.; Downing, M.E.; Wright, L.L.

1994-09-01T23:59:59.000Z

315

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360.degree./n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1997-01-01T23:59:59.000Z

316

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360{degree}/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs.

Shimer, D.W.; Lange, A.C.

1997-03-11T23:59:59.000Z

317

Testing a new direct load control power line communication system  

SciTech Connect

South Carolina Electric and Gas is currently performing direct load control communications over power lines without using a power line carrier. This is the result of testing a load management system that combines the existing substation solid-state recording with voltage regulation capability. Using the solid-state recorder's extended control functions, the existing substation tap changer, a new patent-pending power line communications technique, and a patented voltage-step load control receiver, the system extends normal two-way communication between the utility operations and the substation with a one-way power line link to virtually any load. By varying the voltage level slightly, the system digitizes up to 32 different load control messages. The new voltage-step communication technique uses the substation's load tap changer to communicate one-way with the receivers over existing power lines. South Carolina Electric and Gas and the manufacturers have been performing a two-phase test of the load control system. Phase one testing showed that the percentage of successful load control message reception was 98%. Phase two testing is still in progress. Results to date show no deterioration of reception or equipment. Conclusions thus far are that the load management system is compatible with all installed utility equipment, and offers reliable direct load control.

Weers, D.D.; Shamsedin, M.A.

1987-07-01T23:59:59.000Z

318

Fiber-optic voltage sensor  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, C.B.

1990-12-31T23:59:59.000Z

319

Fiber-optic voltage sensor  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, C.B.

1990-01-01T23:59:59.000Z

320

Portec Voltage Regulators: for Emergency Diesel Generators  

Science Conference Proceedings (OSTI)

This report contains information to help utilities address emergency diesel generator voltage regulator issues.

2004-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Current Status  

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

Current Status Current Status > Content on this page requires a newer version of Adobe Flash Player. Get Adobe Flash player July 31, 1942 The Army Corp of Engineers leases 1,025 acres of the Cook County Forest Preserve to build a research facility. November 1942 Under the direction of Enrico Fermi, a group of scientists at the University of Chicago begin building Chicago Pile-1 (CP-1). Security and secracy were essential. December 2, 1942 Enrico Fermi's team creates the world's first self-sustaining nuclear chain reaction using the CP-1 reactor under Stagg Field at the University of Chicago. CP-1 1943 The experiments under Stagg Field shut down, and the scientists move to a 19 acre section of the leased forest preserve, known as Site A. CP-1 is reconstructed and modified at Site A and renamed Chicago Pile 2 (CP-2).

322

Probabilistic voltage assessment and VAR compensation  

SciTech Connect

The system voltage profile subject to system elements' forced outage is accessed. Two system voltage reliability indexes are evaluated: the loss of voltage probability, and the expected voltage violation. A similar set of two voltage reliability indexes are also calculated for every load bus in the system. A simple VAR compensation approach is introduced. It enhances the voltage profile assuming a maximum of three overlapping element outages can occur. For purposes of demonstration, the system and load bus voltage reliability indexes are calculated for the AEP 30-bus system. Results of applying the proposed VAR compensation scheme to the 30-bus system are also presented and discussed.

Sharaf, T.A.M.; Berg, G.J.

1988-01-01T23:59:59.000Z

323

Optically triggered high voltage switch network and method for switching a high voltage  

DOE Patents (OSTI)

An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

El-Sharkawi, Mohamed A. (Renton, WA); Andexler, George (Everett, WA); Silberkleit, Lee I. (Mountlake Terrace, WA)

1993-01-19T23:59:59.000Z

324

Power and Voltage Smooth Control of Doubly Fed Induction Generator  

Science Conference Proceedings (OSTI)

Doubly-fed induction generator (DFIG) is the leading in wind power technology currently. In this paper, decoupling control of DFIG is studied and a new energy storage device is used in the smooth control of DFIG system's power and voltage. This new method ... Keywords: Doubly fed induction generator, Energy storage device, Decoupling control

An-Ren Ma, Cai-Xia Wang, Zhi-Wen Zhou, Tao Wu

2012-07-01T23:59:59.000Z

325

Control Techniques to Eliminate Voltage Emergencies in High Performance Processors  

E-Print Network (OSTI)

negligible impact on perfor­ mance and energy. With the ITRS roadmap predicting aggres­ sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re­ ferred to as the dI/dt problem, can cause supply voltage fluc­ tuations

Martonosi, Margaret

326

Control Techniques to Eliminate Voltage Emergencies in High Performance Processors  

E-Print Network (OSTI)

negligible impact on perfor- mance and energy. With the ITRS roadmap predicting aggres- sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re- ferred to as the dI/dt problem, can cause supply voltage fluc- tuations

Gupta, Rajiv

327

Voltage holding study of 1 MeV accelerator for ITER neutral beam injector  

Science Conference Proceedings (OSTI)

Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration, which leads to discharge initiation at lower voltage. To reduce the electric field concentration in the MeV accelerator, gaps between the grid supports were expanded and curvature radii at the support corners were increased. After the modifications, the accelerator succeeded in sustaining -1 MV in vacuum without beam acceleration. However, the beam energy was still limited at a level of 900 keV with a beam current density of 150 A/m{sup 2} (346 mA) where the 3 x 5 apertures were used. Measurement of the beam profile revealed that deflection of the H{sup -} ions was large and a part of the H{sup -} ions was intercepted at the acceleration grid. This causes high heat load on the grids and the breakdowns during beam acceleration. To suppress the direct interception, new grid system was designed with proper aperture displacement based on a 3D beam trajectory analysis. As the result, the beam deflection was compensated and the voltage holding during the beam acceleration was improved. Beam parameter of the MeV accelerator was increased to 980 keV, 185 A/m{sup 2} (427 mA), which is close to the requirement of ITER accelerator (1 MeV, 200 A/m{sup 2}).

Taniguchi, M.; Kashiwagi, M.; Umeda, N.; Dairaku, M.; Takemoto, J.; Tobari, H.; Tsuchida, K.; Yamanaka, H.; Watanabe, K.; Kojima, A.; Hanada, M.; Sakamoto, K.; Inoue, T. [Japan Atomic Energy Agency (JAEA), 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

2012-02-15T23:59:59.000Z

328

Current measurement apparatus  

DOE Patents (OSTI)

Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

Umans, Stephen D. (Belmont, MA)

2008-11-11T23:59:59.000Z

329

Contracting Polymer with Current  

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

Contracting Polymer with Current Contracting Polymer with Current Name: Ian Status: student Grade: 9-12 Location: PA Country: USA Date: Summer 2011 Question: Hello and thank you in advance. I have previously read of a material ( a kind of "rubber") that contracts when an electric current is applied. My question is what is this material, how does it work/what is it made of? Thank you very much. Replies: Hi Ian, I believe the material you are referring to is a kind of piezoelectric rubber. Piezoelectric materials (usually they are special types of ceramics or crystals) produce an electrical voltage when compressed of otherwise subjected to stress. They also do the opposite... they slightly expand or contract when a voltage is applied. But the amount they expand or contract is very small indeed. For example, one square meter of the recently discovered piezoelectric rubber materials typically contracts a mere 100 picometers for ever applied volt. Translated into everyday measurements, this means that if you apply a voltage of 1 Volt to a one foot long piece of this rubber, it will only contract less than half a billionth of an inch! Applying 100 volts will cause it to contract just under 50 billionths of an inch!

330

Eddy Current Rail Inspection Using AC Bridge Techniques  

Science Conference Proceedings (OSTI)

... output of the detection coil is dominated by the direct induced voltage ... Signal Generator ... A custom electronic circuit is used to drive the excitation coil ...

2013-02-27T23:59:59.000Z

331

Transformer current sensor for superconducting magnetic coils  

DOE Patents (OSTI)

The present invention is a current transformer for operating currents larger than 2kA (two kiloamps) that is capable of detecting a millivolt level resistive voltage in the presence of a large inductive voltage. Specifically, the present invention includes substantially cylindrical primary turns arranged to carry a primary current and substantially cylindrical secondary turns arranged coaxially with and only partially within the primary turns, the secondary turns including an active winding and a dummy winding, the active and dummy windings being coaxial, longitudinally separated and arranged to mutually cancel voltages excited by commonly experienced magnetic fields, the active winding but not the dummy winding being arranged within the primary turns.

Shen, S.S.; Wilson, C.T.

1985-04-16T23:59:59.000Z

332

Capabilities of the High Voltage Stress Test System at the Outdoor Test Facility  

DOE Green Energy (OSTI)

We illustrate the capabilities of the High Voltage Stress Test (HVST) which operates continuously in the array field east of the Outdoor Test Facility at the National Renewable Energy Laboratory. Because we know that photovoltaic (PV) modules generating electrical power in both residential and utility-scale array installations will develop high-voltage biases approaching 600 VDC and 1,000 VDC, respectively, we expect such high voltages will result in current leakage between cells and ground, typically through the frames or mounts. We know that inevitably such leakage currents are capable of producing electrochemical corrosion that adversely impacts long-term module performance. With the HVST, we stress or operate PV modules under high-voltage bias, to characterize their leakage currents under all prevailing ambient conditions and assess performance changes emanating from high-voltage stress. We perform this test both on single modules and an active array.

del Cueto, J. A.; Trudell, D.; Sekulic, W.

2005-11-01T23:59:59.000Z

333

Analysis of Low Voltage Ride through Capability in Wind Turbine Based on DFIG  

Science Conference Proceedings (OSTI)

In this paper the coordination of the low voltage ride through capability and the crowbar protection of DFIG are discussed. Different protection strategies for over-current and low voltage protection are presented. Effect of different short-circuit impedance, ... Keywords: doubly fed induction generator (DFIG), low voltges ride through (LVRT), crowbar protection

Shan-Ying Li; Yu Sun; Tao Wu; Yu-Zhi Liang; Xiao Yu; Jian-Ming Zhang

2010-06-01T23:59:59.000Z

334

Study on Control Strategy for DFIG-Based Wind Turbines Under Unbalanced Grid Voltages  

Science Conference Proceedings (OSTI)

Unbalanced input voltages would make doubly fed induction generator (DFIG)-based wind turbine operating performance deteriorate, such as shaft tremble, temperature increasing, and so on, even make it cut out of the power grid. Meanwhile, without proper ... Keywords: DFIG, dual current control, unbalanced input voltages

Changxi Huang, Shuying Yang, Xing Zhang, Zhen Xie

2012-07-01T23:59:59.000Z

335

Home: Directives, Delegations, and Requirements  

NLE Websites -- All DOE Office Websites

content. | Skip to navigation content. | Skip to navigation Site Map Contact Us Current Documents Archived Documents Entire Site only in current section Advanced Search... U.S. Department of Energy Office of Management Directives, Delegations, and Requirements Sections Home Directives Current Directives Draft Directives Archives Delegations Current Delegations Current Designations Rescinded Organizations' Assignment of Responsibility Development & Review RevCom Writers' Tools DPC Corner References News and Updates Help Personal tools You are here: Office of Management » Directives, Delegations, and Requirements Info Home Directives are the Department of Energy's primary means of establishing policies, requirements, responsibilities, and procedures for Departmental elements and contractors. Directive

336

Network for minimizing current imbalances in a faradaic battery  

SciTech Connect

A circuit for connecting a faradaic battery with circuitry for monitoring the condition of the battery includes a plurality of voltage divider networks providing battery voltage monitoring nodes and includes compensating resistors connected with the networks to maintain uniform discharge currents through the cells of the battery. The circuit also provides a reduced common mode voltage requirement for the monitoring circuitry by referencing the divider networks to one-half the battery voltage.

Wozniak, Walter (Dearborn, MI); Haskins, Harold J. (Ann Arbor, MI)

1994-01-01T23:59:59.000Z

337

Proceedings: EPRI/NERC forum on voltage stability  

SciTech Connect

Over the past two decades, the interconnected electric systems serving North America have been increasingly subjected to reductions in generation and transmission capacity reserves, increasing complexity of load character, and the need for power transfer over longer distances. As a result, voltage stability limitations are becoming an important factor for utility personnel to consider when designing and operating an electric system. To address this situation, EPRI and NERC cosponsored a forum to exchange information between the various sectors of the utility industry on voltage control technology. The forum covered available tools and practices; utility operating practices, procedures, and experiences; planning and operating studies; and energy management system (EMS) vendor viewpoints. Participants agreed that a continuing coordinated effort involving all industry groups was needed in the voltage stability area. Attendees also identified specific subject areas of importance to help direct future studies. Individual papers are indexed separately.

Maratukulam, D. (ed.) (Kennedy (Thomas), Florissant, MO (United States))

1993-05-01T23:59:59.000Z

338

Optical Technology Division 1998 - Current Directions  

Science Conference Proceedings (OSTI)

... Our new implementation of SFG relies on femtosecond lasers and nonlinear optics to generate ultrafast, spectrally-broad, IR pulses. ...

339

NIST Quantum Physics Division 2000 - Current Directions  

Science Conference Proceedings (OSTI)

... Recent work addresses the creation, utilization, and study of "ultrafast" laser pulses, which can be applied to investigations of semiconductor ...

340

NIST Quantum Physics Division 1999 - Current Directions  

Science Conference Proceedings (OSTI)

... Recent work addresses the creation, utilization, and study of "ultrafast" laser pulses, which can be applied to investigations of semiconductor ...

Note: This page contains sample records for the topic "voltage direct current" 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

NIST Optical Technology Div. 2000 - Current Directions  

Science Conference Proceedings (OSTI)

... known physical principles that relate radiance to fundamental physics: Planck's equation of black body (thermal) radiation, Schwinger's equation of ...

342

Direct current, closed furnace silicon technology  

Science Conference Proceedings (OSTI)

The dc closed furnace technology for smelting silicon offers technical operating challenges, as well as, economic opportunities for off-gas recovery, reduced electrode consumption, reduced reductant oxidation losses, reduced energy consumption, and improved silicon recovery. The 10 mva dc closed furnace is located in East Selkirk, Manitoba. Construction of this pilot plant was started in September 1990. Following successful commissioning of the furnace in 1992, a number of smelting tests have been conducted aimed at optimization of the furnace operation and the raw material mix. The operation of a closed furnace is significantly different from an open furnace operation. The major difference being in the mechanical movement of the mix, off-gas recovery, and inability to observe the process. These differences made data collection and analysis critical in making operating decisions. This closed furnace was operated by computer control (state of the art in the smelling industry).

Dosaj, V.D. [Dow Corning Corp., Midland, MI (United States); May, J.B. [Dow Corning Corp., Freeland, MI (United States); Arvidson, A.N. [Meadow Materials, Manitoba (Canada)

1994-05-01T23:59:59.000Z

343

Optical Technology Division 1999 - Current Directions  

Science Conference Proceedings (OSTI)

... for applications in chemical analysis and detection, including atmospheric remote sensing, emissions monitoring, catalysis, industrial process ...

344

NIST Ionizing Radiation Division 1999 - Current Directions  

Science Conference Proceedings (OSTI)

... effect relationships for radiation-induced stochastic ... validate the EPR dose assessment methods ... Calibration of Low-Energy Photon Brachytherapy ...

345

NIST Ionizing Radiation Division 1998 - Current Directions  

Science Conference Proceedings (OSTI)

... Cs gamma-ray ranges, and the low-energy photon ... beam, and a high-dose- rate Gammacell used in our radiation-processing dosimetry ...

346

NIST Quantum Physics Division 1998 - Current Directions  

Science Conference Proceedings (OSTI)

... These include quantitative measurements of the basic thermodynamics and energetics of condensates and their response to standing-wave ...

347

NIST Atomic Physics Division 2000 - Current Directions  

Science Conference Proceedings (OSTI)

... Although these data are needed for magnetic fusion research, astronomy, and industry, there is ... Physics of Cold, Trapped Gases of Neutral Atoms. ...

348

Voltage unbalance effects on induction motor performance  

Science Conference Proceedings (OSTI)

The reliability of electric drives and driven motors depends on the quality of the power supply voltage especially in the critical industrial process. In this work, a theoretical study of the effects of voltage unbalances, sags and swells on induction ... Keywords: efficiency, power losses and derating factor, sags, symmetrical components, voltage unbalance

L. Refoufi; H. Bentarzi; F. Z. Dekhandji

2006-09-01T23:59:59.000Z

349

High voltage design structure for high temperature superconducting device  

DOE Patents (OSTI)

In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

Tekletsadik, Kasegn D. (Rexford, NY)

2008-05-20T23:59:59.000Z

350

Influence of voltage drop to electric drive with induction motor and voltage sourced inverter  

Science Conference Proceedings (OSTI)

This paper solves problematic of immunity from the voltage drop of the power supply of the electric drive with induction motor with Voltage-Fed inverter. There are reflected opportune control algorithms for the quickly to change of working regime from ... Keywords: electric drive with induction motor, electric drive with voltage sourced inverter, voltage drop

P. Beneš; J. Fo?t; M. Pittermann

2011-09-01T23:59:59.000Z

351

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

352

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

353

Dynamic Voltage Regulation Using Distributed Energy Resources  

Science Conference Proceedings (OSTI)

Many distributed energy resources (DE) are near load centres and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide ancillary services such as voltage regulation, nonactive power compensation, and power factor correction. A synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Voltage control schemes of the inverter and the synchronous condenser are developed. The experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously, while the dynamic response of the inverter is faster than the synchronous condenser; and that integrated voltage regulation (multiple DE perform voltage regulation) can increase the voltage regulation capability, increase the lifetime of the equipment, and reduce the capital and operation costs.

Xu, Yan [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL

2007-01-01T23:59:59.000Z

354

High-voltage crowbar circuit with cascade-triggered series ignitrons  

DOE Patents (OSTI)

A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors.

Baker, William R. (Orinda, CA)

1980-01-01T23:59:59.000Z

355

High-voltage crowbar circuit with cascade-triggered series ignitrons  

DOE Patents (OSTI)

A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors. 1 fig.

Baker, W.R.

1980-11-04T23:59:59.000Z

356

Geothermal Energy: Current abstracts  

DOE Green Energy (OSTI)

This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

Ringe, A.C. (ed.)

1988-02-01T23:59:59.000Z

357

Blocking diodes and fuses in low-voltage PV systems  

DOE Green Energy (OSTI)

Instructions and labels supplied with listed PV modules and the requirements of the National Electrical Code (NEC) dictate that a series fuse shall be used to protect the module against backfeed currents. Few of the hundreds of thousands of low-voltage (12, 24, and 48-volt) stand-alone photovoltaic (PV) power systems use series fuses on each module or string of modules. Tests and simulations at the Southwest Technology Development Institute (TDI) and at Sandia National Laboratories (SNL) have established that the absence of these fuses can pose significant fire and safety hazards even on 12-volt PV systems. If the system has sufficient backfeed voltage and current, it is possible that a ground fault in the wiring or inside a module can result in the destruction of a PV module.

Wiles, J.C. [New Mexico State Univ., Las Cruces, NM (United States). Southwest Technology Development Inst.; King, D.L. [Sandia National Labs., Albuquerque, NM (United States). Photovoltaic Systems R and D

1997-11-01T23:59:59.000Z

358

Effect of voltage dynamics on response properties in a model of sensory hair cell  

E-Print Network (OSTI)

Sensory hair cells in auditory and vestibular organs rely on active mechanisms to achieve high sensitivity and frequency selectivity. Recent experimental studies have documented self-sustained oscillations in hair cells of lower vertebrates on two distinct levels. First, the hair bundle can undergo spontaneous mechanical oscillations. Second, somatic electric voltage oscillations across the baso-lateral membrane of the hair cell have been observed. We develop a biophysical model of the bullfrog's saccular hair cell consisting of two compartments, mechanical and electrical, to study how the mechanical and the voltage oscillations interact to produce coherent self-sustained oscillations and how this interaction contributes to the overall sensitivity and selectivity of the hair cell. The model incorporates nonlinear mechanical stochastic hair bundle system coupled bi-directionally to a Hodgkin-Huxley type system describing somatic ionic currents. We isolate regions of coherent spontaneous oscillations in the parameter space of the model and then study how coupling between compartments affect sensitivity of the hair cell to external mechanical perturbations. We show that spontaneous electrical oscillations may enhance significantly the sensitivity and selectivity of the hair cell.

Rami Amro; Alexander B. Neiman

2012-09-27T23:59:59.000Z

359

Understanding the unbalanced-voltage problem in wind turbine generation  

DOE Green Energy (OSTI)

Most wind turbines are equipped with line-connected induction generators. Induction generators are very attractive as wind turbine generators due to their low cost, ruggedness and the need for little or no maintenance. At constant frequency, the induction generator operates in a small range of speeds and, therefore, it operated with a small range of slips with respect to synchronous speed. Compared to a synchronous generator, an induction generator provides lower stiffness, thus alleviating the mechanical stress. In a weak power system network, an unbalanced load at the distribution lines can cause unbalanced voltage conditions. If an induction generator is connected to an unbalanced voltage, the resulting stator current will be unbalanced. The unbalanced current creates unequal heating (hot spots) on the stator winding. The heat may increase the winding temperature, which degrades the insulation of the winding, i.e., the life expectancy of the winding. Unbalanced currents also create torque pulsation on the shaft resulting in audible noise and extra mechanical stress. This paper explores the unbalanced voltage problem in induction generators. The levels of unbalance and the loads are varied. Experimental and predicted results are presented in this paper.

Muljadi, E.; Butterfield, C.P.; Batan, T.; Yildirim, D.

2000-02-28T23:59:59.000Z

360

Definition: Operating Voltage | Open Energy Information  

Open Energy Info (EERE)

Voltage Voltage Jump to: navigation, search Dictionary.png Operating Voltage The voltage level by which an electrical system is designated and to which certain operating characteristics of the system are related; also, the effective (root-mean-square) potential difference between any two conductors or between a conductor and the ground. The actual voltage of the circuit may vary somewhat above or below this value.[1] Related Terms system References ↑ Glossary of Terms Used in Reliability Standards An LikeLike UnlikeLike You like this.Sign Up to see what your friends like. inline Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Operating_Voltage&oldid=480559" Categories: Definitions ISGAN Definitions What links here Related changes

Note: This page contains sample records for the topic "voltage direct current" 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
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361

The effect of DVR location for enhancing voltage sag  

Science Conference Proceedings (OSTI)

Recently, Dynamic Voltage Restorer (DVR) has become a popular power electronic device as a protection for sensitive loads from voltage sag. Voltage sag widely known as one of the major problem in power quality, it is defined as a short reduction of voltage ... Keywords: dynamic voltage restorer, power quality, voltage sag

Rohanim Ibrahim; Ahmed M. A. Haidar; M. Zahim; Herbert Iu

2010-03-01T23:59:59.000Z

362

Lowering Power using the Voltage Identification Bit  

E-Print Network (OSTI)

Voltage identification is a form of adaptive voltage scaling (AVS). The voltage-identification technique described in this application note enables certain devices in the Virtex®-7 family to be operated at a lower voltage of 0.9V while delivering the same specified performance as that of a device operating at the nominal supply voltage of 1.0V. Voltage identification capable devices consume approximately 30 % lower worst case (maximum) static power and correspondingly dissipate less heat. Reduced power consumption is a desirable characteristic and one that Xilinx 7 series FPGAs fulfill in multiple ways. The primary purpose of the voltage-identification technique is to reduce the worst-case power consumption of-1C devices. However, the significance of the voltage-identification technique goes beyond an individual device dissipating less energy, it also can lower the overall system cost. Power supplies and thermal management requirements are normally specified based on the worst-case power demands of all the system’s components. Although the 7 series FPGAs-1C devices are the most cost-effective, the total cost of a product is the sum of all parts, and costs associated with the power supply and thermal management can be significant. The voltage-identification technique specifically reduces worst-case power consumption, which reduces the overall costs associated with specifying a larger power supply, requiring a heat sink, adding forced air cooling, or including similar devices. This application note shows the technical aspects of implementing the voltage-identification technique and introduces a reference design for the VC707 evaluation kit. It also explains how voltage identification fits into the complete power portfolio of Virtex-7 FPGAs and highlights the benefits of using the voltage-identification technique to reduce power consumption and system costs.

Ken Chapman; Jameel Hussein

2012-01-01T23:59:59.000Z

363

Emergency Diesel Generator Voltage Regulator Guidelines  

Science Conference Proceedings (OSTI)

This product kit, containing six separate documents, provides information to help utilities address emergency diesel generator voltage regulator issues and maintenance.

2005-12-20T23:59:59.000Z

364

Enhancing Open Circuit Voltage by Combining Thermoelectric ...  

Science Conference Proceedings (OSTI)

Enhancing Open Circuit Voltage by Combining Thermoelectric Materials and Dye -Sensitized Solar Cell in Series · Estimation of Compressive Strength of High ...

365

Group 3: Humidity, Temperature, and Voltage (Presentation)  

DOE Green Energy (OSTI)

Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.

Wohlgemuth, J.

2013-05-01T23:59:59.000Z

366

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, Pĺl Kristian Myhrer

2010-01-01T23:59:59.000Z

367

Quantum Voltage System Development and Dissemination  

Science Conference Proceedings (OSTI)

... of the unit of electric potential difference, the volt, and precise techniques for measuring voltage are essential to the electrical ... Facilities/Tools Used: ...

2012-11-14T23:59:59.000Z

368

Stability issues in IC Low Drop Out voltage regulators  

E-Print Network (OSTI)

Performance issues of IC Low Drop Out (LDO) voltage regulators, with specific reference to stability, are discussed in this thesis. Evaluation of existing frequency compensation schemes and their performances across operating loads is presented. The problem of instability of the LDO voltage regulator at low Electo Static Resistance (ESR) of the load capacitors and the consequences of this problem are highlighted. As a solution to some of the discussed problems, an alternate LDO voltage regulator topology that is stable with low Electro Static Resistance (ESR) capacitive loads is presented. The proposed scheme, instead of relying on the zero generated by the load capacitor and its ESR combination for stability, generates a zero internally. The LDO voltage regulator is implemented and fabricated in AMI 0.5mm CMOS technology through MOSIS service. It is demonstrated that this scheme realizes robust frequency compensation, facilitates use of Multi Layer Ceramic Capacitors (MLCC) for load of LDO regulators, and improves transient response and noise performance. Test results from the prototype provide an evaluation of the most important parameters of the regulator: ground current, load regulation, line regulation, output noise and start-up time.

Chava, Krishna Chaitanya

2002-01-01T23:59:59.000Z

369

Leakage Current Reduction Techniques for 7T SRAM Cell in 45 nm Technology  

Science Conference Proceedings (OSTI)

In this paper the impact of gate leakage on 7T static random access memory (SRAM) is described and three techniques for reducing gate leakage currents and sub threshold leakage currents are examined. In first technique, the supply voltage is decreased. ... Keywords: CMOS, Gate leakage current, SRAM, Stand-by power, Sub threshold current, Voltage level switch

Shyam Akashe, Sanjay Sharma

2013-07-01T23:59:59.000Z

370

Model of ionic currents through microtubule nanopores and the lumen  

E-Print Network (OSTI)

It has been suggested that microtubules and other cytoskeletal filaments may act as electrical transmission lines. An electrical circuit model of the microtubule is constructed incorporating features of its cylindrical structure with nanopores in its walls. This model is used to study how ionic conductance along the lumen is affected by flux through the nanopores when an external potential is applied across its two ends. Based on the results of Brownian dynamics simulations, the nanopores were found to have asymmetric inner and outer conductances, manifested as nonlinear IV curves. Our simulations indicate that a combination of this asymmetry and an internal voltage source arising from the motion of the C-terminal tails causes a net current to be pumped across the microtubule wall and propagate down the microtubule through the lumen. This effect is demonstrated to enhance and add directly to the longitudinal current through the lumen resulting from an external voltage source, and could be significant in amplifying low-intensity endogenous currents within the cellular environment or as a nano-bioelectronic device.

Holly Freedman; Vahid Rezania; Avner Priel; Eric Carpenter; Sergei Y. Noskovd; Jack A. Tuszynski

2009-08-10T23:59:59.000Z

371

Aalborg Universitet Mitigation of Voltage Sags in CIGRE Low Voltage Distribution Network  

E-Print Network (OSTI)

software version 15.0. Index Terms--Wind Turbine Generator (WTG), Photovoltaic (PV), Voltage Source of voltage sags. I. INTRODUCTION Power quality, reliability and stability are the prime requirement of modern

Bak-Jensen, Birgitte

372

RF heating and current drive on NSTX with high  

SciTech Connect

NSTX is a small aspect ratio tokamak (R = 0.85 m, a = 0.65 m). The High Harmonic Fast Wave (HHFW) system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ~3 MW for 100-400 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with significant fractions (0.4) of bootstrap current. Differences in the loop voltage are observed depending on whether the array is phased to drive current in the co- or counter-current directions. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial rf power deposition and driven current profiles have been calculated with ray tracing and kinetic full-wave codes and compared with measurements.

Ryan, Philip Michael [ORNL; Peng, Yueng Kay Martin [ORNL

2003-01-01T23:59:59.000Z

373

Low voltage ride-through capability improvement of wind power generation using dynamic voltage restorer  

Science Conference Proceedings (OSTI)

Recently, the total amount of generation from wind power plants has been increased all over the world. In this situation, a large amount of disconnection of wind generation may give a serious influence in the power system. Consequently, Low Voltage Ride-Through ... Keywords: dynamic voltage restorer, energy storage, fault ride-through, fixed-speed induction generator, low voltage ride-through, voltage sag, wind power generation

Naohiro Hasegawa; Teruhisa Kumano

2010-02-01T23:59:59.000Z

374

Voltage Stability Studies for Southern Company Services  

Science Conference Proceedings (OSTI)

This report describes a study conducted under an EPRI Tailored Collaboration project to develop and demonstrate procedures for the assessment of voltage security of the Southern Electric System (SES). The contractor used EPRI steady-state analysis tools including VSTAB (Voltage STABility assessment program) to assess stability margins and verified them using EPRI dynamic tools including ETMSP (Extended Transient / Mid-term Stability Program).

1997-12-31T23:59:59.000Z

375

Voltage regulation in linear induction accelerators  

DOE Patents (OSTI)

Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor when it is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.

Parsons, W.M.

1991-03-19T23:59:59.000Z

376

Voltage regulation in linear induction accelerators  

DOE Patents (OSTI)

Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.

Parsons, W.M.

1992-12-29T23:59:59.000Z

377

Strain-optic voltage monitor wherein strain causes a change in the optical absorption of a crystalline material  

DOE Patents (OSTI)

A voltage monitor which uses the shift in absorption edge of crystalline material to measure strain resulting from electric field-induced deformation of piezoelectric or electrostrictive material, providing a simple and accurate means for measuring voltage applied either by direct contact with the crystalline material or by subjecting the material to an electric field.

Weiss, Jonathan D. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

378

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

379

Ultra-low voltage resonant tunnelling diode electroabsorption modulator  

E-Print Network (OSTI)

Embedding a double barrier resonant tunnelling diode (RTD) in an unipolar InGaAlAs optical waveguide gives rise to a very low driving voltage electroabsorption modulator (EAM) at optical wavelengths around 1550 nm. The presence of the RTD within the waveguide core introduces high non-linearity and negative differential resistance in the current-voltage (I-V) characteristic of the waveguide. This makes the electric field distribution across the waveguide core strongly dependent on the bias voltage: when the current decreases from the peak to the valley there is an increase of the electric field across the depleted core. The electric field enhancement in the core-depleted layer causes the Franz-Keldysh absorption band-edge to red shift, which is responsible for the electroabsorption effect. High frequency ac signals as low as 100 mV can induce electric field high speed switching, producing substantial light modulation (up to 15 dB) at photon energies slightly lower than the waveguide core band-gap energy. The k...

Figueiredo, J M L; Stanley, C R

2002-01-01T23:59:59.000Z

380

High Voltage Safety Act | Department of Energy  

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

High Voltage Safety Act High Voltage Safety Act High Voltage Safety Act < Back Eligibility Commercial Construction Developer General Public/Consumer Industrial Installer/Contractor Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Georgia Program Type Safety and Operational Guidelines Siting and Permitting The purpose of the High Voltage Safety Act is to prevent injury to persons and property and interruptions of utility service resulting from accidental or inadvertent contact with high-voltage electric lines by providing that no work shall be done in the vicinity of such lines unless and until the owner or operator thereof has been notified of such work and has taken the appropriate safety measures. The Georgia Public Service Commission requires

Note: This page contains sample records for the topic "voltage direct current" 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.


381

Flexible method for monitoring fuel cell voltage  

DOE Patents (OSTI)

A method for equalizing the measured voltage of each cluster in a fuel cell stack wherein at least one of the clusters has a different number of cells than the identical number of cells in the remaining clusters by creating a pseudo voltage for the different cell numbered cluster. The average cell voltage of the all of the cells in the fuel cell stack is calculated and multiplied by a constant equal to the difference in the number of cells in the identical cell clusters and the number of cells in the different numbered cell cluster. The resultant product is added to the actual voltage measured across the different numbered cell cluster to create a pseudo voltage which is equivalent in cell number to the number of cells in the other identical numbered cell clusters.

Mowery, Kenneth D. (Noblesville, IN); Ripley, Eugene V. (Russiaville, IN)

2002-01-01T23:59:59.000Z

382

Surface Wind Direction Variability  

Science Conference Proceedings (OSTI)

Common large shifts of wind direction in the weak-wind nocturnal boundary layer are poorly understood and are not adequately captured by numerical models and statistical parameterizations. The current study examines 15 datasets representing a ...

Larry Mahrt

2011-01-01T23:59:59.000Z

383

High Power, High Voltage FETs in Linear Applications: A User's Perspective  

SciTech Connect

The specifications of the current crop of highpower, high-voltage field-effect transistors (FETs) can lure a designer into employing them in high-voltage DC equipment. Devices with extremely low on-resistance and very high power ratings are available from several manufacturers. However, our experience shows that high-voltage, linear operation of these devices at near-continuous duty can present difficult reliability challenges at stress levels well-below their published specifications. This paper chronicles the design evolution of a 600 volt, 8 ampere shunt regulator for use with megawatt-class radio transmitters, and presents a final design that has met its reliability criteria.

N. Greenough, E. Fredd, S. DePasquale

2009-09-21T23:59:59.000Z

384

SRAM leakage suppression by minimizing standby supply voltage  

E-Print Network (OSTI)

Suppressing the leakage current in memories is critical in low-power design. By reducing the standby supply voltage (VDD) to its limit, which is the Data Retention Voltage (DRV), leakage power can be substantially reduced. This paper explores how low DRV can be in a standard low leakage SRAM module and analyzes how DRV is affected by parameters such as process variations, chip temperature, and transistor sizing. An analytical model for DRV as a function of process and design parameters is presented, and forms the base for further design space explorations. This model is verified using simulations as well as measurements from a 4KB SRAM chip in a 0.13?m technology. It is demonstrated that an SRAM cell state can be preserved at sub-300mV standby V DD, with more than 90 % leakage power savings. 1.

Huifang Qin; Yu Cao; Dejan Markovic; Andrei Vladimirescu; Jan Rabaey

2004-01-01T23:59:59.000Z

385

Analysis of Solar Cell Quality Using Voltage Metrics: Preprint  

DOE Green Energy (OSTI)

The highest efficiency solar cells provide both excellent voltage and current. Of these, the open-circuit voltage (Voc) is more frequently viewed as an indicator of the material quality. However, since the Voc also depends on the band gap of the material, the difference between the band gap and the Voc is a better metric for comparing material quality of unlike materials. To take this one step further, since Voc also depends on the shape of the absorption edge, we propose to use the ultimate metric: the difference between the measured Voc and the Voc calculated from the external quantum efficiency using a detailed balance approach. This metric is less sensitive to changes in cell design and definition of band gap. The paper defines how to implement this metric and demonstrates how it can be useful in tracking improvements in Voc, especially as Voc approaches its theoretical maximum.

Toberer, E. S.; Tamboli, A. C.; Steiner, M.; Kurtz, S.

2012-06-01T23:59:59.000Z

386

Touch and Step Voltage Measurements on Field Installed Ground Grid Overlaid with Gravel and Asphalt Beds  

Science Conference Proceedings (OSTI)

Gravel and asphalt are commonly used as surfacing materials in and around substations. Both the electrical characteristics of the surfacing material and its moisture condition substantially affect the exposure (step, touch) voltage and the resulting current. This project evaluates the effects of various types of surfacing materials (three gravel types and asphalt) and conditions (dry and wet) on step and touch voltages in and around substations.

2010-12-21T23:59:59.000Z

387

Engineering Technical Training Modules - Medium Voltage System Protection and Coordination Version 1.0  

Science Conference Proceedings (OSTI)

The purpose of this training module is to provide a basic understanding of protective relaying and coordination typically provided for medium voltage power systems. This module provides a discussion on current and potential transformers, the protective relays typically used as well as considerations for equipment protection and coordination or selective tripping. Medium voltage motor, transformer, and bus protection applications are covered. Lesson 4 focuses on emergency diesel generator protection in n...

2011-08-09T23:59:59.000Z

388

Ionization tube simmer current circuit  

DOE Patents (OSTI)

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Steinkraus, Jr., Robert F. (Livermore, CA)

1994-01-01T23:59:59.000Z

389

Ionization tube simmer current circuit  

DOE Patents (OSTI)

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

Steinkraus, R.F. Jr.

1994-12-13T23:59:59.000Z

390

JGI - Directions  

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

Map to JGI Directions from Directions from key local start points, public transit Home > About Us > Map to JGI UC logo DOE logo Contact Us Credits Disclaimer Access...

391

Electrical voltages and resistances measured to inspect metallic cased wells and pipelines  

DOE Patents (OSTI)

A cased well in the earth is electrically energized with A.C. current. Voltages are measured from three voltage measurement electrodes in electrical contact with the interior of the casing while the casing is electrically energized. In a measurement mode, A.C. current is conducted from a first current carrying electrode within the cased well to a remote second current carrying electrode located on the surface of the earth. In a calibration mode, current is passed from the first current carrying electrode to a third current carrying electrode located vertically at a different position within the cased well, where the three voltage measurement electrodes are located vertically in between the first and third current carrying electrodes. Voltages along the casing and resistances along the casing are measured to determine wall thickness and the location of any casing collars present so as to electrically inspect the casing. Similar methods are employed to energize a pipeline to measure the wall thickness of the pipeline and the location of pipe joints to electrically inspect the pipeline.

Vail, III, William Banning (Bothell, WA); Momii, Steven Thomas (Seattle, WA)

2001-01-01T23:59:59.000Z

392

Electrical voltages and resistances measured to inspect metallic cased wells and pipelines  

DOE Patents (OSTI)

A cased well in the earth is electrically energized with A.C. current. Voltages are measured from three voltage measurement electrodes in electrical contact with the interior of the casing while the casing is electrically energized. In a measurement mode, A.C. current is conducted from a first current carrying electrode within the cased well to a remote second current carrying electrode located on the surface of the earth. In a calibration mode, current is passed from the first current carrying electrode to a third current carrying electrode located vertically at a different position within the cased well, where the three voltage measurement electrodes are located vertically in between the first and third current carrying electrodes. Voltages along the casing and resistances along the casing are measured to determine wall thickness and the location of any casing collars present so as to electrically inspect the casing. Similar methods are employed to energize a pipeline to measure the wall thickness of the pipeline and the location of pipe joints to electrically inspect the pipeline.

Vail, III, William Banning (Bothell, WA); Momii, Steven Thomas (Seattle, WA)

2000-01-01T23:59:59.000Z

393

Unlikely Combination of Experiments With a Novel High-Voltage CIGS Photovoltaic Array: Preprint  

DOE Green Energy (OSTI)

A new high-voltage array comprising bipolar strings of copper indium gallium diselenide (CIGS) photovoltaic (PV) modules was inaugurated in 2005. It is equipped with a unique combination of tests, which likely have never before been deployed simultaneously within a single array: full current-voltage (I-V) traces, high-voltage leakage current measurements, and peak-power tracking or temporal stepped-bias profiling. The array nominally produces 1 kW power at 1 sun. The array's electrical characteristics are continuously monitored and controlled with a programmable electronic load interfaced to a data acquisition system (DAS), that also records solar and meteorological data. The modules are mounted with their frames electrically isolated from earth ground, in order to facilitate measurement of the leakage currents that arise between the high voltage bias developed in the series-connected cells and modules and their mounting frames. Because the DAS can perform stepped biasing of the array as a function of time, synchronous detection of the leakage current data with alternating bias is available. Leakage current data and their dependence on temperature and voltage are investigated. Array power data are analyzed across a wide range of varying illuminations and temperatures from the I-V traces. Array performance is also analyzed from an energy output perspective using peak-power tracking data.

del Cueto, J. A.; Sekulic, B. R.

2006-05-01T23:59:59.000Z

394

High-Compression-Ratio; Atkinson-Cycle Engine Using Low-Pressure Direct Injection and Pneumatic-Electronic Valve Actuation Enabled by Ionization Current and Foward-Backward Mass Air Flow Sensor Feedback  

DOE Green Energy (OSTI)

This report describes the work completed over a two and one half year effort sponsored by the US Department of Energy. The goal was to demonstrate the technology needed to produce a highly efficient engine enabled by several technologies which were to be developed in the course of the work. The technologies included: (1) A low-pressure direct injection system; (2) A mass air flow sensor which would measure the net airflow into the engine on a per cycle basis; (3) A feedback control system enabled by measuring ionization current signals from the spark plug gap; and (4) An infinitely variable cam actuation system based on a pneumatic-hydraulic valve actuation These developments were supplemented by the use of advanced large eddy simulations as well as evaluations of fuel air mixing using the KIVA and WAVE models. The simulations were accompanied by experimental verification when possible. In this effort a solid base has been established for continued development of the advanced engine concepts originally proposed. Due to problems with the valve actuation system a complete demonstration of the engine concept originally proposed was not possible. Some of the highlights that were accomplished during this effort are: (1) A forward-backward mass air flow sensor has been developed and a patent application for the device has been submitted. We are optimistic that this technology will have a particular application in variable valve timing direct injection systems for IC engines. (2) The biggest effort on this project has involved the development of the pneumatic-hydraulic valve actuation system. This system was originally purchased from Cargine, a Swedish supplier and is in the development stage. To date we have not been able to use the actuators to control the exhaust valves, although the actuators have been successfully employed to control the intake valves. The reason for this is the additional complication associated with variable back pressure on the exhaust valves when they are opened. As a result of this effort, we have devised a new design and have filed for a patent on a method of control which is believed to overcome this problem. The engine we have been working with originally had a single camshaft which controlled both the intake and exhaust valves. Single cycle lift and timing control was demonstrated with this system. (3) Large eddy simulations and KIVA based simulations were used in conjunction with flow visualizations in an optical engine to study fuel air mixing. During this effort we have devised a metric for quantifying fuel distribution and it is described in several of our papers. (4) A control system has been developed to enable us to test the benefits of the various technologies. This system used is based on Opal-RT hardware and is being used in a current DOE sponsored program.

Harold Schock; Farhad Jaberi; Ahmed Naguib; Guoming Zhu; David Hung

2007-12-31T23:59:59.000Z

395

The high current, fast, 100ns, Linear Transformer Driver (LTD) developmental project at Sandia National Laboratories.  

Science Conference Proceedings (OSTI)

Sandia National Laboratories, Albuquerque, N.M., USA, in collaboration with the High Current Electronic Institute (HCEI), Tomsk, Russia, is developing a new paradigm in pulsed power technology: the Linear Transformer Driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high current and high voltage pulses straight out of the cavity with out any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. This is because the output pulse rise time and width can be easily tailored to the specific application needs. In this paper we briefly summarize the developmental work done in Sandia and HCEI during the last few years, and describe our new MYKONOS Sandia High Current LTD Laboratory.

Ward, Kevin S.; Long, Finis W.; Sinebryukhov, Vadim A. (High Current Electronic Institute (HCEI), Tomsk, Russia); Kim, Alexandre A. (High Current Electronic Institute (HCEI), Tomsk, RUSSIA); Wakeland, Peter Eric (Ktech Corporation, Albuquerque, NM); McKee, G. Randall; Woodworth, Joseph Ray; McDaniel, Dillon Heirman; Fowler, William E.; Mazarakis, Michael Gerrassimos; Porter, John Larry, Jr.; Struve, Kenneth William; Stygar, William A.; LeChien, Keith R.; Matzen, Maurice Keith

2010-04-01T23:59:59.000Z

396

Performance of a voltage peak detection-based flickermeter  

Science Conference Proceedings (OSTI)

Voltage fluctuations and rapid voltage changes lead to lamps flickering and disturbance of visual perception may occur consequently. For evaluation of the flicker severity level by means of voltage measurement there was developed an instrument called ... Keywords: Matlab Simulink, flickermeter, interharmonics, performance analysis, voltage fluctuation, voltage peak detection

Jiri Drapela

2009-12-01T23:59:59.000Z

397

Voltage controlled spintronics device for logic applications.  

SciTech Connect

We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistor-like concepts and re-programmable logic gates based on VCR elements.

Bader, S. D.; You, C.-Y.

1999-09-03T23:59:59.000Z

398

Voltage controlled spintronic devices for logic applications  

SciTech Connect

We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistorlike concepts and reprogrammable logic gates based on VCR elements. (c) 2000 American Institute of Physics.

You, Chun-Yeol [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bader, S. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2000-05-01T23:59:59.000Z

399

Interphase power controller with voltage injection  

Science Conference Proceedings (OSTI)

This paper introduces a new family of Interphase Power Controllers (IPC) based on the principle of voltage injection commonly used in phase-shifting transformers (PST). The voltage injection IPC exhibits power (active and reactive) control characteristics similar to previously defined IPC's and retains their inherent qualities: passive control, short circuit limitation and voltage decoupling. It also provides more flexibility for the adjustment of the operating points. Two promising topologies are described in more detail. One of them offers the potential of retrofitting existing phase-shifting transformers into full-fledged IPC's.

Beauregard, F.; Brochu, J.; Morin, G.; Pelletier, P. (Centre d'Innovation sur le Transport d'Energie du Quebec, Varennes, Quebec (Canada))

1994-10-01T23:59:59.000Z

400

Electric current locator  

DOE Patents (OSTI)

The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

King, Paul E. (Corvallis, OR); Woodside, Charles Rigel (Corvallis, OR)

2012-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

A capacitor-less low drop-out voltage regulator with fast transient response  

E-Print Network (OSTI)

Power management has had an ever increasing role in the present electronic industry. Battery powered and handheld applications require power management techniques to extend the life of the battery and consequently the operation life of the device. Most systems incorporate several voltage regulators which supply various subsystems and provide isolation among such subsystems. Low dropout (LDO) voltage regulators are generally used to supply low voltage, low noise analog circuitry. Each LDO regulator demands a large external capacitor, in the range of a few microfarads, to perform. These external capacitors occupy valuable board space, increase the IC pin count, and prohibit system-on-chip (SoC) solutions. The presented research provides a solution to the present bulky external capacitor LDO voltage regulators with a capacitor-less LDO architecture. The large external capacitor was completely removed and replaced with a reasonable 100pF internal output capacitor, allowing for greater power system integration for SoC applications. A new compensation scheme is presented that provides both a fast transient response and full range ac stability from a 0mA to 50mA load current. A 50mA, 2.8V, capacitor-less LDO voltage regulator was fabricated in a TSMC 0.35um CMOS technology, consuming only 65uA of ground current with a dropout voltage of 200mV. Experimental results show that the proposed capacitor-less LDO voltage regulator exceeds the current published works in both transient response and ac stability. The architecture is also less sensitive to process variation and loading conditions. Thus, the presented capacitor-less LDO voltage regulator is suitable for SoC solutions.

Milliken, Robert Jon

2005-12-01T23:59:59.000Z

402

BGE_Comments_CurrentComms.pdf  

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

Reading (based Reading (based on hourly reads) Cellular network 5000 30 minutes 19.2K >90% <15 sec >95% 4 1 2 Direct Load Control 22 250K 8 hours 1K 100% <120 sec >99% 2 1 2 Real time pricing At the customer premises At charging stations 53 1755 8 hours 9600 bps >90% 5 sec <5 per mo. >95% 5 2 1 CBC-5000 2330 CBC-7000 1621 LVC N/A 638 4 hours N/A N/A N/A N/A N/A N/A N/A See comment See comment N/A N/A Customer Calls N/A N/A N/A N/A N/A N/A N/A N/A Applications Distributed Generation Management in-Home Display of Customer Usage Automated Feeder Switching Transformer Monitoring Voltage and Current Monitoring 8 hours 1K >60% Capacitor Bank Control Fault Current Indicator 10 sec >99% 4 1 2 Quantified Estimates Ranking of Relative Importance of Each Estimated Number of End Point Devices to

403

Property:Nominal Voltage | Open Energy Information  

Open Energy Info (EERE)

Nominal Voltage Nominal Voltage Jump to: navigation, search Property Name Nominal Voltage Property Type Number This is a property of type Number. Pages using the property "Nominal Voltage" Showing 22 pages using this property. D Distributed Generation Study/10 West 66th Street Corp + 480 + Distributed Generation Study/615 kW Waukesha Packaged System + 480 + Distributed Generation Study/Aisin Seiki G60 at Hooligans Bar and Grille + 240 + Distributed Generation Study/Arrow Linen + 480 + Distributed Generation Study/Dakota Station (Minnegasco) + 0 + Distributed Generation Study/Elgin Community College + 4,160 + Distributed Generation Study/Emerling Farm + 480 + Distributed Generation Study/Floyd Bennett + 480 + Distributed Generation Study/Harbec Plastics + 480 +

404

Assessment of Voltage Security Methods and Tools  

Science Conference Proceedings (OSTI)

To ensure voltage-secure operation of a power system, VAR control devices must be optimally placed and operated. This project assessed tools and methods that claim to help utilities meet these needs and recommended specific enhancements to these tools.

1995-10-26T23:59:59.000Z

405

An in depth examination of semi floating gate ultra low voltage flip-flops for high speed applications.  

E-Print Network (OSTI)

??In this thesis 4 different ultra low voltage (ULV) flip-flops are presented. Floating gates has been exploited to significantly increase the drain-source current. This technique… (more)

Simenstad, Erik Jonathan

2013-01-01T23:59:59.000Z

406

System for increasing corona inception voltage of insulating oils  

DOE Patents (OSTI)

The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil.

Rohwein, Gerald J. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

407

Spark gap with low breakdown voltage jitter  

SciTech Connect

Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.

Rohwein, Gerald J. (Albuquerque, NM); Roose, Lars D. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

408

Voltage Control Optimization to Improve Transmission Efficiency  

Science Conference Proceedings (OSTI)

An optimal power flow solution is unique from a conventional power flow solution in that an objective function and user-specified constraints are enforced and satisfied to reach a valid solution. This report presents an analytical study on the optimization of power flow in order to minimize reactive power losses via the modification of generator voltage schedules and transmission switched shunt status. The study examines the potential benefits and applicability of near-real-time voltage control ...

2012-11-08T23:59:59.000Z

409

Cell Voltage Noise Reduction Based on Wavelet in Aluminum ...  

Science Conference Proceedings (OSTI)

Presentation Title, Cell Voltage Noise Reduction Based on Wavelet in Aluminum ... cell voltage signals collected in aluminium electrolysis process are with high ...

410

Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum ...  

Science Conference Proceedings (OSTI)

Dubal Cell Voltage Drop Initiatives towards Low Energy High Amperage Cells · Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum Electrolysis ...

411

Appendix C: California ISO Real Time Voltage Security Assessment...  

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

C: California ISO Real Time Voltage Security Assessment (VSA) Prototype Functional SpecificationsPrototype Development Title Appendix C: California ISO Real Time Voltage Security...

412

Appendix B: California ISO Real Time Voltage Security Assessment...  

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

B: California ISO Real Time Voltage Security Assessment (VSA) Summary Report Title Appendix B: California ISO Real Time Voltage Security Assessment (VSA) Summary Report Publication...

413

Appendix A: California ISO Real Time Voltage Security Assessment...  

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

A: California ISO Real Time Voltage Security Assessment (VSA) Project: Summary of Survey Results on Methodologies for use in Real-Time Voltage Security Assessment Title Appendix A:...

414

Green Island Power Authority Transmission Voltage Support System...  

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

Green Island Power Authority Transmission Voltage Support System Project Green Island Power Authority Transmission Voltage Support System Project Power point presentation...

415

Look-ahead voltage and load margin contingency selection functions for large-scale power systems  

SciTech Connect

Given the current operating condition (obtained from the real-time data), the near-term load demand at each bus (obtained from short-term load forecast), and the generation dispatch (say, based on economic dispatch), the authors present in this paper a load margin measure (MW and/or MVAR) to assess the system`s ability to withstand the forecasted load and generation variations. The authors also present a method to predict near-term system voltage profiles. The proposed look-ahead measure and the proposed voltage prediction are then applied to contingency selections for the near-term power system in terms of load margins to collapse and of the bus voltage magnitudes. They evaluate the proposed load-ahead measure and the voltage profile prediction on several power systems including a 1169-bus power system with 53 contingencies with promising results.

Chiang, H.D.; Wang, C.S.; Flueck, A.J. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering

1997-02-01T23:59:59.000Z

416

High speed flux feedback for tuning a universal field oriented controller capable of operating in direct and indirect field orientation modes  

SciTech Connect

The direct (d) and quadrature (q) components of flux, as sensed by flux sensors or determined from voltage and current measurements in a direct field orientation scheme, are processed rapidly and accurately to provide flux amplitude and angular position values for use by the vector rotator of a universal field-oriented (UFO) controller. Flux amplitude (linear or squared) is provided as feedback to tune the UFO controller for operation in direct and indirect field orientation modes and enables smooth transitions from one mode to the other.

De Doncker, Rik W. A. A. (Schenectady, NY)

1992-01-01T23:59:59.000Z

417

High speed flux feedback for tuning a universal field oriented controller capable of operating in direct and indirect field orientation modes  

SciTech Connect

The direct (d) and quadrature (q) components of flux, as sensed by flux sensors or determined from voltage and current measurements in a direct field orientation scheme, are processed rapidly and accurately to provide flux amplitude and angular position values for use by the vector rotator of a universal field-oriented (UFO) controller. Flux amplitude (linear or squared) is provided as feedback to tune the UFO controller for operation in direct and indirect field orientation modes and enables smooth transitions from one mode to the other. 3 figs.

De Doncker, R.W.A.A.

1992-09-01T23:59:59.000Z

418

Modeling and Optimization of PEMFC Systems and its Application to Direct Hydrogen Fuel Cell Vehicles  

E-Print Network (OSTI)

Current Cath. S.R. Batt. Volt. H2 Storage and Delivery StackStack Current H2 Utility Stack Volt Cath. Outlet Press.Comp Current Batt. Volt. Stoic. Ratio Stack Voltage Water/

Zhao, Hengbing; Burke, Andy

2008-01-01T23:59:59.000Z

419

Variable current speed controller for eddy current motors  

DOE Patents (OSTI)

A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

1982-03-12T23:59:59.000Z

420

Current Titles  

Science Conference Proceedings (OSTI)

This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

Various

2006-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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.


421

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

422

FORMATION FIELDS AND CURRENT EFFICIENCIES IN THE ANODIC OXIDATION OF ZIRCONIUM: A DIRECT COMPARISON OF HIGH-POTENTIAL FORMATION FIELDS WITH THOSE DERIVED FROM LOW-POTENTIAL CHARGING CURVES  

SciTech Connect

Formation fields at selected constant currents were obtained from high- potential unitary formation rates and polarographic current efficiency measurements carried out over the potential range, 20 to 130 volts. These values are compared with formation fields derived from low-potential unitary formation rates alone, in the potential range below 2 v. Results are reported for abraded Kroll process metal at 750 mu a/cm/sup 2/, for abraded and for chemically polished iodide process metal at 100 and 750 mu a/cm/sup 2/ and 100 mu a/cm/sup 2/, respectively. Ionic current efficiencies are reported for several current densities in the high-potential range and for the low-potential localized oxygen evolution process. (auth)

Adams, G.B. Jr.; Lee, T.; Van Bysselberghe, P.

1957-01-01T23:59:59.000Z

423

JGI - Directions  

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

Directions Address DOE Joint Genome Institute 2800 Mitchell Drive Walnut Creek, CA 94598 From Oakland Airport Follow Airport exit signs onto AIRPORT DR. Turn RIGHT onto HEGENBERGER...

424

Cascode buffer for monolithic voltage conversion operating at high input supply voltages  

E-Print Network (OSTI)

A high-to-low switching DC-DC converter that operates at input supply voltages up to two times as high as the maximum voltage permitted in a nanometer CMOS technology is proposed in this paper. The circuit technique is based on a cascode bridge that maintains the steady-state voltage differences among the terminals of all of the transistors within a range imposed by a specific fabrication technology. The proposed circuit technique permits the full integration of active and passive devices of a switching DC-DC converter with a high voltage conversion ratio in a standard low voltage CMOS process. An efficiency of 87.8 % is achieved for 3.6 volts to 0.9 volts conversion assuming

Volkan Kursun; Gerhard Schrom; Vivek K. De; Eby G. Friedman; Siva G. Narendra

2005-01-01T23:59:59.000Z

425

Motor voltage high harmonics influence to efficient energy usage  

Science Conference Proceedings (OSTI)

Analysis of the effect of non-sinusoidal voltages on the three-phase induction motor is presented in the paper. When the induction motors are supplied by a rectangular shape of the voltage inverter with high levels of harmonic voltage (Uh,i ... Keywords: energy efficiency, harmonics, induction motor, non-sinusoidal voltage, power losses

Miloje M. Kostic; Branka B. Kostic

2011-07-01T23:59:59.000Z

426

Distribution System Voltage Performance Analysis for High-Penetration Photovoltaics  

DOE Green Energy (OSTI)

This report examines the performance of commonly used distribution voltage regulation methods under reverse power flow.

Liu, E.; Bebic, J.

2008-02-01T23:59:59.000Z

427

Optimal Compensation Algorithms for a Dynamic Voltage Restorer  

Science Conference Proceedings (OSTI)

The Dynamic Voltage Restorer (DVR) as an electronics based custom device, is used to protect sensitive loads from the voltage sags in the power distribution system. With the rapid technology advancement in industrial control processes, it is experiencing ... Keywords: Dynamic Voltage Restorer (DVR), power quality, voltage sag, Zero Active Power Compensation (ZAPC), Minimal Active Power Compensation (MAPC)

Deng Pan; Chen Zhongming; Jiang Peng; Abdelkrim Benchaib; Guillaume De Preville

2010-06-01T23:59:59.000Z

428

Analysis of Voltage Rise Effect on Distribution Network with Distributed  

E-Print Network (OSTI)

appearance of hidden loads and affect the voltage profile of low voltage distribution network. To overcomeAnalysis of Voltage Rise Effect on Distribution Network with Distributed Generation M. A. Mahmud. This paper presents a detail analysis of how does voltage rise on distribution network due to the penetration

Pota, Himanshu Roy

429

Shootthrough fault protection system for bipolar transistors in a voltage source transistor inverter  

SciTech Connect

Faulted bipolar transistors in a voltage source transistor inverter are protected against shootthrough fault current, from the filter capacitor of the d-c voltage source which drives the inverter over the d-c bus, by interposing a small choke in series with the filter capacitor to limit the rate of rise of that fault current while at the same time causing the d-c bus voltage to instantly drop to essentially zero volts at the beginning of a shootthrough fault. In this way, the load lines of the faulted transistors are effectively shaped so that they do not enter the second breakdown area, thereby preventing second breakdown destruction of the transistors.

Wirth, W.F.

1982-01-12T23:59:59.000Z

430

Developments in line-voltage thermostats  

Science Conference Proceedings (OSTI)

A thermostat that provides reliable, accurate temperature control is the key to a comfortable, efficient space-heating system. The lack of a commercially available line-voltage thermostat that is affordable and performs well has been a significant factor in limiting the comfort and popularity of zoned residential electric heating systems. With EPRI support, two manufacturers have developed innovative, electronics-based line-voltage thermostats that offer a cost-effective control option for creating a comfortable environment with zoned electric heat. These thermostats also may help reduce energy consumption.

Kesselring, J.

1992-09-01T23:59:59.000Z

431

The high current, fast, 100ns, Linear Transformer Driver (LTD) developmental project at Sandia Laboratories and HCEI.  

SciTech Connect

Sandia National Laboratories, Albuquerque, N.M., USA, in collaboration with the High Current Electronic Institute (HCEI), Tomsk, Russia, is developing a new paradigm in pulsed power technology: the Linear Transformer Driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high current and high voltage pulses straight out of the cavity with out any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. This is because the output pulse rise time and width can be easily tailored to the specific application needs. In this paper we briefly summarize the developmental work done in Sandia and HCEI during the last few years, and describe our new MYKONOS Sandia High Current LTD Laboratory. An extensive evaluation of the LTD technology is being performed at SNL and the High Current Electronic Institute (HCEI) in Tomsk Russia. Two types of High Current LTD cavities (LTD I-II, and 1-MA LTD) were constructed and tested individually and in a voltage adder configuration (1-MA cavity only). All cavities performed remarkably well and the experimental results are in full agreement with analytical and numerical calculation predictions. A two-cavity voltage adder is been assembled and currently undergoes evaluation. This is the first step towards the completion of the 10-cavity, 1-TW module. This MYKONOS voltage adder will be the first ever IVA built with a transmission line insulated with deionized water. The LTD II cavity renamed LTD III will serve as a test bed for evaluating a number of different types of switches, resistors, alternative capacitor configurations, cores and other cavity components. Experimental results will be presented at the Conference and in future publications.

Ward, Kevin S. (Ketech Corporation, Albuquerque, NM); Long, Finis W.; Sinebryukhov, Vadim A. (High Current Electronic Institute (HCEI), Tomsk, Russia); Kim, Alexandre A. (High Current Electronic Institute (HCEI), Tomsk, Russia); Wakeland, Peter Eric (Ketech Corporation, Albuquerque, NM); McKee, G. Randall; Woodworth, Joseph Ray; McDaniel, Dillon Heirman; Fowler, William E.; Mazarakis, Michael Gerrassimos; Porter, John Larry, Jr.; Struve, Kenneth William; Savage, Mark Edward; Stygar, William A.; LeChien, Keith R.; Matzen, Maurice Keith

2010-09-01T23:59:59.000Z

432

BATTERY AWARE TASK SCHEDULING FOR A SYSTEM-ON-A-CHIP USING VOLTAGE/CLOCK SCALING  

E-Print Network (OSTI)

BATTERY AWARE TASK SCHEDULING FOR A SYSTEM-ON-A-CHIP USING VOLTAGE/CLOCK SCALING Princey Chowdhury Engineering Tempe AZ 85287 ABSTRACT Battery lifetime is a critical parameter in the operation of mobile computing devices. The lifetime of such devices is directly dependent on the battery discharge profile

Chakrabarti, Chaitali

433

System Voltage Potential-Induced Degradation Mechanisms in PV Modules and Methods for Test: Preprint  

DOE Green Energy (OSTI)

Over the past decade, degradation and power loss have been observed in PV modules resulting from the stress exerted by system voltage bias. This is due in part to qualification tests and standards that do not adequately evaluate for the durability of modules to the long-term effects of high voltage bias experienced in fielded arrays. High voltage can lead to module degradation by multiple mechanisms. The extent of the voltage bias degradation is linked to the leakage current or coulombs passed from the silicon active layer through the encapsulant and glass to the grounded module frame, which can be experimentally determined; however, competing processes make the effect non-linear and history-dependent. Appropriate testing methods and stress levels are described that demonstrate module durability to system voltage potential-induced degradation (PID) mechanisms. This information, along with outdoor testing that is in progress, is used to estimate the acceleration factors needed to evaluate the durability of modules to system voltage stress. Na-rich precipitates are observed on the cell surface after stressing the module to induce PID in damp heat with negative bias applied to the active layer.

Hacke, P.; Terwilliger, K.; Smith, R.; Glick, S.; Pankow, J.; Kempe, M.; Kurtz, S.; Bennett, I.; Kloos, M.

2011-07-01T23:59:59.000Z

434

High Voltage Testing of a 5-meter Prototype Triaxial HTS Cable  

SciTech Connect

High voltage tests were performed on a 5-m long prototype triaxial HTS cable (supplied by Ultera) at ORNL in preparation for installation of a 200-m HTS cable of the same design at the AEP utility substation in Columbus, Ohio. The triaxial design comprises three concentric phases and shield around a common former with the phase to phase dielectric at cryogenic temperature. Advantages of this design include increased current density, a reduced amount of HTS tape needed, and reduced heat load. The phase to phase voltage will be 13.2 kVrms (7.6 kVrms to ground). Preliminary testing was done on half-scale and full-scale terminations which successfully passed AC withstand, partial discharge, and impulse tests. High voltage tests conducted on the 5-m cable with the cable straight and after bending 90 degrees were ac withstand to 39 kVrms, partial discharge inception, and a minimum of 10 positive and 10 negative lightning waveform impulses at 110 kV. Phase to phase insulation was tested by applying high voltage to each phase one at a time with all the other phases grounded. Partial discharge data will be presented. The 5-m prototype triaxial HTS cable passed all the HV tests performed, with a PD inception voltage significantly above the required voltage.

Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Tuncer, Enis [ORNL; Pace, Marshall O [ORNL; Gouge, Michael J [ORNL; Demko, Jonathan A [ORNL; Lindsay, David T [ORNL

2007-01-01T23:59:59.000Z

435

Group 3: Humidity, Temperature and Voltage (Presentation)  

SciTech Connect

This is a summary of the work of Group 3 of the International PV QA Task Force. Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.

Wohlgemuth, J.

2013-09-01T23:59:59.000Z

436

High voltage VLF testing of power cables  

SciTech Connect

This publication describes a laboratory test program conducted with the objective to develop a test that would replace the existing dc withstand test. The article describes the methodology used to establish the voltage duration and magnitude of VLF (0.1 Hz) high voltage field tests suitable for crosslinked polyethylene (XLPE) insulated power cable. The results show that the voltage breakdown of laboratory aged XLPE cable at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz cause very little damage to the cable, and that 0.1 Hz testing appears to be a satisfactory alternate to dc testing. Preliminary values are suggested for voltage magnitude and time duration of cable acceptance, maintenance and proof tests at 0.1 Hz for XLPE cable rated up to 35 kV. A program is underway to similarly evaluate samples of service-aged XLPE cable; as well as to demonstrate the use of the preliminary test values at typical utility installations.

Eager, G.S.; Katz, C.; Fryszczyn, B. [Cable Technology Labs., Inc., New Brunswick, NJ (United States); Densley, J. [Ontario Hydro, Toronto, Ontario (Canada); Bernstein, B.S. [EPRI, Washington, DC (United States)

1997-04-01T23:59:59.000Z

437

Incorporating Voltage Fluctuations of the Power Distribution Network into the Transient Analysis of CMOS Logic Gates  

Science Conference Proceedings (OSTI)

Decreased power supply levels have reduced the tolerance to voltage changes within power distribution networks in CMOS integrated circuits. High on-chip currents, required to charge and discharge large on-chip loads while operating at high frequencies, ... Keywords: IR drops, power distribution network, system-on-a-chip

Kevin T. Tang; Eby G. Friedman

2002-05-01T23:59:59.000Z

438

Real time prelocalisation of electrical defaults on high voltage underground cable (single-phase case)  

Science Conference Proceedings (OSTI)

This paper proposes an assistance tool to the prelocalisation of the insulation defaults affecting electrical single-phase cables by using voltage and current measurements available in source substation. An equivalent network modeling defaults to the ... Keywords: default distance, distributed parameters, insulation default, prelocalisation, sheath, underground cable

Thameur Aloui; Fathi Ben Amar; Nizar Derbel; Hsan Hadj Abdallah

2010-05-01T23:59:59.000Z

439

Study on reactive power optimization problem taking the line current as state variable  

Science Conference Proceedings (OSTI)

The math model of optimization problem is established by describing the electric power network equations as the hybrid form with node voltage and line current based on ? equivalence circuit of power equipment, there the objective function is performed ... Keywords: line current, node voltage, optimal power flow, power flow, reactive power optimization

Zhang Jinsong; Wang Chengmin; Zhang Gong; Hou Zhijian

2005-10-01T23:59:59.000Z

440

Energy Currents  

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

7 7 Energy Currents Survey Result Our thanks to all of you who responded to our reader survey. We were pleased that many of you find this a useful publication. Your opinions will help us improve it further. The CBS News' readers include a variety of professions. 17% of respondents were consultants, 15% were engineers, 11% were teachers, 11% were scientists, 10% were program managers. The remainder included contractors, designers, marketing professionals policy analysts, journalists and others. Ranked according to highest response first, the majority of readers work in education, various levels of government, utilities, non-profit organizations, and a variety of private concerns. A surprisingly large number, 52% of the respondents, are Internet users and 23% have browsed the World Wide Web. 8% have browsed the Center's Web site

Note: This page contains sample records for the topic "voltage direct current" 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.


441

Energy Currents  

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

1 1 Energy Currents LBL Scientist Joins Clinton Administration Art Rosenfeld Art Rosenfeld, former head of LBL's Center for Building Science, has been named a senior advisor in the U.S. Department of Energy, serving under Assistant Secretary for Energy Efficiency and Renewable Energy Christine Ervin. His appointment began July 1. In Washington, Rosenfeld will sit on President Clinton's National Science and Technology Council. He will also serve as national spokesperson for the Administration's "Cool Communities" program and will help steer through the political process a proposed new "government-sponsored enterprise"- called EFFIE MAE for Energy Efficiency Mortgage and Loan Agency-that would guarantee loans for retrofitting energy-inefficient public buildings.

442

Passive fault current limiting device  

DOE Patents (OSTI)

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

Evans, D.J.; Cha, Y.S.

1999-04-06T23:59:59.000Z

443

Mesoscale Current Fields Observed with a Shipboard Profiling Acoustic Current Meter  

Science Conference Proceedings (OSTI)

Measurements of the near-surface currents obtained with a shipboard profiling acoustic current meter during the POLYMODE Local Dynamics Experiment are discussed. The large-scale spatial structure of the directly measured currents is very similar ...

Lloyd Regier

1982-08-01T23:59:59.000Z

444

An efficient CMOS rectifier with low-voltage operation for RFID tags  

Science Conference Proceedings (OSTI)

A high-efficiency CMOS rectifier for radio-frequency identification (RFID) applications is presented. Using an on-chip generated clock signal, a new switching scheme is proposed to enhance the power efficiency of the conventional 4 transistor (4T)-cell ... Keywords: frequency 950 MHz, efficient CMOS rectifier, low-voltage operation, RFID tags, radio-frequency identification applications, on-chip generated clock signal, power efficiency, conventional 4 transistor-cell rectifier, charge-transfer transistors, small leakage current, external gate-boosting technique, nominal standard threshold voltage, MOS transistors, CMOS technology, power conversion efficiency

P. Kamalinejad; S. Mirabbasi; V. C. M. Leung

2011-07-01T23:59:59.000Z

445

The Constant Voltage Transformer (CVT) for Mitigating Effects of Voltage Sags on Industrial Equipment  

E-Print Network (OSTI)

Electric quality problems associated with power interactions between distribution and industrial process control systems can be prevented. Surveys of large users that buy power at the transmission and distribution voltages turn up relatively few complaints about the quality of their incoming power, while surveys of small users connected at secondary voltages tum up numerous complaints about the quality of their incoming power. Three major changes in the characteristics of customer loads and power distribution systems have altered the nature of the power quality equation: (I) greater sensitivity of devices and equipment to electric power variations, (2) the interconnection of sensitive loads in extensive networks and automated processes, and (3) an increase in loads that use power electronics in some type of power conversion configuration [1][2]. This paper presents applications of the constant-voltage transformer (CVT) for mitigating the effects of electric service voltage sags on industrial equipment in an oil refinery. Unlike conventional transformers, the CVT or ferro-resonant transformer allows the core to become saturated with magnetic flux, which maintains a relatively constant output voltage during input voltage variations such as undervoltages, overvoltages, and harmonic distortion.

Ferraro, R. J.; Osborne, R.; Stephens, R.

2000-04-01T23:59:59.000Z

446

Electrical system architecture having high voltage bus  

DOE Patents (OSTI)

An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

2011-03-22T23:59:59.000Z

447

Sacramento Area Voltage Support Environmental Impact Statement  

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

E E R R A N E V A D A R E G I O N Sacramento Area Voltage Support DRAFT ENVIRONMENTAL IMPACT STATEMENT DRAFT ENVIRONMENTAL IMPACT STATEMENT DOE/EIS-0323 NOVEMBER 2002 COVER SHEET Title: Sacramento Area Voltage Support Draft Environmental Impact Statement (EIS) Lead Agency: Western Area Power Administration (Western) Location: Alameda, Contra Costa, Placer, Sacramento, San Joaquin, and Sutter Counties, State of California. EIS Number: DOE/EIS-0323 Contact: Ms. Loreen McMahon, Environmental Project Manager Western Area Power Administration Sierra Nevada Region 114 Parkshore Drive Folsom, CA 95630 (916) 353-4460 (916) 985-1936 fax email: mcmahon@wapa.gov Website: Information is also available on our website: www.wapa.gov Hotline: 1-877-913-4440 (toll-free) Abstract The Western Area Power Administration's Central Valley Project transmission system forms an integral part of

448

DEEP WATER ISOTOPIC CURRENT ANALYZER  

DOE Patents (OSTI)

A deepwater isotopic current analyzer, which employs radioactive isotopes for measurement of ocean currents at various levels beneath the sea, is described. The apparatus, which can determine the direction and velocity of liquid currents, comprises a shaft having a plurality of radiation detectors extending equidistant radially therefrom, means for releasing radioactive isotopes from the shaft, and means for determining the time required for the isotope to reach a particular detector. (AEC)

Johnston, W.H.

1964-04-21T23:59:59.000Z

449

NONDESTRUCTIVE EDDY CURRENT TESTING  

DOE Patents (OSTI)

An eddy current testing device is described for measuring metal continuity independent of probe-to-sample spacing. An inductance would test probe is made a leg of a variable impedance bridge and the bridge is balanced with the probe away from the sample. An a-c signal is applied across the input terminals of the bridge circuit. As the probe is brought into proximity with the metal sample, the resulting impedance change in the probe gives an output signal from the bridge whose phase angle is proportional to the sample continuity and amplitude is proportional to the probe-tosample spacing. The output signal from the bridge is applied to a compensating network where, responsive to amplitude changes from the bridge output signal, a constant phased voltage output is maintained when the sample is continuous regardless of probe-to-sample spacing. A phase meter calibrated to read changes in resistivity of the metal sample measures the phase shift between the output of the compensating network and the original a-c signal applied to the bridge.

Renken, C.J. Jr.

1961-05-23T23:59:59.000Z

450

Electro-optic voltage sensor head  

DOE Patents (OSTI)

The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Woods, Gregory K. (Cornelius, OR)

1999-01-01T23:59:59.000Z

451

Electro-optic voltage sensor head  

DOE Patents (OSTI)

The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

Crawford, T.M.; Davidson, J.R.; Woods, G.K.

1999-08-17T23:59:59.000Z

452

Voltage spike detection in high field superconducting accelerator magnets  

SciTech Connect

A measurement system for the detection of small magnetic flux changes in superconducting magnets, which are due to either mechanical motion of the conductor or flux jump, has been developed at Fermilab. These flux changes are detected as small amplitude, short duration voltage spikes, which are {approx}15mV in magnitude and lasts for {approx}30 {micro}sec. The detection system combines an analog circuit for the signal conditioning of two coil segments and a fast data acquisition system for digitizing the results, performing threshold detection, and storing the resultant data. The design of the spike detection system along with the modeling results and noise analysis will be presented. Data from tests of high field Nb{sub 3}Sn magnets at currents up to {approx}20KA will also be shown.

Orris, D.F.; Carcagno, R.; Feher, S.; Makulski, A.; Pischalnikov, Y.M.; /Fermilab

2004-12-01T23:59:59.000Z

453

Performance-Aware Power Management in Embedded Controllers with Multiple-Voltage Processors  

E-Print Network (OSTI)

The goal of this work is to minimize the energy dissipation of embedded controllers without jeopardizing the quality of control (QoC). Taking advantage of the dynamic voltage scaling (DVS) technology, this paper develops a performance-aware power management scheme for embedded controllers with processors that allow multiple voltage levels. The periods of control tasks are adapted online with respect to the current QoC, thus facilitating additional energy reduction over standard DVS. To avoid the waste of CPU resources as a result of the discrete voltage levels, a resource reclaiming mechanism is employed to maximize the CPU utilization and also to improve the QoC. Simulations are conducted to evaluate the performance of the proposed scheme. Compared with the optimal standard DVS scheme, the proposed scheme is shown to be able to save remarkably more energy while maintaining comparable QoC.

Xia, Feng; Ma, Longhua; Sun, Youxian; Dong, Jinxiang

2008-01-01T23:59:59.000Z

454

A new method and instrument for touch and step voltage measurements  

SciTech Connect

This paper describes a new method and instrument for measuring touch and step voltages near a grounding system, for example in and around a substation. The hardware, software, and testing procedures are an extension of the smart ground multimeter, developed under EPRI sponsorship. The instrument injects a transient electric current between the ground under testing and an auxiliary ground, and it measures ground potential differences (GPDs) at up to six locations. The GPD measurements are processed with software which rejects external noise using correlation methods. Subsequently, statistical estimation methods are used to extract the touch or step voltages from the thousands of measurement points normalized with the system short circuit capability. Knowledge of the short circuit capability of the substation allows the quick measurements of the touch and step voltages.

Meliopoulos, A.P.S. (Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering); Patel, S. (Georgia Power Co., Atlanta, GA (United States)); Cokkinides, G.J. (Univ. of South Carolina, Columbia, SC (United States). Dept. of Electrical and Computer Engineering)

1994-10-01T23:59:59.000Z

455

Standby Power Reduction Using Dynamic Voltage Scaling and Canary Flip-Flop Structures  

E-Print Network (OSTI)

Lowering during standby mode reduces power by decreasing both voltage and current. Analysis of flip-flop structures shows how low the voltage can scale before destroying the state information. Measurements of a 0.13- m, dual--- test chip show that reducing to near the point where state is lost gives the best power savings. We show that "canary" flip-flops provide a mechanism for observing the proximity to failure for the flip-flops. The canary flip-flops enable closed-loop standby voltage scaling for achieving savings near the optimum. This approach potentially provides over 2 higher savings than an optimal open-loop approach without loss of state.

Benton H. Calhoun; Anantha P. Chandrakasan; Anantha P. Ch

2004-01-01T23:59:59.000Z

456

Multilevel-Dc-Bus Inverter For Providing Sinusoidal And Pwm Electrical Machine Voltages  

DOE Patents (OSTI)

A circuit for controlling an ac machine comprises a full bridge network of commutation switches which are connected to supply current for a corresponding voltage phase to the stator windings, a plurality of diodes, each in parallel connection to a respective one of the commutation switches, a plurality of dc source connections providing a multi-level dc bus for the full bridge network of commutation switches to produce sinusoidal voltages or PWM signals, and a controller connected for control of said dc source connections and said full bridge network of commutation switches to output substantially sinusoidal voltages to the stator windings. With the invention, the number of semiconductor switches is reduced to m+3 for a multi-level dc bus having m levels. A method of machine control is also disclosed.

Su, Gui-Jia (Knoxville, TN)

2005-11-29T23:59:59.000Z

457

Physical design with multiple on-chip voltages  

Science Conference Proceedings (OSTI)

Supply voltage is one of the dominant factors that determine the timing performance and power consumption of VLSI chips. For digital systems with a single supply voltage, some logic devices typically operate faster or more frequently than necessary, ...

Chunhong Chen

2002-04-01T23:59:59.000Z

458

The design, construction, and operation of long-distance high-voltage electricity transmission technologies.  

SciTech Connect

This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.

Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

2008-03-03T23:59:59.000Z

459

Entropy of Chaotic Oscillations of Currents in the Chua Circuit and its HMM Analysis  

E-Print Network (OSTI)

We study entropy of chaotic oscillation of electrical currents in the Chua's circuit controlled by triggering a pulse that brings the orbit that goes onto an unstable branch back to a stable branch. A numerical simulation of the voltage of the two capacitors and the current that flows on an inductor of the Chua's circuit reveals various oscillation patterns as the conductance that is connected between the two capacitors and directly connected to an inductor is varied. At small conductance, the Lissajous graph of the voltage of the two capacitors shows a spiral, while at high conductance a double scroll pattern appears. The entropy of the current that flows on the inductor is alocal minimum in the spiral state which is in the steady state, while it is maximum in the stable double scroll state. The stable double scroll samples are analyzed by using the Hidden Markov Model (HMM) and the eigenvectors of the transition matrix of long time series are found to be strictly positive but those of unstable short time series have negative components. We thus confirm maximum entropy production in the double scroll of the longest time series around the right fixed point, while the local minimum entropy production occurs in the spiral around the left fixed point.

Sadataka Furui

2010-03-03T23:59:59.000Z

460

NIST Online Museum of Quantum Voltage Standards, 1990s  

Science Conference Proceedings (OSTI)

... (Artifact 7, Citation: SP Benz, "Superconductor-normal-superconductor junctions for programmable voltage standards," Appl. Phys. Lett., vol. 67, pp. ...

2013-02-28T23:59:59.000Z

Note: This page contains sample records for the topic "voltage direct current" 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

Activated Sintering, Spark Plasma Sintering and High Voltage ...  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Novel Synthesis and Consolidation of Powder Materials : Activated Sintering, Spark Plasma Sintering and High Voltage Electric Discharge ...

462

Dubal Cell Voltage Drop Initiatives towards Low Energy High ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Aluminum Reduction Technology. Presentation Title, DUBAL CELL VOLTAGE ...

463

Temperature Fitting Method Predicting Equidistant Voltage Drop of ...  

Science Conference Proceedings (OSTI)

High Temperature Compression Test to Determine the Anode Paste ... Temperature Fitting Method Predicting Equidistant Voltage Drop of Anode Nod in  ...

464

Development of the Platform-Mounted Dynamic Voltage Restorer (PMDVR)  

Science Conference Proceedings (OSTI)

The uninterrupted supply of electrical power is critical for many commercial utility customers with sensitive loads. A voltage sag of a few cycles could cause loss of many thousands of dollars due to lost production from process stoppage and associated clean-up issues. The Platform Mounted Dynamic Voltage Restorer (PMDVR) is a distribution voltage level device that compensates for changes in supply line voltage to maintain acceptable input power to customers.

1998-12-31T23:59:59.000Z

465

Remote field eddy current inspection  

SciTech Connect

The Remote Field Eddy Current (RFEC) technique uses an internal probe to inspect conducting tubes nondestructively. A coaxial solenoidal exciter, energized with low frequency AC, and detector coils near the inside of the pipe wall are separated by about two pipe diameters to obtain through wall transmission and equal sensitivity to defects on the outside or inside of the pipe wall. Calculation methods are outlined and the voltage plane polar plot signal representation for defect measurement is described. Slit defect interactions in ferromagnetic and non-ferromagnetic tubes are discussed. Defect-induced anomalous fields are interpreted in terms of anomalous source eddy current and missing magnetization defect models. The use of computer animations to represent the time variations of high resolution field measurements and calculations is described.

Atherton, D.L. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Physics

1995-11-01T23:59:59.000Z

466

System for increasing corona inception voltage of insulating oils  

DOE Patents (OSTI)

The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil. 5 figs.

Rohwein, G.J.

1998-05-19T23:59:59.000Z

467

Research of Dynamic Voltage Restorer Based on Repetitive Control Strategy  

Science Conference Proceedings (OSTI)

This paper introduces a dynamic voltage restorer with independent three-phase structure, which is controlled on repetitive control strategy. Computer simulation of the whole repetitive control system is performed by Matlab/Simulink, and the results show ... Keywords: Dynamic Voltage Restorer, Repetitive Control, Voltage Sag

Tianyu Liu

2012-10-01T23:59:59.000Z

468

Distributed Generation Source Stiffness and Its Impact on Voltage Distortion  

Science Conference Proceedings (OSTI)

Distributed generators with loads that create high harmonics can cause excessive voltage distortion. This report's objective was to evaluate under controlled laboratory conditions voltage distortion resulting from application of nonlinear load for three different types of rotary generators and one inverter-based generator. Test results also were used to verify the analytical model for predicting voltage distortion from nonlinear load application.

2001-11-27T23:59:59.000Z

469

Selective compensation of voltage harmonics in grid-connected microgrids  

E-Print Network (OSTI)

1 Selective compensation of voltage harmonics in grid-connected microgrids Mehdi Savaghebia , Juan is proposed for selective compensation of main voltage harmonics in a grid- connected microgrid. The aim level. Keywords Distributed Generator (DG); microgrid; grid-connected; voltage harmonics compensation. 1

Vasquez, Juan Carlos

470

Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid  

E-Print Network (OSTI)

Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid Mehdi Savaghebi1 microgrid. The aim of the proposed control approach is to enhance the voltage quality at the point of common unbalance. Keywords-distributed generation; microgrid; secondary control; voltage unbalance compensation I

Vasquez, Juan Carlos

471

Aternating current photovoltaic building block - Energy ...  

A modular apparatus for and method of alternating current photovoltaic power generation comprising via a photovoltaic module, generating power in the form of direct ...

472

Transient electrophoretic current in a nonpolar solvent  

E-Print Network (OSTI)

The transient electric current of surfactants dissolved in a nonpolar solvent is investigated both experimentally and theoretically in the parallel-plate geometry. Due to a low concentration of free charges the cell can be completely polarized by an external voltage of several volts. In this state, all the charged micelles are compacted against the electrodes. After the voltage is set to zero the reverse current features a sharp discharge spike and a broad peak. This shape and its variation with the compacting voltage are reproduced in a one-dimensional drift-diffusion model. The model reveals the broad peak is formed by a competition between an increasing number of charges drifting back to the middle of the cell and a decreasing electric field that drives the motion. After complete polarization is achieved, the shape of the peak stops evolving with further increase of the compacting voltage. The spike-peak separation time grows logarithmically with the charge content in the bulk. The time peak is a useful measure of the micelle mobility. Time integration of the peak yields the total charge in the system. By measuring its variation with temperature, the activation energy of bulk charge generation has been found to be 0.126 eV.

Pavel Kornilovitch; Yoocharn Jeon

2011-08-06T23:59:59.000Z

473

Available Technologies: High Voltage Compatible, Fully ...  

APPLICATIONS OF TECHNOLOGY: Small pixel, scientific CCDs where good point spread function (PSF) is required; High quantum efficiency direct detection ...

474