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1

A High Voltage Direct Current Generator  

Science Journals Connector (OSTI)

When powdered materials are blown through metal tubes by means of compressed air considerable quantities of electricity are produced by contact electrification. It was found that 6×10-5 coulombs could be produced per gram of diatomaceous earth, a form of silica, blown through a short length of copper tube. A generator of extremely high voltage is proposed, and a small scale model of such a generator is described, by means of which currents of 8×10-5 amperes at 260 kilovolts were generated.

Richard E. Vollrath

1932-10-15T23:59:59.000Z

2

Summary of multiterminal high-voltage direct current transmission technology  

SciTech Connect (OSTI)

This report summarizes the present state of multiterminal (MT) high-voltage direct current (HVDC) power transmission. The purpose is to reassess the need for HVDC circuit breakers and to identify needed research for MT HVDC. The fundamentals of this technology are presented, and previous research and development is reviewed. Although no MT HVDC systems have yet been built, many concepts have been proposed. Some require a dc breaker, and others do not. Both options have advantages and disadvantages for various applications, so the selection will depend on the proposed application. Research is needed to define operating characteristics of various MT HVDC systems. In some applications, dc breakers will be useful, so research into HVDC interruption should continue. Also, dc fault detection and control algorithms for MT systems should be studied.

Biggs, R.B.; Jewell, W.T.

1984-05-01T23:59:59.000Z

3

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

SciTech Connect (OSTI)

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

4

Partial discharge measurements on a high voltage direct current mass impregnated paper cable  

SciTech Connect (OSTI)

Partial discharge measurement has been a good tool for the quality assurance of cables under alternating voltage. With the growing interest in High Voltage Direct Current cables it seems therefore logical to extend this technique for use at direct voltage. The paper describes this technique as used on a HVDC cable with mass impregnated paper. The different phases of operation (no load, full load, cooling phase, etc.) are characterized by a different discharge behavior. Special attention is given to the dangerous cooling phase. Models have been developed which can explain the discharge patterns that were measured. This paper gives an insight in the electrical behavior of a HVDC cable with mass impregnated paper insulation.

Jeroense, M.J.P. [NKF KABEL B.V., Delft (Netherlands); Kreuger, F.H. [Delft Univ. of Technology (Netherlands)

1996-12-31T23:59:59.000Z

5

Current-based direct power control of a DFIG under unbalanced grid voltage  

Science Journals Connector (OSTI)

Abstract A novel current-based direct power control (CB-DPC) strategy for a grid-connected doubly-fed induction generator (DFIG) is proposed. The reported control scheme is applicable to DFIG-based variable-speed wind turbines that operate under unbalanced network voltages. The required DFIG rotor voltage for precise regulation of the stator active and reactive output powers and accurate elimination of their inherent pulsations are directly obtained using a nonlinear integral sliding-mode control (ISMC) scheme. Compared with other control methods, the proposed strategy is simpler since it is not based on the symmetrical components theory, does not need multiple synchronous coordinate transformations, and only requires DFIG voltage and current values as its inputs. Constant switching frequency of the rotor-side converter (RSC) is achieved by means of space vector pulse-width modulation (SVPWM) technique. Uncertainties in the parameters of the generator are included in the design. A compensation strategy is also proposed for tracking error mitigation of the powers that occur due to elimination of the chattering phenomena in the ISMC scheme. Simulation results on a 2MW DFIG under different operating conditions are presented to validate the effectiveness and robustness of the proposed method.

Mohammad Farshadnia; Seyed Abbas Taher

2014-01-01T23:59:59.000Z

6

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

7

Recommended practice for fire protection for electric generating plants and high voltage direct current converter stations. 2005 ed.  

SciTech Connect (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

8

Direct numerical simulation of electroconvective instability and hysteretic current-voltage response of a permselective membrane  

E-Print Network [OSTI]

We present a systematic, multiscale, fully detailed numerical modeling for dynamics of fluid flow and ion transport covering Ohmic, limiting, and overlimiting current regimes in conductance of ion-selective membrane. By ...

Pham, Van Sang

9

Epidemiologic study of Holstein dairy cow performance and reproduction near a high-voltage direct - current powerline  

SciTech Connect (OSTI)

The development and operation of a high-voltage direct-current (HVDC) transmission line in rural Minnesota generated public concern over potential adverse effects to nearby residents and their livestock. Electrical parameters near an HVDC line decline rapidly with distance, but effects on ambient space charge have been detected out to 1 mile. To identify potential adverse effects of HVDC line operation on livestock, case-control and cohort study methods were used to examine various indices of Holstein performance in relation to distance from the line and the onset of line operation. It was believed that these indices would reflect changes in physiologic function or overt health effects that might arise from the HVDC environment. High-quality performance data from existing Dairy Herd Improvement Association (DHIA) records were obtained for 97% of qualifying herds located within 10 miles of the line. The large number of animals and years of observation provided high statistical power to detect even small systematic changes in performance. No significant differences in milk production or reproductive capacity were associated with presumed exposure to the HVDC environment. The absence of measurable effects in a large sentinel animal population may have implications for the assessment of human health risks related to HVDC transmission lines.

Martin, F.B.; Bender, A.; Steuernagel, G.; Robinson, R.A.; Revsbech, R.; Sorensen, D.K.; Williamson, N.; Williams, A.

1986-01-01T23:59:59.000Z

10

Measurements of the volt-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps  

SciTech Connect (OSTI)

The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1??m and 100??m. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100??m interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted electrons, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.

Klas, M.; Matej?ik, Š. [Department of Experimental Physics, Comenius University, Mlynskadolina F2, 84248 Bratislava (Slovakia); Radjenovi?, B.; Radmilovi?-Radjenovi?, M. [Institute of Physics, University of Belgrade, P.O. Box 57, 11080 Belgrade (Serbia)

2014-10-15T23:59:59.000Z

11

Current vs. Voltage Feedback Amplifiers  

E-Print Network [OSTI]

?' In most applications, the differences between current feedback (CFB) and voltage feedback (VFB) are not apparent. Today's CFB and VFB amplifiers have comparable performance, but there are cer- tain unique Performance · Feedback Freedom Aside from the well-known attribute of CFB amplifiers, gain

Lanterman, Aaron

12

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

SciTech Connect (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

13

NREL: Measurements and Characterization - Current Versus Voltage  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

14

Non-contact current and voltage sensor  

DOE Patents [OSTI]

A detachable current and voltage sensor provides an isolated and convenient device to measure current passing through a conductor such as an AC branch circuit wire, as well as providing an indication of an electrostatic potential on the wire, which can be used to indicate the phase of the voltage on the wire, and optionally a magnitude of the voltage. The device includes a housing that contains the current and voltage sensors, which may be a ferrite cylinder with a hall effect sensor disposed in a gap along the circumference to measure current, or alternative a winding provided through the cylinder along its axis and a capacitive plate or wire disposed adjacent to, or within, the ferrite cylinder to provide the indication of the voltage.

Carpenter, Gary D; El-Essawy, Wael; Ferreira, Alexandre Peixoto; Keller, Thomas Walter; Rubio, Juan C; Schappert, Michael A

2014-03-25T23:59:59.000Z

15

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.

Renda, George F. (Plainsboro, NJ)

1992-01-01T23:59:59.000Z

16

Superconducting Fault Current Limiter for Transmission Voltage  

Science Journals Connector (OSTI)

Within a collaboration of American Superconductor, Siemens, Nexans and Southern California Edison one electrical phase of a resistive superconducting fault current limiter for the 115 kV transmission voltage level has been designed and manufactured. The active part of the limiter consists of 63 bifilar coils made of 12 mm wide steel-stabilized YBCO conductor and is housed in a cryostat operated at 5 bar and 74 K. The first phase was completely assembled and successfully subjected to power switching tests and high voltage tests. The basic design of the system and the test results are reported. The work was funded in part by US-DOE under Contract Number DE-FC26-07NT43243.

Hans-Peter Kraemer; Wolfgang Schmidt; Hong Cai; Bruce Gamble; David Madura; Tim MacDonald; Joe McNamara; Walther Romanosky; Greg Snitchler; Nicolas Lallouet; Frank Schmidt; Syed Ahmed

2012-01-01T23:59:59.000Z

17

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

18

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

19

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, Joseph H. (N. Huntingdon, PA); Mikesell, Harvey E. (McMurray, PA); Jha, Kamal N. (Bethel Park, PA)

1998-01-01T23:59:59.000Z

20

Optical crystal based devices for current and voltage measurement  

SciTech Connect (OSTI)

A prerequisite for safe, stable operation of an electric power system is accurate, reliable measurement of the system parameters, in particular, current and voltage. Traditionally this has been achieved on High Voltage (HV) systems by expensive, bulky iron-cored current transformers (CTs) and capacitor voltage transformers (VTs). Both these devices are increasingly coming under review in modern power systems due to their cost, safety implications for personnel and surrounding plant if failure occurs, installation time and indeed substation land requirements. This paper describes novel designs for magneto-optic and electro-optic crystal sensors providing potentially separate and combined current and voltage measurement. The results of testing programs are presented and details of the work associated with field trials given.

Cruden, A.; Richardson, Z.J.; McDonald, J.R.; Andonovic, I. [Univ. of Strathclyde (United Kingdom)] [Univ. of Strathclyde (United Kingdom)

1995-07-01T23:59:59.000Z

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

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

22

Voltage-dependent calcium channels and currents in native neurons and other cells have been divided into high voltage  

E-Print Network [OSTI]

Voltage-dependent calcium channels and currents in native neurons and other cells have been divided than one subtype of channel. A new subfamily of voltage-dependent calcium channel á1 subunit genes. 1999), having four domains, each with a voltage sensor and a pore-forming P loop. However

Dolphin, Annette C.

23

Outdoor PV Module Degradation of Current-Voltage Parameters: Preprint  

SciTech Connect (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

24

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

25

Rotor current transient analysis of DFIG-based wind turbines during symmetrical voltage faults  

Science Journals Connector (OSTI)

Abstract The impact of grid voltage fault on doubly fed induction generators (DFIGs), especially rotor currents, has received much attention. So, in this paper, the rotor currents of based-DFIG wind turbines are considered in a generalized way, which can be widely used to analyze the cases under different levels of voltage symmetrical faults. A direct method based on space vector is proposed to obtain an accurate expression of rotor currents as a function of time for symmetrical voltage faults in the power system. The presented theoretical analysis is simple and easy to understand and especially highlights the accuracy of the expression. Finally, the comparable simulations evaluate this analysis and show that the expression of the rotor currents is sufficient to calculate the maximum fault current, DC and AC components, and especially helps to understand the causes of the problem and as a result, contributes to adapt reasonable approaches to enhance the fault ride through (FRT) capability of DFIG wind turbines during a voltage fault.

Yu Ling; Xu Cai; Ningbo Wang

2013-01-01T23:59:59.000Z

26

Current Direct Neutrino Mass Experiments  

E-Print Network [OSTI]

In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

Drexlin, G; Mertens, S; Weinheimer, C

2013-01-01T23:59:59.000Z

27

3D MHD modelling of the glidarc behaviour of a low current high voltage DC plasma torch Journal of Physics D: Applied Physics  

E-Print Network [OSTI]

in terms of: global behaviour, arc length, mean voltage and glidarc frequency. 1. Introduction The non-thermal on magnetohydrodynamic (MHD) modelling of atmospheric pressure direct current (DC) plasma torch operating at low current3D MHD modelling of the glidarc behaviour of a low current ­ high voltage DC plasma torch Journal

Paris-Sud XI, Université de

28

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

29

Electric Field Calculations on Dry-Type Medium Voltage Current Transformers.  

E-Print Network [OSTI]

??This research presents potential and electric field calculations on medium voltage (MV) epoxy insulated outdoor current transformers (CTs) using a numeri-cal calculation approach. Two designs… (more)

Lakshmichand Jain, Sandeep Kumar

2012-01-01T23:59:59.000Z

30

Current mode integrators and their applications in low-voltage high frequency CMOS signal processing  

E-Print Network [OSTI]

Low voltage CMOS fully differential integrators for high frequency continuous-time filters using current-mode techniques are presented.. Current mode techniques are employed to avoid the use of the floating differential pair, in order to achieve...

Smith, Sterling Lane

2012-06-07T23:59:59.000Z

31

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

32

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

33

Dynamic voltage-current characteristics for a water jet plasma arc  

SciTech Connect (OSTI)

A virtual instrument technology is used to measure arc current, arc voltage, dynamic V-I characteristics, and nonlinear conductance for a cone-shaped water jet plasma arc under ac voltage. Experimental results show that ac arc discharge mainly happens in water vapor evaporated from water when heated. However, due to water's cooling effect and its conductance, arc conductance, reignition voltage, extinguish voltage, and current zero time are very different from those for ac arc discharge in gas work fluid. These can be valuable to further studies on mechanism and characteristics of plasma ac discharge in water, and even in gas work fluid.

Yang Jiaxiang; Lan Sheng; Xu Zuoming [College of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin, Heilongjiang 150040 (China)

2008-05-05T23:59:59.000Z

34

The high voltage problem in the saturated core HTS fault current limiter  

Science Journals Connector (OSTI)

A small model of a one-phase saturated core HTS fault current limiter was developed. It consists of an iron core, an AC coil and a DC HTS coil. The HTS coil comprised six 126 turns double-pancakes (ID 70 mm), wound after heat treatment from Bi-2223 multifilamentary tape in Ag matrix. A fault simulation circuit was set up to characterize the dynamic properties of the model limiter. The voltages and currents of the AC coil and the DC HTS coil were measured through a computer-based data acquisition system. The tests have shown that the limiter has a fast response and the first current peak can be easily limited, but a high voltage will be induced on the DC HTS coil side during the fault state. This high voltage can badly affect the DC current equipment on the DC HTS coil side. The origin and value of the high voltage can be explained using a transformer model. For a limiter with n1 turns AC coil and n2 turns DC coil, the largest induced voltage will be roughly close to (n2/n1)U, where U is the rated voltage of the limiter. To commercialize this kind of limiter, the high voltage problem must be solved. Some different designs were introduced to lower the induced voltage.

Y.F. He; J.H. Li; X.H. Zong; J. Sun; Y.N. Wang; C.L. Wu; J.X. Wang

2003-01-01T23:59:59.000Z

35

Ocean indicators Current knowledge and future directions  

E-Print Network [OSTI]

Ocean indicators Current knowledge and future directions Brian Burke, NOAA Fisheries Brian.Burke@noaa.gov #12;· Review of ocean indicator work · Forecasting · Indicator gaps and the importance of mechanistic understanding · Plugging in to management #12;Haeseker et al. 2012 Ocean survival is low and variable #12;-10 -5

36

Current Directions in Freight and Logistics Industry  

E-Print Network [OSTI]

Current Directions in Freight and Logistics Industry CTS Freight and Logistics Symposium November- the-box #12;Perspective Be sure to look-up from time-to-time #12;Why Discuss Freight and Logistics....Large Part of the Economy Logistics Cost As A Percent of GDP ­ 10% Source: CSCMP State of Logistics 2007 #12

Minnesota, University of

37

The current-voltage characteristic of a hot-cathode electric arc at low pressures  

Science Journals Connector (OSTI)

It has been shown that in a hot-cathode electric arc operating at low pressures of the working ... drop arises that results in an increase in discharge voltage with current even before the transition of the discharge

C. P. Nikulin

2011-03-01T23:59:59.000Z

38

Comparison of resonant current regulators for DFIG during grid voltage distortion  

Science Journals Connector (OSTI)

We investigate two different kinds of resonant current regulators for a doubly fed induction generator (DFIG) under distorted grid voltage conditions: proportional ... part. Based on the mathematical model of DFIG

Yi-peng Song; Heng Nian

2013-12-01T23:59:59.000Z

39

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

Science Journals Connector (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

40

Manufacturing challenges of optical current and voltage sensors for utility applications  

SciTech Connect (OSTI)

Measurement of voltages and currents in power transmission and distribution systems are critical to the electric utility industry for both revenue metering and reliability. Nonconventional instrument transformers based on intensity modulation of optical signals have been reported in the literature for more than 20 years. Recently described devices using passive bulk optical sensor elements include the Electro-Optic Voltage Transducer (EOVT) and Magneto-Optic Current Transducer (MOCT). These technologies offer substantial advantages over conventional instrument transformers in accuracy, optical isolation bandwidth, environmental compatibility, weight and size. This paper describes design and manufacturing issues associated with the EOVT and the Optical Metering Unit (OMU) recently introduced by ABB with field installation results presented for prototype units in the 345 kV and 420 kV voltage classes. The OMU incorporates an EOVT and MOCT to monitor the voltage and current on power transmission lines using a single free-standing device.

Yakymyshyn, C.P. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Brubaker, M.A. [Los Alamos National Lab., NM (United States); Johnston, P.M. [Johnston (Paul M.), Raleigh, NC (United States); Reinbold, C. [ABB High Voltage Switchgear, Greensburg, PA (United States)

1997-12-01T23:59:59.000Z

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.


41

High-voltage direct current handbook: First edition  

SciTech Connect (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

42

Dynamic modeling and direct power control of wind turbine driven DFIG under unbalanced network voltage conditions  

Science Journals Connector (OSTI)

This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the po...

Jia-bing Hu; Yi-kang He; Lie Xu

2008-12-01T23:59:59.000Z

43

Fundamental properties of field emission-driven direct current microdischarges  

SciTech Connect (OSTI)

For half a century, it has been known that the onset of field emission in direct current microdischarges with gap sizes less than 10 {mu}m can lead to breakdown at applied voltages far less than predicted by Paschen's law. It is still unclear how field emission affects other fundamental plasma properties at this scale. In this work, a one-dimensional fluid model is used to predict basic scaling laws for fundamental properties including ion density, electric field due to space charge, and current-voltage relations in the pre-breakdown regime. Computational results are compared with approximate analytic solutions. It is shown that field emission provides an abundance of cathode electrons, which in turn create large ion concentrations through ionizing collisions well before Paschen's criterion for breakdown is met. Breakdown due to ion-enhanced field emission occurs when the electric field due to space charge becomes comparable to the applied electric field. Simple scaling analysis of the 1D Poisson equation demonstrates that an ion density of n{sub +} Almost-Equal-To 0.1V{sub A}{epsilon}{sub 0}/qd{sup 2} is necessary to significantly distort the electric field. Defining breakdown in terms of this critical ion density leads analytically to a simple, effective secondary emission coefficient {gamma}{sup Prime} of the same mathematical form initially suggested by Boyle and Kisliuk [Phys. Rev. 97, 255 (1955)].

Rumbach, Paul; Go, David B. [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2012-11-15T23:59:59.000Z

44

Fault current limiting and voltage sag mitigation by means of a resonant type FCL  

Science Journals Connector (OSTI)

In this paper a resonant type of fault current limiter and its application are presented. During normal operation of circuit, the thyristors is off and the resonant branches are short circuit. Therefore there is not any voltage drop on FCL. In this way, ... Keywords: bypass resistance, fault analysis, power quality, resonant type fault current limiter

M. S. Mohebbi Nazar; M. Abapour

2006-08-01T23:59:59.000Z

45

Current-voltage model of LED light sources Szymon Bczkowski, Stig Munk-Nielsen  

E-Print Network [OSTI]

Current-voltage model of LED light sources Szymon Bczkowski, Stig Munk-Nielsen Department of Energy shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity radiation into visible light, are gradually being replaced by light-emitting diodes. The invention of LEDs

Munk-Nielsen, Stig

46

Ca2 -dependent activation of Cl currents in Xenopus oocytes is modulated by voltage  

E-Print Network [OSTI]

Ca2 -dependent activation of Cl currents in Xenopus oocytes is modulated by voltage NICK CALLAMARAS, University of California Irvine, Irvine, California 92697-4550 Callamaras, Nick, and Ian Parker. Ca2 278: C667­C675, 2000.-- Ca2 -activated Cl currents (ICl,Ca) were examined using fluorescence confocal

Parker, Ian

47

Role of bias voltage and tunneling current in the perpendicular displacements of freestanding graphene via scanning  

E-Print Network [OSTI]

graphene via scanning tunneling microscopy Peng Xu, Steven D. Barber, Matthew L. Ackerman, James Kevin measurements of freestanding graphene as a function of applied bias voltage and tunneling current setpoint, the graphene approaches the STM tip, while, on the other hand, when the tunneling current is increased

Thibado, Paul M.

48

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

49

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

50

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.

Kikta, Thomas J. (Pittsburgh, PA); Mitchell, Ronald D. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

51

Geomagnetically induced currents in the Uruguayan high-voltage power grid  

Science Journals Connector (OSTI)

......currents in the Uruguayan high-voltage power grid R. Caraballo 1 2 L. Sanchez Bettucci...simple topology of the Uruguayan power grid provides some advantages in the calculation...transformers at the South African power grid during the Halloween storm in 2003......

R. Caraballo; L. Sánchez Bettucci; G. Tancredi

2013-01-01T23:59:59.000Z

52

Effects of Magnesium on Inactivation of the Voltage-gated Calcium Current in  

E-Print Network [OSTI]

Effects of Magnesium on Inactivation of the Voltage-gated Calcium Current in Cardiac Myocytes H-dependent inactivation can be modulated by changes in cytoplasmic Mg~+. INTRODUCTION Magnesium is an important constituent of the intracellular milieu. Despite the importance of magnesium as an essential cofactor

53

Efficient Computation of Sensitivity Coefficients of Node Voltages and Line Currents in Unbalanced Electrical Networks  

E-Print Network [OSTI]

The problem of optimal control of power distribution systems is becoming increasingly compelling due to the progressive penetration of distributed energy resources in this specific layer of the electrical infrastructure. Distribution systems are, indeed, experiencing significant changes in terms of operation philosophies that are often based on optimal control strategies relying on the computation of linearized dependencies between controlled (e.g. voltages) and control variables (e.g. power injections). As the implementation of these strategies in real-time controllers imposes stringent time constraints, the derivation of analytical dependency between controlled and control variables becomes a non-trivial task to be solved. With reference to optimal voltage and power flow controls, this paper aims at providing an analytical derivation of node voltage and line current flows as a function of the nodal power injections. Compared to other approaches presented in the literature, the one proposed here is based on ...

Christakou, Konstantina; Paolone, Mario; Tomozei, Dan-Cristian

2012-01-01T23:59:59.000Z

54

Distributed Voltage and Current Control of Multi-Terminal High-Voltage Direct  

E-Print Network [OSTI]

to AC transmission systems. Off-shore wind farms also typically require HVDC power transmission This work was supported in part by the European Commission by the Hycon2 project, the Swedish Research

Dimarogonas, Dimos

55

Modeling and improvement of direct power control of DFIG under unbalanced grid voltage condition  

Science Journals Connector (OSTI)

Abstract This paper presents analysis and control of a doubly-fed induction generator (DFIG)-based wind generation system operating under unbalanced grid voltage condition. The DFIG system is modeled in synchronous positive reference frame. System behavior and operation of both the generator and the grid side converter (GSC) under unbalanced condition is illustrated by definition of oscillating power terms in the synchronous reference frame. This analysis makes it possible to control both the active and reactive power generation by means of direct power control (DPC) technique. It is shown that considering the DFIG model in synchronous reference frame simplifies the power terms extraction. Moreover, alternative DFIG control targets such as reducing unbalanced stator current, torque and power pulsations minimization, are considered. In addition, by the proposed method, the oscillation of the stator output power is compensated by the GSC, to ensure constant power output from the overall DFIG generation system. The validation of results has been performed through simulation results on a 2 MW DFIG wind generation system.

Mohammad Jafar Zandzadeh; Abolfazl Vahedi

2014-01-01T23:59:59.000Z

56

The role of linear and voltage-dependent ionic currents in the generation of slow wave oscillations  

E-Print Network [OSTI]

inward current is not necessary for generating oscillations. Instead, a current INL that is linear. The current INL can be considered a linear approximation to the negative-conductance region of the current­voltage relation- ship of a regenerative inward current. Using a simple conductance-based model, we show that INL

Bose, Amitabha

57

Measurement of semiconductor local carrier concentration from displacement current-voltage curves with a scanning vibrating probe  

Science Journals Connector (OSTI)

A theoretical equation has been fitted to displacement current-voltage curves of semiconductor in order to obtain the local carrier concentration of the semiconductor. The distance between a semiconductor surface and a scanning probe is changed sinusoidally and is adjusted as small as a few nm at which tunneling current flows. Displacement current due to the change in electric flux from the semiconductor surface to the scanning probe flows periodically in accordance with the vibration of the scanning probe, and it is separated from tunneling current using a two-phase lock-in amplifier. The displacement current-probe voltage curve is analyzed by taking into account two-dimensional electric flux profile from the semiconductor surface. It is realized that the lateral resolution of the displacement current depends on the probe voltage and that it is between one-eighth and one-fifteenth smaller than the top radius of the probe since the depletion-layer width of the semiconductor is determined by the probe voltage, the distance, and the carrier concentration. The theoretical displacement current-voltage curves are in good agreement with the measurement in both voltage regions where the majority carriers are accumulated and depleted. The local carrier concentration can be determined by fitting the theoretical displacement current-voltage curve with the experimental results.

Yutaka Majima; Yutaka Oyama; Mitsumasa Iwamoto

2000-07-15T23:59:59.000Z

58

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

Open Energy Info (EERE)

Mauna Loa Northeast Rift Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Mauna Loa...

59

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

Open Energy Info (EERE)

Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Cove Fort Area - Liquid (Warpinski, Et...

60

Variable current-voltage TPV device for use in a thermophotovoltaic energy conversion system  

DOE Patents [OSTI]

A front-side or back-side illuminated variable current-voltage thermophotovoltaic device comprises a support substrate; isolation layers disposed on the support substrate; a plurality of cells disposed on the isolation layers, each of the cells including a base layer and an emitter layer; an insulating member disposed between each of the cells configured to isolate each cell from adjacent cells; an ohmic contact configured to connect each cell to another cell in series; and a spectral control device disposed on top of the cells and/or on the bottom surface of the support substrate.

Charache, Greg W. (Clifton Park, NY); Baldasaro, Paul F. (Clifton Park, NY); Campbell, Brian C. (Scotia, NY)

2000-01-01T23:59:59.000Z

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.


61

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

62

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

63

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

64

Soft commutated direct current motor [summary of proposed paper  

SciTech Connect (OSTI)

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

65

Development of a technique for ex-reactor heating of electrodes and for obtaining voltage-current characteristics of multi-cell thermionic fuel elements  

SciTech Connect (OSTI)

This paper presents results of development of a technique for ex-reactor heating with simultaneous recording of voltage-current characteristics of multi-cell thermionic fuel elements (TFE). Heating pulses were applied to electrodes of a thermionic energy converter (TIC), and between these pulses in the antiphase to them there were applied shorter pulses. The TIC emitter was heated by energy of an electric current flowing from the collector (back current heating). Comparison of TIC voltage-current characteristics, obtained for direct (using electric heater) and back current (current from the collector) heating, shows that for the same conditions they differ only slightly. Significant difference may be observed in the case of different profiles along the collector working surface. Results are given of the investigation of multi-cell thermionic fuel assemblies conducted using this technique. The developed technique of the TFE diagnostics can be successfully employed to assess the device quality. Pre-loop testing of multi-cell TFE by the method of back currents allows for cost effective and expeditious thermovacuum treatment of the TFE on thermal stands and for checking of its serviceability prior to its mounting into an irradiation loop or reactor-converter, enables improvements to the TFE design, monitoring of its electric parameters, for example, after vibration testing, and TFE accelerated testing in the most arduous conditions (thermocycling, loss of vacuum, etc.).

Kalandarishvili, A.G.; Mailov, G.M.; Igumnov, B.N.; Bisko, V.A. [I.N. Vekua Sukhumi Inst. for Physics and Engineering, Tbilisi (Georgia)

1995-12-31T23:59:59.000Z

66

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 (OSTI)

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

67

Extrinsic and intrinsic nonlinear current-voltage characteristics in charge ordered oxides  

Science Journals Connector (OSTI)

We present a systematic study to clarify the origin of nonlinear I-Vcharacteristics widely observed in charge ordered oxides. The experiments performed on the charge ordered YbFe2O4single crystals demonstrate that the I-V behavior strongly depends on the measurement parameters such as the width and strength of applied voltage/current pulse the time interval between two subsequent pulses and the time delay before reading a data. Correspondingly three regimes are identified: (i) steep nonlinear I-V behavior induced by self-heating when the pulse width is big and/or the time interval is short; (ii) smooth nonlinear I-Vcharacteristic in the low field range when the electric pulse width is small and the time interval is long enough owing to sliding of charge density wave; (iii) abrupt collapse of charge order/charge density wave at high electric fields. A proper measurement scheme must be employed in order to distinguish the intrinsic effects associated with electric field modulation of charge order from the extrinsic self-heating effect.

F. Wang; T. Zou; Y. Liu; L.-Q. Yan; Y. Sun

2012-01-01T23:59:59.000Z

68

Application-Directed Voltage Scaling Johan Pouwelse, Koen Langendoen, and Henk Sips  

E-Print Network [OSTI]

--Clock (and voltage) scheduling is an important tech- nique to reduce the energy consumption of processors that sup- port voltage scaling. It is difficult, however, to achieve good re- sults using only statistics to the scheduler control- ling the clock speed and processor voltage. This paper describes our Energy Priority

Pouwelse, Johan

69

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).

70

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

SciTech Connect (OSTI)

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

71

Direct Power Control of Doubly-Fed Generator Based Wind Turbine Converters to Improve Low Voltage  

E-Print Network [OSTI]

Control (DPC) is discussed for Low Voltage Ride Through (LVRT) of DFIG based wind turbine converters power integration state that doubly fed induction generator (DFIG) controllers should be capable and maintaining dc bus voltage, then the DFIG will stay online during the disturbance. A fast acting controller

Kimball, Jonathan W.

72

Voltage stabilization system in traction substation of urban electric transport  

Science Journals Connector (OSTI)

The direct current-voltage stabilization system using a high-frequency link in traction substations of urban electric transport based on applying...

S. V. Shapiro; S. F. Muftiev

2011-02-01T23:59:59.000Z

73

Research on short-circuit current of doubly fed induction generator under non-deep voltage drop  

Science Journals Connector (OSTI)

Abstract The transient characteristics of power systems with large-scale doubly fed wind turbines undergo profound changes. Doubly fed induction generators (DFIG) under non-deep voltage drop generate short-circuit currents, which involves complicated electromagnetism and control coupling. This phenomenon has only been partially studied in the literature. Thus, this paper presents a detailed analysis of the short-circuit current of DFIG, with particular attention to the influence of converter adjustment. The dynamics of generator and converter control were simultaneously analyzed by vector analysis in uniform coordinate space. The generation mechanism, composition, and analytical expressions of short-circuit current were proposed. DFIG models were constructed to calculate the initial and steady-state short-circuit current. Simulation and experiment were performed to verify the efficacy of the proposed analyses.

Jinxin Ouyang; Xiaofu Xiong

2014-01-01T23:59:59.000Z

74

Effect of current compliance and voltage sweep rate on the resistive switching of HfO{sub 2}/ITO/Invar structure as measured by conductive atomic force microscopy  

SciTech Connect (OSTI)

The electrical characterization of HfO{sub 2}/ITO/Invar resistive switching memory structure was studied using conductive atomic force microscopy (AFM) with a semiconductor parameter analyzer, Agilent 4156C. The metal alloy Invar was used as the metal substrate to ensure good ohmic contact with the substrate holder of the AFM. A conductive Pt/Ir AFM tip was placed in direct contact with the HfO{sub 2} surface, such that it acted as the top electrode. Nanoscale current-voltage (I-V) characteristics of the HfO{sub 2}/ITO/Invar structure were measured by applying a ramp voltage through the conductive AFM tip at various current compliances and ramp voltage sweep rates. It was found that the resistance of the low resistance state (RLRS) decreased with increasing current compliance value, but resistance of high resistance state (RHRS) barely changed. However, both the RHRS and RLRS decreased as the voltage sweep rate increased. The reasons for this dependency on current compliance and voltage sweep rate are discussed.

Wu, You-Lin, E-mail: ylwu@ncnu.edu.tw; Liao, Chun-Wei [Department of Electrical Engineering, National Chi Nan University, Puli, Nantou, Taiwan (China); Ling, Jing-Jenn [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Puli, Nantou, Taiwan (China)

2014-06-16T23:59:59.000Z

75

Geomagnetically induced currents in the Uruguayan high-voltage power grid  

Science Journals Connector (OSTI)

......magnetic field due to an elementary ionospheric current...calculation. Let M elementary currents I, be placed...Earth's surface due to an elementary unit amplitude current...The horizontal electric field at the surface...earthed nodes linked by resistances R ij (i, j......

R. Caraballo; L. Sánchez Bettucci; G. Tancredi

2013-01-01T23:59:59.000Z

76

Method and apparatus for correcting eddy current signal voltage for temperature effects  

DOE Patents [OSTI]

An apparatus and method for measuring physical characteristics of an electrically conductive material by the use of eddy-current techniques and compensating measurement errors caused by changes in temperature includes a switching arrangement connected between primary and reference coils of an eddy-current probe which allows the probe to be selectively connected between an eddy current output oscilloscope and a digital ohm-meter for measuring the resistances of the primary and reference coils substantially at the time of eddy current measurement. In this way, changes in resistance due to temperature effects can be completely taken into account in determining the true error in the eddy current measurement. The true error can consequently be converted into an equivalent eddy current measurement correction.

Kustra, Thomas A. (N. Huntingdon, PA); Caffarel, Alfred J. (Pittsburgh, PA)

1990-01-01T23:59:59.000Z

77

Suppression of current fluctuations in a crossed ExB field system for low-voltage plasma immersion treatment  

SciTech Connect (OSTI)

Plasma transport in a hybrid dc vacuum arc plasma source for ion deposition and plasma immersion treatment is considered. It is found that external crossed electric and magnetic fields near the substrate can significantly reduce the relative amplitude of ion current fluctuations I{sub f} at the substrate surface. In particular, I{sub f} decreases with the applied magnetic field when the bias voltage exceeds 300 V, thus allowing one to reduce the deviations from the rated process parameters. This phenomenon can be attributed to an interaction between the metal-plasma jet from the arc source and the discharge plasma in the crossed fields.

Levchenko, I.; Keidar, M.; Ostrikov, K.; Yu, M.Y. [School of Physics, University of Sydney, Sydney NSW 2006 (Australia); Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); School of Physics, University of Sydney, Sydney NSW 2006 (Australia); Institute for Theoretical Physics I, Ruhr University Bochum, Bochum 44780 (Germany)

2006-01-01T23:59:59.000Z

78

A straightforward method to extract the shunt resistance of photovoltaic cells from current–voltage characteristics of mounted arrays  

Science Journals Connector (OSTI)

A straightforward non-invasive method is proposed to accurately evaluate the shunt resistance of an elementary cell of a photovoltaic module connected in an installed string without requiring prior knowledge of the parameters of the intrinsic diodes. The approach relies on the measurement of the current–voltage characteristic of the whole string after intentionally shading the selected cell. Calibrated PSPICE simulations are employed to illustrate the method and test its reliability. As a case study, the shunt resistances of several cells belonging to a series array of 10 commercial panels are determined.

Vincenzo d’Alessandro; Pierluigi Guerriero; Santolo Daliento; Matteo Gargiulo

2011-01-01T23:59:59.000Z

79

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

80

An investigation of the quality of the output voltage, current, and energy relationships of independent inverters with transformers with a rotating magnetic field  

Science Journals Connector (OSTI)

It is analyzed how commutator circuits of independent inverters with transformers with rotating magnetic fields influence the quality of the output voltage and current. Based on a harmonic analysis of curve fo...

A. I. Cherevko; M. M. Muzyka

2009-02-01T23:59:59.000Z

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.


81

Voltage sensing based built-in current sensor for IDDQ test  

E-Print Network [OSTI]

Quiescent current leakage test of the VDD supply (IDDQ Test) has been proven an effective way to screen out defective chips in manufacturing of Integrated Circuits (IC). As technology advances, the traditional IDDQ test is facing more and more...

Xue, Bin

2006-04-12T23:59:59.000Z

82

Thin-Film Inductor Designs and Materials for High-Current Low-Voltage Power  

E-Print Network [OSTI]

metals in a ceramic matrix such as Al2O3. Conventionally they are deposited using reactive sputtering still induce eddy currents that result in substantial losses [17]. Granular composite magnetic materials

83

Direct-current-like Phase Space Manipulation Using Chirped Alternating Current Fields  

SciTech Connect (OSTI)

Waves in plasmas can accelerate particles that are resonant with the wave. A dc electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. Whereas wave-particle acceleration mechanisms have been widely discussed in the literature, this work discusses the direct analogy between wave acceleration and dc field acceleration in a particular parameter regime explored in previous works. Apart from the academic interest of this correspondence, there may be practical advantages in using waves to mimic dc electric fields, for example, in driving plasma current with high efficiency.

P.F. Schmit and N.J. Fisch

2010-02-01T23:59:59.000Z

84

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

85

Investigation of Voltage and Current Variations in a Multiphase AC Electric Arc System  

E-Print Network [OSTI]

of the most promising directions. The method of plasma pyrolysis and gasification, where at waste processing in the plasma torch up to high temperatures, as an oxidative agent at incineration of low-calorie waste products an excess-air coefficient, reduces total amount of secondary gaseous waste generated at incineration

Boyer, Edmond

86

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  

SciTech Connect (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

87

Reduction of Shaft Voltages and Bearing Currents in Five-Phase Induction Motor  

E-Print Network [OSTI]

-phase system It is clear that sequence 1 and 4 are equivalent; same sequence with opposite direction. The same holds true for sequences 2 and 3. Therefore, only sequence 1, 3, and 5 will be used. Fig. 14 shows the three sequences along with the qd vectors... ) ( ) [ ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ] ( ) [ ] ( 16 ) 18 The derivation could be done using the following basic trigonometric identities. 1. ( ) ( ) ( ) 2. ( ) ( ) 3. ( ) ( ) 4. ( ) ( ) ( ) ( ) 5...

Hussain, Hussain

2012-07-16T23:59:59.000Z

88

Identification of ions near HVDC (high-voltage direct-current) transmission lines: Final report  

SciTech Connect (OSTI)

Positive and negative ion species were identified and studied at two separate field sites and one laboratory site. The first field study was conducted under an operating HVDC transmission line. The second was near a HVDC test line and measurements were performed with the line in both an energized and de-energized state. During clear, sunny days HSO/sub 4//sup /minus///center dot/H/sub 2/SO/sub 4/ was observed to be the dominant negative ion in the natural ion spectrum. At night, however, HSO/sub 4//sup /minus// core ions virtually disappeared, and were replaced by NO/sub 3//sup /minus// core ions and their first nitric acid cluster. Both negative spectra also typically contained lesser concentrations of the malonate ion. The transmission line negative spectra were similar but were typically dominated by the NO/sub 3//sup /minus// core ions during both day and night. The positive ions observed under HVDC lines were typically either NH/sub 4//sup +/ or C/sub 5/H/sub 6/N/sup +/, which reacted with higher proton affinity species (such as methylpyridines, trimethylamine and quinoline) farther from or in the absence of the transmission line. The observed differences between natural and anthropogenic ion spectra near HVDC lines are attributed primarily to a shortening of ion lifetimes by the strong electric field associated with the HVDC lines. One exception is the production of potassium and probably sodium based ions from the decomposition of insects in transmission line coronas. 22 refs., 29 figs.

Eisele, F.L.

1989-05-01T23:59:59.000Z

89

Mechanism behind self-sustained oscillations in direct current glow discharges and dusty plasmas  

SciTech Connect (OSTI)

An alternative explanation to the mechanism behind self-sustained oscillations of ions in direct current (DC) glow discharges is provided. Such description is distinguished from the one provided by the fluid models, where oscillations are attributed to the positive feedback mechanism associated with photoionization of particles and photoemission of electrons from the cathode. Here, oscillations arise as consequence of interaction between an ion and the surface charges induced by it at the bounding electrodes. Such mechanism provides an elegant explanation to why self-sustained oscillations occur only in the negative resistance region of the voltage-current characteristic curve in the DC glow discharges. Furthermore, this alternative description provides an elegant explanation to the formation of plasma fireballs in the laboratory plasma. It has been found that oscillation frequencies increase with ion's surface charge density, but at the rate which is significantly slower than it does with the electric field. The presented mechanism also describes self-sustained oscillations of ions in dusty plasmas, which demonstrates that self-sustained oscillations in dusty plasmas and DC glow discharges involve common physical processes.

Cho, Sung Nae [Devices R and D Center, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Mt. 14-1 Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea, Republic of)

2013-04-15T23:59:59.000Z

90

Electrochemical synthesis of nanosized hydroxyapatite by pulsed direct current method  

SciTech Connect (OSTI)

Synthesis of nanosized of hydroxyapatite (HA) by electrochemical pulsed direct current (PDC) method has been studied. The aim of this work is to study the influence of various PDC parameters (pH initial, electrode distance, duty cycle, frequency, and amplitude) on particle surface area of HA powders. The electrochemical synthesis was prepared in solution Ca{sup 2+}/EDTA{sup 4?}/PO{sub 4}{sup 3+} at concentration 0.25/0.25/0.15 M for 24 h. The electrochemical cell was consisted of two carbon rectangular electrodes connected to a function generator to produce PDC. There were two treatments for particles after electrosynthesized, namely without aging and aged for 2 days at 40 °C. For both cases, the particles were filtered and washed by demineralized water to eliminate the impurities and unreacted reactants. Then, the particles were dried at 100 °C for 2 days. The dried particles were characterized by X-ray diffraction, surface area analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectra and thermogravimetric and differential thermal analysis. HA particles can be produced when the initial pH > 6. The aging process has significant effect on the produced HA particles. SEM images of HA particles showed that the powders consisted of agglomerates composed of fine crystallites and have morphology plate-like and sphere. The surface area of HA particles is in the range of 25 – 91 m{sup 2}/g. The largest particle surface area of HA was produced at 4 cm electrode distance, 80% cycle duty, frequency 0.1 Hz, amplitude 9 V and with aging process.

Nur, Adrian; Rahmawati, Alifah; Ilmi, Noor Izzati; Affandi, Samsudin; Widjaja, Arief [Departement of Chemical Engineering, Faculty of Industrial Technology, Sepuluh Nopember Institute of Technology, Kampus ITS Sukolilo, Surabaya 60111 (Indonesia)

2014-02-24T23:59:59.000Z

91

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

SciTech Connect (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

92

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

E-Print Network [OSTI]

Students' understanding of direct current resistive electrical circuits Paula Vetter Engelhardta regarding direct current resistive electric circuits often differ from the accepted explanations. At present of direct cur- rent DC resistive electric circuits concepts. DIRECT has been designed for use with high

Zollman, Dean

93

Apparatuses and method for converting electromagnetic radiation to direct current  

DOE Patents [OSTI]

An energy conversion device may include a first antenna and a second antenna configured to generate an AC current responsive to incident radiation, at least one stripline, and a rectifier coupled with the at least one stripline along a length of the at least one stripline. An energy conversion device may also include an array of nanoantennas configured to generate an AC current in response to receiving incident radiation. Each nanoantenna of the array includes a pair of resonant elements, and a shared rectifier operably coupled to the pair of resonant elements, the shared rectifier configured to convert the AC current to a DC current. The energy conversion device may further include a bus structure operably coupled with the array of nanoantennas and configured to receive the DC current from the array of nanoantennas and transmit the DC current away from the array of nanoantennas.

Kotter, Dale K; Novack, Steven D

2014-09-30T23:59:59.000Z

94

Lightning strikes to tall objects: Currents inferred from far electromagnetic fields versus directly measured currents  

E-Print Network [OSTI]

-field-to-current conversion factors for lightning strikes to tall objects for (1) the initial peak current at the object top. These far-field-to-current conversion factors are needed for proper interpretation of peak currents reported-field-to-current conversion factor for lightning strikes to flat ground based on the transmission line model and (b

Florida, University of

95

Direct Laser Cladding , Current Status and Future Scope of Application  

Science Journals Connector (OSTI)

During the last decades Direct Laser Cladding has become an established technique in many ... oil drilling components. Continuous wave (CW) lasers with a power up to 18 kW ... with three or more axes, enabling ...

A. Weisheit; A. Gasser; G. Backes; T. Jambor…

2013-01-01T23:59:59.000Z

96

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

97

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

98

Propagation direction reversal of ionization zones in the transition between high and low current magnetron sputtering  

SciTech Connect (OSTI)

Past research has revealed the propagation of dense, asymmetric ionization zones in both high and low current magnetron discharges. Here we report about the direction reversal of ionization zone propagation as observed with fast cameras. At high currents, zones move in the E B direction with velocities of 103 to 104 m/s. However at lower currents, ionization zones are observed to move in the opposite, the -E B direction, with velocities ~;; 103 m/s. It is proposed that the direction reversal is associated with the local balance of ionization and supply of neutrals in the ionization zone.

School of Materials Science and Engineering, State Key Lab for Materials Processing and Die & Mold Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Department of Physics, University of California Berkeley, Berkeley, California 94720, USA; Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA; Yang, Yuchen; Liu, Jason; Liu, Lin; Anders, André

2014-12-11T23:59:59.000Z

99

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"

100

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

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101

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

102

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"

103

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

104

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"

105

Experimental evaluation of actual delivered dose using mega-voltage cone-beam CT and direct point dose measurement  

SciTech Connect (OSTI)

Radiation therapy in patients is planned by using computed tomography (CT) images acquired before start of the treatment course. Here, tumor shrinkage or weight loss or both, which are common during the treatment course for patients with head-and-neck (H and N) cancer, causes unexpected differences from the plan, as well as dose uncertainty with the daily positional error of patients. For accurate clinical evaluation, it is essential to identify these anatomical changes and daily positional errors, as well as consequent dosimetric changes. To evaluate the actual delivered dose, the authors proposed direct dose measurement and dose calculation with mega-voltage cone-beam CT (MVCBCT). The purpose of the present study was to experimentally evaluate dose calculation by MVCBCT. Furthermore, actual delivered dose was evaluated directly with accurate phantom setup. Because MVCBCT has CT-number variation, even when the analyzed object has a uniform density, a specific and simple CT-number correction method was developed and applied for the H and N site of a RANDO phantom. Dose distributions were calculated with the corrected MVCBCT images of a cylindrical polymethyl methacrylate phantom. Treatment processes from planning to beam delivery were performed for the H and N site of the RANDO phantom. The image-guided radiation therapy procedure was utilized for the phantom setup to improve measurement reliability. The calculated dose in the RANDO phantom was compared to the measured dose obtained by metal-oxide-semiconductor field-effect transistor detectors. In the polymethyl methacrylate phantom, the calculated and measured doses agreed within about +3%. In the RANDO phantom, the dose difference was less than +5%. The calculated dose based on simulation-CT agreed with the measured dose within±3%, even in the region with a high dose gradient. The actual delivered dose was successfully determined by dose calculation with MVCBCT, and the point dose measurement with the image-guided radiation therapy procedure.

Matsubara, Kana, E-mail: matsubara-kana@hs.tmu.ac.jp [Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku Tokyo (Japan); Kohno, Ryosuke [National Cancer Center Hospital East, Chiba (Japan); National Cancer Center Research Institute, Chiba (Japan); Nishioka, Shie; Shibuya, Toshiyuki; Ariji, Takaki; Akimoto, Tetsuo [National Cancer Center Hospital East, Chiba (Japan); Saitoh, Hidetoshi [Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku Tokyo (Japan)

2013-07-01T23:59:59.000Z

106

Active electron energy distribution function control in direct current discharge using an auxiliary electrode  

SciTech Connect (OSTI)

The electron energy distribution functions are studied in the low voltage dc discharge with a constriction, which is a diaphragm with an opening. The dc discharge glows in helium and is sustained by the electron current emitted from a heated cathode. We performed kinetic simulations of dc discharge characteristics and electron energy distribution functions for different gas pressures (0.8 Torr-4 Torr) and discharge current of 0.1 A. The results of these simulations indicate the ability to control the shape of the electron energy distribution functions by variation of the diaphragm opening radius.

Schweigert, I. V. [Institute of Theoretical and Applied Mechanics, Novosibirsk 630090 (Russian Federation) [Institute of Theoretical and Applied Mechanics, Novosibirsk 630090 (Russian Federation); George Washington University, Washington, DC 20052 (United States); Kaganovich, I. D. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Demidov, V. I. [West Virginia University, Morgantown, WV 26506 (United States) [West Virginia University, Morgantown, WV 26506 (United States); St. Petersburg State University, St. Petersburg (Russian Federation)

2013-10-15T23:59:59.000Z

107

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

108

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.

Droege, Thomas F. (Batavia, IL)

1989-01-01T23:59:59.000Z

109

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

110

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"

111

Constant voltage electro-slag remelting control  

DOE Patents [OSTI]

A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an electrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable. 1 fig.

Schlienger, M.E.

1996-10-22T23:59:59.000Z

112

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.

113

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

114

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

115

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

Broader source: Energy.gov (indexed) [DOE]

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

116

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

117

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.

118

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

119

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

120

The Effect of Propane on Atomic Spectrometric Signals in the Direct-Current Plasma  

Science Journals Connector (OSTI)

The addition of small amounts of propane to the direct-current plasma (DCP) affects the emission signal of analyte species in the plasma. In the normal analytical region of the...

McCreary, Terry W; Long, Gary L

1988-01-01T23:59:59.000Z

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.


121

Stray current interference control for HVDC earth currents  

SciTech Connect (OSTI)

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

122

Parallel electric fields in the upward current region of the aurora: Indirect and direct observations  

E-Print Network [OSTI]

Parallel electric fields in the upward current region of the aurora: Indirect and direct In this article we present electric field, magnetic field, and charged particle observations from the upward current region of the aurora focusing on the structure of electric fields at the boundary between

California at Berkeley, University of

123

ELSEVIER Bioelectrochemistry and Bioenergetics 35 (1994) 99-101 Low level direct current -cell culture fibroblast model  

E-Print Network [OSTI]

ELSEVIER Bioelectrochemistry and Bioenergetics 35 (1994) 99-101 Low level direct current - cell;100 U. Batista et al. / Bioelectrochemistry and Bioenergetics 35 (1994) 99-101 2.2. Direct current

Ljubljana, University of

124

Magnetic relaxation, current-voltage characteristics, and possible dissipation mechanisms for high-Tc superconducting thin films of Y-Ba-Cu-O  

Science Journals Connector (OSTI)

We propose a mechanism that may account for the temperature-insensitive relaxation of the magnetic-shielding current in epitaxial thin films of YBa2Cu3O7-?. We show that such relaxation is related to the shape of the current-voltage (J-E) characteristic of the superconductor in its critical state. The weak temperature dependence of the relaxation implies a temperature-insensitive J-E characteristic that resembles that of conventional type-II superconductors when a spatial variation of critical current density (Jc) is present. We suggest such a distribution of Jc as an explanation for the apparently large and temperature-insensitive relaxation observed in YBa2Cu3O7-?.

J. Z. Sun; C. B. Eom; B. Lairson; J. C. Bravman; T. H. Geballe

1991-02-01T23:59:59.000Z

125

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,

126

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

127

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

128

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;

129

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

130

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

131

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.

132

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

133

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

134

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

135

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

136

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

137

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"

138

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

139

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"

140

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)

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 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

142

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

143

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

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 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

146

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

147

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

148

Testing of a 50 kA, 50 kV current interrupter with I sup 2 t preheating and long recovery voltage  

SciTech Connect (OSTI)

The Confinement Physics Research Facility (CPRF) presently being constructed at Los Alamos in a next generation Reversed Field Pinch (RFP) plasma experiment. An inductive energy transfer system, employing a 50 kA, 50 kV dc current interrupter, is being utilized for initiating the plasma current. These performance requirements (50 kA, 50 kV) had yet to be realized in a reliable switching system, development of this current interrupter system was initiated. A switch test bay with a 50 kA battery bank has been built at Los Alamos to test the interrupter in conditions which will exist in the CPRF experiment. Many switch parameters were measured to provide information on the current interrupting characteristics and reliability. Some of these diagnostics include voltage, current, pre and post I{sup 2}t contact resistance, opening speed and position, arc voltage, and stem temperature. To determine any long term changes, all shots and data channels are computer indexed, and may be easily recalled for review. Extensive testing was performed on Siemens D-10 vacuum interrupter. Test parameter space included 55 kA, 40 kV (per bottle); di/dt of 2250 A/{mu}s, I{sup 2}t of 5 {times} 10{sup 9} amp{sup 2} sec; and 20 kV-200 msec RC recovery decay. Circuit parameters effect opening reliability. Circuit data and the associated testing results will be presented along with long term trends of switch performance under normal'' conditions. 12 figs.

Reass, W.A.; Boenig, H.J.; Melton, J.G. (Los Alamos National Lab., NM (USA))

1989-01-01T23:59:59.000Z

149

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

E-Print Network [OSTI]

for power system dynamic models, including a third order representation of high voltage direct current (HVDC power limits, HVDC firing angle limits and voltage dependent current order limits (VDCOL) are shown the derivation of individual component Lyapunov functions for simplified models of HVDC links connected

Cañizares, Claudio A.

150

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

151

The MAPS Program in the Pacific Northwest: Current Status and Future Direction  

E-Print Network [OSTI]

The MAPS Program in the Pacific Northwest: Current Status and Future Direction Report Submitted #12;#12;The MAPS Program in the Pacific Northwest - i TABLE OF CONTENTS EXECUTIVE SUMMARY........................................................................................................................................... 10 Adult Capture Rates and Station Longevity at MAPS Stations in the Pacific Northwest Region

DeSante, David F.

152

Nickel catalyst faceting in plasma-enhanced direct current chemical vapor deposition of carbon nanofibers  

E-Print Network [OSTI]

1 Nickel catalyst faceting in plasma-enhanced direct current chemical vapor deposition of carbon vapor deposition with Ni catalysts on the top of nanofibers. Transmission electron microscopy was used to study the morphology and crystallography of Ni catalysts, which are essential for the nucleation

Paris-Sud XI, Université de

153

Direct evidence for local oscillatory current sources and intracortical phase gradients in turtle  

E-Print Network [OSTI]

Direct evidence for local oscillatory current sources and intracortical phase gradients in turtle of several species. In turtle, these oscillations take the form of linear and circular traveling waves the origin of wave propagation in turtle visual cortex, we performed simultaneous measurements of the local

Kleinfeld, David

154

Current Directions of Structural Health Monitoring and Control in USA Satish Nagarajaiah1,  

E-Print Network [OSTI]

Current Directions of Structural Health Monitoring and Control in USA Satish Nagarajaiah1,§, 1 Prof.,Dept. of Civil & Env./Dept of Mech. Eng. & Mat. Sc., Rice Univ., Houston, TX 77005, U.S.A. 2 Prof.,Dept. of Mech. Aero. and Struc. Eng., Washington Univ., St. Louis, MO 63130, U.S.A. 3 Asst. Prof

Lynch, Jerome P.

155

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

156

Voltage-dependent G protein-mediated inhibition of neuronal Ca channels is characterized by an inhibition of current  

E-Print Network [OSTI]

protein-mediated inhibition of neuronal N-type (á1B) and PÏQ-type (á1A) calcium currents is mediated on the intracellular loop that links transmembrane domains I and II (De Waard, Liu, Walker, Scott, Gurnett & Campbell of Physiology (1998), 509.1, pp.15--27 15 Facilitation of rabbit á1B calcium channels: involvement of endogenous

Dolphin, Annette C.

157

A Novel Neutral Point Potential Stabilization Technique Using the Information of Output Current Polarities and Voltage Vector  

E-Print Network [OSTI]

- This paper proposes a new neutral point potential control technique for the three-level neutral-point-clamped PWM inverter. Utilizing the phase current polarity information, this technique distributes including the zero power factor condition. Detailed analysis and computer simulations show the superiority

Hava, Ahmet

158

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

SciTech Connect (OSTI)

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

159

EIS-0107: Mead-Phoenix +500-kV Direct Current Transmission Line  

Broader source: Energy.gov [DOE]

The U.S. Department of Energy’s Western Area Power Administration (WAPA) prepared this statement to analyze the potential environmental and socioeconomic impacts arising from WAPA and regional project sponsors’ proposal to construct a 500 kilovolt (kV) alternating current (AC) transmission line with the capability to be upgraded later to 500kV direct current (DC), connecting the Westwing Substation, located north of Phoenix, Arizona, with a new McCullough II Substation, located approximately 14 miles west of Boulder City, Nevada. This statement modifies a previously prepared federal statement from which the participants' election to proceed had not occurred at the time this statement was prepared.

160

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

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161

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

162

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

163

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

164

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

165

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

166

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

167

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

168

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

169

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

170

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

171

The effects of direct-current magnetic fields on turtle retinas vitro  

SciTech Connect (OSTI)

Direct-current magnetic fields of 10 to 100 gauss cause a significant short-term reduction of the in vitro electroretinographic b-wave response in turtle retina. This response compression is not accompanied by the usual reduction in retinal sensitivity that occurs with background illumination. Furthermore, this effect is obtained only briefly after the offset of ambient lighting in the diurnal light-dark cycle of nonhibernating animals.

Raybourn, M.S.

1983-05-13T23:59:59.000Z

172

The effect of a direct current field on the microparticle charge in the plasma afterglow  

SciTech Connect (OSTI)

Residual charges of individual microparticles forming dense clouds were measured in a RF discharge afterglow. Experiments were performed under microgravity conditions on board the International Space Station, which ensured particle levitation inside the gas volume after the plasma switch-off. The distribution of residual charges as well as the spatial distribution of charged particles across the cloud were analyzed by applying a low-frequency voltage to the electrodes and measuring amplitudes of the resulting particle oscillations. Upon “free decharging” conditions, the charge distribution had a sharp peak at zero and was rather symmetric (with charges concentrated between ?10e and +10e), yet positively and negatively charged particles were homogeneously distributed over the cloud. However, when decharging evolved in the presence of an external DC field (applied shortly before the plasma switch-off) practically all residual charges were positive. In this case, the overall charge distribution had a sharp peak at about +15e and was highly asymmetric, while the spatial distribution exhibited a significant charge gradient along the direction of the applied DC field.

Wörner, L. [Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany) [Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany); Groupe de Recherches sur l'Energétique des Milieux Ionisés, UMR7344, CNRS, Univ. Orléans, F-45067 Orléans (France); Ivlev, A. V.; Huber, P.; Hagl, T.; Thomas, H. M.; Morfill, G. E. [Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany)] [Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany); Couëdel, L. [Centre National de la Recherche Scientifique, Aix-Marseille-Université, Laboiratoire de Physique des Intéractions Ioniques et Moléculaires, UMR 7345, 13397 Marseille cedex 20 (France)] [Centre National de la Recherche Scientifique, Aix-Marseille-Université, Laboiratoire de Physique des Intéractions Ioniques et Moléculaires, UMR 7345, 13397 Marseille cedex 20 (France); Schwabe, M. [Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany) [Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany); Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720 (United States); Mikikian, M.; Boufendi, L. [Groupe de Recherches sur l'Energétique des Milieux Ionisés, UMR7344, CNRS, Univ. Orléans, F-45067 Orléans (France)] [Groupe de Recherches sur l'Energétique des Milieux Ionisés, UMR7344, CNRS, Univ. Orléans, F-45067 Orléans (France); Skvortsov, A. [Yuri Gagarin Cosmonauts Training Center, RU-141160 Star City (Russian Federation)] [Yuri Gagarin Cosmonauts Training Center, RU-141160 Star City (Russian Federation); Lipaev, A. M.; Molotkov, V. I.; Petrov, O. F.; Fortov, V. E. [Joint Institute for High Temperatures, RU-125412 Moscow (Russian Federation)] [Joint Institute for High Temperatures, RU-125412 Moscow (Russian Federation)

2013-12-15T23:59:59.000Z

173

Study of asymmetries of Cd(Zn)Te devices investigated using photo-induced current transient spectroscopy, Rutherford backscattering, surface photo-voltage spectroscopy, and gamma ray spectroscopies  

SciTech Connect (OSTI)

Despite these recent advancements in preparing the surface of Cd(Zn)Te devices for detector applications, large asymmetries in the electronic properties of planar Cd(Zn)Te detectors are common. Furthermore, for the development of patterned electrode geometries, selection of each electrode surface is crucial for minimizing dark current in the device. This investigation presented here has been carried out with three objectives. Each objective is oriented towards establishing reliable methods for the selection of the anode and cathode surfaces independent of the crystallographic orientation. The objectives of this study are (i) investigate how the asymmetry in I-V characteristics of Cd(Zn)Te devices may be associated with the TeO2 interfacial layer using Rutherford backscattering to study the structure at the Au-Cd(Zn)Te interface, (ii) develop an understanding of how the concentration of the active traps in Cd(Zn)Te varies with the external bias, and (iii) propose non-destructive methods for selection of the anode and cathode which are independent of crystallographic orientation. The spectroscopic methods employed in this investigation include Rutherford backscattering spectroscopy, photo-induced current transient spectroscopy, and surface photo-voltage spectroscopy, as well as gamma ray spectroscopy to demonstrate the influence on detector properties.

Crocco, J.; Bensalah, H.; Zheng, Q.; Dieguez, E. [Crystal Growth Laboratory, Universidad Autonoma de Madrid, Madrid Spain (Spain); Corregidor, V.; Avles, E. [Instituto Tecnologico e Nuclear UFA, Sacavem (Portugal); Castaldini, A.; Fraboni, B.; Cavalcoli, D.; Cavallini, A. [PHoS Laboratory, Department of Physics, University of Bologna, Bologna (Italy); Vela, O. [Centro de Investigacion Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain)

2012-10-01T23:59:59.000Z

174

Coulomb contribution to the direct current electrical conductivity of dense partially ionized plasmas  

Science Journals Connector (OSTI)

The Coulomb contribution to the electrical conductivity of partially ionized plasmas is discussed and its general behavior is investigated. Recent experiments on the direct current conductivity in shock wave induced argon and xenon plasmas are analyzed in this context. Within the relaxation time approach the Coulomb contribution is extracted by eliminating the contribution of scattering from neutrals. Alternatively the Coulomb contribution can be calculated directly within linear-response theory. In particular from the latter approach a generalized Spitzer factor is derived for taking into account electron-electron interactions within the relaxation time approximation. Experimental results for the Coulomb contribution to the electrical conductivity are in reasonable agreement with an interpolation formula derived from linear-response theory.

J. R. Adams; N. S. Shilkin; V. E. Fortov; V. K. Gryaznov; V. B. Mintsev; R. Redmer; H. Reinholz; G. Röpke

2007-01-01T23:59:59.000Z

175

Four-point probe measurements of a direct current potential drop on layered conductive cylinders  

Science Journals Connector (OSTI)

We have determined the steady state electric field due to direct current flowing via point contacts at the cylindrical surface of a uniformly layered conductive rod of finite length. The solution allows one to use four-point probe potential drop measurements to estimate the conductivity or thickness of the layer assuming that the other parameters are known. The electrical potential in the rod has a zero radial derivative at its surface except at the injection and extractions points. This means that the required solution can be expressed in terms of a Green's function satisfying a Neumann boundary condition. Four-point measurements have been made to demonstrate the validity of theoretical results.

Yi Lu; John R Bowler

2012-01-01T23:59:59.000Z

176

Characteristics of a Direct Current-driven plasma jet operated in open air  

SciTech Connect (OSTI)

A DC-driven plasma jet has been developed to generate a diffuse plasma plume by blowing argon into the ambient air. The plasma plume, showing a cup shape with a diameter of several centimeters at a higher voltage, is a pulsed discharge despite a DC voltage is applied. The pulse frequency is investigated as a function of the voltage under different gap widths and gas flow rates. Results show that plasma bullets propagate from the hollow needle to the plate electrode by spatially resolved measurement. A supposition about non-electroneutral trail of the streamer is proposed to interpret these experimental phenomena.

Li, Xuechen; Bao, Wenting [College of Physics Science and Technology, Hebei University, Baoding 071002 (China) [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Key Laboratory of Photo-Electronics Information Materials of Hebei Province, Baoding 071002 (China); Di, Cong; Jia, Pengying [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)] [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

2013-09-30T23:59:59.000Z

177

Onset of chaos and dc current-voltage characteristics of rf-driven Josephson junctions in the low-frequency regime  

Science Journals Connector (OSTI)

A comprehensive picture of the dc current-voltage (I-V) characteristics of rf-driven Josephson junctions in the low-frequency regime is presented. The boundary of the low-frequency regime is roughly defined by the junction characteristic frequency for overdamped junctions, and by the inverse of the junction damping time for underdamped junctions. An adiabatic model valid for the low-frequency regime is used to describe the overall shapes of the I-V curves, which is in good agreement with both the numerical simulations and the experimental results. For underdamped junctions, the Shapiro steps are the prominent features on the I-V curves if the rf frequency is sufficiently below the boundary. As the rf frequency is increased towards the boundary, large negatively-going tails on top of the Shapiro steps are observed both experimentally and numerically. Numerical simulations using the resistively- and capacitively-shunted-junction model (RCSJ model) reveal that the negatively-going tail is a signature of the low-frequency boundary of the junction chaotic regime. With use of the adiabatic model and the existence of plasma oscillations for underdamped junctions, the onset of chaos and its effect on the Shapiro steps can be fully explained. The high-frequency limit of the adiabatic model and the chaotic behavior of the Josephson junctions beyond the low-frequency regime are also briefly discussed.

C. C. Chi and C. Vanneste

1990-12-01T23:59:59.000Z

178

Anti-addiction drug ibogaine inhibits voltage-gated ionic currents: A study to assess the drug's cardiac ion channel profile  

SciTech Connect (OSTI)

The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Na{sub v}1.5 sodium and Ca{sub v}1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (? 10 ?M) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. - Highlights: • We study effects of anti-addiction drug ibogaine on ionic currents in cardiomyocytes. • We assess the cardiac ion channel profile of ibogaine. • Ibogaine inhibits hERG potassium, sodium and calcium channels. • Ibogaine’s effects on ion channels are a potential source of cardiac arrhythmias. • 18-Methoxycoronaridine has a lower affinity for cardiac ion channels than ibogaine.

Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes [Center for Physiology and Pharmacology, Department of Neurophysiology and -pharmacology, Medical University of Vienna, 1090 Vienna (Austria); Hilber, Karlheinz, E-mail: karlheinz.hilber@meduniwien.ac.at [Center for Physiology and Pharmacology, Department of Neurophysiology and -pharmacology, Medical University of Vienna, 1090 Vienna (Austria); Sandtner, Walter [Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna (Austria)

2013-12-01T23:59:59.000Z

179

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

180

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

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

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

182

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

183

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

SciTech Connect (OSTI)

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

184

Nonlocal control of electron temperature in short direct current glow discharge plasma  

SciTech Connect (OSTI)

To demonstrate controlling the electron temperature in nonlocal plasma, experiments have been performed on a short (without positive column) dc glow discharge with a cold cathode by applying different voltages to the conducting discharge wall. The experiments have been performed for low-pressure noble gas discharges. The applied voltage can modify trapping the energetic electrons emitted from the cathode sheath and arising from the atomic and molecular processes in the plasma within the device volume. This phenomenon results in the energetic electrons heating the slow plasma electrons, which consequently modifies the electron temperature. Furthermore, a numerical model of the discharge has demonstrated the electron temperature modification for the above case.

Demidov, V. I. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine”, ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A.; Stepanova, O. M. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); Kurlyandskaya, I. P. [International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine”, ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); St. Petersburg University of State Fire Service of EMERCOM RF, Murmansk Branch, Murmansk 183040 (Russian Federation)

2014-09-15T23:59:59.000Z

185

Ionization of Group II A Elements in the Direct Current Plasma: Effects of Ionization Potential on Emission Profiles  

Science Journals Connector (OSTI)

Studies of background corrected ion and atom emission profiles of the group IIA elements in the two-electrode direct current plasma show great variation in both vertical and...

Williams, Ronald R; Coleman, Geoffrey N

1981-01-01T23:59:59.000Z

186

Hemodynamic responses in rat brain during transcranial direct current stimulation: a functional near-infrared spectroscopy study  

Science Journals Connector (OSTI)

In the present study, we monitored hemodynamic responses in rat brains during transcranial direct current stimulation (tDCS) using functional near-infrared spectroscopy (fNIRS). Seven...

Han, Chang-Hee; Song, Hyuna; Kang, Yong-Guk; Kim, Beop-Min; Im, Chang-Hwan

2014-01-01T23:59:59.000Z

187

Measuring surface ocean wave height and directional spectra using an Acoustic Doppler Current Profiler from an autonomous underwater vehicle  

E-Print Network [OSTI]

The Acoustic Doppler Current Profiler (ADCP) is a proven technology which is capable of measuring surface wave height and directional information, however it is generally limited to rigid, bottom mounted applications which ...

Haven, Scott

2012-01-01T23:59:59.000Z

188

Control of Analyte Electrolysis in Electrospray Ionization Mass Spectrometry Using Repetitively Pulsed High Voltage  

SciTech Connect (OSTI)

Analyte electrolysis using a repetitively pulsed high voltage ion source was investigated and compared to that using a regular, continuously operating direct current high voltage ion source in electrospray ionization mass spectrometry. The extent of analyte electrolysis was explored as a function of the length and frequency of the high voltage pulse using the model compound reserpine in positive ion mode. Using +5 kV as the maximum high voltage amplitude, reserpine was oxidized to its 2, 4, 6 and 8-electron oxidation products when direct current high voltage was employed. In contrast, when using a pulsed high voltage, oxidation of reserpine was eliminated by employing the appropriate high voltage pulse length and frequency. This effect was caused by inefficient mass transport of the analyte to the electrode surface during the duration of the high voltage pulse and the subsequent relaxation of the emitter electrode/ electrolyte interface during the time period when the high voltage was turned off. This mode of ESI source operation allows for analyte electrolysis to be quickly and simply switched on or off electronically via a change in voltage pulse variables.

Kertesz, Vilmos [ORNL; Van Berkel, Gary J [ORNL

2011-01-01T23:59:59.000Z

189

Charge-pump voltage converter  

DOE Patents [OSTI]

A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

Brainard, John P. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

2009-11-03T23:59:59.000Z

190

Low-voltage gyrotrons  

SciTech Connect (OSTI)

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

191

Simulation of an Ar/NH{sub 3} low pressure magnetized direct current discharge  

SciTech Connect (OSTI)

A two-dimensional fluid model has been used to investigate the properties of plasma in an Ar/NH{sub 3} low pressure magnetized direct current discharge. We compared the simulation results with the theoretical and experimental results of the other gas discharge in which the magnetic field is considered. Results that obtained using this method are in good agreement with literature. The simulation results show that the positive ammonia ion density follows the positive argon ion density. The Ar{sub 2}{sup +} density is slightly higher than the Ar{sup +} density at 100 mTorr. The largest ammonia ion is NH{sub 3}{sup +} ion, followed by NH{sub 2}{sup +}, NH{sub 4}{sup +}, and NH{sup +} ions. The contribution of NH{sup +} ions to the density of the positive ammonia ions is marginal. The influence of pressure on the plasma discharge has been studied by simulation, and the mechanisms have been discussed. The average plasma density increases as pressure increased. The plasma density appears to be more inhomogeneous than that at the lower pressure. The ratio of charge particles changed as pressure increased. The Ar{sup +} density is slightly higher than the Ar{sub 2}{sup +} density as the pressure increased. It makes NH{sub 4}{sup +} ratio increase as pressure increased. It shows that the electron temperature drops with rising pressure by numerical calculation.

Li Zhi [School of Science, University of Science and Technology Liaoning, Anshan 114051 (China); School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao Zhen [School of Chemistry and Life Science, Anshan Normal University, Anshan 114007 (China); School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051 (China); Li Xuehui [Physiccal Science and Technical College, Dalian University, Dalian 116622 (China)

2013-01-15T23:59:59.000Z

192

Formation of ozone and oxidation of methane in a direct current corona discharge  

E-Print Network [OSTI]

than in the positive corona when using air, while the reverse was observed with oxygen. At low currents and high gas flow rates, the ozone production rate increased linearly with corona current independent of gas flow rate. At high currents... humidity) and positive corona. Their results show: (1) a linear relation between ozone concentration and corona current; (2) an (non- linear) inverse relation between the ozone concentration and air flow; and (3) for a given corona current, the ozone...

Tangirala, Umashanker

1976-01-01T23:59:59.000Z

193

Optimal Voltage Control of the Southern Norwegian Power Grid.  

E-Print Network [OSTI]

??This thesis contains the synthesis, analysis and simulation results of an automatic optimal voltage controller for the Southern Norwegian power grid. Currently the high voltage… (more)

Hannisdal, Erik Lundegaard

2011-01-01T23:59:59.000Z

194

ABBGroup-1-High voltage lab  

E-Print Network [OSTI]

;©ABBGroup-3- 3-Sep-07 Where does one use circuit breakers? High voltage (HV) circuit breakers are keyA DISTRIBUTION MEDIUM AND LOW VOLTAGE HV circuit breakers #12;©ABBGroup-4- 3-Sep-07 When a breaker fails to interrupt the current... Fault arc at a disconnector Fault arc in a substation #12;©ABBGroup-5- 3-Sep-07

Basse, Nils Plesner

195

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

196

Effects of Transcranial Direct Current Stimulation (tDCS) on Human Memory.  

SciTech Connect (OSTI)

Training a person in a new knowledge base or skill set is extremely time consuming and costly, particularly in highly specialized domains such as the military and the intelligence community. Recent research in cognitive neuroscience has suggested that a technique called transcranial direct current stimulation (tDCS) has the potential to revolutionize training by enabling learners to acquire new skills faster, more efficiently, and more robustly (Bullard et al., 2011). In this project, we tested the effects of tDCS on two types of memory performance that are critical for learning new skills: associative memory and working memory. Associative memory is memory for the relationship between two items or events. It forms the foundation of all episodic memories, so enhancing associative memory could provide substantial benefits to the speed and robustness of learning new information. We tested the effects of tDCS on associative memory, using a real-world associative memory task: remembering the links between faces and names. Working memory refers to the amount of information that can be held in mind and processed at one time, and it forms the basis for all higher-level cognitive processing. We investigated the degree of transfer between various working memory tasks (the N-back task as a measure of verbal working memory, the rotation-span task as a measure of visuospatial working memory, and Raven's progressive matrices as a measure of fluid intelligence) in order to determine if tDCS-induced facilitation of performance is task-specific or general.

Matzen, Laura E.; Trumbo, Michael Christopher Stefan

2014-10-01T23:59:59.000Z

197

Direct-current substrate bias effects on amorphous silicon sputter-deposited films for thin film transistor fabrication  

SciTech Connect (OSTI)

The effect that direct current (dc) substrate bias has on radio frequency-sputter-deposited amorphous silicon (a-Si) films has been investigated. The substrate bias produces a denser a-Si film with fewer defects compared to unbiased films. The reduced number of defects results in a higher resistivity because defect-mediated conduction paths are reduced. Thin film transistors (TFTs) that were completely sputter deposited were fabricated and characterized. The TFT with the biased a-Si film showed lower leakage (off-state) current, higher on/off current ratio, and higher transconductance (field effect mobility) than the TFT with the unbiased a-Si film.

Jun, Seung-Ik; Rack, Philip D.; McKnight, Timothy E.; Melechko, Anatoli V.; Simpson, Michael L. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200 (United States); Molecular Scale Engineering and Nanoscale Technologies Research Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2005-09-26T23:59:59.000Z

198

> REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 1 Abstract--In high current, high voltage, high temperature  

E-Print Network [OSTI]

and high current applications, such as HVDC transmission [1] or pulsed power application [2], a thyristor

Paris-Sud XI, Université de

199

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

200

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:

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201

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

SciTech Connect (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 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{sup 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.

Mitic, S.; Morfill, G. E. [Max-Planck-Institut fuer extraterrestrische Physik, D-85741 Garching (Germany); Klumov, B. A. [Joint Institute for High Temperatures, Moscow 125412 (Russian Federation); Khrapak, S. A. [Max-Planck-Institut fuer extraterrestrische Physik, D-85741 Garching (Germany); Joint Institute for High Temperatures, Moscow 125412 (Russian Federation)

2013-04-15T23:59:59.000Z

202

Effect of Low Level Direct Current on in Vivo Tumor Growth in Hamsters  

Science Journals Connector (OSTI)

...The treatment current was provided by a battery powered constant current source. The...in tumor mass with treatment was due to thermal effects from heating caused by passage...in these experiments are not caused by thermal factors. It is noted that under our experimental...

Sharon L. David; Darryl R. Absolom; Charles R. Smith; John Gams; and Morley A. Herbert

1985-11-01T23:59:59.000Z

203

Cancer Stem Cells--Perspectives on Current Status and Future Directions: AACR Workshop on Cancer Stem Cells  

E-Print Network [OSTI]

Cancer Stem Cells--Perspectives on Current Status and Future Directions: AACR Workshop on Cancer Hospital for Sick Children, Toronto, Ontario, Canada; 4 Terry Fox Laboratory BC Cancer Research Center, Vancouver, British Columbia, Canada; 5 Moores University of California San Diego Cancer Center; 6 The Salk

Wahl, Geoffrey M.

204

Nickel-hydrogen voltage-efficiency model  

SciTech Connect (OSTI)

A model for providing voltage vs. current relationships and coulombic efficiency has been developed applicable to Nickel-Hydrogen (NiH{sub 2}) batteries. The performance relationships can be used directly in dynamic electrical energy storage system models or customized by predicting the particular case of voltage as a function of applied current. The algorithm utilizes electrochemical models for competing cell reactions: a single Butler-Volmer equation for the main NiH{sub 2} reaction, and a Tafel relationship for oxygen generation. For the main NiH{sub 2} reaction, the dependence on state-of-charge is introduced via a Nerstian term containing concentrations of active materials present. Oxygen recombination and self-discharge are modeled as first order reactions. Model parameters are determined by a modified Marquardt algorithm to provide a best-fit of both voltage and pressure data to the physical model. The data fit is from electrical characterization tests which may include capacity measurements or repeated electrical cycling at specified depths-of-discharge or with particular regimens. It has been found that test performance data covering a wide domain of the independent variables (temperature, current, and state-of-charge) will produce a well-behaved model.

Hafen, D.P.; Armantrout, J.D. [Lockheed Martin Missiles and Space, Sunnyvale, CA (United States)

1996-12-31T23:59:59.000Z

205

High voltage stability performance of a gamma ray detection device  

SciTech Connect (OSTI)

An industrial grade digital radiation survey meter device is currently being developed at Malaysian Nuclear Agency. This device used a cylindrical type Geiger Mueller (GM) which acts as a detector. GM detector operates at relatively high direct current voltages depend on the type of GM tube. This thin/thick walled cylindrical type of GM tube operates at 450-650 volts range. Proper value and stability performance of high voltage are important parameters to ensure that this device give a reliable radiation dose measurement. This paper will present an assessment of the stability and performance of the high voltage supply for radiation detector. The assessment is performed using System Identification tools box in MATLAB and mathematical statistics.

Abdullah, Nor Arymaswati; Lombigit, Lojius; Rahman, Nur Aira Abd [Technical Support Division, Malaysian Nuclear Agency, 43000 Kajang, Selangor (Malaysia)

2014-02-12T23:59:59.000Z

206

A novel voltage and frequency controller for standalone DFIG based Wind Energy Conversion System  

Science Journals Connector (OSTI)

Abstract This paper presents a new speed-sensorless control strategy for a stand-alone doubly-fed induction generator supplying energy to an isolated load. The method is based on the root mean square (rms) detection scheme. The generated stator voltage is controlled via rotor currents. Amplitude of stator voltage and its frequency are controlled simultaneously. The output signals from the voltage controllers are the reference signals for the rotor current amplitude and frequency of the stator voltage is regulated with the help of frequency control loop. This developed direct voltage control method is applicable for both the balanced and unbalanced load and also for standalone and grid connected mode. The control pulses for the rotor side converter is supplied by the hysteresis controller which is operated on the error signal calculated between actual and reference rotor currents. This paper also provides the brief idea about the voltage and frequency control on modern Autonomous DFIG based Wind Energy Systems via single phase mathematical model of standalone DFIG system. A short state-of-the-art review on mechanical position/speed sensorless control schemes for autonomous DFIG based \\{WESs\\} is presented, which helps the present researcher and students working in this area. These include stator flux oriented control techniques; direct voltage control techniques; MARS observer based techniques for autonomous DFIG-based variable-speed WESs. Simulation results obtained from a 2MVA DFIG system, prototype in MATLab/Simulink, are presented and discussed in this paper.

Rishabh Dev Shukla; Ramesh Kumar Tripathi

2014-01-01T23:59:59.000Z

207

Accelerated Status Exceptionally promising current UCI undergraduate Engineering students may petition for streamlined admission directly  

E-Print Network [OSTI]

Accelerated Status Exceptionally promising current UCI undergraduate Engineering students may numbered 200-289. How to Petition: Students are required to submit an Accelerated Status Petition Form) to the Graduate Student Affairs Office (5400 Engineering Hall). Students may join the Accelerated Status at any

Mease, Kenneth D.

208

Accelerated Status Exceptionally promising current UCI undergraduate Engineering students may petition for streamlined admission directly  

E-Print Network [OSTI]

Accelerated Status Exceptionally promising current UCI undergraduate Engineering students may numbered 200-289. How to Petition: Students are required to submit an Accelerated Status Petition Form) to the Graduate Student Affairs Office (305 Rockwell Engineering Center). Students may join the Accelerated Status

Mease, Kenneth D.

209

A novel direct torque control for induction motor drive system with low torque ripple and current distortion utilising FPGA  

Science Journals Connector (OSTI)

The conventional Direct Torque Control (DTC) is known to produce quick and robust response in ac drives. However, during steady state, notable torque and current pulsations occur. They are reflected in speed estimation, torque response and also produce acoustic noise. In this paper, a novel Space Vector Modulated Direct Torque Control (SVM-DTC) with Low Pass Filter (LPF) for induction motor drive system is proposed, which features low torque ripple, low current distortion and fixed switching frequency. The proposed scheme has been implemented on the Xilinx Spartan 3E FPGA, both simulation and experimental results show that the proposed system can dramatically improve the steady state performance while preserving the dynamic performance of the conventional DTC.

R. Rajendran; N. Devarajan

2013-01-01T23:59:59.000Z

210

Direct  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

interactions, and the pollutant emission is hence directly proportional to the bulk neutral density. Simultaneously monitoring the total emission at 1040 nm and the...

211

Low voltage nonprimary explosive detonator  

DOE Patents [OSTI]

A low voltage, electrically actuated, nonprimary explosive detonator is disclosed wherein said detonation is achieved by means of an explosive train in which a deflagration-to-detonation transition is made to occur. The explosive train is confined within a cylindrical body and positioned adjacent to low voltage ignition means have electrical leads extending outwardly from the cylindrical confining body. Application of a low voltage current to the electrical leads ignites a self-sustained deflagration in a donor portion of the explosive train which then is made to undergo a transition to detonation further down the train.

Dinegar, Robert H. (Los Alamos, NM); Kirkham, John (Newbury, GB2)

1982-01-01T23:59:59.000Z

212

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)

2010-05-04T23:59:59.000Z

213

Theoretical investigation of direct and phonon-assisted tunneling currents in InAlGaAs/InGaAs bulk and quantum-well interband tunnel junctions for multijunction solar cells  

Science Journals Connector (OSTI)

Direct and phonon-assisted tunneling currents in InAlGaAs-InGaAs bulk and double-quantum-well interband tunnel heterojunctions are simulated rigorously using the nonequilibrium Green's function formalism for coherent and dissipative quantum transport in combination with a simple two-band tight-binding model for the electronic structure. A realistic band profile and the associated built-in electrostatic field are obtained via self-consistent coupling of the transport formalism to Poisson's equation. The model reproduces experimentally observed features in the current-voltage characteristics of the devices, such as the pronounced current enhancement in the quantum-well junction as compared to the bulk junction and the structure appearing in the negative-differential resistance regime due to quantization of emitter states. Local maps of density of states and the current spectrum reveal the impact of quasibound states, electric fields, and electron-phonon scattering on the interband tunneling current. In this way, resonances appearing in the current through the double-quantum-well structure in the negative-differential resistance regime can be related to the alignment of subbands in the coupled quantum wells.

U. Aeberhard

2013-02-05T23:59:59.000Z

214

First-cut design of an all-superconducting 100-T direct current magnet  

SciTech Connect (OSTI)

A 100-T magnetic field has heretofore been available only in pulse mode. This first-cut design demonstrates that a 100-T DC magnet (100?T) is possible. We base our design on: Gadolinium-based coated superconductor; a nested-coil formation, each a stack of double-pancake coils with the no-insulation technique; a band of high-strength steel over each coil; and a 12-T radial-field limit. The 100?T, a 20?mm cold bore, 6-m diameter, 17-m height, with a total of 12?500-km long superconductor, stores an energy of 122 GJ at its 4.2-K operating current of 2400?A. It requires a 4.2-K cooling power of 300?W.

Iwasa, Yukikazu, E-mail: iwasa@jokaku.mit.edu; Hahn, Seungyong [Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139 (United States)] [Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139 (United States)

2013-12-16T23:59:59.000Z

215

Low voltage vertical recording preamplifier for hard disk drives  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . 4 2 Input drivers of the preamplifier along with the decoupling caps and parasitics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Voltage bias voltage sensing scheme . . . . . . . . . . . . . . . . . . . 8 4 Current bias current... sensing scheme . . . . . . . . . . . . . . . . . . 9 5 Current bias scheme which common mode sense voltage to DE . . . . 10 6 Decoupling the inputs of the differential pair using feedback . . . . . 11 7 Barkhausen noise...

Mellachervu, Ramachandra Murthy

2004-11-15T23:59:59.000Z

216

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

217

Current status, architecture, and future directions for the international space station electric power system  

SciTech Connect (OSTI)

The Electric Power System (EPS) on the International Space Station Alpha has undergone several significant changes over the last year, as major design decisions have been made for the overall station. While the basic topology and system elements have remained as they were under the Freedom program, there are important differences in connectivity, assembly sequence, and start-up. The key drivers for these changes in architecture have been the goal to simplify verification, and most significantly, the introduction of extensive Russian participation in the program. Having the Russians join the international community in this project has resulted in an expanded station size, larger crew, and almost doubled the observable surface of the earth covered by the station. For the power system it has meant additional interfaces for power transfer, and new challenges for solar tracking at the higher inclination orbit. This paper reviews the current architecture and emphasizes the new features that have evolved, as the design for the new, larger station has developed. Additionally, the possible application of developing technology to the station, and other future missions is considered.

Gholdston, E.; Hartung, J.; Friefeld, J. [Rockwell International, Canoga Park, CA (United States). Rocketdyne Division

1995-12-31T23:59:59.000Z

218

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

219

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

Broader source: Energy.gov [DOE]

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.

220

Self consistent radio-frequency wave propagation and peripheral direct current plasma biasing: Simplified three dimensional non-linear treatment in the 'wide sheath' asymptotic regime  

SciTech Connect (OSTI)

A minimal two-field fluid approach is followed to describe the radio-frequency (RF) wave propagation in the bounded scrape-off layer plasma of magnetic fusion devices self-consistently with direct current (DC) biasing of this plasma. The RF and DC parts are coupled by non-linear RF and DC sheath boundary conditions at both ends of open magnetic field lines. The physical model is studied within a simplified framework featuring slow wave (SW) only and lateral walls normal to the straight confinement magnetic field. The possibility is however kept to excite the system by any realistic 2D RF field map imposed at the outer boundary of the simulation domain. The self-consistent RF + DC system is solved explicitly in the asymptotic limit when the width of the sheaths gets very large, for several configurations of the RF excitation and of the target plasma. In the case of 3D parallelepipedic geometry, semi-analytical results are proposed in terms of asymptotic waveguide eigenmodes that can easily be implemented numerically. The validity of the asymptotic treatment is discussed and is illustrated by numerical tests against a quantitative criterion expressed from the simulation parameters. Iterative improvement of the solution from the asymptotic result is also outlined. Throughout the resolution, key physical properties of the solution are presented. The radial penetration of the RF sheath voltages along lateral walls at both ends of the open magnetic field lines can be far deeper than the skin depth characteristic of the SW evanescence. This is interpreted in terms of sheath-plasma wave excitation. Therefore, the proper choice of the inner boundary location is discussed as well as the appropriate boundary conditions to apply there. The asymptotic scaling of various quantities with the amplitude of the input RF excitation is established.

Colas, L.; Jacquot, J.; Hillairet, J.; Goniche, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Heuraux, S.; Faudot, E. [IJL-P2M UMR 7198 CNRS, F-54506 Vandoeuvre les Nancy (France); Crombe, K. [Department of Applied Physics, Ghent University, B-9000 Ghent (Belgium); Kyrytsya, V. [LPP-ERM/KMS, Association Euratom-'Belgian State', TEC Partner, Brussels (Belgium)

2012-09-15T23:59:59.000Z

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.


221

Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe  

SciTech Connect (OSTI)

This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core.

Prevosto, L.; Mancinelli, B. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina)] [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina) [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600) Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina)

2013-12-15T23:59:59.000Z

222

Modulated voltage metastable ionization detector  

SciTech Connect (OSTI)

Metastable ionization detectors used for chromatographic analysis usually employa fixed high voltage for the ionization potential. For this reason, the operating range is limited to about three orders of magnitude. By use of the technique disclosed in the instant invention, operating ranges of about nine orders of magnitude are obtained. The output current from a metastable ionization detector (MID) is applied to a modulation voltage circuit. An adjustment is made to balance out the background current, and an output current, above background, is applied to an input of a strip chart recorder. For low level concentrations, i.e., low detected output current, the ionization potential will be at a maximum and the metastable ionization detector will operate at its most sensitive level. When the detected current from the metastable ionization detector increases above a predetermined threshold level, a voltage control circuit is activated which turns on a high voltage transistor which acts to reduce the ionization potential. The ionization potential applied to the metastable ionization detector is then varied so as to maintain the detected signal level constant. The variation in ionization potential is now related to the concentration fo the constituent and a representative amplitude is applied to another input of said strip chart recorder.

Carle, G. C.; Humphry, D. E.; Kojiro, D. R.

1985-08-27T23:59:59.000Z

223

Ignition distributor voltage generator  

SciTech Connect (OSTI)

This patent describes a voltage pulse generator and ignition distributor comprising, a base, a shaft rotatably supported by the base, a distributor cap supported by the base having a center electrode and circumferentially spaced outer electrodes. The pulse generator and ignition distribution also include a first rotor driven by the shaft formed of electrical insulating material having electrically conductive means connected to the center terminal and a portion that rotates past the outer electrodes. The portion of the electrically conductive means that rotates past the outer electrodes is spaced from the outer electrodes to form a gap therebetween. A voltage pulse generator comprises a second rotor driven by the shaft, at least one permanent magnet and an annular pickup coil supported by the base. The pickup coil has inner turns and outer turns, the beginning turn of the inner turns connected to a first lead and the last turn of the outer turns connected to a second lead, the outer turns enclosing the inner turns. The pickup coil also has a circuit connected directly between the second lead and ground which is operative to provide a direct conductive path to ground for high frequency energy capacitively coupled to the outer turns from the gap discharge between the electrically conductive means of the first rotor and an outer electrode, the outer turns forming a grounded shield for the inner turns.

Boyer, J.A.

1986-11-04T23:59:59.000Z

224

HVDC Connected Offshore Wind Power Plants: Review and Outlook of Current Research  

E-Print Network [OSTI]

HVDC Connected Offshore Wind Power Plants: Review and Outlook of Current Research Jakob Glasdam-of-the-art review on grid integration of large offshore wind power plants (OWPPs) using high voltage direct voltage is to acquire in- depth knowledge of relevant operating phenomena in the offshore OWPP grid, rich with power

Bak, Claus Leth

225

Study on reduction in electric field, charged voltage, ion current and ion density under HVDC transmission lines by parallel shield wires  

SciTech Connect (OSTI)

An important problem in the design and operation of HVDC transmission lines is to reduce electrical field effects such as ion flow electrification of objects, electric field, ion current and ion density at ground level in the vicinity of HVDC lines. Several models of shield wire were tested with the Shiobara HVDC test line. The models contain typical stranded wires that are generally used to reduce field effects at ground level, neutral conductors placed at lower parts of the DC line, and an ''earth corona model'' to cancel positive or negative ions intentionally by generating ions having opposite polarity to ions flowing into the wire. This report describes the experimental results of the effects of these shield wires and a method to predict shielding effects.

Amano, Y.; Sunaga, Y.

1989-04-01T23:59:59.000Z

226

Wind Power Plant Voltage Stability Evaluation: Preprint  

SciTech Connect (OSTI)

Voltage stability refers to the ability of a power system to maintain steady voltages at all buses in the system after being subjected to a disturbance from a given initial operating condition. Voltage stability depends on a power system's ability to maintain and/or restore equilibrium between load demand and supply. Instability that may result occurs in the form of a progressive fall or rise of voltages of some buses. Possible outcomes of voltage instability are the loss of load in an area or tripped transmission lines and other elements by their protective systems, which may lead to cascading outages. The loss of synchronism of some generators may result from these outages or from operating conditions that violate a synchronous generator's field current limit, or in the case of variable speed wind turbine generator, the current limits of power switches. This paper investigates the impact of wind power plants on power system voltage stability by using synchrophasor measurements.

Muljadi, E.; Zhang, Y. C.

2014-09-01T23:59:59.000Z

227

Implications of Pulser Voltage Ripple  

SciTech Connect (OSTI)

In a recent set of measurements obtained by G. Kamin, W. Manning, A. Molvik, and J. Sullivan, the voltage waveform of the diode pulser had a ripple of approximately {+-}1.3% of the 65 kV flattop voltage, and the beam current had a larger corresponding ripple of approximately {+-}8.4% of the 1.5 mA average current at the location of the second Faraday cup, approximately 1.9 m downstream from the ion source. The period of the ripple was about 1 {mu}s. It was initially unclear whether this large current ripple was in fact a true measurement of the current or a spurious measurement of noise produced by the pulser electronics. The purpose of this note is to provide simulations which closely match the experimental results and thereby corroborate the physical nature of those measurements, and to provide predictions of the amplitude of the current ripples as they propagate to the end of linear transport section. Additionally analytic estimates are obtained which lend some insight into the nature of the current fluctuations and to provide an estimate of what the maximum amplitude of the current fluctuations are expected to be, and conversely what initial ripple in the voltage source is allowed, given a smaller acceptable tolerance on the line charge density.

Barnard, J J

2011-12-21T23:59:59.000Z

228

ABBGroup-1-High voltage lab  

E-Print Network [OSTI]

A DISTRIBUTION MEDIUM AND LOW VOLTAGE HV circuit breakers #12;©ABBGroup-4- 3-Sep-07 When a breaker fails to interrupt the current... Fault arc at a disconnector Fault arc in a substation #12;©ABBGroup-5- 3-Sep-07/costs A detailed understanding of arc physics and fluid dynamics is necessary for the development of HV circuit

Basse, Nils Plesner

229

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

230

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

231

Theoretical investigation of the effect of hydrogen addition on the formation and properties of soliton in direct current argon plasma  

SciTech Connect (OSTI)

In this study the effect of hydrogen addition on the formation and properties of soliton in direct-current (DC) argon plasma is theoretically investigated. By coupling fluid equations with Poisons equation for such multi-component plasma, the Mach number and amplitude of the soliton are determined following pseudo potential method. Addition of hydrogen in argon discharge leads to the decrease of electron, Ar{sup +} ion density while a reverse trend was observed for ArH{sup +} and hydrogen like ions. It was found that presence of hydrogen like ions in argon plasma affects the formation of soliton with its amplitude significantly decreases as concentration of hydrogen increases. On the other hand, increase in ion to electron temperature ratios of the lighter ions in the discharge also has a significant influence on the amplitude and formation of soliton. The inverse relation between solitons width and amplitude is found to be consistent for the entire range of study.

Saikia, P., E-mail: partha.008@gmail.com; Goswami, K. S.; Saikia, B. K. [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur, Kamrup, Assam-782 402 (India)] [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur, Kamrup, Assam-782 402 (India)

2014-03-15T23:59:59.000Z

232

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

233

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

234

Ancillary service details: Voltage control  

SciTech Connect (OSTI)

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

235

Current balancing for battery strings  

DOE Patents [OSTI]

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

236

Lowering of the firing voltage and reducing of the discharge delay time in alternating current plasma display panels by a discontinuous spin-coated LaB{sub 6} film on the MgO protective layer  

SciTech Connect (OSTI)

A spin coated LaB{sub 6} discontinuous film is covered on MgO protective layer to improve the discharge performance of alternating current plasma display panels. Under the premise of high transmittance of more than 90%, a very small amount of polycrystal LaB{sub 6} powders added in an organic solvent are chosen as the coating solution. The discharge characteristics results show that with 250 torr 5% Xe-Ne pressure, the firing voltage and discharge delay time of the test panel with LaB{sub 6}/MgO double protective layer are decreased by 13.4% and 36.5%, respectively, compared with that of conventional MgO protective layer, likely owing to the low work function of LaB{sub 6.} Furthermore, the aging time of the proposed structure is comparable to that of pure MgO protective layer. Therefore, it will not increase the production costs and is highly suitable to be applied for alternating current plasma display panels with low electrical power consumption.

Deng, Jiang, E-mail: dj78291@163.com [School of Physical Electronic, University of Electronic Science and Technology of China, No.4, Section 2, Jianshe North Road, 610054 Chengdu (China)] [School of Physical Electronic, University of Electronic Science and Technology of China, No.4, Section 2, Jianshe North Road, 610054 Chengdu (China); Zeng, Baoqing [School of Physical Electronic, University of Electronic Science and Technology of China, No.4, Section 2, Jianshe North Road, 610054 Chengdu (China) [School of Physical Electronic, University of Electronic Science and Technology of China, No.4, Section 2, Jianshe North Road, 610054 Chengdu (China); Zhongshan Institute, University of Electronic Science and Technology of China, 528402 zhongshan (China); Wang, Xiaoju; Lin, Zulun; Qi, Kangcheng; Cao, Guichuan [School of Opto-electronic Information, University of Electronic Science and Technology of China, No.4, Section 2, Jianshe North Road, 610054 Chengdu (China)] [School of Opto-electronic Information, University of Electronic Science and Technology of China, No.4, Section 2, Jianshe North Road, 610054 Chengdu (China)

2014-03-15T23:59:59.000Z

237

Study of the Stability of a Direct Stator Current Controller for a Doubly-Fed Induction Machine using the Complex  

E-Print Network [OSTI]

to renewable energy (wind farms in particular). The proposed control algorithm offers the advantages of proven large speed variations around the synchronous speed. Another advantage is that the power electronic voltage is adopted. This uncommon approach allows for a decomposition of the active and reactive powers

Batlle, Carles

238

Direct and indirect capture of carriers into the lasing ground state and the light-current characteristic of quantum dot lasers  

SciTech Connect (OSTI)

We calculate the light-current characteristic (LCC) of a quantum dot (QD) laser under the conditions of both direct and indirect capture of carriers from the optical confinement layer into the lasing ground state in QDs. We show that direct capture is a dominant process determining the ground-state LCC. Only when direct capture is slow, the role of indirect capture (capture into the QD excited state and subsequent intradot relaxation to the ground state) becomes important.

Wu, Yuchang, E-mail: yuchangw@vt.edu; Asryan, Levon V., E-mail: asryan@vt.edu [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)

2014-03-14T23:59:59.000Z

239

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

240

Comparisons of complex network based models and direct current power flow model to analyze power grid vulnerability under intentional attacks  

Science Journals Connector (OSTI)

Abstract Many scholars have applied complex network based models to investigate power grid vulnerability, but how effective are these models to capture the real performance is an interesting topic. This paper selects two typical complex network based models, including a purely topological model (PTM) and a betweenness based model (BBM), as well as a direct current power flow model (DCPFM), to simulate the topology-based and flow-based vulnerability of power grid under degree, betweenness, maximum traffic and importance based intentional attacks. The relationships of vulnerability results from different models are analyzed and discussed for model comparisons. Taking IEEE 300 power grid with line capacity set proportional to tolerant parameter tp as example, the results show that there exists a critical node attack intensity A I = 0.147 , above which the three models produce almost identical topology-based vulnerability results under each attack strategy at any t p ? 1 , while producing identical flow-based vulnerability results from PTM and DCPFM occurs at A I > 0.147 , and A I > 0.73 for BBM and DCPFM, which indicates that the PTM can better approach the DCPFM for flow-based vulnerability analysis under intentional attacks. Similar results are also found for intentional edge attacks and other power grids.

Min Ouyang; Lijing Zhao; Zhezhe Pan; Liu Hong

2014-01-01T23:59:59.000Z

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.


241

The Matrix Converter Drive Performance Under Abnormal Input Voltage Conditions  

E-Print Network [OSTI]

that generates variable magnitude variable frequency output voltage from the ac utility line. It has high power voltage disturbance related performance issues of the MC drive. Since the MC is a direct frequencyThe Matrix Converter Drive Performance Under Abnormal Input Voltage Conditions Jun-Koo Kang

Hava, Ahmet

242

Low voltage operation of plasma focus  

Science Journals Connector (OSTI)

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 ? ? 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 focusinductance. 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.

Rohit Shukla; S. K. Sharma; P. Banerjee; R. Das; P. Deb; T. Prabahar; B. K. Das; B. Adhikary; A. Shyam

2010-01-01T23:59:59.000Z

243

Comparisons of purely topological model, betweenness based model and direct current power flow model to analyze power grid vulnerability  

Science Journals Connector (OSTI)

This paper selects three frequently used power grid models including a purely topological model (PTM) a betweennness based model (BBM) and a direct current power flow model (DCPFM) to describe three different dynamical processes on a power grid under both single and multiple component failures. Each of the dynamical processes is then characterized by both a topology-based and a flow-based vulnerability metrics to compare the three models with each other from the vulnerability perspective. Taking as an example the IEEE 300 power grid with line capacity set proportional to a tolerance parameter tp the results show non-linear phenomenon: under single node failures there exists a critical value of tp?=?1.36 above which the three models all produce identical topology-based vulnerability results and more than 85% nodes have identical flow-based vulnerability from any two models; under multiple node failures that each node fails with an identical failure probability fp there exists a critical fp?=?0.56 above which the three models produce almost identical topology-based vulnerability results at any tp???1 but producing identical flow-based vulnerability results only occurs at fp?=?1. In addition the topology-based vulnerability results can provide a good approximation for the flow-based vulnerability under large fp and the priority of PTM and BBM to better approach the DCPFM for vulnerability analysis mainly depends on the value of fp. Similar results are also found for other failure types other system operation parameters and other power grids.

2013-01-01T23:59:59.000Z

244

Analysis of Lightning-induced Voltages in Overhead Transmission Lines  

Science Journals Connector (OSTI)

Abstract In this work we study the coupling of lightning induced voltages in Overhead Transmission Lines .The study is led directly in the time domain with hold in account the effect of a finite conductivity of the soil. After discretization by the method so-called FDTD (Finite Difference Time Domain) of the lines equations excited by a lightning wave and the application in every node of the network in current and voltage, we deduct a equations system, of which the resolution permits us to deduct the induced electric quantities in every node of the network. In order to confirm our theoretical work, we present a set of applications that allows validating this study.

Mostefa. Boumaiza; Djamel. Labed

2014-01-01T23:59:59.000Z

245

Method of detecting the direction of arcing faults on power distribution feeders  

E-Print Network [OSTI]

of overcurrent relays, which Journal model is IEEE transactions on Power Delivery is required for distribution system reliability. The traveling wave directionality al- gorithms also require fairly substantial change in voltage for proper operation... is of significant magnitude to cause a current reversal in the case of a reverse fault [18]. 2. Traveling Wave Relaying The need for more accurate and fast detection of fault and direction of very high voltage transmission lines, was the base of invention...

Fernando, W. Anand Krisantha

2012-06-07T23:59:59.000Z

246

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

247

Currently, there is a substantial research and development effort directed toward optical signal processing and electronic signal processing for fiber-optic communications. Much of the work  

E-Print Network [OSTI]

Abstract Currently, there is a substantial research and development effort directed toward optical signal processing and electronic signal processing for fiber-optic communications. Much of the work for telecommunication services. For optical signal proc- essing, a variety of approaches are available for implementing

Wu, Shin-Tson

248

Constant voltage ultracapacitor  

Science Journals Connector (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 these converters typically do not operate if the voltage of the ultracapacitor drops below 1?V. In addition DC-DC converters suffer from well-known size/efficiency tradeoffs. This paper introduces a novel new ultracapacitor that is characterized by constant voltage. The new ultracapacitor does not utilize familiar energy conversion principles. Rather operation depends on an embedded electromechanical system that actually alters the capacitance of the ultracapacitor as the device is discharged. Due to a simple proportionality relationship between charge capacitance and voltage the voltage remains constant. Theoretical and experimental investigations have shown that the embedded mechanism for altering the capacitance has an efficiency of 99% or higher.

Ezzat G. Bakhoum

2012-01-01T23:59:59.000Z

249

Voltage balanced multilevel voltage source converter system  

DOE Patents [OSTI]

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

250

Voltage balanced multilevel voltage source converter system  

DOE Patents [OSTI]

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

251

Substation voltage upgrading  

SciTech Connect (OSTI)

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

252

Electro-optical voltage sensor head  

DOE Patents [OSTI]

A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

Woods, Gregory K. (Idaho Falls, ID)

1998-01-01T23:59:59.000Z

253

Abstract--Circuit breakers are crucial components for power system operation. The currently adapted time-directed  

E-Print Network [OSTI]

1 Abstract--Circuit breakers are crucial components for power system operation. The currently be This work was supported in part by Mitsubishi Electric Research Laboratories and PSerc consortium, an NSF I used to select the most appropriate maintenance strategy. During the maintenance or repair work

254

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

255

Graz University of Technology Institute of High Voltage Engineering and System Performance  

E-Print Network [OSTI]

.hspt@tugraz.at u www.hspt.tugraz.at Institute of High Voltage Engineering and System Performance Test Laboratory systems Test of insulators, fittings and accessories Testing of high voltage equipment Impulse voltage and current tests On-site-test of medium voltage cables Electrical methods in environmental technology

256

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

257

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

258

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

259

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

260

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

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

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

SciTech Connect (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

262

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

263

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

264

Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants  

SciTech Connect (OSTI)

Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media monitoring, and/or personal exposure modeling. However, emerging research reveals that the greatest progress comes from integration among two or more of these efforts.

McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

2007-02-01T23:59:59.000Z

265

High-voltage engineering  

E-Print Network [OSTI]

High-voltage engineering covers the application, the useful use and proper working of high voltages and high fields. Here we give some introductory examples, i.e., ‘septa’ and ‘kicker’ at the Large Hadron Collider (14 TeV), the Super Proton Synchrotron (450 GeV) and the Proton Synchrotron (26 GeV) accelerators as found at the European Orginization for Nuclear Research (CERN) today. We briefly cover the theoretical foundation (Maxwell equations) and aspects of numerical field simulation methods. Concepts relating to electrical fields, insulation geometry and medium and breakdown are introduced. We discuss ways of generating high voltages with examples of AC sources (50/60 Hz), DC sources, and pulse sources. Insulation and breakdown in gases, liquids, solids and vacuum are presented, including Paschen’s law (breakdown field and streamer breakdown). Applications of the above are discussed, in particular the general application of a transformer. We briefly discuss measurement techniques of partial disch...

Gaxiola, E

2006-01-01T23:59:59.000Z

266

Low voltage ride-through capability improvement of DFIG-based wind turbines under unbalanced voltage dips  

Science Journals Connector (OSTI)

Abstract This paper proposes a competent and effective scheme to enhance the ride-through capability of DFIG-based wind turbines under unbalanced voltage dip conditions. The proposed method is realized through joint use of the rotor-side converter control and a three-phase stator damping resistor (SDR) placed in series with the stator windings. By means of an asymmetrical SDR idea, during the unbalanced voltage dip the SDR resistors are activated only in phase(s) experiencing low voltage. Then, the rotor current is controlled such that no unbalance voltage appears on the stator voltage. The proposed ride-through approach limits the peak values of the rotor inrush current, electromagnetic torque and DFIG transient response at the times of occurrence and clearing the fault. It also suppresses fluctuation of the electromagnetic torque and DFIG transient response appeared during unbalanced voltage dips due to negative sequence component.

Mohsen Rahimi; Mostafa Parniani

2014-01-01T23:59:59.000Z

267

Measurement of high voltage using Rutherford backscattering spectrometry  

E-Print Network [OSTI]

A novel variation of Rutherford Backscattering Spectrometry (RBS) has been utilized to measure a high voltage collected on an aluminum target by Direct Energy Conversion. The maximum high voltage on the target was measured to be 97.5 kV +/- 2 kV...

Abrego, Celestino Pete

2007-04-25T23:59:59.000Z

268

Low resistivity Ga-doped ZnO thin films of less than 100 nm thickness prepared by ion plating with direct current arc discharge  

SciTech Connect (OSTI)

Low resistivity Ga-doped ZnO films were prepared on a glass substrate by ion plating with direct current arc discharge. Thickness dependent changes in the electrical properties of the films are reported, focusing on the thin films of less than 100 nm thickness. Structural analyses showed that the thinnest film of 30 nm thickness consists of well-oriented columnar grains normal to the substrate, and the resistivity was as low as 4.4x10{sup -4} {omega} cm. The changes in lattice strain and c-axis fluctuation with the growth of grains are also shown to be associated with the electrical properties.

Yamada, Takahiro; Miyake, Aki; Kishimoto, Seiichi; Makino, Hisao; Yamamoto, Naoki; Yamamoto, Tetsuya [Kochi University of Technology, 185, Miyanokuchi, Tosayamada, Kami, Kochi 782-8502 (Japan)

2007-07-30T23:59:59.000Z

269

Electro-optic voltage sensor for sensing voltage in an E-field  

DOE Patents [OSTI]

A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

Woods, Gregory K. (Idaho Falls, ID); Renak, Todd W. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

270

Design and applications of a flicker voltage generator  

SciTech Connect (OSTI)

In this paper, a 200W flicker voltage generator is made by using microcomputers and linear amplification circuits. The modulation amplitudes and frequencies based on the UIE {Delta}V{sub 10} evaluation can be arbitrarily assigned by software with high accuracy. The flicker voltage signals measured at the customer side also can be re-generated. Some applications, such as evaluating the effects of flicker voltage on incandescent and compact fluorescent lamps (CFLs), are also made. From experimental tests by use of the flicker voltage generator, the properties of some compact fluorescent lamps and incandescent lamps are compared. Those properties describe the relation between input voltage variation and output flux of lamps, such that there is direct description of influences of flicker voltages on lamps.

Chang, W.N.; Wu, C.J. [National Taiwan Inst. of Tech., Peitow-Taipei (Taiwan, Province of China). Dept. of Electrical Engineering

1995-12-31T23:59:59.000Z

271

Joule heating generated by spin current through Josephson junctions  

SciTech Connect (OSTI)

We theoretically study the spin-polarized current flowing through a Josephson junction (JJ) in a spin injection device. When the spin-polarized current is injected from a ferromagnet in a superconductor (SC), the charge current is carried by the superconducting condensate (Cooper pairs), while the spin-up and spin-down currents flow in equal magnitude but in the opposite direction in a SC, because of no quasiparticle charge current in the SC. This indicates that not only the Josephson current but also the spin current flow across JJ at zero bias voltage, thereby generating Joule heating by the spin current. The result provides a new method for detecting the spin current by measuring Joule heating at JJ. {copyright} 2001 American Institute of Physics.

Takahashi, S.; Yamashita, T.; Koyama, T.; Maekawa, S.; Imamura, H.

2001-06-01T23:59:59.000Z

272

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

273

OMNI SMARTPUMP: DIRECT CURRENT POWERED  

E-Print Network [OSTI]

completed grant projects. The purpose of the FAR is to provide a concise summary and independent assessment Program, please visit the Commission's Web site at http://www.energy.ca.gov/research/index.html. #12;Page

274

Direct current power transmission systems  

SciTech Connect (OSTI)

This book represents text on HVDC transmission available. It deals with the various aspects of the state of the art in HVDC transmission technology. This book presents many aspects of interactions of AC/DC systems. Modeling and analysis of DC systems are also discussed in detail.

Padiyar, K.R.

1991-01-01T23:59:59.000Z

275

High-voltage supply for backward-wave tube  

SciTech Connect (OSTI)

A high-current high-voltage supply for a backward-wave tube is described that uses a generalppurpose semiconductor converter with pulse-width modulation and two-stage regulation. The load current is up to 250 mA for load voltages of from 0.5 to 4.5 kV. The voltage staiblity is less than or equal to 5 x 10/sup -6/. the root-mean-square output ripple is less than or equal to 2 x 10/sup -6// The supply is equipped with high-speed (5 usec) load-breakdown protection.

Bryvkhanov, A.N.; Kosarev, P.M.; Latushkin, S.T.; Yudin, L.I.

1986-04-01T23:59:59.000Z

276

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

277

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

SciTech Connect (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

February 2008 Rev 21 1/49 Very low drop voltage regulators with inhibit  

E-Print Network [OSTI]

. In the three terminal configuration the device has the same electrical performance, but is fixed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 4. Dropout voltage vs output current

Berns, Hans-Gerd

280

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

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

Transient recovery voltage considerations in the application of medium voltage circuit breakers  

SciTech Connect (OSTI)

Medium Voltage Circuit Breakers can fail to interrupt 3-phase fault currents when power systems have Transient Recovery Voltage (TRV) characteristics which exceed the rating of the circuit breaker. This paper examines the application of 13.8kV generation and load switchgear for an oil refinery in which circuit parameters as originally designed would have exceeded the 13.8kV circuit breakers TRV ratings had corrective measures not been taken. This paper illustrates this case and discusses the basis of TRV, how TRV is assessed, and alternative actions taken to bring circuits to within the 13.8 kV circuit breaker ratings.

Swindler, D.L.; Schwartz, P.; Hamer, P.S.; Lambert, S.R.

1995-12-31T23:59:59.000Z

282

Substation voltage upgrading  

SciTech Connect (OSTI)

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

283

Design & Fabrication of a High-Voltage Photovoltaic Cell  

SciTech Connect (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

284

Inverter Using Current Source Topology  

Broader source: Energy.gov (indexed) [DOE]

of the new current-fed Trans-ZSI with wider motoring operation range V in 100 V, transformer turns ratio2 * Comparison of voltage boost ratio vs. duty ratio D A New...

285

LM111/LM211/LM311 Voltage Comparator  

E-Print Network [OSTI]

LM111/LM211/LM311 Voltage Comparator 1.0 General Description The LM111, LM211 and LM311 are voltage comparators that have input currents nearly a thousand times lower than devices like the LM106 or LM710A. Both the inputs and the outputs of the LM111, LM211 or the LM311 can be isolated from system ground

Lanterman, Aaron

286

Bias current influence on the characteristic of the magnetic-controlled switcher type fault current limiter  

Science Journals Connector (OSTI)

A novel magnetic-controlled switcher type fault current limiter (FCL) for high voltage electric network is presented. The current limiting principle of the FCL and the bias current influence on the characteristic...

Yan-xia Pan ???; Jian-guo Jiang ???

2009-06-01T23:59:59.000Z

287

Temperature controlled high voltage regulator  

DOE Patents [OSTI]

A temperature controlled high voltage regulator for automatically adjusting the high voltage applied to a radiation detector is described. The regulator is a solid state device that is independent of the attached radiation detector, enabling the regulator to be used by various models of radiation detectors, such as gas flow proportional radiation detectors.

Chiaro, Jr., Peter J. (Clinton, TN); Schulze, Gerald K. (Knoxville, TN)

2004-04-20T23:59:59.000Z

288

Threshold voltage extraction circuit  

E-Print Network [OSTI]

=Vos* (point of inflection in t/In-V&s), the drain current flowing in M2 and Ml would correspond to the square-law current equation of In; ? (kp/2);(W/L)i (Vcs; ? Vr) . (17) Thus, 4Im = Im and t/Inz/VIm ? 0. 5. By plotting the graph of ratio t... can also be expressed as VGS2 VGS/ slope = ~ (4) Let 4~ = I then t//t ? 2I, then by equating (3) and (4), Vr can be obtained with a simple expression as Vr = 2Vost ? Vcr. Linear Extrapolation Method This method is similar...

Hoon, Siew Kuok

2012-06-07T23:59:59.000Z

289

Electric Currents Electric Current  

E-Print Network [OSTI]

coefficient of resistivity Electric Power: = = = Also, = . So, = = 2 = 2 Unit of Power(P): Watt (WChapter 18 Electric Currents #12;Electric Current: Flow of electric charge Current is flow of positive charge. In reality it's the electron moves in solids- Electron current. #12;Ohm's Law : Resistance

Yu, Jaehoon

290

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.

291

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

292

Saving Megawatts with Voltage Optimization  

E-Print Network [OSTI]

that had been installed at several electric utility distribution substations in the U.S. and Canada. These systems, being operated in Conservation Voltage Regulation mode, have provided significant energy conservation where they have been installed...

Wilson, T.; Bell, D.

2010-01-01T23:59:59.000Z

293

Kirchhoff voltage law corrected for radiating circuits  

E-Print Network [OSTI]

When a circular loop composed by a RLC is put to oscillate, the oscillation will eventually vanish in an exponentially decaying current, even considering superconducting wires, due to the emission of electric and magnetic dipole radiation. In this work we propose a modification on the Kirchhoff voltage law by adding the radiative contributions to the energy loss as an effective resistance, whose value is relatively small when compared to typical resistance value, but fundamental to describe correctly real circuits. We have also analysed the change in the pattern of the radiation spectra emitted by the circuit as we vary both the effective and electrical resistance.

Lara, Vitor

2014-01-01T23:59:59.000Z

294

Voltage Regulator Chip: Power Supplies on a Chip  

SciTech Connect (OSTI)

ADEPT Project: CPES at Virginia Tech is finding ways to save real estate on a computer's motherboard that could be used for other critical functions. Every computer processor today contains a voltage regulator that automatically maintains a constant level of electricity entering the device. These regulators contain bulky components and take up about 30% of a computer's motherboard. CPES at Virginia Tech is developing a voltage regulator that uses semiconductors made of gallium nitride on silicon (GaN-on-Si) and high-frequency soft magnetic material. These materials are integrated on a small, 3D chip that can handle the same amount of power as traditional voltage regulators at 1/10 the size and with improved efficiency. The small size also frees up to 90% of the motherboard space occupied by current voltage regulators.

None

2010-09-01T23:59:59.000Z

295

The Effect of Offcut Angle on Electrical Conductivity of Direct Wafer-Bonded n-GaAs/n-GaAs Structures for Wafer-Bonded Tandem Solar Cells  

E-Print Network [OSTI]

9: Current vs voltage for various electrical test points of9. Current vs voltage for various electrical test points ofvs voltage (J-V) curves in Figure 11. Our observations indicated that sulfur passivation improves the electrical

Yeung, King Wah Sunny

2012-01-01T23:59:59.000Z

296

Accurately measuring current-voltage characteristics of tunnel diodes  

E-Print Network [OSTI]

nanoelectronics and optoelectronics, spintronics, MBE andand millimeter electronics/optoelectronics, and quantum

Bao, Mingqiang; Wang, Kang L

2006-01-01T23:59:59.000Z

297

Determination of the inductance of imploding wire array Z-pinches using measurements of load voltage  

SciTech Connect (OSTI)

The inductance of imploding cylindrical wire array z-pinches has been determined from measurements of load voltage and current. A thorough analysis method is presented that explains how the load voltage of interest is found from raw signals obtained using a resistive voltage divider. This method is applied to voltage data obtained during z-pinch experiments carried out on the MAGPIE facility (1.4 MA, 240 ns rise-time) in order to calculate the load inductance and thereafter the radial trajectory of the effective current sheath during the snowplough implosion. Voltage and current are monitored very close to the load, allowing these calculations to be carried out without the need for circuit modelling. Measurements give a convergence ratio for the current of between 3.1 and 5.7 at stagnation of the pinch.

Burdiak, G. C.; Lebedev, S. V.; Hall, G. N.; Harvey-Thompson, A. J.; Suzuki-Vidal, F.; Swadling, G. F.; Khoory, E.; Pickworth, L.; Bland, S. N.; Grouchy, P. de; Skidmore, J. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)

2013-03-15T23:59:59.000Z

298

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

299

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

300

On the scaling of rf and dc self-bias voltages with pressure in electronegative capacitively coupled plasmas  

SciTech Connect (OSTI)

Higher gas densities and lower diffusion losses at higher operating pressures typically lead to increased charged species densities (and hence flux) for a constant power deposition in capacitively coupled plasmas (CCP). As a result, one would expect that the bias radio-frequency (rf) voltage required to deposit a given power in a CCP reactor decreases with increasing operating pressure. These observations may not hold true in multiple frequency CCPs, commonly used for dielectric etching in microelectronics fabrication, due to nonlinear interactions between the rf sources. Wafer-based measurements of the rf and self-generated direct current (dc) bias voltages in a dual-frequency capacitively coupled electronegative plasma were made, which indicate that the rf and dc voltages vary nonmonotonically with pressure. These experimental results are presented in this paper and a computational plasma model is used to explain the experimental observations for varying 60 MHz and 13 MHz powers in the Ar/CF{sub 4}/CHF{sub 3} plasma over a pressure range of 25 to 400 mTorr. The authors found that while the ion density increases with pressure, the increase is most dominant near the electrode with the high frequency source (60 MHz). The rf and dc bias voltages are ultimately influenced by both charged species density magnitudes and spatial profiles.

Agarwal, Ankur; Dorf, Leonid; Rauf, Shahid; Collins, Ken [Applied Materials Inc., 974 E. Arques Avenue, M/S 81312, Sunnyvale, California 94085 (United States)

2012-03-15T23:59:59.000Z

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.


301

A 90 µm × 64 µm 225 µW class-AB CMOS differential flipped voltage follower with output driving capability up to 100 pF  

Science Journals Connector (OSTI)

A compact differential flipped voltage follower (DFVF) with low power consumption, capable to deliver currents several orders of magnitude larger than its quiescent current and with large capacitive loads is presented. In the proposed circuit, a current ... Keywords: Analog CMOS, Current comparators, Current conveyors, Flipped voltage followers, Winner-Takes-All circuits

C. Muñiz-Montero; L. A. Sánchez-Gaspariano; J. J. Camacho-Escoto; L. A. Villa-Vargas; H. Molina-Lozano; J. E. Molinar-Solís

2013-10-01T23:59:59.000Z

302

Voltage, energy and power in electric circuits  

E-Print Network [OSTI]

Voltage, energy and power in electric circuits Science teaching unit #12;Disclaimer The Department-2008DVD-EN Voltage, energy and power in electric circuits #12;#12;© Crown copyright 2008 1The National Strategies | Secondary Voltage, energy and power in electric circuits 00094-2008DVD-EN Contents Voltage

Berzins, M.

303

Thermal stability of Al- and Zr-doped HfO{sub 2} thin films grown by direct current magnetron sputtering  

SciTech Connect (OSTI)

Ultrathin HfO{sub 2} dielectric films doped with Al and Zr were grown on p-type Si(100) substrates by dc magnetron sputtering, and their microstructural and electrical properties were examined. Compositions and chemical states of the dielectric films were analyzed by Rutherford backscattering spectrometry and x-ray photoelectron spectroscopy. The HfO{sub 2} films doped with Zr were crystallized even from the as-deposited state, however, the crystallization temperature of the HfO{sub 2} film doped with 16% Al{sub 2}O{sub 3} was delayed up to 900 deg. C. As the annealing temperature increases, high-resolution transmission electron microscopy analyses of all doped HfO{sub 2} films showed an increase of the interfacial layer thickness due to the diffusion of small partial pressure of oxygen in annealing ambient. Our results also showed that the addition of Al{sub 2}O{sub 3} to 14% is not useful for blocking the oxygen diffusion through the (HfO{sub 2}){sub 0.86}(Al{sub 2}O{sub 3}){sub 0.14} film. From the capacitance-voltage measurements, the dielectric constants of the Al- and Zr-doped HfO{sub 2} thin films were measured to be 18.7 and 7.6, respectively.

Hong, Yeong-Eui; Kim, Yong-Seok; Do, Kihoon; Lee, Dongwon; Ko, Dae-Hong; Ku, Ja-Hum; Kim, Hyoungsub [Department of Ceramic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-749 (Korea, Republic of); Semiconductor R and D Division, Samsung Electronics Co, Ltd., San no. 24, Nongseo-Ri, Kiheung-Eup, Yongin-City, Kyunggi-Do 449-711 (Korea, Republic of); Department of Advanced Materials Engineering, Sungkyunkwan University, 300 Chunchun-Dong, Jangan-Ku, Suwon 440-746 (Korea, Republic of)

2005-09-15T23:59:59.000Z

304

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

305

Power and Voltage Smooth Control of Doubly Fed Induction Generator  

Science Journals Connector (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

306

Trace Analysis and Speciation for Cr(VI) and Cr(III) via HPLC-Direct Current Plasma Emission Spectroscopy (HPLC-DCP)  

Science Journals Connector (OSTI)

......chromium content, and were then free/e-dried prior to storage and preservation. It was this freeze-dried material that...current interests in possible chromium levels to be found in seawater and/or biological samples taken from the Georges Bank area......

I.S. Krull; K.W. Panaro; L.L. Gershman

1983-10-01T23:59:59.000Z

307

Integrating a Feature Selection Algorithm for Classification of Voltage Sags Originated in Transmission and Distribution Networks  

Science Journals Connector (OSTI)

As a global problem in the power quality area, voltage sags are matter of high interest for both utilities and customers. With a view to resolving the problem of sag source location in the power network, this paper introduces a new method based on dimension ... Keywords: Direction, Hybrid Method, Mpca, Voltage Sag

Abbas Khosravi; Toni Martinez; Joaquim Melendez; Joan Colomer; Jorge Sanchez

2007-06-01T23:59:59.000Z

308

LM193/LM293/LM393/LM2903 Low Power Low Offset Voltage Dual Comparators  

E-Print Network [OSTI]

LM193/LM293/LM393/LM2903 Low Power Low Offset Voltage Dual Comparators General Description The LM clock timers; multivibrators and high voltage digital logic gates. The LM193 series was designed to directly interface with TTL and CMOS. When operated from both plus and minus power supplies, the LM193

Lanterman, Aaron

309

Leakage resistance and current inferred from CDIF operating data  

SciTech Connect (OSTI)

Axial leakage current is difficult to measure directly. Spacial and temporal variations tend to cloud the interpretation of local measurements such as the current or voltage between any two neighboring electrodes. Also the measurement process itself tends to affect the result in an unpredictable manner. Therefore it is desireable to seek an indirect method that is based upon averages over a distance equivalent to one duct diameter or more, does not perturb the system, and is based upon data already collected. An indirect method is described here together with the results obtained when it is applied to nearly all CDIF runs. When correlated, the data suggest that leak current is primarily a function of Hall parameter and Faraday current while only weakly dependent upon axial field. Possible reasons for this discussed. 4 refs., 7 figs.

Rosa, R.J.

1990-01-01T23:59:59.000Z

310

Meter Any Wire, Anywhere by Virtualizing the Voltage Channel Thomas Schmid, David Culler, Prabal Dutta  

E-Print Network [OSTI]

Meter Any Wire, Anywhere by Virtualizing the Voltage Channel Thomas Schmid, David Culler, Prabal}@eecs.umich.edu culler@cs.berkeley.edu Abstract AC power meters require both voltage and current to be sampled physical proximity and fed into a single power metering de- vice. In this paper, we explore the viability

Dutta, Prabal

311

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

312

Reduction of interference on substation low voltage wiring  

SciTech Connect (OSTI)

This paper describes test results and mitigation methods of electromagnetic interference (EMI) on control and low voltage circuits in substations caused by air disconnect switch operation. The tests are focused on a comparison between unshielded and shielded circuits from capacitively coupled voltage transformers (CCVT) and other equipment circuits in the vicinity. New test data are presented comparing unshielded and shielded cables and transient currents on all connections to the CCVT including the pedestal and ground strap. The paper gives a practical and understandable explanation of the causes of EMI in substations and how shielded cable and parallel ground conductors reduce interference. Design guidelines are listed in the Conclusion.

Gavazza, R.J. [Pacific Gas and Electric Co., San Francisco, CA (United States)] [Pacific Gas and Electric Co., San Francisco, CA (United States); Wiggins, C.M. [Carl M. Wiggins and Associates, Friendswood, TX (United States)] [Carl M. Wiggins and Associates, Friendswood, TX (United States)

1996-07-01T23:59:59.000Z

313

Temperature rise testing of current transformers: improvement in test method.  

E-Print Network [OSTI]

??The nature of electric power generation, transmission and distribution systems frequently faces high voltages, high currents, or a combination of both. Electric phenomena as well… (more)

Garduno, Hideki

2012-01-01T23:59:59.000Z

314

Current Status  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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).

315

Comparative study of voltage oriented and frequency coordinated control of grid connected doubly fed induction generator  

Science Journals Connector (OSTI)

In this paper a comparative study between voltage oriented control (VOC) and frequency coordinated control (FCC) of grid connected doubly fed induction generator (DFIG) is presented. The two method controls are deeply done on DFIG converter sides grid side converter (GSC) and rotor side converter (RSC). The VOC method permanently maintains the DFIG reactive power to zero values to achieve stable voltage. This control is implemented by regulating the rotor direct axis reference current in RSC using grid reactive power. On the other hand the FCC has employed the active power obtaining from the system frequency deviation to control the rotor quadrature axis reference current in the RSC. The GSC is the same in two studies and its applied vector controlled method. The comparison study between the two methods is conducted at a steady and dynamic state under constant and variable wind speeds. The simulation results are carried out by using PSCAD/EMTDC electromagnetic transient program to validate the comparison study between two methods control of DFIG. The outcomes of the simulation show that the VOC is very convenient when the DFIG operated at transient mode and variable wind speeds while the FCC is feasible and effective for steady-state mode applications. Furthermore the FCC method has an ability to reduce the active and reactive powers ripples as well as decreasing torque harmonics. Both of two methods had fewer transient recovery values of output parameters which ensure safety dynamic response of DFIG and power system. This study contributes significantly to choose the suitable control of the DFIG converters according to electrical grid operation conditions. In addition if a joint control has been applied to these two methods the wind power gained strong and flexible control of the frequency and voltage for different operating conditions.

Li Yang

2014-01-01T23:59:59.000Z

316

Accelerator System Development at High Voltage Engineering  

SciTech Connect (OSTI)

Throughout the years, HVE has continuously extended the capabilities of its accelerator systems to meet the rising demands from a diverse field of applications, among which are deep level ion implantation, micro-machining, neutron production for biomedical research, isotope production or accelerator mass spectrometry. Characteristic for HVE accelerators is the coaxial construction of the all solid state power supply around the acceleration tubes. With the use of solid state technology, the accelerators feature high stability and very low ripple. Terminal voltages range from 1 to 6 MV for HVE Singletrons and Tandetrons. The high-current versions of these accelerators can provide ion beams with powers of several kW. In the last years, several systems have been built with terminal voltages of 1.25 MV, 2 MV and 5 MV. Recently, the first system based on a 6 MV Tandetron has passed the factory tests. In this paper we describe the characteristics of the HVE accelerator systems and present as example recent systems.

Klein, M. G.; Gottdang, A.; Haitsma, R. G.; Mous, D. J. W. [High Voltage Engineering Europa B.V., P.O. Box 99, Amersfoort 3800 AB (Netherlands)

2009-03-10T23:59:59.000Z

317

Contracting Polymer with Current  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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!

318

Backstepping DC Voltage Control in a Multi-terminal HVDC System Connecting Offshore Wind Farms  

Science Journals Connector (OSTI)

Wind power is projected to play an important ... current and future power systems. To integrate offshore wind farms to the existing onshore grid, voltage source ... in a safe range. To distribute transmitted wind

Xiaodong Zhao; Kang Li; Yusheng Xue

2014-01-01T23:59:59.000Z

319

Analysis of three-phase rectifiers with constant-voltage loads  

E-Print Network [OSTI]

This work presents a quantitative analysis of the operating characteristics of three-phase diode bridge rectifiers with AC-side reactance and constant-voltage loads. We focus on the case where the AC-side currents vary ...

Caliskan, Vahe

320

High-voltage pulsed discharge in an electron source with a plasma cathode  

Science Journals Connector (OSTI)

The nature of and mechanism for producing a high-voltage discharge in an electron source with a plasma cathode are investigated. The possibility of generating pulsed electron currents with an amplitude of 103–104

S. P. Bugaev; F. Ya. Zagulov

1973-10-01T23:59:59.000Z

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.


321

Automatic Voltage Control of Electrical Systems  

Science Journals Connector (OSTI)

... to have complete automatic voltage regulation and it also has supervisory control for its main substations. By a careful application of automatically controlled regulators it is shown that the voltage ...

1934-01-20T23:59:59.000Z

322

Onset voltage of corona on coated conductors  

SciTech Connect (OSTI)

This paper is aimed for investigating the effect of surface coating on the positive and negative onset voltages of corona from stressed conductor as a pre-requisite for onset-voltage calculation. The electric field is accurately calculated by the charge simulation technique. The calculated onset voltages agreed satisfactorily with those measured experimentally for bare conductors. The effect of coating-layer thickness and permittivity as well as conductor radius and height on the onset-voltage values is discussed.

Abdel-Salam, M. [Assiut Univ. (Egypt). Electrical Engineering Dept.; Abo-Shal, Y. [SCECO-East, Dammam (Saudi Arabia). Electrical Engineering Div.

1995-12-31T23:59:59.000Z

323

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

Science Journals Connector (OSTI)

The impact of different voltage source converter (VSC) faults on the low voltage ride through (LVRT) capability of the doubly fed induction generator (DFIG) is also investigated. Faults such as fire-through of the VSC switches and short circuit across the DC-link capacitor are considered in this paper. The impact of internal VSC faults when they occur within the grid side converter (GSC) and rotor side converter is investigated. A proper static synchronous compensator (STATCOM) controller to mitigate the effects of these faults is proposed. The DFIG compliance with numerous and recently released LVRT grid codes under these faults with and without the STATCOM is examined and compared. Simulation results indicate that these types of faults have a severe impact on the DFIG voltage profile especially when these faults occur in the GSC. This is attributed to the fact that the GSC directly regulates the point of common coupling (PCC) voltage. Moreover the proposed controller is capable of bringing the voltage profile at the PCC to the nominal steady state level and hence maintaining the connection of the wind turbine during the various studied faults.

H. R. Pota

2013-01-01T23:59:59.000Z

324

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

325

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

326

Home: Directives, Delegations, and Requirements  

Broader source: All U.S. Department of Energy (DOE) Office Webpages

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

327

Overmodulation in Current Controlled Drives  

E-Print Network [OSTI]

220 Chapter 5 Overmodulation in Current Controlled Drives 5.1 Introduction The performance of voltage feedforward controlled constant V f PWM-VSI drives is insu cient for most industrial processes performance control methods. Electric traction, el- evators, textile machines, paper and plastic machines

Hava, Ahmet

328

Changing Direct Current to Alternating Current by Means of Thyratrons  

Science Journals Connector (OSTI)

...Laboratory, General Electric Company. | Journal Article...LABORATORY, GENERAL ELECTRIC COMPANY Read before the...alternating for transmission of electric power has many well recognized...method of controlling an arc discharge by means of a grid...

Albert W. Hull

1936-01-01T23:59:59.000Z

329

A static voltage-current characteristic for the low current DC arc  

E-Print Network [OSTI]

systems has failed to detect arcing faults numerous times with disastrous consequences. The fault leaves a charred furrow, known as the ''arc track'', through Kapton cable insulation. Tests by NASA and others have confirmed that the average circuit...

Moores, Gregory Lee

2012-06-07T23:59:59.000Z

330

Geothermal Energy: Current abstracts  

SciTech Connect (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

331

Anomalous - viscosity current drive  

DOE Patents [OSTI]

An apparatus and method for maintaining a steady-state current in a toroidal magnetically confined plasma. An electric current is generated in an edge region at or near the outermost good magnetic surface of the toroidal plasma. The edge current is generated in a direction parallel to the flow of current in the main plasma and such that its current density is greater than the average density of the main plasma current. The current flow in the edge region is maintained in a direction parallel to the main current for a period of one or two of its characteristic decay times. Current from the edge region will penetrate radially into the plasma and augment the main plasma current through the mechanism of anomalous viscosity. In another aspect of the invention, current flow driven between a cathode and an anode is used to establish a start-up plasma current. The plasma-current channel is magnetically detached from the electrodes, leaving a plasma magnetically insulated from contact with any material obstructions including the cathode and anode.

Stix, Thomas H. (Princeton, NJ); Ono, Masayuki (Princeton Junction, NJ)

1988-01-01T23:59:59.000Z

332

Application of evolutionary algorithms for the planning of urban distribution networks of medium voltage  

E-Print Network [OSTI]

Abstract—Currently, an important issue in power distribution is the need to optimize medium voltage (mv) networks serving urban areas. This paper shows how an evolutionary algorithm can be used as the basis for the type of efficient algorithm such optimization demands. The search for optimal network solution will be restricted to a graph defined from the urban map, so each graph branch represents a trench. The solution space (networks) is assumed with “loop feeder circuits”: networks with two electrical paths from the high voltage/medium voltage (hv/mv) substations to the customers. In the optimization process, the investment and loss load costs are considered taking into account the constraints of conductor capacities and voltage drop. The investment costs will take into account that some cables can be lying in the same trench. The process was applied for a Spanish city of 200 000 inhabitants. Index Terms—Evolutionary algorithm, medium voltage network planning, network design, urban distribution network. I.

unknown authors

2002-01-01T23:59:59.000Z

333

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

334

High voltage load resistor array  

DOE Patents [OSTI]

A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

Lehmann, Monty Ray (Smithfield, VA)

2005-01-18T23:59:59.000Z

335

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

SciTech Connect (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

336

High Voltage Electrolyte for Lithium Batteries  

Broader source: Energy.gov (indexed) [DOE]

battery using high voltage high energy cathode materials to enable large-scale, cost competitive production of the next generation of electric-drive vehicles. To...

337

Pacific Direct Current Intertie (PDCI) Upgrade Project  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Accommodate increased power transmission - The upgrade will allow even more clean power, including hydro, wind and solar, to reach markets that need it. Upgrading and...

338

Coupled numerical modelling of power loss generation in busbar system of low-voltage switchgear  

Science Journals Connector (OSTI)

Abstract This paper presents a coupled mathematical model of the heat transfer processes in an electric switchgear. The considered problem required the computation of the detailed distribution of the power losses and all the heat transfer modes (radiation, convection, and conduction) within a unit. In this complex thermal analysis, different definitions of electric busbar heating were considered and compared. The most advanced model, which couples the thermal and electromagnetic fields in two ways, was also compared with the simplified approaches. First, the direct current loading of the busbar, which neglected the alternating current effects, was considered. Second, models that included only one method of coupling were calculated for different assumed average busbar temperatures. Finally, the model with the two-way coupling, which took the eddy currents and proximity effects into account, was simulated using an iteration loop between the electromagnetic and fluid flow solvers. This study employed a geometrical model of industrial low-voltage switchgear. The presented mathematical model was also validated against temperature measurements carried out by a certified laboratory. The obtained results show that a fully coupled model produces very satisfactory agreement between computed and experimental data.

Mateusz Bedkowski; Jacek Smolka; Krzysztof Banasiak; Zbigniew Bulinski; Andrzej J. Nowak; Tomasz Tomanek; Adam Wajda

2014-01-01T23:59:59.000Z

339

Direct active and reactive power control of 3-level NPC-fed DFIG considering power ripple minimisation  

Science Journals Connector (OSTI)

Despite the advantages of three-level neutral point clamp (NPC) converters compared with standard voltage source inverters (VSIs), most of the direct power control (DPC) strategies for doubly fed induction generator (DFIG) reported in the literature, only utilise VSIs. As regards three-level NPC converter generates higher number of voltage vectors compared with standard VSIs, This paper presents a DPC strategy for DFIG using three-level NPC converters in which three-level NPC voltage vectors are employed to reduce large power ripples of conventional DPC. Therefore, a new optimised switching table is derived. Using this table, DFIG provides not only elaborate active and reactive powers which track their reference values very well, but also large power ripple is compensated. Also, because of ripple reduction, total harmonic distortion of rotor current, stator current, stator voltage and grid line-to-line voltage is reduced in proposed strategy compared with conventional DPC. Simulation results show the effectiveness of proposed method and have a reasonable correspondence with theoretical and mathematical analysis.

Milad Yousefi-Talouki; Parviz Ramezanpour

2014-01-01T23:59:59.000Z

340

International Journal of Systems Science, 2000, volume 31, number 4, pages 519 527 Multi machine power system excitation control design via theories  

E-Print Network [OSTI]

voltage direct current (HVDC) power control design and static voltage condensor (SVC) control design (Lu

Qu, Zhihua

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

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

342

STATCOM-based voltage and frequency regulator for stand-alone asynchronous generator  

Science Journals Connector (OSTI)

This paper presents a STATCOM-based voltage and frequency regulation for stand-alone asynchronous generator feeding linear and nonlinear loads. The SEIG have inherent poor voltage and frequency regulation. The voltage and frequency depend upon the load current and power factor of the load with fixed excitation capacitor employing unregulated turbines. The changing consumer load requires variable reactive power compensation for excitation requirement. Consumer load contains harmonics and performance of SEIG is largely affected by these load harmonics. A current controlled voltage source inverter working as STATCOM is used for harmonic elimination, load balancing and variable reactive power compensation. A DC chopper with dump load is connected across DC bus capacitor to regulate varying consumer load. The control algorithm has been first co-simulated with processor in the loop (PIL) and then experimentally validated. The transient behaviour of developed prototype system for application and removal of balanced, unbalanced, nonlinear load is investigated.

Dheeraj Kumar Palwalia

2014-01-01T23:59:59.000Z

343

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

SciTech Connect (OSTI)

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

344

Monitoring voltage collapse margin with synchrophasors across transmission corridors with multiple lines and multiple contingencies  

E-Print Network [OSTI]

We use synchrophasor measurements of the complex voltage and current at both ends of multiple transmission lines that connect areas of a power system to monitor the online voltage collapse margin. A new reduction is used to reduce the multiple transmission lines to a single line equivalent and determine how to combine the synchrophasor measurements. Generator reactive power limits can be accommodated. The results show that this methodology can capture the effect of multiple contingencies inside the transmission corridors, giving awareness to the operators about the severity of contingencies with respect to voltage stability.

Ramirez, Lina

2014-01-01T23:59:59.000Z

345

Advanced Gate Drive for the SNS High Voltage Converter Modulator  

SciTech Connect (OSTI)

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

346

Linear inductive voltage adders (IVA) for advanced hydrodynamic radiography  

SciTech Connect (OSTI)

The electron beam which drifts through the multiple cavities of conventional induction linacs (LIA) is replaced in an IVA by a cylindrical metal conductor which extends along the entire length of the device and effectuates the addition of the accelerator cavity voltages. In the approach to radiography, the linear inductive voltage adder drives a magnetically immersed electron diode with a millimeter diameter cathode electrode and a planar anode/bremsstrahlung converter. Both anode and cathode electrodes are immersed in a strong (15--50 T) solenoidal magnetic field. The electron beam cross section is approximately of the same size as the cathode needle and generates a similar size, very intense x-ray beam when it strikes the anode converter. An IVA driven diode can produce electron beams of equal size and energy as a LIA but with much higher currents (40--50 kA versus 4--5 kA), simpler hardware and thus lower cost. The authors present here first experimental validations of the technology utilizing HERMES 3 and SABRE IVA accelerators. The electron beam voltage and current were respectively of the order of 10 MV and 40 kA. X-ray doses of up to 1 kR {at} 1 m and spot sizes as small as 1.7 mm (at 200 R doses) were measured.

Mazarakis, M.G.; Boyes, J.D.; Johnson, D.L. [and others

1998-09-01T23:59:59.000Z

347

Thermally-induced voltage alteration for integrated circuit analysis  

DOE Patents [OSTI]

A thermally-induced voltage alteration (TIVA) apparatus and method are disclosed for analyzing an integrated circuit (IC) either from a device side of the IC or through the IC substrate to locate any open-circuit or short-circuit defects therein. The TIVA apparatus uses constant-current biasing of the IC while scanning a focused laser beam over electrical conductors (i.e. a patterned metallization) in the IC to produce localized heating of the conductors. This localized heating produces a thermoelectric potential due to the Seebeck effect in any conductors with open-circuit defects and a resistance change in any conductors with short-circuit defects, both of which alter the power demand by the IC and thereby change the voltage of a source or power supply providing the constant-current biasing. By measuring the change in the supply voltage and the position of the focused and scanned laser beam over time, any open-circuit or short-circuit defects in the IC can be located and imaged. The TIVA apparatus can be formed in part from a scanning optical microscope, and has applications for qualification testing or failure analysis of ICs.

Cole, Jr., Edward I. (Albuquerque, NM)

2000-01-01T23:59:59.000Z

348

Novel passive lossless turn-on snubber for voltage source inverters  

SciTech Connect (OSTI)

A novel passive lossless turn-on snubber with a soft clamped turn-off snubber circuit for voltage source inverters is proposed. The energy trapped in the snubber is recovered into the dc supply and load without any active devices, associated control circuitry, or resistors. The overshoot voltage on the switches is clamped, and the peak switch current is low, making this snubber suitable for use in high-power insulated gate bipolar transistor (IGBT) inverters.

He, X.; Qian, Z.M. [Zhejiang Univ., Hangzhou (China). Dept. of Electrical Engineering; Finney, S.J.; Williams, B.W. [Heriot-Watt Univ., Edinburgh (United Kingdom). Dept. of Computing and Electrical Engineering

1997-01-01T23:59:59.000Z

349

Non-transposed, three phase transmission lines: a study of their effect on load voltages.  

E-Print Network [OSTI]

TRANSMISSION LINES A S'PJDY OF THEIR EFFECT ON LOAD VOLTAGES A Thesis By Robert Dean Chenoweth August 1951 NON-TRANSPOSED~ THREE PHASE TRANSMISSION LINES A STUDY OF THEIR EFFECT ON LOAD VOLTAGES A Thesis Submitted to the Faculty of the Agricultural... all large blocks of alternating current power are transmitted from the generating station to the load by means of three phase transmission lines. With present day equipment this method is economical and when ~ properly designed gives very...

Chenoweth, Robert Dean

2012-06-07T23:59:59.000Z

350

DESIGN AND IMPLEMENTATION OF A FUZZY LOGIC-BASED VOLTAGE CONTROLLER FOR VOLTAGE REGULATION  

E-Print Network [OSTI]

1 DESIGN AND IMPLEMENTATION OF A FUZZY LOGIC-BASED VOLTAGE CONTROLLER FOR VOLTAGE REGULATION In this paper the design and implementation of a fuzzy logic-based controller is described for regulating the output voltage of a synchronous generator. An automated fuzzy logic-based control strategy is presented

LaMeres, Brock J.

351

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

352

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

353

Development of High Voltage Electron Microscope  

Science Journals Connector (OSTI)

......Cockcroft Walton Type High Voltage Generator. O Power Line O Fig. 4...pressure in the tank to the atmospheric pressure by removing freon...pump using liquid nitrogen. Water buffer and liquid nitrogen...base plate of high voltage generator. Four poles stand on this......

Shinjiro KATAGIRI; Hirokazu KIMURA; Susumu OZASA; Kazumi SHIRAISHI

1969-01-01T23:59:59.000Z

354

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. 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, William M. (Santa Fe, NM)

1992-01-01T23:59:59.000Z

355

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

356

Limitations of High-Voltage Insulation  

Science Journals Connector (OSTI)

... materials such as impregnated paper. The important electrical properties of the materials used for the insulation of high-voltage circuits are conductivity and electric strength. The conductivity measures the ability ... a million times between themselves, but they are all classified as available for high-voltage insulation.

1938-01-08T23:59:59.000Z

357

High Voltage Safety Act | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

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

358

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

SciTech Connect (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

359

Resonant tunneling with high peak to valley current ratio in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers at room temperature  

SciTech Connect (OSTI)

We have investigated carrier transport in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers by room temperature current-voltage measurements. Resonant tunneling signatures accompanied by current peaks are observed. Carrier transport in the multi-layers were analyzed by plots of ln(I/V{sup 2}) as a function of 1/V and ln(I) as a function of V{sup 1/2}. Results suggest that besides films quality, nc-Si and barrier sub-layer thicknesses are important parameters that restrict carrier transport. When thicknesses are both small, direct tunneling dominates carrier transport, resonant tunneling occurs only at certain voltages and multi-resonant tunneling related current peaks can be observed but with peak to valley current ratio (PVCR) values smaller than 1.5. When barrier thickness is increased, trap-related and even high field related tunneling is excited, causing that multi-current peaks cannot be observed clearly, only one current peak with higher PVCR value of 7.7 can be observed. While if the thickness of nc-Si is large enough, quantum confinement is not so strong, a broad current peak with PVCR value as high as 60 can be measured, which may be due to small energy difference between the splitting energy levels in the quantum dots of nc-Si. Size distribution in a wide range may cause un-controllability of the peak voltages.

Chen, D. Y., E-mail: cdy7659@126.com [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China); Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Sun, Y.; He, Y. J. [Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Xu, L.; Xu, J. [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China)

2014-01-28T23:59:59.000Z

360

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

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.


361

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

362

High-voltage R-F feedthrough bushing  

DOE Patents [OSTI]

Described is a multi-element, high voltage radio frequency bushing for transmitting 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, G.F.

1982-09-03T23:59:59.000Z

363

Researchers map atomic movements that trigger voltage fade in...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

map atomic movements that trigger voltage fade in high-energy-density batteries January 22, 2015 Voltage and capacity curves from an LMR-NMC high-energy cathode show voltage fade...

364

Currents on MDT end plugs  

E-Print Network [OSTI]

A sample of MDT tubes was irradiated in the CERN X5 facility to study their aging behaviour. Part of these tubes were subjected to a glow discharge cleaning (sputtering) with reversed high voltage up to 1660 mC/cm. Current and Ohmic resistance measurements on these tubes gave the same null result as for non-irradiated tubes. The inner plastic surface of one end plug was analysed through the XPS technique. No traces of aluminium were found.

Paschhoff, V

1998-01-01T23:59:59.000Z

365

Pulse and Hold Switching Current Readout of Superconducting Quantum Circuits  

E-Print Network [OSTI]

;#12;Abstract Josephson junction qubits are promising candidates for a scalable quantum processor. Such qubits on the switching of a Josephson junction from the zero voltage state to a finite voltage state. The Josephson a switching current detector by analyzing the phase space of a Josephson junction circuit with frequency

Haviland, David

366

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 +

367

BGE_Comments_CurrentComms.pdf  

Broader source: Energy.gov (indexed) [DOE]

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

368

Surface Wind Direction Variability  

Science Journals Connector (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

369

Vehicle Technologies Office Merit Review 2014: High-Voltage Solid...  

Broader source: Energy.gov (indexed) [DOE]

High-Voltage Solid Polymer Batteries for Electric Drive Vehicles Vehicle Technologies Office Merit Review 2014: High-Voltage Solid Polymer Batteries for Electric Drive Vehicles...

370

High-Voltage Solid Polymer Batteries for Electric Drive Vehicles...  

Broader source: Energy.gov (indexed) [DOE]

High-Voltage Solid Polymer Batteries for Electric Drive Vehicles High-Voltage Solid Polymer Batteries for Electric Drive Vehicles 2013 DOE Hydrogen and Fuel Cells Program and...

371

High-Voltage Solid Polymer Batteries for Electric Drive Vehicles...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

High-Voltage Solid Polymer Batteries for Electric Drive Vehicles High-Voltage Solid Polymer Batteries for Electric Drive Vehicles 2012 DOE Hydrogen and Fuel Cells Program and...

372

Cathode Synthesis and Voltage Fade: Designed Solutions Based...  

Broader source: Energy.gov (indexed) [DOE]

Cathode Synthesis and Voltage Fade: Designed Solutions Based on Theory Cathode Synthesis and Voltage Fade: Designed Solutions Based on Theory 2013 DOE Hydrogen and Fuel Cells...

373

Addressing the Voltage Fade Issue with Lithium-Manganese-Rich...  

Broader source: Energy.gov (indexed) [DOE]

Addressing the Voltage Fade Issue with Lithium-Manganese-Rich Oxide Cathode Materials Addressing the Voltage Fade Issue with Lithium-Manganese-Rich Oxide Cathode Materials 2013 DOE...

374

High voltage overhead long transmission line design and fault analysis.  

E-Print Network [OSTI]

??The goal of this project is to design a reliable high voltage overhead long transmission line that satisfies specific design criteria including voltage regulation, efficiency,… (more)

Elzain, Mohamed Ali

2011-01-01T23:59:59.000Z

375

Integrated polymer solar cells in serial architecture with patterned charge-transporting MoOx for miniature high-voltage sources  

Science Journals Connector (OSTI)

We develop miniature high-voltage sources from polymer solar cells (PSCs) with charge-transporting molybdenum oxide (MoOx) integrated in a serial architecture through sacrificial layer (SL)-assisted patterning. The MoOx layer, being patterned by the lift-off process of the SL of a hydrophobic fluorinated-polymer, as a hole transporting layer plays a critical role on the reduction of the dark current and the increase of a high open circuit voltage of an integrated PSC array. The underlying mechanism lies primarily on the elimination of the lateral charge pathways in the MoOx layer in the presence of the electrode interconnection. Two miniature voltage sources consisting of 20 PSCs and 50 PSCs are demonstrated in the operation of a liquid crystal display and an organic field-effect transistor, respectively. Our SL-assisted integration approach will be directly applicable for implementing the self-power sources made of the PSCs into a wide range of the electronic and optoelectronic devices.

Seong-Min Cho; Chang-Min Keum; Hea-Lim Park; Min-Hoi Kim; Jin-Hyuk Bae; Sin-Doo Lee

2014-01-01T23:59:59.000Z

376

Departmental Directives Program  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

To define requirements and responsibilities for implementing the Department of Energy (DOE) Directives Program in support of the Secretary's memorandum of September 10, 2007, Principles Governing Departmental Directives. See also the current list of Directives Requiring Further Documentation, as required by Appendix D of this Order. Cancels DOE P 251.1A, DOE O 251.1B, DOE M 251.1-1B.

2007-09-10T23:59:59.000Z

377

Superharmonic Injection Locked Quadrature LC VCO Using Current Recycling Architecture  

E-Print Network [OSTI]

. This thesis investigates a coupling mechanism to implement a quadrature voltage controlled oscillator using indirect injection method. The coupling network in this QVCO couples the two LC cores with their super-harmonic and it recycles its bias current back...

Kalusalingam, Shriram

2011-02-22T23:59:59.000Z

378

Direct solar energy conversion and storage through coupling between photoelectrochemical and ferroelectric effects  

Science Journals Connector (OSTI)

Harvesting and storing solar energy has become more and more important. Current solid-state photovoltaic cells and conventional photoelectrochemical cells are not capable of directly storing the converted energy which has to be facilitated by connecting to external storing devices. We demonstrate a device architecture that can convert and store solar energy in the electrical form within an intrinsically single structure. Mobile charge is internally stored based on the coupling between photoelectrochemical and ferroelectric effects. The tested device architecture can be photo-charged under 1000 W/m2 of white light to an open-circuit voltage of 0.47V with a capacity of 37.62 mC/cm2. After removal of the light source the mobile charge stored lasts more than 8 hours and the open-circuit output voltage lasts more than 24 hours.

Chi-Wei Lo; Chensha Li; Hongrui Jiang

2011-01-01T23:59:59.000Z

379

Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries  

SciTech Connect (OSTI)

Rechargeable Mg batteries are attractive energy storage systems and could bring cost-effective energy solutions. Currently, however, no practical cathode current collectors that can withstand high voltages in Mg2+ electrolytes has been identified and therefore cathode research is greatly hindered. Here we identified that two metals, Mo and W, are electrochemically stable through formation of surface passive layers. The presented results could have significant impacts on the developments of high voltage Mg batteries.

Cheng, Yingwen; Liu, Tianbiao L.; Shao, Yuyan; Engelhard, Mark H.; Liu, Jun; Li, Guosheng

2014-01-01T23:59:59.000Z

380

Distribution System Voltage Performance Analysis for High-Penetration Photovoltaics  

SciTech Connect (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

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

High Voltage Testing of a 5-meter Prototype Triaxial HTS Cable  

SciTech Connect (OSTI)

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

382

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

383

Physical simulation study of dynamic voltage instability  

SciTech Connect (OSTI)

This paper presents a physical simulation of the dynamic behavior of voltage instability in an interconnected multimachine environment. The dynamic evolving process leading to eventual voltage collapse, the scenario of the progressive reactive support reduction resulting from the MXL protection relays, the OLTC operation, and the effect of switched-in capacitor banks are examined using physical facilities in the laboratory. The physical simulation results are also compared with digital simulation results. This physical investigation provides a reliable foundation for the effective development of assessment approaches and countermeasures.

Tso, S.K.; Zhu, T.X. [Univ. of Hong Kong (Hong Kong); Zeng, Q.Y. [Electric Power Research Inst., Beijing (China); Lo, K.L. [Univ. of Strathclyde, Glasgow (United Kingdom). Dept. of Electrical and Electrical Engineering

1995-12-31T23:59:59.000Z

384

TCSC as a Transient Voltage Stabilizing Controller Garng Huang and Tong Zhu  

E-Print Network [OSTI]

drawback that infinitive bus is not a good model for a generator for voltage stability studies since only that the generator field current limiting action limits the output of the reactive power, which is essential performance are included in the test system. These elements include induction motors, on-load tap-changer t

385

Strongly nonlinear dynamics of electrolytes in large ac voltages Laurits Hjgaard Olesen,1,2  

E-Print Network [OSTI]

the results have been developed for over a century 1 . Current applications include energy storage; published 2 July 2010 We study the response of a model microelectrochemical cell to a large ac voltage of frequency comparable to the inverse cell relaxation time. To bring out the basic physics, we consider

386

Photoemission currentspacecraft voltage relation: Key to routine, quantitative low-energy plasma measurements  

E-Print Network [OSTI]

Photoemission current�spacecraft voltage relation: Key to routine, quantitative low-energy plasma measurements J. D. Scudder and Xuejun Cao Department of Physics and Astronomy, University of Iowa, Iowa City F/C. The photoemission current function is found to be time independent using nearly 10 months of GGS-Polar data from

California at Berkeley, University of

387

Experimental and Numerical Study of Co-ordination of Resistive-Type Superconductor Fault Current Limiter and Relay Protection  

Science Journals Connector (OSTI)

Superconducting fault current limiter (SFCL) has become one of the most ideal current limiting devices to solve the problem of increasing short-circuit current in high-voltage power grid. This paper...

Y. Chen; S. Li; J. Sheng; Z. Jin; Z. Hong…

2013-11-01T23:59:59.000Z

388

Discrete sliding mode control strategy for direct real and reactive power regulation of wind driven DFIG  

Science Journals Connector (OSTI)

Abstract This paper investigates a discrete sliding mode control (DSMC) strategy for direct real and reactive power regulation for wind driven doubly fed induction generator (DFIG). The real and reactive power errors are eliminated by directly calculating the rotor control voltages through DSMC. In the stator stationary reference frame, direct real and reactive power control strategy is implemented. Therefore, it does not require the angular information of the stator and rotor currents or voltages. It does not involve any extra current loops which results into simple design. The use of constant converter switching frequency via space vector pulse width modulation eases the AC harmonic filter design and improves the power quality. The use of fast and flexible discrete controller makes the system competent with modern digital world. Detailed simulations have been carried out to validate the method. The simulation results reveal that the real and reactive power references are followed smoothly even in the presence of speed perturbations and performance of the system is robust against parameter variations and system disturbances.

V.N. Pande; U.M. Mate; Shailaja Kurode

2013-01-01T23:59:59.000Z

389

Statistical Power Grid Analysis Considering Log-Normal Leakage Current Variations  

Science Journals Connector (OSTI)

As discussed in Part II, process-induced variability has huge impacts on chip leakage currents, owing to the exponential relationship between subthreshold leakage current I sub and threshold voltage...

Ruijing Shen; Sheldon X.-D. Tan; Hao Yu

2012-01-01T23:59:59.000Z

390

1.2 MVA High-Tc Superconducting Fault Current Limiter  

Science Journals Connector (OSTI)

A 3-phase high Tc superconducting fault current limiter with a rated power of 1.2 ... a special partial melt process. The nominal current and voltage of the device are 70 ... 3-phase short circuit tests with a pr...

W. Paul; M. Chen; M. Lakner; J. Rhyner; L. Widenhorn…

1998-01-01T23:59:59.000Z

391

The characteristics of voltage degradation of a proton exchange membrane fuel cell under a road operating environment  

Science Journals Connector (OSTI)

Abstract A real-life testing experiment of a proton exchange membrane fuel cell (PEMFC) and the basic characteristics of its voltage degradation are presented. A general package radio system (GPRS)-based remote monitoring system was used as the data acquisition method, and the non-linear regression method was used to estimate PEMFC's polarization curve within specific iso-interval periods. The voltage degradation rate was calculated using the differential method, and its average level was also analyzed. The experimental results indicated that the voltage degradation rate at a specific current density featured a bathtub-like curve, exhibiting 1) infant degradation, 2) steady degradation, 3) and accelerated degradation.

Xinfeng Zhang; Yang Rui; Zhang Tong; Xu Sichuan; Shen Yong; Ni Huaisheng

2014-01-01T23:59:59.000Z

392

Control of a final gating charge transition by a hydrophobic residue in the S2 segment of a K+ channel voltage sensor  

Science Journals Connector (OSTI)

...The recording pipette resistance was 0.8 to 1.5 M...fluorometric approach to local electric field measurements in a voltage-gated...Horn R ( 2005 ) Focused electric field across the voltage...sensor reveals a focused electric field . Nature 427 : 548 – 553 . 18 Chen...current noise produced by elementary transitions in Shaker potassium...

Jérôme J. Lacroix; Francisco Bezanilla

2011-01-01T23:59:59.000Z

393

Electro-optic high voltage sensor  

DOE Patents [OSTI]

A small sized electro-optic voltage sensor capable of accurate measurement of high levels of voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation into the sensor. A polarization beam displacer serves as a filter to separate the input beam into two beams with orthogonal linear polarizations. The beam displacer is oriented in such a way as to rotate the linearly polarized beams such that they enter a Pockels crystal having at a preferred angle of 45 degrees. The beam displacer is therefore capable of causing a linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels electro-optic effect induces a differential phase shift on the major and minor axes of the input beam as it travels through the Pockels crystal, which causes the input beam to be elliptically polarized. A reflecting prism redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization representing the major and minor axes. The system may include a detector for converting the output beams into electrical signals, and a signal processor for determining the voltage based on an analysis of the output beams. The output beams are amplitude modulated by the frequency of the electric field and the amplitude of the output beams is proportional to the magnitude of the electric field, which is related to the voltage being measured.

Davidson, James R. (Idaho Falls, ID); Seifert, Gary D. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

394

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 2, APRIL 2006 477 Voltage-Source Active Power Filter Based on  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 2, APRIL 2006 477 Voltage-Source Active compensate load current harmonics, keeping better-quality sinusoidal currents from the source. The simulated MODERN power electronics have contributed a great deal to the development of new powerful applications

Catholic University of Chile (Universidad Católica de Chile)

395

Some Features of an Electrostatic Generator and Ion Source for High Voltage Research  

Science Journals Connector (OSTI)

A compact generator of the Van de Graaff type is described in which several new features have been incorporated. Short-circuit current of one milliampere is available. When operating at 600 kv as voltage supply for accelerating protons or deutersons, 130?a of charged particles at the target have been obtained from an unusual low voltage capillary arc source. In normal operation as a neutron generator, the equivalent of 15 curies of radon-beryllium is readily produced by the reaction Li+D, and 60 curies by the D on D reaction.

I. A. Getting; J. B. Fisk; H. G. Vogt

1939-12-01T23:59:59.000Z

396

Distribution System Voltage Regulation by Distributed Energy Resources  

SciTech Connect (OSTI)

This paper proposes a control method to regulate voltages in 3 phase unbalanced electrical distribution systems. A constrained optimization problem to minimize voltage deviations and maximize distributed energy resource (DER) active power output is solved by harmony search algorithm. IEEE 13 Bus Distribution Test System was modified to test three different cases: a) only voltage regulator controlled system b) only DER controlled system and c) both voltage regulator and DER controlled system. The simulation results show that systems with both voltage regulators and DER control provide better voltage profile.

Ceylan, Oguzhan [ORNL; Liu, Guodong [ORNL; Xu, Yan [ORNL; Tomsovic, Kevin [University of Tennessee, Knoxville (UTK)

2014-01-01T23:59:59.000Z

397

Four Phase Switched Reluctance Motor Direct Torque Control  

Science Journals Connector (OSTI)

The three-phase switched reluctance motor direct torque control method mostly is a simple transplantation of the three-phase AC asynchronous motor direct torque control method, not suitable for arbitrary-phase switched reluctance motor. In this paper, ... Keywords: SRM, Direct torque control, Flux vector, Voltage vector, Switched rule

Wang Mianhua

2011-01-01T23:59:59.000Z

398

Development of a quantum-voltage-calibrated noise thermometer at NIM  

SciTech Connect (OSTI)

A quantum-voltage-calibrated Johnson-noise thermometer was developed at NIM, which measures the Boltzmann constant k by comparing the thermal noise across a 100 ? sense resistor at the temperature of the triple point of water with the pseudo-random frequency-comb voltage waveform synthesized with a bipolar-pulse-driven quantum-voltage-noise source. A measurement with integration period of 10 hours and bandwidth of 640 kHz resulted in a relative offset of 0.5×10{sup ?6} from the current CODATA value of k, and a type A relative standard uncertainty of 23×10{sup ?6}. Benefiting from closely matched noise powers and transmission-line impedances and small nonlinearities in the cross-correlation electronics, the derived k shows self-consistent values and standard uncertainties for different measurement bandwidths.

Qu, J.; Zhang, J. T.; Fu, Y. [National Institute of Metrology, Beijing 100013, P. R. (China)] [National Institute of Metrology, Beijing 100013, P. R. (China); Rogalla, H.; Pollarolo, A.; Benz, S. P. [National Institute of Standards and Technology, Boulder, CO 80305 (United States)] [National Institute of Standards and Technology, Boulder, CO 80305 (United States)

2013-09-11T23:59:59.000Z

399

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

400

The design, construction, and operation of long-distance high-voltage electricity transmission technologies.  

SciTech Connect (OSTI)

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

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

Hedge-algebra-based voltage controller for a self-excited induction generator  

Science Journals Connector (OSTI)

Abstract This paper presents an indirect rotor-flux-oriented (IRFO) control system of the self-excited induction generator (SEIG) in which excitation is achieved by means of a current-controlled voltage source inverter (CC-VSI) and a single electrolytic capacitor. In the proposed control scheme, both the iron losses and the magnetic saturation are taken into account and calculated online. The main objective is to keep the DC voltage across the capacitor constant and equal to the reference value, regardless of changes in the rotor speed and load. The study is mainly focused on the DC voltage control and, more specifically, on selection of the appropriate DC voltage controller. Besides considering widely accepted types of controllers, i.e., the classical PI controller and the fuzzy logic (FL) controller, this paper proposes an alternative solution – a new type of DC voltage controller based on hedge algebra. To our best knowledge, this is the first time that such a controller is considered for application in electrical engineering. The performance of the developed hedge algebra (HA) controller is evaluated through comparison with the optimal-tuned classical PI controller and the Sugeno-type FL controller. The simulation and experimental analysis are carried out in reasonably wide ranges of the DC voltage, load and rotor speed, including the case of a variable rotor speed. It is shown that the proposed HA controller provides superior performance in terms of tracking the reference DC voltage value as well as robustness to speed and load disturbances in the system.

Dinko Vukadinovi?; Mateo Baši?; Cat Ho Nguyen; Nhu Lan Vu; Tien Duy Nguyen

2014-01-01T23:59:59.000Z

402

Effect of DC voltage pulses on memristor behavior.  

SciTech Connect (OSTI)

Current knowledge of memristor behavior is limited to a few physical models of which little comprehensive data collection has taken place. The purpose of this research is to collect data in search of exploitable memristor behavior by designing and implementing tests on a HP Labs Rev2 Memristor Test Board. The results are then graphed in their optimal format for conceptualizing behavioral patterns. This series of experiments has concluded the existence of an additional memristor state affecting the behavior of memristors when pulsed with positively polarized DC voltages. This effect has been observed across multiple memristors and data sets. The following pages outline the process that led to the hypothetical existence and eventual proof of this additional state of memristor behavior.

Evans, Brian R.

2013-10-01T23:59:59.000Z

403

Voltage spike detection in high field superconducting accelerator magnets  

SciTech Connect (OSTI)

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

404

Sacramento Area Voltage Support Environmental Impact Statement  

Broader source: Energy.gov (indexed) [DOE]

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

405

High voltage electric substation performance in earthquakes  

SciTech Connect (OSTI)

This paper examines the performance of several types of high voltage substation equipment in past earthquakes. Damage data is provided in chart form. This data is then developed into a tool for estimating the performance of a substation subjected to an earthquake. First, suggests are made about the development of equipment class fragility curves that represent the expected earthquake performance of different voltages and types of equipment. Second, suggestions are made about how damage to individual pieces of equipment at a substation likely affects the post-earthquake performance of the substation as a whole. Finally, estimates are provided as to how quickly a substation, at various levels of damage, can be restored to operational service after the earthquake.

Eidinger, J. [G and E Engineering Systems, Oakland, CA (United States); Ostrom, D. [Southern California Edison, Rosemead, CA (United States); Matsuda, E. [Pacific Gas and Electric, San Francisco, CA (United States)

1995-12-31T23:59:59.000Z

406

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

407

Power-One produces the industry's broadest selection of linear power supplies with output voltages from 5 volts through 250 volts. Rugged  

E-Print Network [OSTI]

-A 5V @ 9A (Note 1,5) N 5V HD5-12/OVP-A 5V @ 12A (Note 1,5) D HE5-18/OVP-A 5V @ 18A (Note 1,5) E F5 regulatory standards, and is CE Marked to the Low Voltage Directive (LVD). INTERNATIONAL SERIES LINEARS marked to Low Voltage Directive · 100% Burn-In · 2 Year Warranty · Overvoltage Protection (OVP) Standard

Berns, Hans-Gerd

408

Low Voltage White Phosphorescent OLED Achievements  

Broader source: Energy.gov [DOE]

Universal Display Corporation (UDC) and its research partners at Princeton University and the University of Southern California have succeeded in developing a white phosphorescent OLED (PHOLED™) that achieved a record efficiency of 20 lumens per watt. This achievement is the result of the team's collaborative efforts to increase the efficiency of PHOLED lighting by focusing on two critical factors: lowering the drive voltages and increasing the amount of light extracted.

409

Classification of Voltage Sags Based on MPCA Models  

Science Journals Connector (OSTI)

In this paper, we introduce a new framework for classification of short duration voltage reductions in the area of Power Quality Monitoring using Multiway Principal Component Analysis (MPCA). Firstly, we recast the sags occurred in High Voltage (HV) ...

Abbas Khosravi; Joaquim Melendez; Joan Colomer

2007-06-01T23:59:59.000Z

410

A BIST Technique for RF Voltage-Controlled Oscillators  

Science Journals Connector (OSTI)

A built-in self-test (BIST) architecture is proposed for voltage-controlled oscillators (VCO) operating at multigigahertz frequencies. By utilizing a frequency divider and a frequency-to-voltage converter (FVC), the output frequency and tuning range ...

Hsieh-Hung Hsieh; Yen-Chih Huang; Liang-Hung Lu; Guo-Wei Huang

2007-10-01T23:59:59.000Z

411

Low voltage amplifier architecture for high speed switched capacitor circuits  

E-Print Network [OSTI]

This work concentrates on circuit realization of high speed and low voltage switched capacitor circuits, with emphasis on the operational transconductance amplifier (OTA). An overview of switched capacitor circuits is given. Speed and voltage...

Shankar, Asit

2012-06-07T23:59:59.000Z

412

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

413

Analysis and design of an electronic voltage ratchet  

E-Print Network [OSTI]

and decay. Impulse voltages are produced through the discharging of 0, capacitor into a shaping network consisting of resistors and a. capacitor as is shown in Figure 2. 9. The operation of the impulse generator is as follows. Capacitor Ci is charged from... voltage shaping network. as possible in order to reduce oscillations in the wavefront and wavetail portions of the impulse voltage [1). The impulse voltage generator requires a, highly charged capacitor or bank of capacitors. Capacitors may be charged...

Menendez, Jorge Carlos

2012-06-07T23:59:59.000Z

414

LM2907LM2917FrequencytoVoltageConverter February 1995  

E-Print Network [OSTI]

TL H 7942 LM2907LM2917FrequencytoVoltageConverter February 1995 LM2907 LM2917 Frequency to Voltage Converter General Description The LM2907 LM2917 series are monolithic frequency to voltage converters doubling for low ripple full input protection in two versions (LM2907-8 LM2917-8) and its output swings

Wedeward, Kevin

415

Experimental Verification of Overlimiting Current by Surface Conduction and Electro-osmotic Flow in Microchannels  

E-Print Network [OSTI]

Possible mechanisms of overlimiting current in unsupported electrolytes, exceeding diffusion limitation, have been intensely studied for their fundamental significance and applications to desalination, separations, sensing, and energy storage. In bulk membrane systems, the primary physical mechanism is electro-convection, driven by electro-osmotic instability on the membrane surface. It has recently been predicted that confinement by charged surfaces in microchannels or porous media favors two new mechanisms, electro-osmotic flow (EOF) and surface conduction (SC), driven by large electric fields in the depleted region acting on the electric double layers on the sidewalls. Here, we provide the first direct evidence for the transition from SC to EOF above a critical channel height, using in situ particle tracking and current-voltage measurements in a micro/nanofluidic device. The dependence of the over-limiting conductance on channel depth (d) is consistent with theoretical predictions, scaling as d^-1 for SC a...

Nam, Sungmin; Heo, Joonseong; Lim, Geunbae; Bazant, Martin Z; Sung, Gunyong; Kim, Sung Jae

2014-01-01T23:59:59.000Z

416

Energy Currents  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

417

Energy Currents  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

418

Polarized electron beams at milliampere average current  

SciTech Connect (OSTI)

This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

Poelker, Matthew [JLAB

2013-11-01T23:59:59.000Z

419

Method of Controlling Corona Effects and Breakdown Voltage of Small Air Gaps Stressed by Impulse Voltages  

E-Print Network [OSTI]

This paper investigates the influence of a resistor on the dielectric behavior of an air gap. The resistor is connected in series with the air gap and the latter is stressed by impulse voltage. Air gap arrangements of different geometry with either the rod or the plate grounded are stressed with impulse voltages of both positive and negative polarity. The resistor is connected in series with the air gap in the return circuit connecting the gap with the impulse generator. The method followed involves the investigation of the graphs of the charging time concerning the air gaps capacitances, in connection to the value of the resistor, the geometry of the gap, the effect of grounding and the polarity effect. It is determined that the charging time of the air gap increases, as the value of the resistor increases. It is also determined that the peak voltage value of the fully charged air gap decreases as the value of the resistor increases. The results of the mathematical and simulation analysis are compared with the results of the oscillograms taken from experimental work. In addition and consequently to the above results it is concluded from the experimental work that the in series connection of the resistor in the circuit has significant influence on corona pulses (partial discharges) occurring in the gap and on the breakdown voltage of the gap. A new method of controlling the corona effects and consequently the breakdown voltage of small air gaps stressed by impulse voltage of short duration in connection to the ground effect and the polarity effect has arisen. Furthermore through mathematical analysis of the charging graphs obtained from simulation and experimental oscillograms there was a calculation of the values of the capacitance of the air gaps in relation to their geometry and the results were compared to the values calculated with mathematical analysis.

Athanasios Maglaras; Trifon Kousiouris; Frangiskos Topalis; Dimitrios Katsaros; Leandros A. Maglaras; Konstantina Giannakopoulou

2014-10-15T23:59:59.000Z

420

2.3-MW Medium-Voltage, Three-Level Wind Energy Inverter Applying a Unique Bus Structure and 4.5-kV Si/SiC Hybrid Isolated Power Modules: Preprint  

SciTech Connect (OSTI)

A high-efficiency, 2.3-MW, medium-voltage, three-level inverter utilizing 4.5-kV Si/SiC (silicon carbide) hybrid modules for wind energy applications is discussed. The inverter addresses recent trends in siting the inverter within the base of multimegawatt turbine towers. A simplified split, three-layer laminated bus structure that maintains low parasitic inductances is introduced along with a low-voltage, high-current test method for determining these inductances. Feed-thru bushings, edge fill methods, and other design features of the laminated bus structure provide voltage isolation that is consistent with the 10.4-kV module isolation levels. Inverter efficiency improvement is a result of the (essential) elimination of the reverse recovery charge present in 4.5-kV Si PIN diodes, which can produce a significant reduction in diode turn-off losses as well as insulated-gate bipolar transistor (IGBT) turn-on losses. The hybrid modules are supplied in industry-standard 140 mm x 130 mm and 190 mm x 130 mm packages to demonstrate direct module substitution into existing inverter designs. A focus on laminated bus/capacitor-bank/module subassembly level switching performance is presented.

Erdman, W.; Keller, J.; Grider, D.; VanBrunt, E.

2014-11-01T23:59:59.000Z

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

Thermal generation currents in hydrogenated amorphous silicon p?i?n structures  

Science Journals Connector (OSTI)

Dark conductivity in amorphous siliconp?i?n devices arising from thermal generation through bulk defect states is explored. The current decays slowly after a voltage is applied due to depletion of charge from the undoped layer and is voltage dependent due to a field?enhanced generation rate. Creation of metastable bulk defects by light soaking reversibly increases the current. The steady?state generation current is dervied from the measuredrelaxation time and depletion charge.

R. A. Street

1990-01-01T23:59:59.000Z

422

Chemical detection and laser wavelength stabilization employing spectroscopic absorption via laser compliance voltage sensing  

DOE Patents [OSTI]

Systems and methods are disclosed that provide a direct indication of the presence and concentration of an analyte within the external cavity of a laser device that employ the compliance voltage across the laser device. The systems can provide stabilization of the laser wavelength. The systems and methods can obviate the need for an external optical detector, an external gas cell, or other sensing region and reduce the complexity and size of the sensing configuration.

Taubman, Matthew S; Phillips, Mark C

2014-03-18T23:59:59.000Z

423

High-efficiency solar cells fabricated from direct-current magnetron sputtered n-indium tin oxide onto p-InP grown by atmospheric pressure metalorganic vapor phase epitaxy  

SciTech Connect (OSTI)

Solar cells based on dc magnetron sputtered indium tin oxide onto epitaxially grown films of p-InP have been fabricated and analyzed. The best cells had a global efficiency of 18.4% and an air mass zero (AMO) efficiency of 16.0%. The principal fabrication variable considered was the constituency of the sputtering gas and both argon/hydrogen and argon/oxygen mixtures have been used. The former cells have the higher efficiencies, are apparently stable, and exhibit almost ideal junction characteristics. The latter cells are relatively unstable and exhibit much higher ideality factors and reverse saturation current densities. The temperature dependence of the reverse saturation current indicates totally different charge transfer mechanisms in the two cases.

Li, X.; Wanlass, M.W.; Gessert, T.A.; Emery, K.A.; Coutts, T.J.

1989-05-01T23:59:59.000Z

424

Calmodulin and calcium differentially regulate the neuronal Nav1.1 voltage-dependent sodium channel  

SciTech Connect (OSTI)

Highlights: {yields} Both Ca{sup ++}-Calmodulin (CaM) and Ca{sup ++}-free CaM bind to the C-terminal region of Nav1.1. {yields} Ca{sup ++} and CaM have both opposite and convergent effects on I{sub Nav1.1}. {yields} Ca{sup ++}-CaM modulates I{sub Nav1.1} amplitude. {yields} CaM hyperpolarizes the voltage-dependence of activation, and increases the inactivation rate. {yields} Ca{sup ++} alone antagonizes CaM for both effects, and depolarizes the voltage-dependence of inactivation. -- Abstract: Mutations in the neuronal Nav1.1 voltage-gated sodium channel are responsible for mild to severe epileptic syndromes. The ubiquitous calcium sensor calmodulin (CaM) bound to rat brain Nav1.1 and to the human Nav1.1 channel expressed by a stably transfected HEK-293 cell line. The C-terminal region of the channel, as a fusion protein or in the yeast two-hybrid system, interacted with CaM via a consensus C-terminal motif, the IQ domain. Patch clamp experiments on HEK1.1 cells showed that CaM overexpression increased peak current in a calcium-dependent way. CaM had no effect on the voltage-dependence of fast inactivation, and accelerated the inactivation kinetics. Elevating Ca{sup ++} depolarized the voltage-dependence of fast inactivation and slowed down the fast inactivation kinetics, and for high concentrations this effect competed with the acceleration induced by CaM alone. Similarly, the depolarizing action of calcium antagonized the hyperpolarizing shift of the voltage-dependence of activation due to CaM overexpression. Fluorescence spectroscopy measurements suggested that Ca{sup ++} could bind the Nav1.1 C-terminal region with micromolar affinity.

Gaudioso, Christelle; Carlier, Edmond; Youssouf, Fahamoe [INSERM U641, Institut Jean Roche, Marseille F-13344 (France) [INSERM U641, Institut Jean Roche, Marseille F-13344 (France); Universite de la Mediterranee, Faculte de Medecine Secteur Nord, IFR 11, Marseille F-13344 (France); Clare, Jeffrey J. [Eaton Pharma Consulting, Eaton Socon, Cambridgeshire PE19 8EF (United Kingdom)] [Eaton Pharma Consulting, Eaton Socon, Cambridgeshire PE19 8EF (United Kingdom); Debanne, Dominique [INSERM U641, Institut Jean Roche, Marseille F-13344 (France) [INSERM U641, Institut Jean Roche, Marseille F-13344 (France); Universite de la Mediterranee, Faculte de Medecine Secteur Nord, IFR 11, Marseille F-13344 (France); Alcaraz, Gisele, E-mail: gisele.alcaraz@univmed.fr [INSERM U641, Institut Jean Roche, Marseille F-13344 (France) [INSERM U641, Institut Jean Roche, Marseille F-13344 (France); Universite de la Mediterranee, Faculte de Medecine Secteur Nord, IFR 11, Marseille F-13344 (France)

2011-07-29T23:59:59.000Z

425

Directives Help  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

All DOE directives are available through this site. While it may seem overwhelming, given the number of documents, we have provided a number of ways in which you may get to the information you need.

426

Safe epoxy encapsulant for high voltage magnetics  

SciTech Connect (OSTI)

This paper describes the use of Formula 456, an aliphatic amine cured epoxy for impregnating coils and high voltage transformers. Sandia has evaluated a number of MDA-free epoxy encapsulants which relied on either anhydride or other aromatic amine curing agents. The use of aliphatic amine curing agents was more recently evaluated and has resulted in the definition of Formula 456 resin. Methylene dianiline (MDA) has been used for more than 20 years as the curing agent for various epoxy formulations throughout the Department of Energy and much of industry. Sandia National Laboratories began the process of replacing MDA with other formulations because of regulations imposed by OSHA on the use of MDA. OSHA has regulated MDA because it is a suspect carcinogen. Typically the elimination of OSHA-regulated materials provides a rare opportunity to qualify new formulations in a range of demanding applications. It was important to take full advantage of that opportunity, although the associated materials qualification effort was costly. Small high voltage transformers are one of those demanding applications. The successful implementation of the new formulation for high reliability transformers will be described. The test results that demonstrate the parts are qualified for use in DOE weapon systems will be presented.

Sanchez, R.O.; Archer, W.E.

1998-01-01T23:59:59.000Z

427

Effect of Applied Toroidal Electric Field on the Growth/Decay of Plateau-Phase Runaway Electron Currents in DIII-D  

SciTech Connect (OSTI)

Large relativistic runaway electron currents (0.1-0.5 MA) persisting for similar to 100 ms are created in the DIII-D tokamak during rapid discharge shut down caused by argon pellet injection. Slow upward and downward ramps in runaway currents were found in response to externally applied loop voltages. Comparison between the observed current growth/decay rate and the rate expected from the knock-on avalanche mechanism suggests that classical collisional dissipation of runaways alone cannot account for the measured growth/damping rates. It appears that a fairly constant anomalous dissipation rate of order 10 s(-1) exists, possibly stemming from radial transport or direct orbit losses to the vessel walls, although the possibility of an apparent loss due to current profile shrinking cannot be ruled out at present.

Hollmann, E. M. [University of California, San Diego; Parks, P. B. [General Atomics; Humphrey, D. A. [General Atomics, San Diego; Brooks, N. H. [General Atomics, San Diego; Commaux, Nicolas JC [ORNL; Eidietis, N. W. [General Atomics, San Diego; Evans, T.E. [General Atomics, San Diego; James, A. N. [University of California, San Diego; Jernigan, T. C. [Oak Ridge National Laboratory (ORNL); Jernigan, Thomas C [ORNL; Munoz, J. [Oak Ridge Associated Universities (ORAU); Strait, E. J. [General Atomics, San Diego; Tsui, C. [University of Toronto, Toronto, ON, Canada; Wesley, J. C. [General Atomics; Yu, J.H. [University of California, San Diego

2011-01-01T23:59:59.000Z

428

IEEE Applied Power Elecb"onics Confererice (APEC '93) Record, pp. 58-64, San Diego, March 1993. Current-Fed Multi-Resonant DC-DC Converter  

E-Print Network [OSTI]

.: +(972) 57461-561; FAX: +(972) 57281-340; Email: SBY@BGUEE.BI1NET Department of ElecUical and Computer at the output, a high voltage gain and zero voltage switching over a iarge range of output voitage against short circuit at the output while maintaining Zero Voltage Switching (ZVS) or Zero Current

429

Power Smoothing Control in a Grid-Connected Marine Current Turbine System for Compensating  

E-Print Network [OSTI]

Power Smoothing Control in a Grid-Connected Marine Current Turbine System for Compensating Swell d-axis and q-axis inductances g, g Grid inductance and resistance Pole pair number R Turbine blade-axis and q-axis voltages Turbine and generator power difference , g Rotor position, grid voltage angle

Boyer, Edmond

430

Design of a Robust Digital Current Controller for a Grid Connected Interleaved Inverter  

E-Print Network [OSTI]

Design of a Robust Digital Current Controller for a Grid Connected Interleaved Inverter M. A for a three- phase voltage source grid-connected interleaved inverter. Each phase consists of 6 half small output filter capacitors are required which provide high impedance to grid voltage harmonics

431

Gridless, very low energy, high-current, gaseous ion source  

SciTech Connect (OSTI)

We have made and tested a very low energy gaseous ion source in which the plasma is established by a gaseous discharge with electron injection in an axially diverging magnetic field. A constricted arc with hidden cathode spot is used as the electron emitter (first stage of the discharge). The electron flux so formed is filtered by a judiciously shaped electrode to remove macroparticles (cathode debris from the cathode spot) from the cathode material as well as atoms and ions. The anode of the emitter discharge is a mesh, which also serves as cathode of the second stage of the discharge, providing a high electron current that is injected into the magnetic field region where the operating gas is efficiently ionized. In this discharge configuration, an electric field is formed in the ion generation region, accelerating gas ions to energy of several eV in a direction away from the source, without the use of a gridded acceleration system. Our measurements indicate that an argon ion beam is formed with an energy of several eV and current up to 2.5 A. The discharge voltage is kept at less than 20 V, to keep below ion sputtering threshold for cathode material, a feature which along with filtering of the injected electron flow, results in extremely low contamination of the generated ion flow.

Vizir, A. V.; Oks, E. M. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation); State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Shandrikov, M. V.; Yushkov, G. Yu. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation)

2010-02-15T23:59:59.000Z

432

Eliminate Voltage Unbalance | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

unbalance. Unbalanced currents lead to torque pulsations, increased vibrations and mechanical stresses, increased losses resulting in lower efficiency, and motor overheating,...

433

Generation of high charge state ions in vacuum arc ion sources by a ``current jump'' method  

SciTech Connect (OSTI)

In the investigation of ion charge state distributions (CSD) in vacuum arc plasmas, good correlation between increase in arc operating voltage and mean ion charge state has been established. Therefore, to increase the mean charge state of a vacuum arc plasma, it is necessary to find ways to increase the arc operating voltage. The voltage can be increased via transients associated with the arc current by means of which a rather high operation voltage can be established across the discharge gap. Experiments were performed both in Tomsk and Berkeley with the discharge system of a vacuum arc ion source. To effect a step current rise an additional power supply was connected to the usual vacuum arc supply. This power supply made it possible to increase the vacuum arc current up to 1 kA for several {micro}s. As a rule the current jump was produced after 100--200 {micro}s into the main discharge pulse when all principal parameters of the vacuum arc were already established. To measure the CSD a time-of-flight method was used. As followed from experiments, superposition of a short, high current pulse to the vacuum arc current pulse is accompanied by a jump in arc operation voltage. Subsequently during the current step the voltage falls exponentially to one hundred volts after the completion of the current jump, and the arc voltage takes its conventional value (20--40V). Because of this increase in arc operation voltage, an enhancement of high charge station ion fractions was observed. For example, with a Ti-cathode with conventional arc parameters there is only very small value to Ti{sup 4+} ion fraction in the vacuum arc plasma. Applying strong magnetic field increases the fraction of these ions up to 20% of the total beam current. The current jump enhanced this value up to 40%.

Bugaev, A.S.; Oks, E.M.; Yushkov, G.Y.; Brown, I.G.

1999-07-01T23:59:59.000Z

434

A dc superconducting fault current limiter using die-pressed  

Science Journals Connector (OSTI)

A model of a superconducting fault current limiter on a polycrystalline high-temperature superconductor basis is checked in the dc short circuit regime. Protection of load takes place under the conditions described in this paper. The use of ceramic materials with superconducting-normal metal-superconducting Josephson junction network having an S-type current-voltage characteristic (CVC) is shown to be effective for fault current limiter devices.

A G Mamalis; M I Petrov; D A Balaev; K A; D M Gohfeld; S V Militsyn; S G; V I Kirko; I N Vottea

2001-01-01T23:59:59.000Z

435

Properties of dielectric-barrier-free atmospheric pressure microplasma driven by submicrosecond dc pulse voltage  

SciTech Connect (OSTI)

Atmospheric pressure microplasma driven by dc pulse is developed. This device has a simple structure comprised of a flowing helium (He) feed gas and dielectric-free metal electrodes without an external current limiting resistor. It is shown that a stable glow mode plasma can be sustained without arc runaway by limiting the voltage pulse width to shorter than 300 ns. The properties of the device are reported in terms of discharge current waveforms, rotational temperature of N{sub 2}{sup +}, and spatiotemporally resolved optical emission characteristics.

Ha, Chang-Seung; Choi, Joon-Young; Kim, Dong-Hyun; Park, Chung-Hoo; Lee, Hae June; Lee, Ho-Jun [Department of Electrical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

2009-08-10T23:59:59.000Z

436

Optical fiber imaging for high speed plasma motion diagnostics: Applied to low voltage circuit breakers  

SciTech Connect (OSTI)

An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1x10{sup 6} images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker.

McBride, J. W. [School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Balestrero, A.; Tribulato, G. [ABB SACE DIVISION, ABB S.p.A., Via Baioni, Bergamo 35 IT-24123 (Italy); Ghezzi, L. [ABB SACE DIVISION, ABB S.p.A., Viale dell'Industria, Vittuone (MI)18 IT-20010 (Italy); Cross, K. J. [Taicaan Ltd., 2 Venture Road, Southampton Science Park, Southampton, Hampshire SO16 7NP (United Kingdom)

2010-05-15T23:59:59.000Z

437

210 nature neuroscience volume 5 no 3 march 2002 Calcium entry into cells through voltage-gated Ca2+ channels  

E-Print Network [OSTI]

voltage-gated Ca2+ channels initiates a wide range of cellular processes including protein phosphorylation, gene expression and neurotransmitter release1. Neuronal Ca2+ channels consist of a pore-forming 1 by neurotransmitters inhibits Cav2.1 and Cav2.2 channels, which mediate P/Q-type and N- type Ca2+ currents

Palczewski, Krzysztof

438

High-brightness, high-current ion sources  

SciTech Connect (OSTI)

Several existing high-current dc ion sources are presented that yield positive ions and are based on gas discharges. Their common features are then outlined: extraction systems, required plasma qualities, and the production of ions from solid materials. Finally, from well-established laws, scaling rules for high-brightness ion beams are derived taking one specific case to determine the numerical constants. These rules predict that the current values of transportable beams scale proportionally to the 3/2 power of the extraction voltage, whereas the brightness strongly decreases with rising voltage.

Keller, R.

1985-01-01T23:59:59.000Z

439

High Temperature, High Voltage Fully Integrated Gate Driver Circuit  

Broader source: Energy.gov (indexed) [DOE]

driver circuit, 5-V on- chip voltage regulator, short-circuit protection, undervoltage lockout, bootstrap capacitor, dead time controller and temperature sensor * 0.8-micron,...

440

fault diagnosis of a high voltage transmission line using waveform ...  

E-Print Network [OSTI]

Oct 4, 2013 ... FAULT DIAGNOSIS OF A HIGH VOLTAGE TRANSMISSION LINE USING ... Fault types such as single line to ground, line to line, double line to ...

Ripunjoy Phukan

2013-10-04T23:59:59.000Z

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.


441

Treatment of model inland brackish groundwater reverse osmosis concentrate with electrodialysis — Part II: Sensitivity to voltage application and membranes  

Science Journals Connector (OSTI)

Abstract The objective of this research was to investigate the sensitivity of electrodialysis performance to variations in voltage application and membranes when treating brackish water reverse osmosis concentrate waste. Synthetic BWRO concentrates from Arizona and Texas of 7890–14,800 mg/L total dissolved solids were prepared with poly-phosphonate antiscalants. Experimentation was performed using a laboratory-scale electrodialyzer with two sets of membranes (AMV-CMV and PCSA-PCSK) with a nominal transfer area of 64 cm2 per membrane. Flow, pressure, conductivity, temperature, and pH were measured continuously, and periodic samples were analyzed for specific anion and cation concentrations. The BWRO concentrates were successfully treated with stack voltage applications of 0.5–1.5 V/cell-pair for salinity removal ratios up to 99% with current density less than 500 A/m2. This paper highlights that (1) the specific energy consumption was proportional to the applied voltage and equivalent concentration separated (i.e., approximately 0.03 kW h/m3 per Volt/cell-pair applied per meq/L separated); (2) lower voltage applications decreased the relative separation rate of sulfate compared to chloride; and (3) water transport by electro-osmosis was independent of voltage application or resulting current densities, while it is affected by the ion exchange membranes.

W. Shane Walker; Younggy Kim; Desmond F. Lawler

2014-01-01T23:59:59.000Z

442

Geomagnetically induced currents in the Uruguayan high-voltage power grid  

Science Journals Connector (OSTI)

......and uniform electric fields. IEEE Trans. Power Del. (1998) 13(4):1303-1308. Corbo...Geomagnetic disturbances and impacts upon power system operation. The Electric Power Engineering Handbook-Grigsby L.L., ed. (2007) 2nd edn......

R. Caraballo; L. Sánchez Bettucci; G. Tancredi

2013-01-01T23:59:59.000Z

443

Symbolic analysis of analog circuits containing voltage mirrors and current mirrors  

E-Print Network [OSTI]

Nacional de Astro?sica, Optica y Electro nica (INAOE),Nac- ional de Astro?sica, Optica y Electronica (INAOE),

Tlelo-Cuautle, E.; Sánchez-López, C.; Martínez-Romero, E.; Tan, Sheldon X.-D.

2010-01-01T23:59:59.000Z

444

Characteristics of output voltage and current of integrated nanogenerators Rusen Yang,1  

E-Print Network [OSTI]

is important for an independent, wireless, and sustainable operation of nanodevices.1 This is a critical step nanowires for converting mechanical energy into electricity.2­5 The NG takes advantage of the piezoelectric into ionic polarization charges that generate a piezo- electric potential; the Schottky barrier

Wang, Zhong L.

445

Phase-field modeling of switchable diode-like current-voltage ...  

E-Print Network [OSTI]

May 7, 2014 ... numerically minimizing the total free energy of F with respect to polarization ..... polarization showed similar I-V behavior (green line in Fig.

2014-10-12T23:59:59.000Z

446

Effect of interfacial oxide layers on the current-voltage characteristics of Al-Si contacts  

E-Print Network [OSTI]

space charge of opposite sign along with this double layer tends to make the work function independent of the Fermi level in the interior (which in turn depends on the impurity content). The difference in work function between a metal and a semi... for the transition from the semicon- SIll ductor to the metal, Ps and Pm are the density of states at the semi- conductor and metal respectively, f and f are the Fermi functions s m and kt is the crystal momentum component transverse to the barrier . Gray (16...

Nishizono, Taira

2012-06-07T23:59:59.000Z

447

Tunneling current of the contact between impurity-containing graphene nanoribbons  

SciTech Connect (OSTI)

The current-voltage characteristics of a tunneling contact between two graphene nanoribbons containing impurity atoms are obtained based on the previously calculated density of states. The dependences on the nanoribbon geometrical and energy characteristics are calculated.

Belonenko, M. B. [Volgograd Institute of Business (Laboratory of Nanotechnologies) (Russian Federation); Pak, A. V., E-mail: pak.anastasia@gmail.com; Lebedev, N. G. [Volgograd State University (Russian Federation)

2013-05-15T23:59:59.000Z

448

High voltage power supply with modular series resonant inverters  

DOE Patents [OSTI]

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.

Dreifuerst, Gary R. (Livermore, CA); Merritt, Bernard T. (Livermore, CA)

1995-01-01T23:59:59.000Z

449

High voltage power supply with modular series resonant inverters  

DOE Patents [OSTI]

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.

Dreifuerst, G.R.; Merritt, B.T.

1995-07-18T23:59:59.000Z

450

Simplified VO M&V Protocol Simplified Voltage Optimization (VO)  

E-Print Network [OSTI]

Simplified VO M&V Protocol 1 Simplified Voltage Optimization (VO) Measurement and Verification Protocol 1.0 Introduction 1.1 Purpose The Simplified Voltage Optimization (VO) Measurement and Verification requirements, and measurement and verification formulations are included as part of this Protocol. 1

451

Task Scheduling and Voltage Selection for Energy Minimization  

E-Print Network [OSTI]

system con gurations. 1. INTRODUCTION Energy consumption has become a primary concern in today's ICTask Scheduling and Voltage Selection for Energy Minimization Yumin Zhang Synopsys, Inc. 700 East-phase framework that inte- grates task assignment, ordering and voltage selection VS together to minimize energy

Hu, Xiaobo Sharon

452

IMPACT OF DYNAMIC VOLTAGE SCALING (DVS) ON CIRCUIT OPTIMIZATION  

E-Print Network [OSTI]

and dynamic power, respectively. Both gate sizing and Dual-VT are design-time techniques, which are applied to the circuit at a fixed voltage. On the other hand, DVS is a run-time technique and implies that the circuit will be operating at a different voltage...

Esquit Hernandez, Carlos A.

2010-01-16T23:59:59.000Z

453

REFINED RFP LOOP VOLTAGE CALCULATION J.C. Sprott  

E-Print Network [OSTI]

is the stored magnetic energy, Up is the plasma energy, and 'E is the global energy confinement time, which-of-merit for RFP devices is the loop voltage. Low loop voltage implies high plasma temperature and long energy is smallest if the loop is as close to the outside of the shell and as far from the primary windings

Sprott, Julien Clinton

454

LOW VOLTAGE ANALOG CIRCUITS USING STANDARD CMOS TECHNOLOGY  

E-Print Network [OSTI]

LOW VOLTAGE ANALOG CIRCUITS USING STANDARD CMOS TECHNOLOGY Phillip E. Allen, Benjamin J. Blalock, and Gabriel A. Rincon School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta supply voltages in CMOS integrated circuits. As the channel lengths of CMOS technology decrease

Rincon-Mora, Gabriel A.

455

Nonlinear voltages in multiple-lead coherent conductors  

Science Journals Connector (OSTI)

We use the generalized S-matrix approach to study multiple-lead coherent conductors in the case of finite applied voltages. In this framework we discuss the transverse voltage arising in a four-lead conductor with two symmetric biased leads.

Gordey B. Lesovik and Carlo Presilla

1993-01-15T23:59:59.000Z

456

The Cavendish high-voltage laboratory 1935–39  

Science Journals Connector (OSTI)

...the period covered. Nuclear Transmutation|Cavendish...development of high-voltage nuclear transmutation equipment...experimental work in nuclear physics though he continued...a new high-voltage accelerator therefore fell mainly...doubler circuit with six vacuum rectifiers forming a...

1999-01-01T23:59:59.000Z

457

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents [OSTI]

A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

1995-08-08T23:59:59.000Z

458

Derivation of the open-circuit voltage of organic solar cells  

Science Journals Connector (OSTI)

Organic photovoltaic cells have improved in efficiency from 1% two decades ago to over 10% today. Continued improvement necessitates a theoretical understanding of the factors determining efficiency. Organic photovoltaic efficiency can be parameterized in terms of open-circuit voltage, short-circuit current, and fill factor. Here we present a theory that explains the dependencies of open-circuit voltage on semiconductor energy levels, light intensity, solar cell and light-source temperatures, charge-carrier recombination, and external fluorescence efficiency. The present theory also explains why recombination at the donor-acceptor heterointerface is a dominant process in heterojunction-based cells. Furthermore, the Carnot efficiency appears, highlighting the connection to basic thermodynamics. The theory presented here is consistent with and builds on the experimental and theoretical observations already in the literature. Crucially, the present theory can be straightforwardly derived in a line-by-line fashion using standard tools from statistical physics.

Douglas B. Staple; Patricia A. K. Oliver; Ian G. Hill

2014-05-20T23:59:59.000Z

459

Spark-safe low-voltage detonator  

DOE Patents [OSTI]

A column of explosive in a low-voltage detonator which makes it spark-safe ncludes an organic secondary explosive charge of HMX in the form of a thin pad disposed in a bore of a housing of the detonator in an ignition region of the explosive column and adjacent to an electrical ignition device at one end of the bore. The pad of secondary charge has an axial thickness within the range of twenty to thirty percent of its diameter. The explosive column also includes a first explosive charge of CP disposed in the housing bore in the ignition region of the explosive column next to the secondary charge pad on a side opposite from the ignition device. The first CP charge is loaded under sufficient pressure, 25 to 40 kpsi, to provide mechanical confinement of the pad of secondary charge and physical coupling thereof with the ignition device. The explosive column further includes a second explosive charge of CP disposed in the housing bore in a transition region of the explosive column next to the first CP charge on a side opposite from the pad of secondary charge. The second CP charge is loaded under sufficient pressure, about 10 kpsi, to allow occurrence of DDT. The first explosive CP charge has an axial thickness within the range of twenty to thirty percent of its diameter, whereas the second explosive CP charge contains a series of increments (nominally 4) each of which has an axial thickness-to-diameter ratio of one to two.

Lieberman, Morton L. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

460

Bonfire-safe low-voltage detonator  

DOE Patents [OSTI]

A column of explosive in a low-voltage detonator which makes it bonfire-safe includes a first layer of an explosive charge of CP, or a primary explosive, and a second layer of a secondary organic explosive charge, such as PETN, which has a degradation temperature lower than the autoignition temperature of the CP or primary explosives. The first layer is composed of a pair of increments disposed in a bore of a housing of the detonator in an ignition region of the explosive column and adjacent to and in contact with an electrical ignition device at one end of the bore. The second layer is composed of a plurality of increments disposed in the housing bore in a transition region of the explosive column next to and in contact with the first layer on a side opposite from the ignition device. The first layer is loaded under a sufficient high pressure, 25 to 40 kpsi, to achieve ignition, whereas the second layer is loaded under a sufficient low pressure, about 10 kpsi, to allow occurrence of DDT. Each increment of the first and second layers has an axial length-to-diameter ratio of one-half.

Lieberman, Morton L. (Albuquerque, NM)

1990-01-01T23:59:59.000Z

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.


461

Definition: Automated Voltage And Var Control | Open Energy Information  

Open Energy Info (EERE)

Voltage And Var Control Voltage And Var Control Jump to: navigation, search Dictionary.png Automated Voltage And Var Control Automated voltage and VAR control requires coordinated operation of reactive power resources such as capacitor banks, voltage regulators, transformer load-tap changers, and distributed generation (DG) with sensors, controls, and communications systems. These devices could operate autonomously in response to local events or in response to signals from a central control system.[1] View on Wikipedia Wikipedia Definition Also Known As Volt-VAR Control (VVC) Related Terms smart grid, Reactive Power References ↑ SmartGrid.gov 'Description of Functions' An i LikeLike UnlikeLike You like this.Sign Up to see what your friends like. nline Glossary Definition Retrieved from

462

Living and Working Safely Around High-Voltage Power Lines.  

SciTech Connect (OSTI)

High-voltage transmission lines can be just as safe as the electrical wiring in the homes--or just as dangerous. The crucial factor is ourselves: they must learn to behave safely around them. This booklet is a basic safety guide for those who live and work around power lines. It deals primarily with nuisance shocks due to induced voltages, and with potential electric shock hazards from contact with high-voltage lines. References on possible long-term biological effects of transmission lines are shown. In preparing this booklet, the Bonneville Power Administration has drawn on more than 50 years of experience with high-voltage transmission. BPA operates one of the world`s largest networks of long-distance, high-voltage lines. This system has more than 400 substations and about 15,000 miles of transmission lines, almost 4,400 miles of which are operated at 500,000 volts.

United States. Bonneville Power Administration.

2001-06-01T23:59:59.000Z

463

Variable Voltage Substation Electric Fire and Emergency Response  

Broader source: Energy.gov [DOE]

Variable Voltage Substation Electric Fire and Emergency Response My question is from an emergency response perspective. You stated that it took ~ ½ for electricians to de-energize the electrical components before firefighters were allowed in to fight the fire. This delay causes more damage to equipment and potential propagation of the fire. Is there not a “master” breaker or switch? You’ve brought up a very good point. It gave me a good opportunity to discuss this with our Facilities Department and get a better understanding of the infrastructure upgrade plans. The direct answer to your question is “Yes, but…” Yes, there are “master” breakers and switches, but we can’t control them remotely. SLAC’s AC electrical distribution system at present is manual breakers – we have not installed the infrastructure to remotely control them (except see below). We recently underwent an upgrade to our Master Substation that will allow us to remotely control some high voltage breakers in the future, but we aren’t there yet. We do recognize the value in having this capability (and more importantly, our vulnerability in NOT having it), and have begun the preliminary planning to make this happen. One issue were are working on is cyber security for the power distribution networked infrastructure. Before we install the capability to remotely control the main electrical breakers, we are planning the infrastructure with our Information Technologies organization to ensure we have a robust secure network that is protected from unauthorized access. Once the cyber security issues are addressed and funded, we’re probably 5-10 years out from having remote operation capability due to limited resources to fund and install the infrastructure. Having said the above, we do have the capability of remotely opening the VVS Secondary Main Breakers – the ones that send power to the modulator distribution breakers - from our control room. Those breakers are integral parts of our safety systems in that interlock violation causes the breakers to open and remove power to the klystrons. But everything else is manual only. That remote operation capability would not have helped us in this case, as the VVS Secondary Main Breaker was the one that fried. We needed to open the breaker upstream of the VVS. Thanks for your interest. Let me know if I can provide further information.

464

Direct costing  

E-Print Network [OSTI]

oau 5e reduced. Under the same oonOitions, even ~Me on a bread scale entails not mere1y the conduct of the direct oyeraticns cf yrccessing the materials into finished products, but also the performance of auxiliary functions. these may 'ba power y... purposes have been advanced as folkway le Most of a o03RyaxO' 8 products Grc usual13r sold at prices which oovex' full product costs y plus 861ling a%el administrative expenses, plus normal profit. The inventoi~ valuate. on should be consistent...

Browning, Donald Bullock

2012-06-07T23:59:59.000Z

465

Definition: Electric current | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Electric current Jump to: navigation, search Dictionary.png Electric current The flow of electric charge or electrical energy (electricity); commonly measured in amperes.[1][2] View on Wikipedia Wikipedia Definition An electric current is a flow of electric charge through an electrical conductor. Electric charge flows when there is voltage present across a conductor. In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in a plasma. The SI unit for measuring an electric current is the ampere, which is the flow of electric charges through a surface at the rate of one coulomb per second.

466

Autonomous Control of Inverter-Interfaced Distributed Generation Units for Harmonic Current Filtering and  

E-Print Network [OSTI]

Autonomous Control of Inverter-Interfaced Distributed Generation Units for Harmonic Current-interfaced Distributed Generation (DG) units, which can autonomously share harmonic currents and resonance damping, such that harmonic resonances and voltage distortions can be damped. To autonomously share harmonic currents, a droop

Chen, Zhe

467

Improving waveform quality in direct power control of DFIG using fuzzy controller  

Science Journals Connector (OSTI)

This paper proposes a new direct power control (DPC) strategy of double-fed induction generator using fuzzy logic controller. The active and reactive power equations are expanded, and effects of voltage vecto...

H. Z. Boroujeni; M. F. Othman; A. H. Shirdel…

2014-11-01T23:59:59.000Z

468

Efficient Compression and Handling of Current Source Model Library Waveforms  

E-Print Network [OSTI]

, voltage and process space, thus further compounding the library size problem. Finally, the noise and power, e.g., Nangate public library stores waveforms with a minimal number of points, but on a nonEfficient Compression and Handling of Current Source Model Library Waveforms Safar Hatami1 , Peter

Pedram, Massoud

469

Monolithically interconnected GaAs solar cells: A new interconnection technology for high voltage solar cell output  

SciTech Connect (OSTI)

Photovoltaic linear concentrator arrays can benefit from high performance solar cell technologies being developed at AstroPower. Specifically, these are the integration of thin GaAs solar cell and epitaxial lateral overgrowth technologies with the application of monolithically interconnected solar cell (MISC) techniques. This MISC array has several advantages which make it ideal for space concentrator systems. These are high system voltage, reliable low cost monolithically formed interconnections, design flexibility, costs that are independent of array voltage, and low power loss from shorts, opens, and impact damage. This concentrator solar cell will incorporate the benefits of light trapping by growing the device active layers over a low-cost, simple, PECVD deposited silicon/silicon dioxide Bragg reflector. The high voltage-low current output results in minimal 12R losses while properly designing the device allows for minimal shading and resistance losses. It is possible to obtain open circuit voltages as high as 67 volts/cm of solar cell length with existing technology. The projected power density for the high performance device is 5 kW/m for an AMO efficiency of 26% at 1 5X. Concentrator solar cell arrays are necessary to meet the power requirements of specific mission platforms and can supply high voltage power for electric propulsion systems. It is anticipated that the high efficiency, GaAs monolithically interconnected linear concentrator solar cell array will enjoy widespread application for space based solar power needs. Additional applications include remote man-portable or ultra-light unmanned air vehicle (UAV) power supplies where high power per area, high radiation hardness and a high bus voltage or low bus current are important. The monolithic approach has a number of inherent advantages, including reduced cost per interconnect and increased reliability of array connections. There is also a high potential for a large number of consumer products.

Dinetta, L.C.; Hannon, M.H.

1995-10-01T23:59:59.000Z

470

Peak Power Bi-directional Transfer From High Speed Flywheel to Electrical Regulated Bus Voltage System  

E-Print Network [OSTI]

were performed to determine the energy transfer capabilities of a flywheel coupled high speed permanent magnet synchronous machine through the proposed system's energy storage tank. Results are presented

Szabados, Barna

471

Electro-optic voltage sensor with Multiple Beam Splitting  

DOE Patents [OSTI]

A miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

Woods, Gregory K. (Cornelius, OR); Renak, Todd W. (Idaho Falls, ID); Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID)

2000-01-01T23:59:59.000Z

472

Electro-optic voltage sensor with beam splitting  

DOE Patents [OSTI]

The invention is a miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware typically found in the prior art. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

Woods, Gregory K. (Cornelius, OR); Renak, Todd W. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Crawford, Thomas M. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

473

Panel Session: Optimization Techniques in Voltage Collapse Analysis," IEEE PES Summer Meeting, San Diego, July 14, 1998. Applications of Optimization to Voltage Collapse Analysis  

E-Print Network [OSTI]

Panel Session: Optimization Techniques in Voltage Collapse Analysis," IEEE PES Summer Meeting, San Diego, July 14, 1998. Applications of Optimization to Voltage Collapse Analysis Claudio A. Ca|Thispaper describesseveralapplica- tions of optimization for voltage stability analysis VSA of power systems. Voltage stability prob

Cañizares, Claudio A.

474

Built-in voltage of organic bulk heterojuction p-i-n solar cells measured by electroabsorption spectroscopy  

SciTech Connect (OSTI)

We investigate the influence of the built-in voltage on the performance of organic bulk heterojuction solar cells that are based on a p-i-n structure. Electrical doping in the hole and the electron transport layer allows to tune their work function and hence to adjust the built-in voltage: Changing the doping concentration from 0.5 to 32 wt% induces a shift of the work function towards the transport levels and increases the built-in voltage. To determine the built-in voltage, we use electroabsorption spectroscopy which is based on an evaluation of the spectra caused by a change in absorption due to an electric field (Stark effect). For a model system with a bulk heterojunction of BF-DPB and C{sub 60}, we show that higher doping concentrations in both the electron and the hole transport layer increase the built-in voltage, leading to an enhanced short circuit current and solar cell performance.

Siebert-Henze, E., E-mail: ellen.siebert@iapp.de; Lyssenko, V. G.; Fischer, J.; Tietze, M.; Brueckner, R.; Schwarze, M.; Vandewal, K.; Ray, D.; Riede, M.; Leo, K. [Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden (Germany)] [Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden (Germany)

2014-04-15T23:59:59.000Z

475

Restoration and testing of an HTS fault current controller  

SciTech Connect (OSTI)

A three-phase, 1200 A, 12.5 kV fault current controller using three HTS 4 mH coils, was built by industry and tested in 1999 at the Center Substation of Southern California Edison in Norwalk, CA. During the testing, it appeared that each of the three single-phase units had experienced a voltage breakdown, one externally and two internally. Los Alamos National Laboratory (LANL) was asked by DOE to restore the operation of the fault current controller provided the HTS coils had not been damaged during the initial substation tests. When the internally-failed coil vacuum vessels were opened it became evident that in these two vessels, a flashover had occurred at the high voltage bus section leading to the terminals of the superconducting coil. An investigation into the failure mechanism resulted in six possible causes for the flashover. Based on these causes, the high voltage bus was completely redesigned. Single-phase tests were successfully performed on the modified unit at a 13.7 kV LANL substation. This paper presents the postulated voltage flashover failure mechanisms, the new high voltage bus design which mitigates the failure mechanisms, the sequence of tests used to validate the new design, and finally, the results of variable load and short-circuit tests with the single-phase unit operating on the LANL 13.7 kV substation.

Waynert, J. A. (Joseph A.); Boenig, H. (Heinrich E.); Mielke, C. H. (Charles H.); Willis, J. O. (Jeffrey O.); Burley, B. L. (Burt L.)

2002-01-01T23:59:59.000Z

476

Direct power control of grid connected PV systems with three level NPC inverter  

SciTech Connect (OSTI)

This paper presents the control of a three-level Neutral Point Clamped (NPC) voltage source inverter for grid connected photovoltaic (PV) systems. The control method used is the Extended Direct Power Control (EDPC), which is a generic approach for Direct Power Control (DPC) of multilevel inverters based on geometrical considerations. Maximum Power Point Tracking (MPPT) algorithms, that allow maximal power conversion into the grid, have been included. These methods are capable of extracting maximum power from each of the independent PV arrays connected to each DC link voltage level. The first one is a conventional MPPT which outputs DC link voltage references to EDPC. The second one is based on DPC concept. This new MPPT outputs power increment references to EDPC, thus avoiding the use of a DC link voltage regulator. The whole control system has been tested on a three-level NPC voltage source inverter connected to the grid and results confirm the validity of the method. (author)

Alonso-Martinez, Jaime; Eloy-Garcia, Joaquin; Arnaltes, Santiago [Dept. of Electrical Engineering, University Carlos III of Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain)

2010-07-15T23:59:59.000Z

477

Direct Water Splitting under Visible Light with a Nanostructured Photoanode and GaInP2 Photocathode  

SciTech Connect (OSTI)

Thin films of hematite nanorod and GaInP2 were used for direct water splitting under visible light. In open circuit conditions, the potential of hematite shifted cathodically and that of GaInP2 anodically, which generated an open circuit voltage between the two electrodes. In short circuit condition, the combination of the two photoelectrodes can split water under visible light illumination, though with a very low current of {micro}A/cm2 level even at 1 W/cm2 light. By means of chopped light, we found that hematite nanorod has a low photocurrent, which is responsible for the low short circuit current of the 2-electrode combination. The low photoresponse of hematite nanorods is due to the recombination of photo- generated charges, low holes mobility, and short diffusion length.

Wang, H.; Deutsch, T.; Turner, J.

2008-01-01T23:59:59.000Z

478

Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits  

DOE Patents [OSTI]

A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

Campbell, Ann. N. (13170-B Central SE #188, Albuquerque, NM 87123); Anderson, Richard E. (2800 Tennessee NE, Albuquerque, NM 87110); Cole, Jr., Edward I. (2116 White Cloud NE, Albuquerque, NM 87112)

1995-01-01T23:59:59.000Z

479

Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits  

DOE Patents [OSTI]

A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits are disclosed. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits. 17 figs.

Campbell, A.N.; Anderson, R.E.; Cole, E.I. Jr.

1995-11-07T23:59:59.000Z

480

3-TFT OLED Pixel Circuit for High Stability with In-pixel Current Source Ting Liu and James C. Sturm  

E-Print Network [OSTI]

of Materials, Princeton University, Princeton, NJ 08544 USA Abstract A new 3-TFT voltage-programmed pixel-pixel current source, threshold voltage shift compensation, AMOLED pixel circuit 1. Introduction Active) of the OLED is a blanket cathode shared by all the pixels. During a frame time, the pixel operates in two

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