Sample records for dc direct current

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

    E-Print Network [OSTI]

    Tidd, Chad N. (Chad Norman)

    2010-01-01T23:59:59.000Z

    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 ...

  2. Minimization of DC Reactor and Operation Characteristics of Direct-Power-Controlled Current-Source PWM Rectifier

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Minimization of DC Reactor and Operation Characteristics of Direct-Power-Controlled Current describes a direct-power-controlled current-source PWM rectifier, and presents operation characteristics modes on the basis of a relay control technique of instantaneous active and reactive power, using

  3. Bi-directional dc-dc Converter

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

    Purpose of Work for FY08 1. Vehicle modeling, simulation, and operation voltages optimization. 2. DC-DC Power converter and control modeling. 3. Silicon Carbide device...

  4. Bi-directional dc-dc Converter

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

    MTBF Dc-dc Fabrication Validation Data Performance Validation BOM and Cost analysis EMIEMC Custom Components Fabrication Components Validation Vehicle System Review Phase-I...

  5. Bi-Directional DC-DC Converter for PHEV Applications

    SciTech Connect (OSTI)

    Abas Goodarzi

    2011-01-31T23:59:59.000Z

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

  6. Mitigation of geomagnetically induced and dc stray currents. Final report

    SciTech Connect (OSTI)

    Kappenman, J.G.

    1983-12-01T23:59:59.000Z

    This report primarily describes several approaches to mitigate the effects of Geomagnetic Induced Currents (GIC) and dc stray currents in power systems; the engineering and design considerations for a neutral capacitor blocking device; and development and testing of a prototype device of this type. Modeling of the power system for computation of GIC are described. Results from three field tests, for documenting the effects of GIC by injecting direct current (dc) into the neutrals of the transformers, are presented. Several mitigation concepts are discussed and evaluated. The concept of blocking GIC and dc stray currents by a neutral capacitor is addressed in detail. The development and testing of the prototype blocking device is described. The technical requirements and specifications for the application of these devices are also included. A perspective on the economics of GIC mitigation is included. The effect of GIC and dc stray currents on HVdc converter operation, supported by computer simulations, is also discussed.

  7. Author's Copy: J.B. Bancroft, A. Morrison, G. Lachapelle, Validation of GNSS under 500,000 V Direct Current (DC) transmission lines, Computers and Electronics in Agriculture, Volume 83, April 2012, Pages 58-67, ISSN 0168-1699, 10.1016/j.compag.2012.01.013

    E-Print Network [OSTI]

    Calgary, University of

    masking by the towers. Tests were conducted under a set of three transmission lines, two 500 kV DC lines Current (DC) transmission lines, Computers and Electronics in Agriculture, Volume 83, April 2012, Pages 58 Validation of GNSS under 500,000 Volt Direct Current (DC) Transmission Lines J.B. Bancroft*, A. Morrison

  8. Direct current uninterruptible power supply method and system

    DOE Patents [OSTI]

    Sinha, Gautam

    2003-12-02T23:59:59.000Z

    A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

  9. Development of a Novel Bi-Directional Isolated Multiple-Input DC-DC Converter

    SciTech Connect (OSTI)

    Li, H.

    2005-10-24T23:59:59.000Z

    There is vital need for a compact, lightweight, and efficient energy-storage system that is both affordable and has an acceptable cycle life for the large-scale production of electric vehicles (EVs) and hybrid electric vehicles (HEVs). Most of the current research employs a battery-storage unit (BU) combined with a fuel cell (FC) stack in order to achieve the operating voltage-current point of maximum efficiency for the FC system. A system block diagram is shown in Fig.1.1. In such a conventional arrangement, the battery is sized to deliver the difference between the energy required by the traction drive and the energy supplied by the FC system. Energy requirements can increase depending on the drive cycle over which the vehicle is expected to operate. Peak-power transients result in an increase of losses and elevated temperatures which result in a decrease in the lifetime of the battery. This research will propose a novel two-input direct current (dc) dc to dc converter to interface an additional energy-storage element, an ultracapacitor (UC), which is shown in Fig.1.2. It will assist the battery during transients to reduce the peak-power requirements of the battery.

  10. DC-DC converter current source fed naturally commutated brushless DC motor drive 

    E-Print Network [OSTI]

    Khopkar, Rahul Vijaykumar

    2004-11-15T23:59:59.000Z

    inductor and the huge number of turns needed to achieve these values of the inductances lead to huge resistive losses. Therefore, it is shown that it is possible to replace the controlled rectifier and the large inductor with a suitable dc-dc converter...

  11. Soft-commutated direct current motor

    DOE Patents [OSTI]

    Hsu, J.S.

    1999-07-27T23:59:59.000Z

    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.

  12. Near Time-Optimal Transient Response in DC-DC Buck Converters Taking into Account the Inductor Current Limit

    E-Print Network [OSTI]

    -load transient responses [1-15]. In its simplest form, the TOC responds to a step load change with a singleNear Time-Optimal Transient Response in DC-DC Buck Converters Taking into Account the Inductor transient response of a DC-DC buck converter. The concept of current- limited, time-optimal control (CL

  13. Abstract--Environmentally friendly technologies such as photovoltaics and fuel cells are DC sources. In the current power

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Abstract--Environmentally friendly technologies such as photovoltaics and fuel cells are DC sources in pollution [1]. The most well-known green technologies include photovoltaics and wind turbines. Although fuel, fuel cells and photovoltaics, produce direct current (DC). Currently, power system infrastructures

  14. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    SciTech Connect (OSTI)

    Garbesi, Karina; Vossos, Vagelis; Sanstad, Alan; Burch, Gabriel

    2011-10-13T23:59:59.000Z

    An increasing number of energy efficient appliances operate on direct current (DC) internally, offering the potential to use DC from renewable energy systems directly and avoiding the losses inherent in converting power to alternating current (AC) and back. This paper investigates that potential for net-metered residences with on-site photovoltaics (PV) by modeling the net power draw of the ‘direct-DC house’ with respect to today’s typical configuration, assuming identical DC-internal loads. Power draws were modeled for houses in 14 U.S. cities, using hourly, simulated PV-system output and residential loads. The latter were adjusted to reflect a 33% load reduction, representative of the most efficient DC-internal technology, based on an analysis of 32 electricity end-uses. The model tested the effect of climate, electric vehicle (EV) loads, electricity storage, and load shifting on electricity savings; a sensitivity analysis was conducted to determine how future changes in the efficiencies of power system components might affect savings potential. Based on this work, we estimate that net-metered PV residences could save 5% of their total electricity load for houses without storage and 14% for houses with storage. Based on residential PV penetration projections for year 2035 obtained from the National Energy Modeling System (2.7% for the reference case and 11.2% for the extended policy case), direct-DC could save the nation 10 trillion Btu (without storage) or 40 trillion Btu (with storage). Shifting the cooling load by two hours earlier in the day (pre-cooling) has negligible benefits for energy savings. Direct-DC provides no energy savings benefits for EV charging, to the extent that charging occurs at night. However, if charging occurred during the day, for example with employees charging while at work, the benefits would be large. Direct-DC energy savings are sensitive to power system and appliance conversion efficiencies but are not significantly influenced by climate. While direct-DC for residential applications will most likely arise as a spin-off of developments in the commercial sector—because of lower barriers to market entry and larger energy benefits resulting from the higher coincidence between load and insolation—this paper demonstrates that there are substantial benefits in the residential sector as well. Among residential applications, space cooling derives the largest energy savings from being delivered by a direct-DC system. It is the largest load for the average residence on a national basis and is particularly so in high-load regions. It is also the load with highest solar coincidence.

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

    SciTech Connect (OSTI)

    P.F. Schmit and N.J. Fisch

    2010-02-01T23:59:59.000Z

    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.

  16. Direct current power transmission systems

    SciTech Connect (OSTI)

    Padiyar, K.R.

    1991-01-01T23:59:59.000Z

    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.

  17. Application of direct pulsewidth modulation scheme to AC-DC converters: - a way to reduce ripple

    E-Print Network [OSTI]

    Zhang, Yuemin

    1993-01-01T23:59:59.000Z

    Modulation (ISPWM), 4 Direct Pulsewidth Modulation (DPWM). 15 5 Single Phase Half Controlled PWM ac-dc Converter . 6 Single Phase Full controlled PWM ac-dc Converter . 18 18 7 Simulation of SPWM ac-dc Converter. 20 8 Output Voltage Spectra of SPWM ac... 30 Balanced Three Phase Inputs 31 Output Voltage of A Three Phase Full Controlled ac-dc SPWM Converter. 42 32 Output Voltage of A Three Phase Full Controlled ac-dc EPWM Con- verter 33 Output Voltage of A Three Phase Full Controlled ac-dc ISPWM Con...

  18. average current dc: Topics by E-print Network

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

    ??Permanent magnet Brushless DC motor drives are being employed in newlinemany variable speed applications due to their high efficiency, silent operation, newlinecompact size,...

  19. Summary of multiterminal high-voltage direct current transmission technology

    SciTech Connect (OSTI)

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

    1984-05-01T23:59:59.000Z

    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.

  20. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    currently being entirely off-grid is much more costly andcan operate off the DC Flexzone Grid [20] and are developing

  1. Zeroing Transformer's DC Current in Resonant Converters with No Series Capacitors

    E-Print Network [OSTI]

    Gertsman, Student Member, IEEE and Sam Ben-Yaakov ,Fellow, IEEE Power Electronics Laboratory Department: www.ee.bgu.ac.il/~pel Abstract - DC current unbalance in the windings of a transformer may initiate the transformer's DC current to zero by correcting the asymmetry of the drive. This balancing control

  2. Low Cost, High Temperature, High Ripple Current DC Bus Capacitors...

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

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C. ape031liu2010p.pdf More Documents &...

  3. A pulser for medium-frequency modulated direct-current reactive sputter deposition of insulators

    E-Print Network [OSTI]

    Cao, Hui

    for medium-frequency modulated direct-current dc reactive sputter deposition of electrical insulators at the target surface inherent to high- deposition-rate reactive sputtering of electrical insulators. TypicallyA pulser for medium-frequency modulated direct-current reactive sputter deposition of insulators G

  4. Development of Low-Voltage and Large Current DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Development of Low-Voltage and Large Current DC Power Supply with High-Frequency Transformer excellent performance. Keywords DC power supply, low-voltage and large-current, high-frequency transformer Iobe (MACOHO Co., Ltd.) Abstract This paper describes low-voltage and large-current DC power supplies

  5. Effects of stray DC currents on the performance of large core type transformers

    SciTech Connect (OSTI)

    Christini, J.M.; Girgis, R.S. (ABB Power and Company, Inc., Muncie, IN (US))

    1992-01-01T23:59:59.000Z

    This paper presents the results of a study made on the effects of stray DC current on power transformer performance. A circuit model was developed to analyze the magnetic behavior of three-phase five-leg core type transformers. The magnetic field distribution was obtained for several different operating conditions by taking into account core geometry, core design, magnitude of D.C. current, and magnitude of A.C. voltage. The change in transformer performance is discussed.

  6. Sensorless Current Sharing in Digitally Controlled Two-Phase Buck DC-DC Converters

    E-Print Network [OSTI]

    current sharing [3-5, 9-11] and droop control [3, 6, 7]. Active current sharing relies on current sensing, droop control methods emulate a finite output resistance in each paralleled module in order

  7. Multiphase soft switched DC/DC converter and active control technique for fuel cell ripple current elimination

    DOE Patents [OSTI]

    Lai, Jih-Sheng (Blacksburg, VA); Liu, Changrong (Sunnyvale, CA); Ridenour, Amy (Salem, VA)

    2009-04-14T23:59:59.000Z

    DC/DC converter has a transformer having primary coils connected to an input side and secondary coils connected to an output side. Each primary coil connects a full-bridge circuit comprising two switches on two legs, the primary coil being connected between the switches on each leg, each full-bridge circuit being connected in parallel wherein each leg is disposed parallel to one another, and the secondary coils connected to a rectifying circuit. An outer loop control circuit that reduces ripple in a voltage reference has a first resistor connected in series with a second resistor connected in series with a first capacitor which are connected in parallel with a second capacitor. An inner loop control circuit that reduces ripple in a current reference has a third resistor connected in series with a fourth resistor connected in series with a third capacitor which are connected in parallel with a fourth capacitor.

  8. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    a-vis the impact of partial loads on power system componentto test the effect of partial load conditions and possibleto direct-DC savings. Partial load effects reduce estimates

  9. Impact of quasi-dc currents on three-phase distribution transformer installations

    SciTech Connect (OSTI)

    McConnell, B.W.; Barnes, P.R. (Oak Ridge National Lab., TN (United States)); Tesche, F.M. (Tesche (F.M.), Dallas, TX (United States)); Schafer, D.A. (Mission Research Corp., Albuquerque, NM (United States))

    1992-06-01T23:59:59.000Z

    This report summarizes a series of tests designed to determine the response of quasi-dc currents on three-phase power distribution transformers for electric power systems. In general, if the dc injection is limited to the primary side of a step-down transformer, significant harmonic distortion is noted and an increase in the reactive power demand results. For dc injection on the secondary (load) side of the step-down transformer the harmonic content at the secondary side is quite high and saturation occurs with a relatively low level of dc injection; however, the reactive power demand is significantly lower. These tests produced no apparent damage to the transformers. Transformer damage is dependent on the duration of the dc excitation, the level of the excitation, and on thermal characteristics of the transfer. The transformer response time is found to be much shorter than seen in power transformer tests at lower dc injection levels. This shorter response time suggests that the response time is strongly dependent on the injected current levels, and that higher levels of dc injection for shorter durations could produce very high reactive power demands and harmonic distortion within a few tenths of a second. The added reactive power load could result in the blowing of fuses on the primary side of the transformer for even moderate dc injection levels, and neutral currents are quite large under even low-level dc injection. This smoking neutral'' results in high-level harmonic injection into equipment via the neutral and in possible equipment failure.

  10. COMPLETELY DC-FREE DIRECT SEQUENCE SPECTRUM SPREADING SCHEME FOR LOW POWER, LOW COST, DIRECT CONVERSION TRANSCEIVER

    E-Print Network [OSTI]

    Lee, Thomas H.

    call the offset code spreading scheme. By employing the scheme, we can implement a direct- conversion- level design. The direct conversion receiver architecture combined with D-BPSK (differential, there are some design problems. In a direct conversion receiver, DC offset due to carrier leakage and 1/f mixer

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

    E-Print Network [OSTI]

    of the switch conduction and turn-off losses achieved by an energy recovery secondary clamp circuit an improved PSFB DC-DC converter using only a modified energy recovery clamp circuit attached at the secondaryPhase-Shifted Full Bridge DC-DC Converter with Energy Recovery Clamp and Reduced Circulating

  12. Fuzzy Estimation of DC Motor Winding Currents Innovatia Software

    E-Print Network [OSTI]

    Simon, Dan

    stator windings. an attractive alternative to current estimation using In order to implement an e. The fuzzy estimator is applied to actual motor wind- When the stator and rotor °uxes are not aligned the rotor stator winding current estimation. #12;2 Fuzzy Estimation The output of the correction mapping

  13. Development of Low-Voltage and Large-Current DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Development of Low-Voltage and Large-Current DC Power Supply with High-Frequency Transformer-voltage and large-current DC power supply with a high-frequency transformer coupling. The power supply is simply·,Zü"gg"X·C~R,êC"_N^"X Keywords: DC power supply, low-voltage and large-current, high-frequency transformer, leakage inductance 1

  14. Control of current and voltage oscillations in a short dc discharge making use of external auxiliary electrode

    E-Print Network [OSTI]

    Kaganovich, Igor

    Control of current and voltage oscillations in a short dc discharge making use of external://rsi.aip.org/about/rights_and_permissions #12;REVIEW OF SCIENTIFIC INSTRUMENTS 83, 103502 (2012) Control of current and voltage oscillations October 2012) A dc discharge with a hot cathode is subject to current and voltage plasma oscillations

  15. Optimization of Direct Current-Enhanced Radiofrequency Ablation: An Ex Vivo Study

    SciTech Connect (OSTI)

    Tanaka, Toshihiro, E-mail: toshihir@bf6.so-net.ne.jp; Isfort, Peter; Bruners, Philipp; Penzkofer, Tobias [RWTH Aachen University, Applied Medical Engineering, Helmholtz-Institute Aachen (Germany); Kichikawa, Kimihiko [Nara Medical University, Department of Radiology (Japan); Schmitz-Rode, Thomas; Mahnken, Andreas H. [RWTH Aachen University, Applied Medical Engineering, Helmholtz-Institute Aachen (Germany)

    2010-10-15T23:59:59.000Z

    The purpose of this study was to investigate the optimal setting for radiofrequency (RF) ablation combined with direct electrical current (DC) ablation in ex vivo bovine liver. An electrical circuit combining a commercially available RF ablation system with DC was developed. The negative electrode of a rectifier that provides DC was connected to a 3-cm multitined expandable RF probe. A 100-mH inductor was used to prevent electrical leakage from the RF generator. DC was applied for 15 min and followed by RF ablation in freshly excised bovine livers. Electric current was measured by an ammeter. Coagulation volume, ablation duration, and mean amperage were assessed for various DC voltages (no DC, 2.2, 4.5, and 9.0 V) and different RF ablation protocols (stepwise increase from 40 to 80 W, 40 W fixed, and 80 W fixed). Results were compared using Kruskal-Wallis and Mann-Whitney U test. Applying DC with 4.5 or 9.0 V, in combination with 40 W fixed or a stepwise increase of RF energy, resulted in significantly increased zone of ablation size compared with 2.2 V or no DC (P = 0.009). At 4.5 V DC, the stepwise increase of RF energy resulted in the same necrosis size as a 40 W fixed protocol (26.6 {+-} 3.9 vs. 26.5 {+-} 4.0 ml), but ablation duration was significantly decreased (296 {+-} 85 s vs. 423 {+-} 104 s; P = 0.028). Mean amperage was significantly lower at 4.5 V compared with 9.0 V (P = 0.028). Combining a stepwise increase of RF energy with a DC voltage of 4.5 V is most appropriate to increase coagulation volume and to minimize procedure time.

  16. Hybrid high direct current circuit interrupter

    DOE Patents [OSTI]

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

    1998-08-11T23:59:59.000Z

    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.

  17. Hybrid high direct current circuit interrupter

    SciTech Connect (OSTI)

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

    1996-12-31T23:59:59.000Z

    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.

  18. Operation of the DC current transformer intensity monitors at FNAL during run II

    SciTech Connect (OSTI)

    Crisp, J.; Fellenz, B.; Heikkinen, D.; Ibrahim, M.A.; Meyer, T.; Vogel, G.; /Fermilab

    2012-01-01T23:59:59.000Z

    Circulating beam intensity measurements at FNAL are provided by five DC current transformers (DCCT), one per machine. With the exception of the DCCT in the Recycler, all DCCT systems were designed and built at FNAL. This paper presents an overview of both DCCT systems, including the sensor, the electronics, and the front-end instrumentation software, as well as their performance during Run II.

  19. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    and energy-savings potential of using direct current (DC) generated by on-site renewablepotential, benefits, and barriers of using DC generated by on-site renewable energy

  20. Ver.2003.01.27 Development of Low-Voltage and Large-Current DC Power Supply

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    describes low-voltage and large-current DC power supplies with a high-frequency transformer coupling. Two Ver.2003.01.27 Development of Low-Voltage and Large-Current DC Power Supply-bridge inverter, an amorphous-core step down transformer and a schottky diode rectifier. One power supply operates

  1. Dynamic magnetization states of a spin valve in the presence of dc and ac currents: Synchronization, modification, and chaos

    E-Print Network [OSTI]

    Li, Charles

    Dynamic magnetization states of a spin valve in the presence of dc and ac currents: Synchronization and numerical calculations of dynamic magnetization states of a spin valve in the presence of dc and ac currents are expected to appear. In this paper, we consider a simple spin valve as a model system to study the problem

  2. Current Directions in Freight and Logistics Industry

    E-Print Network [OSTI]

    Minnesota, University of

    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

  3. Apparatuses and method for converting electromagnetic radiation to direct current

    DOE Patents [OSTI]

    Kotter, Dale K; Novack, Steven D

    2014-09-30T23:59:59.000Z

    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.

  4. Switch contact device for interrupting high current, high voltage, AC and DC circuits

    DOE Patents [OSTI]

    Via, Lester C.; Witherspoon, F. Douglas; Ryan, John M.

    2005-01-04T23:59:59.000Z

    A high voltage switch contact structure capable of interrupting high voltage, high current AC and DC circuits. The contact structure confines the arc created when contacts open to the thin area between two insulating surfaces in intimate contact. This forces the arc into the shape of a thin sheet which loses heat energy far more rapidly than an arc column having a circular cross-section. These high heat losses require a dramatic increase in the voltage required to maintain the arc, thus extinguishing it when the required voltage exceeds the available voltage. The arc extinguishing process with this invention is not dependent on the occurrence of a current zero crossing and, consequently, is capable of rapidly interrupting both AC and DC circuits. The contact structure achieves its high performance without the use of sulfur hexafluoride.

  5. Ferrosilicon smelting in a direct current furnace

    DOE Patents [OSTI]

    Dosaj, Vishu D. (Midland, MI); May, James B. (Midland, MI)

    1992-12-29T23:59:59.000Z

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

  6. Ferrosilicon smelting in a direct current furnace

    DOE Patents [OSTI]

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

    1992-12-29T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Cho, Sung Nae

    2013-01-01T23:59:59.000Z

    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 fluid models, where oscillations are attributed to 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 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 DC glow discharges. It is found that oscillation frequencies increase with ion's surface charge density, but at the rate which is significantly slower than it does with electric field. The presented mechanism also describes the self-sustained oscillations of ions in dusty plasmas, demonstrating that oscillations in dusty plasmas and DC glow disc...

  8. 232 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 17, NO. 2, MARCH 2002 Current Control Strategy for Brushless DC Motors

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    synchronous motor (PMSM), which is fed with sinusoidal currents 2) brushless dc motor (BDCM), which is fed, the power-to-weight ratio of PMSM and BDCM is higher than equivalent squirrel cage induction machines

  9. DC to DC power converters and methods of controlling the same

    DOE Patents [OSTI]

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

    2012-12-11T23:59:59.000Z

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

  10. Direct current, closed furnace silicon technology

    SciTech Connect (OSTI)

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

    1994-05-01T23:59:59.000Z

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

  11. Impact of quasi-dc currents on three-phase distribution transformer installations. Power Systems Technology Program

    SciTech Connect (OSTI)

    McConnell, B.W.; Barnes, P.R. [Oak Ridge National Lab., TN (United States); Tesche, F.M. [Tesche (F.M.), Dallas, TX (United States); Schafer, D.A. [Mission Research Corp., Albuquerque, NM (United States)

    1992-06-01T23:59:59.000Z

    This report summarizes a series of tests designed to determine the response of quasi-dc currents on three-phase power distribution transformers for electric power systems. In general, if the dc injection is limited to the primary side of a step-down transformer, significant harmonic distortion is noted and an increase in the reactive power demand results. For dc injection on the secondary (load) side of the step-down transformer the harmonic content at the secondary side is quite high and saturation occurs with a relatively low level of dc injection; however, the reactive power demand is significantly lower. These tests produced no apparent damage to the transformers. Transformer damage is dependent on the duration of the dc excitation, the level of the excitation, and on thermal characteristics of the transfer. The transformer response time is found to be much shorter than seen in power transformer tests at lower dc injection levels. This shorter response time suggests that the response time is strongly dependent on the injected current levels, and that higher levels of dc injection for shorter durations could produce very high reactive power demands and harmonic distortion within a few tenths of a second. The added reactive power load could result in the blowing of fuses on the primary side of the transformer for even moderate dc injection levels, and neutral currents are quite large under even low-level dc injection. This ``smoking neutral`` results in high-level harmonic injection into equipment via the neutral and in possible equipment failure.

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

    SciTech Connect (OSTI)

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

    1994-09-01T23:59:59.000Z

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

  13. Low energy electron-enhanced etching of Si(100) in hydrogen/helium direct-current plasma

    E-Print Network [OSTI]

    Dove, Patricia M.

    Low energy electron-enhanced etching of Si(100) in hydrogen/helium direct-current plasma H. P of a dc plasma reactor, and thus receives a large flux of low-energy electrons and hydrogen molecules-0269 Received 7 September 1994; accepted for publication 6 March 1995 Low energy electron-enhanced etching of Si

  14. New leading/trailing edge modulation strategies for two-stage AC/DC PFC adapters to reduce DC-link capacitor ripple current 

    E-Print Network [OSTI]

    Sun, Jing

    2007-09-17T23:59:59.000Z

    AC/DC adapters mostly employ two-stage topology: Power Factor Correction (PFC) pre-regulation stage followed by an isolated DC/DC converter stage. Low power AC/DC adapters require a small size to be competitive. Among their components, the bulk DC...

  15. 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.

  16. In Proc of Direct Methanol Fuel Cell Symposium, 199th Electrochem.l Soc. Mtg, Washington DC, 3/01.

    E-Print Network [OSTI]

    Wang, Chao-Yang

    In Proc of Direct Methanol Fuel Cell Symposium, 199th Electrochem.l Soc. Mtg, Washington DC, 3/01. MATHEMATICAL MODELING OF LIQUID-FEED DIRECT METHANOL FUEL CELLS Z. H. Wang and C. Y. Wang Electrochemical methanol fuel cells (DMFC). Diffusion and convection of both gas and liquid phases are considered

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

    E-Print Network [OSTI]

    Yancey, Billy Ferrall

    2011-08-08T23:59:59.000Z

    Difference Angle Variation 48 2. Input Voltage Deviation 62 B. Control Results 65 1. Input Voltage Deviation and Load Variation 65 2. Input Voltage Deviati on and Load Voltage Variations 68 3. Input Voltage Deviati... control 46 29 Converter currents for Scenario 1 50 30 Center link capacitor voltage for Scenario 1 50 31 Load voltage for Scenario 1 51 32 Original IDC converter currents 51 33 Magnitude of converter currents for Scenario 1 52 34...

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

    SciTech Connect (OSTI)

    Long, W F

    1982-09-01T23:59:59.000Z

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

  19. Phenomena of oscillations in atmospheric pressure direct current glow discharges

    SciTech Connect (OSTI)

    Liu, Fu-cheng [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)] [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Yan, Wen; Wang, De-zhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-12-15T23:59:59.000Z

    Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transform spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.

  20. Auxiliary resonant DC tank converter

    DOE Patents [OSTI]

    Peng, Fang Z. (Knoxville, TN)

    2000-01-01T23:59:59.000Z

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

  1. Amorphous Silicon Thin-Film Transistors with DC Saturation Current Half-Life of More than 100 Years

    E-Print Network [OSTI]

    as the time for the TFT drain current to fall by 50% under DC voltage bias in saturation, the half with either back-channel etched (BCE) or back-channel passivated (BCP) structures (Fig. 1). The BCP structure passivates the back-side of the TFT channel "in situ" at the cost of an extra mask step. The gate nitride

  2. Direct-Current Resistivity Survey At Blue Mountain Area (Fairbank...

    Open Energy Info (EERE)

    Blue Mountain Area (Fairbank Engineering Ltd, 2005) Exploration Activity Details Location Blue Mountain Area Exploration Technique Direct-Current Resistivity Survey Activity Date...

  3. anodal direct current: Topics by E-print Network

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

    a model is (more) Bridges, Nathaniel Reese 2011-01-01 15 Design of Reactances and Transformers Which Carry Direct Current Engineering Websites Summary: Design of Reactances and...

  4. Direct-Current Resistivity Survey At Kilauea Southwest Rift And...

    Open Energy Info (EERE)

    Southwest Rift And South Flank Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Kilauea...

  5. Direct-Current Resistivity At Kilauea Southwest Rift And South...

    Open Energy Info (EERE)

    Southwest Rift And South Flank Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity At Kilauea...

  6. 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...

  7. Magnetic resonance visualization of conductive structures by sequence-triggered direct currents and spin-echo phase imaging

    SciTech Connect (OSTI)

    Eibofner, Frank; Wojtczyk, Hanne; Graf, Hansjörg, E-mail: hansjoerg.graf@med.uni-tuebingen.de, E-mail: drGraf@t-online.de [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)] [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany); Clasen, Stephan [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)] [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)

    2014-06-15T23:59:59.000Z

    Purpose: Instrument visualization in interventional magnetic resonance imaging (MRI) is commonly performed via susceptibility artifacts. Unfortunately, this approach suffers from limited conspicuity in inhomogeneous tissue and disturbed spatial encoding. Also, susceptibility artifacts are controllable only by sequence parameters. This work presents the basics of a new visualization method overcoming such problems by applying sequence-triggered direct current (DC) pulses in spin-echo (SE) imaging. SE phase images allow for background free current path localization. Methods: Application of a sequence-triggered DC pulse in SE imaging, e.g., during a time period between radiofrequency excitation and refocusing, results in transient field inhomogeneities. Dependent on the additional z-magnetic field from the DC, a phase offset results despite the refocusing pulse. False spatial encoding is avoided by DC application during periods when read-out or slice-encoding gradients are inactive. A water phantom containing a brass conductor (water equivalent susceptibility) and a titanium needle (serving as susceptibility source) was used to demonstrate the feasibility. Artifact dependence on current strength and orientation was examined. Results: Without DC, the brass conductor was only visible due to its water displacement. The titanium needle showed typical susceptibility artifacts. Applying triggered DC pulses, the phase offset of spins near the conductor appeared. Because SE phase images are homogenous also in regions of persistent field inhomogeneities, the position of the conductor could be determined with high reliability. Artifact characteristic could be easily controlled by amperage leaving sequence parameters unchanged. For an angle of 30° between current and static field visualization was still possible. Conclusions: SE phase images display the position of a conductor carrying pulsed DC free from artifacts caused by persistent field inhomogeneities. Magnitude and phase images are acquired simultaneously under the same conditions without the use of extra measurement time. The presented technique offers many advantages for precise instrument localization in interventional MRI.

  8. A Superconducting transformer system for high current cable testing

    E-Print Network [OSTI]

    Godeke, A.

    2010-01-01T23:59:59.000Z

    A Superconducting Transformer System for High Current Cablea Direct-Current (DC) superconducting transformer system forhigh current test of superconducting cables. The transformer

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

    SciTech Connect (OSTI)

    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

    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.

  10. Direct-current effects on magnetization reversal properties of submicron-size permalloy patterns for radio-frequency devices.

    SciTech Connect (OSTI)

    Zhang, H.; Hoffmann, A.; Divan, R.; Wang, P.; Clemson Univ.

    2009-01-01T23:59:59.000Z

    Ferromagnetic resonance (FMR) spectroscopy is used to measure direct-current (dc) effects on the magnetization reversal properties of submicron-sized lateral patterned magnetic material. The observed FMR frequency-field relationship shows that for both 240 and 550 nm wide Permalloy (Py) nanowires the coercivity is reduced by {approx}33% when a 50 mA dc passes through the transmission line where the nanowires are incorporated. The temperature dependence of the coercivity has a {radical}T relationship which suggests the coherent rotation mode tendency in such 100 nm thick Py nanowires.

  11. Over-Current Protection Scheme for SiC Power MOSFET DC Circuit Breaker

    E-Print Network [OSTI]

    Zhang, Yuan; Liang, Yung C.

    2015-01-01T23:59:59.000Z

    V. Radun, “SiC based solid state power controller,” in 23tha solid-state circuit breaker based on SiC power MOSFET withSolid-state DC circuit breakers made of the modern wide bandgap power

  12. Investigation of helium ion production in constricted direct current plasma ion source with layered-glows

    SciTech Connect (OSTI)

    Lee, Yuna [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Yeong-Shin [Samsumg Electronics Co. Ltd., Gyeonggi 445-701 (Korea, Republic of)] [Samsumg Electronics Co. Ltd., Gyeonggi 445-701 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of) [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-02-15T23:59:59.000Z

    Generation of helium ions is experimentally investigated with a constricted direct current (DC) plasma ion source operated at layered-glow mode, in which electrons could be accelerated through multiple potential structures so as to generate helium ions including He{sup 2+} by successive ionization collisions in front of an extraction aperture. The helium discharge is sustained with the formation of a couple of stable layers and the plasma ball with high density is created near the extraction aperture at the operational pressure down to 0.6 Torr with concave cathodes. The ion beam current extracted with an extraction voltage of 5 kV is observed to be proportional to the discharge current and inversely proportional to the operating pressure, showing high current density of 130 mA/cm{sup 2} and power density of 0.52 mA/cm{sup 2}/W. He{sup 2+} ions, which were predicted to be able to exist due to multiple-layer potential structure, are not observed. Simple calculation on production of He{sup 2+} ions inside the plasma ball reveals that reduced operating pressure and increased cathode area will help to generate He{sup 2+} ions with the layered-glow DC discharge.

  13. Power links with Ireland -- Excitation of turbine-generator shaft torsional vibrations by variable frequency currents superimposed on DC currents in asynchronous HVDC links

    SciTech Connect (OSTI)

    Hammons, T.J.; Tay, B.W.; Kok, K.L. [Glasgow Univ. (United Kingdom)] [Glasgow Univ. (United Kingdom)

    1995-08-01T23:59:59.000Z

    The paper describes an in-depth analysis of excitation of shaft torsional vibrations in steam-turbine-generator-exciter shafts in close proximity to HVDC converter stations by variable-frequency ripple currents superimposed on the DC currents in asynchronous Links. It extends earlier work to include an in depth analysis of system scaling factors for harmonic currents impressed on generators in Northern Ireland by an inverter and to investigate the phenomena for possible torsional vibrations in the generators by the Link. Frequencies at which shaft torsional vibrations would be excited by modulation product harmonics in 50Hz/50Hz asynchronous Links as a function of deviation in system frequency is reviewed. Relative noncharacteristic current levels for 50Hz/50Hz connectors are illustrated assuming ripple currents at the inverter which gives realistic harmonic voltages in a twelve-pulse bridge. The paper then shows that torques in machines in multi-machine networks may be estimated by proportioning HVDC link harmonic disturbance current appropriately to each machine at risk. It is concluded that variable-frequency ripple currents superimposed on the DC current in asynchronous links can excite sympathetic torsional vibrations in turbine-generator-exciter shafts.

  14. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    SciTech Connect (OSTI)

    J. Grames, R. Suleiman, P.A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M.L. Stutzman

    2011-04-01T23:59:59.000Z

    GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b) limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c) using a large drive laser beam to distribute ion damage over a larger area, and (d) by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  15. Cryogenic direct current superconducting quantum interference device readout circuit

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Cryogenic direct current superconducting quantum interference device readout circuit Michael Mück SQUID readout circuit, which can be operated at liquid helium temperatures. Although room electronics, and feedback coil as short as possible to minimize phase shifts and time delays. Cooling

  16. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    Model Efficiency a PV Inverter (AC House), includes MPPT DC-into today’s PV-system inverters and is therefore omittedinterviewed. c Today’s PV-system inverter minus the MPPT,

  17. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    wind/fuel cell hybrid energy systems. Energy and Buildings,National Energy Modeling System PHEV plug-in hybrid electrica hybrid DC and AC power system that included energy storage

  18. DC attenuation meter

    DOE Patents [OSTI]

    Hargrove, Douglas L.

    2004-09-14T23:59:59.000Z

    A portable, hand-held meter used to measure direct current (DC) attenuation in low impedance electrical signal cables and signal attenuators. A DC voltage is applied to the signal input of the cable and feedback to the control circuit through the signal cable and attenuators. The control circuit adjusts the applied voltage to the cable until the feedback voltage equals the reference voltage. The "units" of applied voltage required at the cable input is the system attenuation value of the cable and attenuators, which makes this meter unique. The meter may be used to calibrate data signal cables, attenuators, and cable-attenuator assemblies.

  19. Analysis of variable-frequency currents superimposed on DC currents in asynchronous HVDC Links in stressing turbine-generator-exciter shafts

    SciTech Connect (OSTI)

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

    1995-03-01T23:59:59.000Z

    Ripple currents on the DC side of both HVDC asynchronous and synchronous Links can excite in some circumstances onerous torsional vibrations in large steam generator shafts. The problem has assumed importance in recent months on account of the HVDC Link between Scotland and Northern Ireland going ahead, on account of the proposed Eire/Wales Link, because AC/DC/AC couplers are to be installed to interconnect the East and West European Grid Systems, and because resonances have been observed on machines in close proximity to AC/DCIAC couplers and HVDC Links. This paper discusses and analyses excitation of shaft torsional vibrations in steam turbine-generator-exciter shafts in close proximity to HVDC converter stations by variable-frequency ripple currents superimposed on DC currents in asynchronous Links. It presents technical knowledge not arranged for convenient reference heretofore in studying possible excitation of turbine-generator-v/ exciter shaft torsional vibrations by non-characteristic HVDC converter harmonic currents if a machine should be considered to be at risk. Shaft torques in multi-machine networks are evaluated by proportioning HVDC Link disturbance currents to each machine at risk using system network data, generator data and fault analysis data considering frequency dependence of the system parameters. This scaling factor is calculated for different scenarios of system operation and load. Equivalent circuits for the synchronous generator are employed appropriately to correlate HVDC Link disturbance current impressed on the generator stator with s state torque excitation from which magnitude of turbine-generator-exciter shaft torque is deduced.

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

    SciTech Connect (OSTI)

    Not Available

    1988-04-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  2. Simulation of the d.c. critical current in superconducting sintered R. Riedinger (1), P. Habig (1), E. K. Hlil (1), M. Arnaud (2) and C. Boulesteix (2)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    microns. The d.c. critical current at zero voltage of such a material is not related to the critical current of the bulk material, but to its granular structure. Indeed, the critical current between two.1051/rphysap:0199000250106700 #12;68 For more compact materials we will be studying here, the critical d

  3. Predicting Air Quality: Current Status and Future Directions

    E-Print Network [OSTI]

    Sandu, Adrian

    Predicting Air Quality: Current Status and Future Directions Gregory R. Carmichael ,a Adrian Sandu, OR 97207, USA Abstract Air quality prediction plays an important role in the management of our envi can predict pollution in an urban air shed with spatial resolution less than a kilometer, and cover

  4. Lung, Artificial: Current Research and Future Directions William J. Federspiel

    E-Print Network [OSTI]

    Federspiel, William J.

    Lung, Artificial: Current Research and Future Directions William J. Federspiel Robert G. Svitek University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A. INTRODUCTION Artificial lungs are medical devices designed to take over or supplement the respiratory function of the lung: oxygenating the blood

  5. Transformer coupling for transmitting direct current through a barrier

    DOE Patents [OSTI]

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

    1987-06-29T23:59:59.000Z

    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.

  6. Transformer coupling for transmitting direct current through a barrier

    DOE Patents [OSTI]

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

    1988-01-01T23:59:59.000Z

    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.

  7. POSITION ESTIMATOR AND SIMPLIFIED CURRENT CONTROL STRATEGY FOR BRUSHLESS-DC MOTORS, USING DSP TECHNOLOGY

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    motor (PMSM), with sinusoidal back emf. This machine has been tested with quasi-square current waveforms

  8. Comparison of direct current and 50?Hz alternating current microscopic corona characteristics on conductors

    SciTech Connect (OSTI)

    Zhang, Shuai, E-mail: zhangshuai94@gmail.com; Zhang, Bo, E-mail: shizbcn@mail.tsinghua.edu.cn; He, Jinliang, E-mail: hejl@tsinghua.edu.cn [State Key Lab of Power Systems, and Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China)

    2014-06-15T23:59:59.000Z

    Corona discharge is one of the major design factors for extra-high voltage and ultra-high voltage DC/AC transmission lines. Under different voltages, corona discharge reveals different characteristics. This paper aims at investigating DC and AC coronas on the microscopic scale. To obtain the specific characteristics of DC and AC coronas, a new measurement approach that utilizes a coaxial wire-cylinder corona cage is designed in this paper, and wires of different diameters are used in the experiment. Based on the measurements, the respective microscopic characteristics of DC and AC coronas are analyzed and compared. With differences in characteristics between DC and AC coronas proposed, this study provides useful insights into DC/AC corona discharges on transmission line applications.

  9. Damping of a parallel ac-dc power system using PID power system stabilizers and rectifier current regulators

    SciTech Connect (OSTI)

    Hsu, Y.Y.; Wang, L. (Dept. of Electrical Engineering, National Taiwan Univ., Taipei (TW))

    1988-09-01T23:59:59.000Z

    A novel approach is presented to improve the dynamic stability of a parallel AC-DC power system. The developed scheme employs a proportional-integral-derivative (PID) power system stabilizer (PSS) and a PID rectifier current regulator (RCR) to enhance the damping for the electromagnetical mode of the system. The parameters of the proposed PID controllers are determined using a unified approach based on modal control theory. Eigenvalue analyses are performed for the system under various operating conditions in order to compare the damping effects provided by the two different control schemes. To demonstrate the effectiveness of the proposed damping schemes under disturbance conditions simulated dynamic response tests based on a nonlinear system model are also performed.

  10. Modal analysis of multiterminal high voltage direct current transmission

    SciTech Connect (OSTI)

    Dagle, J.E.

    1993-12-01T23:59:59.000Z

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

  11. Dependence of the magnitude and direction of the persistent current on the magnetic flux in superconducting rings

    SciTech Connect (OSTI)

    Gurtovoi, V. L.; Dubonos, S. V.; Nikulov, A. V., E-mail: nikulov@ipmt-hpm.ac.ru; Osipov, N. N.; Tulin, V. A. [Russian Academy of Sciences, Institute of Microelectronic Technology and High-Purity Materials (Russian Federation)

    2007-12-15T23:59:59.000Z

    The obtained periodic magnetic-field dependences I{sub c+}({phi}/{phi}{sub 0}) and I{sub c-}({phi}/{phi}{sub 0}) of the critical current measured in opposite directions on asymmetric superconducting aluminum rings has made it possible to explain previously observed quantum oscillations of dc voltage as a result of alternating current rectification. It was found that a higher rectification efficiency of both single rings and ring systems is caused by hysteresis of the current-voltage characteristics. The asymmetry of current-voltage characteristics providing the rectification effect is due to the relative shifts of the magnetic dependences I{sub c-}({phi}/{phi}{sub 0}) = I{sub c+}({phi}/{phi}{sub 0} + {delta}{phi}) of the critical current measured in opposite directions. This shift means that the position of I{sub c+}({phi}/{phi}{sub 0}) and I{sub c-}({phi}/{phi}{sub 0}) minima does not correspond to n + 0.5 magnetic flux {phi} quanta, which is in direct contradiction to measured Little-Parks resistance oscillations. Despite this contradiction, the amplitude I{sub c,an}({phi}/{phi}{sub 0}) = I{sub c+}({phi}/{phi}{sub 0}) - I{sub c-}({phi}/{phi}{sub 0}) of critical current anisotropy oscillations and its variations with temperature correspond to the expected amplitude of persistent current oscillations and its variations with temperature.

  12. DC BUFFERING AND FLOATING CURRENT FOR A HIGH VOLTAGE IMB APPLICATION

    SciTech Connect (OSTI)

    J.L. Morrison

    2014-08-01T23:59:59.000Z

    An interface technique for the latest generation of the Impedance Measurement Box (IMB) has been conceived to enable measurement of impedance spectra for battery modules up to 300V. A 300V capable or higher IMB is an enabling technology for in-situ diagnostics within electric vehicle charging stations or battery back-ups within power distribution sub-stations. It is possible that the existing IMB can be adapted via a 300V interface module to a test battery with voltage significantly greater than 50V. Recently a new concept was conceived for the calibration, algorithm and electronics of the IMB. That algorithm and calibration for that concept have been physically validated. The principal feature of the new electronics is the floating current source excitation of the battery under test. The single ended current excitation of the battery under test, used in the 50V IMB, requires that the negative terminal of the test battery must be the analog ground for the IMB. The new floating current technique allows the test battery to be fully high impedance isolated for a measurement. That isolation will improve IMB noise immunity and enable interrogation of cells internal to a battery module. All these techniques still use the same rapid concept for impedance measurement with the IMB. The purpose of this disclosure is to provide an overview of the analytical validation for three concepts to interface the floating current excitation to a high voltage battery. Recursive simulation models were used in different test scenarios to validate the various new concepts. The analysis will show that it is possible to interface the floating signal current to obtain an impedance measurement on a high voltage test battery. Additionally, the analysis will investigate stress seen by electronics while testing a 300V battery.

  13. Measurement of harmonic currents and evaluation of the dc filter performance of the New England - Hydro-Quebec Phase I HVDC Project

    SciTech Connect (OSTI)

    Garrity, T.F.; Hassan, I.D.; Donahue, J.A.

    1989-01-01T23:59:59.000Z

    Measurements of harmonic currents in the New England-Hydro-Quebec Phase I HVDC Project de transmission line are presented in this paper. Measurements were conducted to determine the cause of increased telephone interference and to evaluate the dc filter performance. The measurements revealed unexpected high levels of 3-pulse harmonic currents in the dc pole conductors. The cause is attributed to imbalances within the 6-pulse bridges caused by the converter transformer and valve stray capacitances to ground. The conventional model of the converter power circuit used as the basis for the dc filter design does not reproduce the measured 3-pulse harmonics. Modification to this model is required to account for the effect of the converter transformer and valve stray capacitances to ground.

  14. The War of the Currents: AC vs. DC Power | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov. Are you sure you wantJoin us for|Idahothe New Funding Constructs for Energy

  15. High-voltage direct current handbook: First edition

    SciTech Connect (OSTI)

    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

    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.

  16. Evaluation of a Current Source Active Power Filter to Reduce the DC Bus Capacitor in a Hybrid Electric Vehicle Traction Drive

    E-Print Network [OSTI]

    Tolbert, Leon M.

    system, additional heat, audible noise, mechanical stress, and vibration [1]. DC bus harmonic current- powered three-phase inverter is used to drive the traction motor. Due to the switching behavior combustion engine, electric motor, and energy storage device (for example, batteries and ultracapacitors

  17. Bi-directional Current-fed Medium Frequency Transformer Isolated AC-DC Converter 

    E-Print Network [OSTI]

    Essakiappan, Somasundaram

    2011-08-08T23:59:59.000Z

    The use of high power converters has increased tremendously. Increased demand for transportation, housing and industrial needs means that more number of power converters interact with the utility power grid. These converters are non...

  18. Bi-directional Current-fed Medium Frequency Transformer Isolated AC-DC Converter

    E-Print Network [OSTI]

    Essakiappan, Somasundaram

    2011-08-08T23:59:59.000Z

    and the development of new grid systems like HVDC transmission lines. The new solution proposed needs to incorporate methods for the renewable sources to receive power for monitoring and control, during periods of zero production. This calls for a power converter...

  19. Development and evaluation of an implantable chronic DC stimulation and measurement probe for nerve regeneration studies 

    E-Print Network [OSTI]

    Macha, Douglas Bryan

    1995-01-01T23:59:59.000Z

    isotropic. The actual field strength or current density induced by the applied current is seldom directly measured in-vivo. This research seeks to evaluate the design of an implantable DC stimulator capable of delivering a constant, stable and measurable...

  20. Measured Savings of DC to AC Drive Retrofit in Plastic Extrusion

    E-Print Network [OSTI]

    Sfeir, R. A.

    2008-01-01T23:59:59.000Z

    This paper presents the potential electrical energy efficiency improvements for utilizing alternating current (AC) motors controlled by variable frequency drives (VFD) in place of direct current (DC) motors to drive plastic extrusion machines. A...

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

    DOE Patents [OSTI]

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

    1996-12-10T23:59:59.000Z

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

  2. Catalog of DC Appliances and Power Systems

    SciTech Connect (OSTI)

    Garbesi, Karina; Vossos, Vagelis; Shen, Hongxia

    2010-10-13T23:59:59.000Z

    This document catalogs the characteristics of current and potential future DC products and power systems.

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

    E-Print Network [OSTI]

    King Jet, TSENG

    2013-01-01T23:59:59.000Z

    tied energy storage systems (ESS) will be voltage to a high-DC/AC converter to interface ESS based on low voltage cellscharging and discharging of the ESS and the control strategy

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

    E-Print Network [OSTI]

    Hwang, J. George

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

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

    SciTech Connect (OSTI)

    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

    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.

  6. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    energy efficient products that utilize DC power internally; the demonstrated energy savings of direct-DC in commercial data centers;energy efficient products that utilize DC power internally, the demonstrated energy savings of direct-DC power use in commercial data centers,

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

    E-Print Network [OSTI]

    Florida, University of

    -field-to-current conversion factor for lightning strikes to flat ground based on the transmission line model and (b currents on tall towers are used for testing the validity of field-to-current conversion equations [e on current measurement location (e.g., near the top or bottom of the tower) and on whether initial or largest

  8. DIRECT-DRIVE AND EDDY-CURRENT SEPTUM MAGNETS June 29, 2001

    E-Print Network [OSTI]

    Kemner, Ken

    DIRECT-DRIVE AND EDDY-CURRENT SEPTUM MAGNETS S. H. Kim June 29, 2001 Abstract -- Two types of thin septum magnets, direct drive and eddy current, were compared mainly in 2-D magnetic aspects. For the eddy-current type, the leakage fields calculated using OPERA-2d were compared with the calculations

  9. Multilevel DC link inverter

    DOE Patents [OSTI]

    Su, Gui-Jia

    2003-06-10T23:59:59.000Z

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  10. Direct-Current Resistivity At Central Nevada Seismic Zone Region

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbs TypeWinds

  11. Direct-Current Resistivity Survey | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At1986) |

  12. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    DC Conversion Loss Savings of Appliances Running on DirectConversion Loss Savings of Appliances Running on Direct DCrunning on AC and, in column B, the avoided AC-DC conversions losses

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

    E-Print Network [OSTI]

    Dimarogonas, Dimos

    }@kth.se.) Abstract: High-voltage direct current (HVDC) is a commonly used technology for long-distance power for multi-terminal HVDC (MTDC) systems is proposed. Under certain conditions on the controller gains factor behind long-distance power transmission. High-voltage direct current (HVDC) is a commonly used

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

    SciTech Connect (OSTI)

    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

    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.

  15. A Direct Inspection of the Displacement Current Using the Phase Measurement

    E-Print Network [OSTI]

    Zi-Hua Weng; Jin-Pan Zhu; Jing-Yan He; Zhi-Min Chen; Huang-Ping Yan; Ying Weng

    2014-08-10T23:59:59.000Z

    After J. C. Maxwell brought forward the concept of displacement currents, H. R. Hertz and other scholars verified the existence of electromagnetic waves in experimental, and then confirmed indirectly the conceptive correctness of displacement currents. During the recent years, along with the evolution of electronic measurement technologies, the researchers are attempting to validate directly the amplitude and orientation of displacement currents in experimental. The paper proposes and achieves one phase measurement experiment to scrutinize the orientation of displacement currents. The study indicates that the existing measurement technology is capable of inspecting directly the amplitude and orientation of displacement currents. The test results do not locate on the predicted range of classical electromagnetic theory presently. The displacement current may not be treatable similar to the conductive current to a certain extent. This conclusion enriches the understanding to the property of displacement currents.

  16. Stochastic ratcheting of two dimensional colloids : Directed current and dynamical transitions

    E-Print Network [OSTI]

    Dipanjan Chakraborty; Debasish Chaudhuri

    2014-07-09T23:59:59.000Z

    We present results of molecular dynamics simulations for two-dimensional repulsively interacting colloids driven by an one dimensional asymmetric and commensurate ratchet potential, switching on and off stochastically. The resultant time- and space-averaged directed current exhibits resonance with change in ratcheting frequency. The resonance frequency itself varies non-monotonically with density. We use scaling arguments to derive analytic expression for the directed current which reproduces these features. Our simulations reveal re-entrant dynamical transitions between solid and modulated liquid phases as a function of ratcheting frequency, associated with the variation of directed current.

  17. Alternating and direct current field effects on the structure-property relationships in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}-x%BaTiO{sub 3} textured ceramics

    SciTech Connect (OSTI)

    Ge, Wenwei; Li, Jiefang; Viehland, D. [Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Maurya, Deepam; Priya, Shashank [Center for Energy Harvesting Materials and Systems (CEHMS), Bio-Inspired Materials and Devices Laboratory (BMDL), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Center for Energy Harvesting Materials and Systems (CEHMS), Bio-Inspired Materials and Devices Laboratory (BMDL), Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-06-03T23:59:59.000Z

    The influence of alternating (ac) and direct current (dc) fields on the structural and dielectric properties of [001]{sub PC} textured Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}-7%BaTiO{sub 3} (NBT-7%BT) ceramics has been investigated. X-ray diffraction measurements revealed that the depolarization at temperature T{sub d} in poled samples resulted from a tetragonal {yields} pseudo-cubic transition on heating. Moderate ac drive and dc bias had opposite influences on T{sub d}: ac drive decreased the T{sub d}, whereas dc bias increased it. These investigations suggested an effective method to expand the working temperature range of NBT-x%BT textured ceramics to a high temperature.

  18. Bi-directional dc-dc Converter

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

    Custom Components Fabrication Components Validation Vehicle System Review with customer Delay of FY09 schedule Design Functional Validation, EMIEMC Production Planning PPAP, APQP...

  19. Quantum transport in a driven disordered potential: onset of directed current and noise-induced current reversal

    E-Print Network [OSTI]

    Denis Makarov; Leonid Kon'kov

    2015-02-06T23:59:59.000Z

    We study motion of a quantum wavepacket in a one-dimensional potential with correlated disorder. Presence of long-range potential correlations allows for existence of both localized and extended states. Weak time-dependent perturbation in the form of a fluctuating plane wave is superimposed onto the potential. This model can be realized in experiments with optically trapped cold atoms. Time-dependent perturbation causes transitions between localized and extended states. Owing to violation of space-time symmetries, there arises atomic current which is codirectional with the wave-like perturbation. However, it is shown that the perturbation can drag atoms only within some limited time interval, and then the current changes its direction. Increasing of the perturbation bandwidth and/or amplitude results in decreasing of the time of current reversal. We argue that onset of the current reversal is associated with inhomogeneity of diffusion in the momentum space.

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Tangirala, Umashanker

    1976-01-01T23:59:59.000Z

    FORMATION OF OZONE AND OXIDATION OF METHANE IN A DIRECT CURRENT CORONA DISCHARGE A Thesis by UMASHANKER TANGIRALA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1976 Major Subject: Chemical Engineering FORMATION OF OZONE AND OXIDATION OF METHANE IN A DIRECT CURRENT CORONA DISCHARGE A Thesis by UMASHANKER TANGIRALA Approved as to style and content by: (Chairman of Committee) ( ad of Department...

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Sensorless Direct Torque Control For Salient ­ Pole PMSM Based on Extended Kalman Filter Fed By AC is proposed. The Direct Torque Control (DTC) technique for PMSM is receiving increasing attention due on the stochastic intromission, in others words, noise. The PMSM is fed by an indirect power electronic converter

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

    E-Print Network [OSTI]

    Ljubljana, University of

    1994-01-01T23:59:59.000Z

    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

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

    SciTech Connect (OSTI)

    Litzenberger, Wayne; Lava, Val

    1994-08-01T23:59:59.000Z

    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).

  5. Proceedings, 2005 International Oil Spill Conference. American Petroleum Institute, Washington, DC. pp. 541-545. Ten Years of Realtime, Near-Surface Current Observations Supporting Oil Spill Response1

    E-Print Network [OSTI]

    2000 barrels of Bunker C oil into the Gulf of Mexico off Texas' coast. Sea conditions dispersedProceedings, 2005 International Oil Spill Conference. American Petroleum Institute, Washington, DC. pp. 541-545. Ten Years of Realtime, Near-Surface Current Observations Supporting Oil Spill Response1

  6. DC arc weld starter

    DOE Patents [OSTI]

    Campiotti, Richard H. (Tracy, CA); Hopwood, James E. (Oakley, CA)

    1990-01-01T23:59:59.000Z

    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  7. Ozone generation by negative direct current corona discharges in dry air fed coaxial wire-cylinder reactors

    SciTech Connect (OSTI)

    Yehia, Ashraf [Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Egypt and Department of Physics, College of Science and Humanitarian Studies in Alkharj, Salman bin Abdulaziz University, P.O. Box 83, Alkharj 11942 (Saudi Arabia)] [Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Egypt and Department of Physics, College of Science and Humanitarian Studies in Alkharj, Salman bin Abdulaziz University, P.O. Box 83, Alkharj 11942 (Saudi Arabia); Mizuno, Akira [Department of Environmental and Life Sciences, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)] [Department of Environmental and Life Sciences, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

    2013-05-14T23:59:59.000Z

    An analytical study was made in this paper for calculating the ozone generation by negative dc corona discharges. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature, and stressed by a negative dc voltage. The current-voltage characteristics of the negative dc corona discharges formed inside the reactor were measured in parallel with concentration of the generated ozone under different operating conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been recalculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters, except in the saturation range for the ozone concentration. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration generated by negative dc corona discharges in dry air fed coaxial wire-cylinder reactors under any operating conditions in range of the investigated parameters.

  8. High efficiency resonant dc/dc converter for solar power applications

    E-Print Network [OSTI]

    Inam, Wardah

    2013-01-01T23:59:59.000Z

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

  9. Growth of tungsten nanoparticles in direct-current argon glow discharges

    SciTech Connect (OSTI)

    Kishor Kumar, K.; Coueedel, L.; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moleculaires, CNRS-Aix-Marseille Universite, 13397 Marseille (France)

    2013-04-15T23:59:59.000Z

    The growth of nanoparticles from the sputtering of a tungsten cathode in DC argon glow discharges is reported. The study was performed at fixed argon pressure and constant discharge current. The growth by successive agglomerations is evidenced. First, tungsten nanocrystallites agglomerate into primary particles, the most probable size of which being {approx}30 nm. Primary particles of this size are observed for all plasma durations and always remain the most numerous in the discharge. Primary particles quickly agglomerate to form particles with size up to {approx}150 nm. For short plasma duration, log-normal functions describe accurately the dust particle size distributions. On the contrary, for long discharge durations, a second hump appears in the distributions toward large particle sizes. In the meantime, the discharge voltage, electron density, and emission line intensities strongly evolve. Their evolutions can be divided in four separate phases and exhibit unusual distinctive features compared to earlier observations in discharges in which particles were growing. The evolution of the different parameters is explained by a competition between the surface state of the tungsten cathode and the influence of the growing nanoparticles. The differences with sputtering glow discharges and chemically active plasmas suggest that the nanoparticle growth and its influence on discharge parameters is system and material dependent.

  10. Effect of the terrestrial magnetic field on direct-current measurements in underground pipelines

    SciTech Connect (OSTI)

    Dzhala, R.M.; Dikmarova, L.P.; Kornienko, V.Yu.

    1995-12-01T23:59:59.000Z

    The effect of the secondary field of an underground pipeline, magnetized by the terrestrial magnetic field, on noncontacting measurements of direct current flowing in it is discussed. The systematic errors of three known measurement methods are compared. A method based on the measurement of the difference between the field components parallel to the terrestrial field component orthogonal to the pipline is identified as the most accurate. 5 refs., 3 figs.

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

    SciTech Connect (OSTI)

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

    2004-08-02T23:59:59.000Z

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

  12. Hall mobility of cuprous oxide thin films deposited by reactive direct-current magnetron sputtering

    E-Print Network [OSTI]

    Lee, Yun Seog

    Cuprous oxide (Cu[subscript 2]O) is a promising earth-abundant semiconductor for photovoltaic applications. We report Hall mobilities of polycrystalline Cu[subscript 2]O thin films deposited by reactive dc magnetron ...

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

    SciTech Connect (OSTI)

    Onar, Omer C [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

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

  14. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

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

    1998-01-01T23:59:59.000Z

    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.

  15. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

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

    1998-06-30T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Batlle, Carles

    Study of the Stability of a Direct Stator Current Controller for a Doubly-Fed Induction Machine #12;Study of the Stability of a Direct Stator Current Controller for a Doubly-Fed Induction Machine to renewable energy (wind farms in particular). The proposed control algorithm offers the advantages of proven

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

    SciTech Connect (OSTI)

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

    1996-12-31T23:59:59.000Z

    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.

  18. Triple voltage dc-to-dc converter and method

    DOE Patents [OSTI]

    Su, Gui-Jia (Knoxville, TN)

    2008-08-05T23:59:59.000Z

    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.

  19. A graphical method for determining electrical conductivity of ionic solutions by direct current

    E-Print Network [OSTI]

    Simpson, Harold Navayne

    1961-01-01T23:59:59.000Z

    ~or Sub)est& CheuAstrg A ORAPHICAL NETHGD FOR DETEBNXNINO ELECTRICAL CONDUCTXVITX OF IONXC SOLUTXONS NX DIRECT CURRENT A Thed. e C A V C CI N g 0 0 C C Approved as 4o style and oontmt by~ ( of Coed, ttee Head of Departaent or Stadent... t ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 12 Ae PtSPktll4LOll df ?ll1dVAdld ~ ~ e ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ t 12 Ee APP4TAld &SR PXOIORFQ ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ ~ ~ ~ ~ 1 3 Ce Phkdd I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ e ~ e ~ ~ ~ 16 1 ~ AppoF44IN ~ ~ t ~ ~ ~ 1 ~ t ~ ~ ~ ~ ~ ~ ~ ~ o...

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

    SciTech Connect (OSTI)

    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

    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.

  1. The Use of DC Glow Discharges as Undergraduate Educational Tools

    SciTech Connect (OSTI)

    Stephanie A. Wissel and Andrew Zwicker, Jerry Ross, and Sophia Gershman

    2012-10-09T23:59:59.000Z

    Plasmas have a beguiling way of getting students excited and interested in physics. We argue that plasmas can and should be incorporated into the undergraduate curriculum as both demonstrations and advanced investigations of electromagnetism and quantum effects. Our device, based on a direct current (DC) glow discharge tube, allows for a number of experiments into topics such as electrical breakdown, spectroscopy, magnetism, and electron temperature.

  2. Structural properties of dusty plasma in direct current and radio frequency gas discharges

    SciTech Connect (OSTI)

    Ramazanov, T. S.; Dzhumagulova, K. N.; Jumabekov, A. N.; Dosbolayev, M. K. [Al Farabi Kazakh National University, IETP, Tole bi 96a, Almaty, 050012 (Kazakhstan)

    2008-05-15T23:59:59.000Z

    This paper presents radial distribution functions of dust particles obtained experimentally in dc and rf discharges. Pressure and interaction energy of dusty particles were calculated on the basis of these functions. The Langevin dynamics computer simulation for each experiment was performed. The comparisons with computer simulations are made.

  3. Radio frequency dc-dc power conversion

    E-Print Network [OSTI]

    Rivas, Juan, 1976-

    2007-01-01T23:59:59.000Z

    THIS THESIS addresses the development of system architectures and circuit topologies for dc-dc power conversion at very high frequencies. The systems architectures that are developed are structured to overcome limitations ...

  4. Measuring bi-directional current through a field-effect transistor by virtue of drain-to-source voltage measurement

    DOE Patents [OSTI]

    Turner, Steven Richard

    2006-12-26T23:59:59.000Z

    A method and apparatus for measuring current, and particularly bi-directional current, in a field-effect transistor (FET) using drain-to-source voltage measurements. The drain-to-source voltage of the FET is measured and amplified. This signal is then compensated for variations in the temperature of the FET, which affects the impedance of the FET when it is switched on. The output is a signal representative of the direction of the flow of current through the field-effect transistor and the level of the current through the field-effect transistor. Preferably, the measurement only occurs when the FET is switched on.

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

    E-Print Network [OSTI]

    Haven, Scott

    2012-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    None

    2012-01-30T23:59:59.000Z

    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.

  7. Voltages across assembly joints due to direct-strike lightning currents

    SciTech Connect (OSTI)

    Dinallo, M.S. [Quatro Corp., Albuquerque, NM (United States); Fisher, R.J. [Sandia National Labs., Albuquerque, NM (United States)

    1994-08-01T23:59:59.000Z

    An extensive set of direct-strike lightning tests has been carried out on a set of facsimile assembly joints of the kinds employed in the design of nuclear weapon cases. Taken as a whole, the test hardware included all the conceptual design elements that are embodied, either singly or in combination, in any specific assembly joint incorporated into any stockpiled weapon. During the present testing, the effects of all key design parameters on the voltages developed across the interior of the joints were investigated under a range of lightning stroke current parameter values. Design parameter variations included the types and number of joint fasteners, mechanical preload, surface finish tolerance and coatings, and the material from which the joint assembly was fabricated. Variations of the simulated lightning stroke current included amplitude (30-, 100-, and 200-kA peak), rise time, and decay time. The maximum voltage observed on any of the test joints that incorporated proper metal-to-metal surface contact was 65 V. Typical response values were more on the order of 20 V. In order to assess the effect of the presence of a dielectric coating (either intentional or as a result of corrosion) between the mating surfaces of a joint, a special configuration was tested in which the mating parts of the test assembly were coated with a 1-mil-thick dielectric anodizing layer. First strokes to these test assemblies resulted in very narrow voltage spikes of amplitudes up to 900 V. The durations of these spikes were less than 0.1 {mu}s. However, beyond these initial spikes, the voltages typically had amplitudes of up to 400 V for durations of 3 to 5 {mu}s.

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

    SciTech Connect (OSTI)

    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

    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.

  9. Mechanism of direct current electrical charge conduction in p-toluenesulfonate doped polypyrrole/carbon composites

    SciTech Connect (OSTI)

    Kumar, Amit [National Physical Laboratory, Council of Scientific and Industrial Research, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Department of Chemistry, Banaras Hindu University, Varanasi 221005 (India); Singh, Rajiv K.; Singh, Hari K.; Singh, Ramadhar, E-mail: ramadhar@mail.nplindia.org [National Physical Laboratory, Council of Scientific and Industrial Research, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Srivastava, Pankaj [Department of Chemistry, Banaras Hindu University, Varanasi 221005 (India)

    2014-03-14T23:59:59.000Z

    Polypyrrole/carbon (PPy/C) composites have been synthesized using varying concentration of p-toluenesulfonate (pTS) dopant by surface initiated in-situ chemical oxidative polymerization. The synthesis and influence of pTS on the structure of the PPy/C composites are confirmed by Fourier transform infrared studies and the morphological features have been examined by scanning electron microscopy. X-ray photoelectron spectroscopy, employed to examine the surface composition and doping level of these composites, confirms the anionic doping into the polymer backbone. Electron spin resonance measurement has been carried out on these samples to identify the nature of the charge carriers and their concentration at different doping levels. The dc electrical conductivity of these composites has been measured in the temperature range ?10–305?K. The observed results have been analyzed in the framework of existing theoretical models. Different Mott's parameters, such as characteristic temperature (T{sub 0}), density of states at the Fermi level (N(E{sub F})), average hopping distance (R), and average hopping energy (W), evaluated from dc conductivity data supports the applicability of Mott's three dimensional variable range hopping mechanism in this system.

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

    E-Print Network [OSTI]

    Battat, James

    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 ...

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

    SciTech Connect (OSTI)

    Matzen, Laura E.; Trumbo, Michael Christopher Stefan

    2014-10-01T23:59:59.000Z

    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.

  12. Summary of electric vehicle dc motor-controller tests

    SciTech Connect (OSTI)

    McBrien, E F; Tryon, H B

    1982-09-01T23:59:59.000Z

    Available performance data for production motors are usually of marginal value to the electric vehicle designer. To provide at least a partial remedy to this situation, tests of typical dc propulsion motors and controllers were conducted as part of the DOE Electric Vehicle Program. The objectives of this program were to evaluate the differences in the performance of dc motors when operating with chopper-type controllers and when operating on direct current; and to gain an understanding of the interactions between the motor and the controller which cause these differences. Toward this end, motor-controller tests performed by the NASA Lewis Research Center provided some of the first published data that quantified motor efficiency variations for both ripple-free (straight dc) and chopper modes of operation. Test and analysis work at the University of Pittsburgh explored motor-controller relationships in greater depth. And to provide additional data, 3E Vehicles tested two small motors, both on a dynamometer and in a vehicle, and the Eaton Corporation tested larger motors, using sophisticated instrumentation and digital processing techniques. All the motors tested were direct-current types. Of the separately excited types, seven were series wound and two were shunt wound. One self-excited permanent magnet type was also tested. Four of the series wound motors used brush shifting to obtain good commutation. In almost all cases, controller limitations constrained the test envelope so that the full capability of the motors could not be explored.

  13. WASHINGTON. DC.

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h J Ircc.p,anc.

  14. Washington, DC'

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h JWJLP-~ . '-WQl.

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

    E-Print Network [OSTI]

    Wahl, Geoffrey M.

    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

  16. The production mechanisms of OH radicals in a pulsed direct current plasma jet

    SciTech Connect (OSTI)

    Liu, X. Y.; Pei, X. K.; Lu, X. P.; Liu, D. W., E-mail: liudw@hust.edu.cn [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, Hubei 430074 (China); Ostrikov, K. [Plasma Nanoscience, CSIRO Materials Science and Engineering, P. O. Box 218, Lindfield, New South Wales 2070 (Australia); School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4000 (Australia)

    2014-09-15T23:59:59.000Z

    The production mechanism of OH radicals in a pulsed DC plasma jet is studied by a two-dimensional (2-D) plasma jet model and a one-dimensional (1-D) discharge model. For the plasma jet in the open air, electron-impact dissociation of H{sub 2}O, electron neutralization of H{sub 2}O{sup +}, as well as dissociation of H{sub 2}O by O(1D) are found to be the main reactions to generate the OH species. The contribution of the dissociation of H{sub 2}O by electron is more than the others. The additions of N{sub 2}, O{sub 2}, air, and H{sub 2}O into the working gas increase the OH density outside the tube slightly, which is attributed to more electrons produced by Penning ionization. On the other hand, the additions of O{sub 2} and H{sub 2}O into the working gas increase the OH density inside the tube substantially, which is attributed to the increased O (1D) and H{sub 2}O concentration, respectively. The gas flow will transport high density OH out of the tube during pulse off period. It is also shown that the plasma chemistry and reactivity can be effectively controlled by the pulse numbers. These results are supported by the laser induced fluorescence measurements and are relevant to several applications of atmospheric-pressure plasmas in health care, medicine, and materials processing.

  17. Current:

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -KWatertowni5W 95.5x-L* d!Qwner contacted n

  18. Current:

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -KWatertowni5W 95.5x-L* d!Qwner contacted

  19. DC source assemblies

    DOE Patents [OSTI]

    Campbell, Jeremy B; Newson, Steve

    2013-02-26T23:59:59.000Z

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

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

    E-Print Network [OSTI]

    Lipo, Thomas

    - as in HVDC transmission for example - as well as in DC-links for high-power current source inverters

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

    E-Print Network [OSTI]

    Pham, Van Sang

    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 ...

  2. Electrochimica Acta 52 (2007) 43174324 Porous current collectors for passive direct methanol fuel cells

    E-Print Network [OSTI]

    Zhao, Tianshou

    2007-01-01T23:59:59.000Z

    experimentally. The measured polarization curves, constant-current discharging behavior and EIS spectra showed in passive DMFCs. Kho et al. [17] investigated the variation in the open circuit volt- age (OCV) and the cell

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

    E-Print Network [OSTI]

    Tangirala, Umashanker

    1976-01-01T23:59:59.000Z

    if they are not deliberately maintained below toxic levels. This kind of air pollution problem is quite different from that of industrial emissions as it calls for the removal of mere traces of contaminant from large volumes of gas. For this purpose, conventional treatment... current corona discharge reactor, over a wide range of experimental conditions. The experi- mental variables were corona current, voltage, reactor radius ratio (Ri/R2), gas flow rate and temperature. Generally, more ozone was produced in the negative...

  4. Directions

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

    Directions Where We Are Directions The Bradbury Science Museum is located at 1350 Central Avenue Los Alamos, NM 87544 Los Alamos (elevation 7,355 feet) is perched high atop the...

  5. Recent developments and future directions Coherently controlled electrical currents at surfaces

    E-Print Network [OSTI]

    of ultrashort current pulses at surfaces. Two phase-locked laser pulses with carrier frequencies a and a/2 of the electrons due to vibronic or electronic excitation within the junction can be neglected. In this regime e­ Metal Sample Excitations Pulses =90° Time­Delayt PhotoemissionPulse Photoelectrons 0.0 0.5 1

  6. Oscillation modes of direct current microdischarges with parallel-plate geometry

    SciTech Connect (OSTI)

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

    2011-10-15T23:59:59.000Z

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

  7. Improved multi-directional eddy current inspection test apparatus for detecting flaws in metal articles

    DOE Patents [OSTI]

    Nance, Roy A. (McMurray, PA); Hartley, William H. (Pittsburgh, PA); Caffarel, Alfred J. (Pittsburgh, PA)

    1984-01-01T23:59:59.000Z

    Apparatus is described for detecting flaws in a tubular workpiece in a single scan. The coils of a dual coil bobbin eddy current inspection probe are wound at a 45.degree. angle to the transverse axis of the probe, one coil having an angular position about the axis about 90.degree. relative to the angular position of the other coil, and the angle of intersection of the planes containing the coils being about 60.degree..

  8. Bi-directional dc-dc Converter | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyand Sustained CoordinationWater

  9. Bi-directional dc-dc Converter | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyand Sustained CoordinationWater10 DOE Vehicle

  10. Bi-directional dc-dc Converter | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergyand Sustained CoordinationWater10 DOE Vehicle09 DOE

  11. Building Scale DC Microgrids

    E-Print Network [OSTI]

    Marnay, Chris

    2013-01-01T23:59:59.000Z

    resources, a 10 kW vertical axis wind turbine, and Fig. 4AC-grid Fig. 3. Vertical axis wind turbine in the AIT DC µ

  12. Building Scale DC Microgrids

    E-Print Network [OSTI]

    Marnay, Chris

    2014-01-01T23:59:59.000Z

    resources, a 10 kW vertical axis wind turbine, and Fig. 4the µgrid Fig. 3. Vertical axis wind turbine in the AIT DC µ

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbs TypeWinds WindDilconWindEnergy

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbs TypeWindsInformation

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbs TypeWindsInformationOpen

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbs TypeWindsInformationOpenOpen

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbs

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformation Kawaihae Area

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformation Kawaihae AreaOpen

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformation Kawaihae

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformation KawaihaeEnergy

  2. Direct-Current Resistivity Survey At Beowawe Hot Springs Area (Garg, Et

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformation KawaihaeEnergyAl.,

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformation

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy2002) | Open

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy2002) |

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy2002) |Open

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy2002) |Open|

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy2002)

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision hasda62829c05bGabbsInformationEnergy2002)Area

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At Lahaina-Kaanapali

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At Lahaina-KaanapaliAl.,

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At

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

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At1986) | Open Energy

  16. Direct-Current Resistivity Survey At Raft River Geothermal Area (1975) |

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At1986) | Open

  17. Direct-Current Resistivity Survey At Soda Lake Area (Combs 2006) | Open

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Energy Information At1986) | OpenEnergy

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

    DOE Patents [OSTI]

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

    2009-08-11T23:59:59.000Z

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

  19. Development of 13-V, 5000-A DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    -voltage and large-current DC power supply with a high-frequency transformer coupling, which is applied to electric. Keywords-DC power supply; low-voltage and large-current; high-frequency transformer; Schottky diodeDevelopment of 13-V, 5000-A DC Power Supply with High-Frequency Transformer Coupling Applied

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

    SciTech Connect (OSTI)

    NONE

    2005-07-01T23:59:59.000Z

    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.

  1. 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. Additional information is available at http://www.blm.gov/wy/st/en/info/NEPA/documents/hdd/transwest.html.

  2. Strategic Directions for Hydrogen Delivery Workshop Proceedings

    Broader source: Energy.gov [DOE]

    Proceedings from the Strategic Directions for Hydrogen Delivery Workshop held May 7-8, 2003 in Washington, DC. Author: Energetics

  3. A Superconducting transformer system for high current cable testing

    SciTech Connect (OSTI)

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

    2010-02-15T23:59:59.000Z

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

  4. Direct

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign: Potential ApplicationYu,EnergyDimitriDirac ChargeDiracDirect

  5. High voltage DC power supply

    DOE Patents [OSTI]

    Droege, Thomas F. (Batavia, IL)

    1989-01-01T23:59:59.000Z

    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.

  6. High voltage DC power supply

    DOE Patents [OSTI]

    Droege, T.F.

    1989-12-19T23:59:59.000Z

    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.

  7. Optimization of spin-torque switching using AC and DC pulses

    SciTech Connect (OSTI)

    Dunn, Tom [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Kamenev, Alex [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-06-21T23:59:59.000Z

    We explore spin-torque induced magnetic reversal in magnetic tunnel junctions using combined AC and DC spin-current pulses. We calculate the optimal pulse times and current strengths for both AC and DC pulses as well as the optimal AC signal frequency, needed to minimize the Joule heat lost during the switching process. The results of this optimization are compared against numeric simulations. Finally, we show how this optimization leads to different dynamic regimes, where switching is optimized by either a purely AC or DC spin-current, or a combination AC/DC spin-current, depending on the anisotropy energies and the spin-current polarization.

  8. DC-DC converter current source fed naturally commutated brushless DC motor drive

    E-Print Network [OSTI]

    Khopkar, Rahul Vijaykumar

    2004-11-15T23:59:59.000Z

    ..............................................................................................1 2 Commutator and brushes.......................................................................................2 3 Back-emf of a three-phase PMSM........................................................................3 4 Power generated... machines and are usually called Permanent Magnet Synchronous Machine (PMSM). In PMSM machines, the slip rings are eliminated and the stator windings are equivalent to the stator windings in synchronous ac machines. While no power is required for field...

  9. A global maximum power point tracking DC-DC converter

    E-Print Network [OSTI]

    Duncan, Joseph, 1981-

    2005-01-01T23:59:59.000Z

    This thesis describes the design, and validation of a maximum power point tracking DC-DC converter capable of following the true global maximum power point in the presence of other local maximum. It does this without the ...

  10. Active dc filter for HVDC system--A test installation in the Konti-Skan DC link at Lindome converter station

    SciTech Connect (OSTI)

    Zhang, Wenyan; Asplund, G. (ABB Power Systems, Ludvika (Sweden). HVDC Division); Aberg, A. (ABB Corporate Research, Lund (Sweden). Dept. of Man-Machine Communication); Jonsson, U. (Svenska Kraftnaet, Vaellingby (Sweden)); Loeoef, O. (Vattenfall AB, Trollhaettan (Sweden). Region Vaestsverige)

    1993-07-01T23:59:59.000Z

    The purpose of introducing active dc filters is to meet the more and more stringent requirement from power utilities on limiting telephone interference caused by harmonic currents from HVdc transmission lines, without unnecessarily increasing the cost of HVdc stations. An active dc filter installed in the Konti-Skan HVdc link is described. The active dc filter is connected at the bottom of an existing passive dc filter at the Lindome station. The active dc filter includes optic harmonic current measuring unit, control system, protection and supervision system, PWM power amplifier, high-frequency transformer, surge arrester, and coupling apparatuses. The active dc filter has small physical size and occupies small ground area. The performance of the active dc filter for eliminating the disturbing harmonics is excellent. To achieve comparable results by passive filters would require something like ten times more high voltage equipment.

  11. Conversion of pure spin current to charge current in amorphous bismuth

    SciTech Connect (OSTI)

    Emoto, H.; Ando, Y.; Shinjo, T.; Shiraishi, M., E-mail: shiraishi@ee.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, Osaka 560-8531 (Japan); Shikoh, E. [Graduate School of Engineering, Osaka City University, Osaka 558-8585 (Japan); Fuseya, Y. [Department of Applied Physics and Chemistry, The University of Electro-Communications, Tokyo 182-8585 (Japan)

    2014-05-07T23:59:59.000Z

    Spin Hall angle and spin diffusion length in amorphous bismuth (Bi) are investigated by using conversion of a pure spin current to a charge current in a spin pumping technique. In Bi/Ni{sub 80}Fe{sub 20}/Si(100) sample, a clear direct current (DC) electromotive force due to the inverse spin Hall effect of the Bi layer is observed at room temperature under a ferromagnetic resonance condition of the Ni{sub 80}Fe{sub 20} layer. From the Bi thickness dependence of the DC electromotive force, the spin Hall angle and the spin diffusion length of the amorphous Bi film are estimated to be 0.02 and 8?nm, respectively.

  12. Performance test results for the Eaton dc developmental power train in an electric test bed vehicle

    SciTech Connect (OSTI)

    Crumley, R.L.; Donaldson, M.R.

    1987-09-01T23:59:59.000Z

    This report presents the results of the tests performed on a direct current (dc) power train in a test bed vehicle developed by the Eaton Corporation for the US Department of Energy (DOE). The tests were performed by EG and G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). The purpose of the INEL testing was to provide test results from which an evaluation of the performance capabilities of the Eaton dc power train could be made and compared with other vehicle propulsion systems. The planned tests were primarily oriented toward road testing, chassis dynamometer testing, and associated dynamometer coastdown tests for road loss determination. Range tests of the Eaton dc test bed vehicle using an ALCO 2200 lead acid battery pack, produced ranges of 97 km at 56 km/h (60 miles at 35 mph), 79 km at 72 km/h (49 miles at 45 mph), and 47 km at 88 km/h (29 miles at 55 mph). The corresponding net dc energy consumptions are 135 Wh/km (217 Wh/mile), 145 Wh/km (233 Wh/mile), and 178 Wh/km (287 Wh/mile). The energy consumption for the D-cycle test was 241 Wh/km (387 Wh/mile). 8 refs., 11 figs., 16 tabs.

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

    SciTech Connect (OSTI)

    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

    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.

  14. Sustainable Energy Utility- D.C. Home Performance (District of Columbia)

    Broader source: Energy.gov [DOE]

    The District of Columbia Sustainable Energy Utility currently offers the D.C. Home Performance program (DCHP). DCHP provides a $500 incentive to properties which successfully complete qualifying...

  15. Prediction of liquid metal alloy radiant properties from measurements of the Hall coefficient and the direct current resistivity

    SciTech Connect (OSTI)

    Havstad, M.A. [Lawrence Livermore National Lab., CA (United States); Qiu, T. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-04-01T23:59:59.000Z

    The thermal radiative properties of high temperature solid and liquid metal alloys are particularly useful to research and development efforts in laser cladding and machining, electron beam welding and laser isotope separation. However the cost, complexity, and difficulty of measuring these properties have forced the use of crude estimates from the Hagen-Rubens relation, the Drude relations, or extrapolation from low temperature or otherwise flawed data (e.g., oxidized). The authors have found in this work that published values for the Hall coefficient and the electrical resistivity of liquid metal alloys can provide useful estimates of the reflectance and emittance of some groups of binary liquid metal and high temperature solid alloys. The estimation method computes the Drude free electron parameters, and thence the optical constants and the radiant properties from the dependence of the Hall coefficient and direct current resistivity on alloy composition (the Hall coefficient gives the free electron density and the resistivity gives the average time between collisions). They find that predictions of the radiant properties of molten cerium-copper alloy, which use the measured variations in the Hall coefficient and resistivity (both highly nonlinear) as a function of alloy fraction (rather than linear combinations of the values of the pure elements) yield a good comparison to published measurements of the variation of the normal spectral emittance (a different but also nonlinear function) of cerium-copper alloy at the single wavelength available for comparison, 0.645 {mu}m. The success of the approach in the visible range is particularly notable because one expects a Drude based approach to improve with increasing wavelength from the visible into the infrared. Details of the estimation method, the comparison between the calculation and the measured emittance, and a discussion of what groups of elements may also provide agreement is given.

  16. A High Power Density DC-DC Converter for Distributed PV Architectures

    SciTech Connect (OSTI)

    Mohammed S. Agamy; Song Chi; Ahmed Elasser; Maja Harfman-Todorovic; Yan Jiang; Frank Mueller; Fengfeng Tao

    2012-06-01T23:59:59.000Z

    In order to maximize solar energy harvesting capabilities, power converters have to be designed for high efficiency and good MPPT and voltage/current performance. When many converters are used in distributed systems, power density also becomes an important factor as it allows for simpler system integration. In this paper a high power density string dc-dc converter suitable for distributed medium to large scale PV installation is presented. A simple partial power processing topology, implemented with all silicon carbide devices provides high efficiency as well as high power density. A 3.5kW, 100kHz converter is designed and tested to verify the proposed methods.

  17. A Direct Stator Current Controller for a Doubly-Fed Induction A. D`oria-Cerezo, M. Bodson, C. Batlle and R. Ortega

    E-Print Network [OSTI]

    Batlle, Carles

    A Direct Stator Current Controller for a Doubly-Fed Induction Machine A. D`oria-Cerezo, M. Bodson-fed induction machine with specific applications to renewable energy (wind farms in particular). The proposed with the classical vector control method, where the doubly-fed induction machine is represented in a stator- flux

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

    SciTech Connect (OSTI)

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

    2013-02-15T23:59:59.000Z

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

  19. Historical Material Analysis of DC745U Pressure Pads

    SciTech Connect (OSTI)

    Ortiz-Acosta, Denisse [Los Alamos National Laboratory

    2012-07-30T23:59:59.000Z

    As part of the Enhance Surveillance mission, it is the goal to provide suitable lifetime assessment of stockpile materials. This report is an accumulation of historical publication on the DC745U material and their findings. It is the intention that the B61 LEP program uses this collection of data to further develop their understanding and potential areas of study. DC745U is a commercially available silicone elastomer consisting of dimethyl, methyl-phenyl, and methyl-vinyl siloxane repeat units. Originally, this material was manufactured by Dow Corning as Silastic{reg_sign} DC745U at their manufacturing facility in Kendallville, IN. Recently, Dow Corning shifted this material to the Xiameter{reg_sign} brand product line. Currently, DC745U is available through Xiameter{reg_sign} or Dow Corning's distributor R. D. Abbott Company. DC745U is cured using 0.5 wt% vinyl-specific peroxide curing agent known as Luperox 101 or Varox DBPH-50. This silicone elastomer is used in numerous parts, including two major components (outer pressure pads and aft cap support) in the W80 and as pressure pads on the B61. DC745U is a proprietary formulation, thus Dow Corning provides limited information on its composition and properties. Based on past experience with Dow Corning, DC745U is at risk of formulation changes without notification to the costumer. A formulation change for DC745U may have a significant impact because the network structure is a key variable in determining material properties. The purpose of this report is to provide an overview of historical DC745U studies and identify gaps that need to be addressed in future work. Some of the previous studies include the following: 1. Spectroscopic characterization of raw gum stock. 2. Spectroscopic, thermal, and mechanical studies on cured DC745U. 3. Nuclear Magnetic Resonance (NMR) and solvent swelling studies on DC745U with different crosslink densities. 4. NMR, solvent swelling, thermal, and mechanical studies on thermally aged DC745U. 5. NMR, solvent swelling, thermal, and mechanical studies on radiolytically aged DC745U. Each area is reviewed and further work is suggested to improve our understanding of DC745U for systems engineering, surveillance, aging assessments, and lifetime assessment.

  20. A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

    SciTech Connect (OSTI)

    Mohammed S. Agamy; Maja Harfman-Todorovic; Ahmed Elasser; Robert L. Steigerwald; Juan A. Sabate; Song Chi; Adam J. McCann; Li Zhang; Frank Mueller

    2012-09-01T23:59:59.000Z

    In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

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

    DOE Patents [OSTI]

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

    1995-05-23T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    1995-01-01T23:59:59.000Z

    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.

  3. Power flow analysis for DC voltage droop controlled DC microgrids

    E-Print Network [OSTI]

    Chaudhary, Sanjay

    loss, such as photovoltaic panels, batteries, fuel cells, LEDs, and electronic loads, DC microgrids sharing and secondary voltage regulation can now be analytically studied, and specialized optimization of the DC microgrid, in term of systematic analysis, protection coordination design, network optimization

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

    E-Print Network [OSTI]

    inspection and preventive maintenance are typically performed. The maintenance schedules and routines usually adapted time-directed maintenance strategy and the emerging new condition-based strategy require has been applied in implementing circuit breaker maintenance and repair tasks. Several potential

  5. Fiber optic current monitor for high-voltage applications

    DOE Patents [OSTI]

    Renda, G.F.

    1992-04-21T23:59:59.000Z

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

  6. DC WRRC REPORT NO. 115 Conference Proceedings

    E-Print Network [OSTI]

    District of Columbia, University of the

    DC WRRC REPORT NO. 115 Conference Proceedings: An Agenda for Black Universities and Colleges. Kargbo Conference Sponsored by The DC Water Resources Research Center University of the District

  7. Convergence Analysis of DC Algorithm for DC programming with ...

    E-Print Network [OSTI]

    2010-09-14T23:59:59.000Z

    In this paper, we consider DC programming with subanalytic data. ... Lojasiewicz inequality is an ingredient tool in Subanalytic Geometry as well as in its ... us list some of the elementary properties of subanalytic sets and subanalytic functions ...

  8. Recovery Act: Integrated DC-DC Conversion for Energy-Efficient Multicore Processors

    SciTech Connect (OSTI)

    Shepard, Kenneth L

    2013-03-31T23:59:59.000Z

    In this project, we have developed the use of thin-film magnetic materials to improve in energy efficiency of digital computing applications by enabling integrated dc-dc power conversion and management with on-chip power inductors. Integrated voltage regulators also enables fine-grained power management, by providing dynamic scaling of the supply voltage in concert with the clock frequency of synchronous logic to throttle power consumption at periods of low computational demand. The voltage converter generates lower output voltages during periods of low computational performance requirements and higher output voltages during periods of high computational performance requirements. Implementation of integrated power conversion requires high-capacity energy storage devices, which are generally not available in traditional semiconductor processes. We achieve this with integration of thin-film magnetic materials into a conventional complementary metal-oxide-semiconductor (CMOS) process for high-quality on-chip power inductors. This project includes a body of work conducted to develop integrated switch-mode voltage regulators with thin-film magnetic power inductors. Soft-magnetic materials and inductor topologies are selected and optimized, with intent to maximize efficiency and current density of the integrated regulators. A custom integrated circuit (IC) is designed and fabricated in 45-nm CMOS silicon-on-insulator (SOI) to provide the control system and power-train necessary to drive the power inductors, in addition to providing a digital load for the converter. A silicon interposer is designed and fabricated in collaboration with IBM Research to integrate custom power inductors by chip stacking with the 45-nm CMOS integrated circuit, enabling power conversion with current density greater than 10A/mm2. The concepts and designs developed from this work enable significant improvements in performance-per-watt of future microprocessors in servers, desktops, and mobile devices. These new approaches to scaled voltage regulation for computing devices also promise significant impact on electricity consumption in the United States and abroad by improving the efficiency of all computational platforms. In 2006, servers and datacenters in the United States consumed an estimated 61 billion kWh or about 1.5% of the nation's total energy consumption. Federal Government servers and data centers alone accounted for about 10 billion kWh, for a total annual energy cost of about $450 million. Based upon market growth and efficiency trends, estimates place current server and datacenter power consumption at nearly 85 billion kWh in the US and at almost 280 billion kWh worldwide. Similar estimates place national desktop, mobile and portable computing at 80 billion kWh combined. While national electricity utilization for computation amounts to only 4% of current usage, it is growing at a rate of about 10% a year with volume servers representing one of the largest growth segments due to the increasing utilization of cloud-based services. The percentage of power that is consumed by the processor in a server varies but can be as much as 30% of the total power utilization, with an additional 50% associated with heat removal. The approaches considered here should allow energy efficiency gains as high as 30% in processors for all computing platforms, from high-end servers to smart phones, resulting in a direct annual energy savings of almost 15 billion kWh nationally, and 50 billion kWh globally. The work developed here is being commercialized by the start-up venture, Ferric Semiconductor, which has already secured two Phase I SBIR grants to bring these technologies to the marketplace.

  9. Washington DC | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin BaxinUmweltVillageGraph HomeWarana Group of CooperativesDC Home

  10. DC Survey 2013 | National Nuclear Security Administration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContract Management Fermi Site OfficeCoursePublicCurrentCurtis110 1 ofDC

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

    SciTech Connect (OSTI)

    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

    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.

  12. Controlling ultrafast currents by the non-linear photogalvanic effect

    E-Print Network [OSTI]

    Wachter, Georg; Lemell, Christoph; Tong, Xiao-Min; Yabana, Kazuhiro; Burgdörfer, Joachim

    2015-01-01T23:59:59.000Z

    We theoretically investigate the effect of broken inversion symmetry on the generation and control of ultrafast currents in a transparent dielectric (SiO2) by strong femto-second optical laser pulses. Ab-initio simulations based on time-dependent density functional theory predict ultrafast DC currents that can be viewed as a non-linear photogalvanic effect. Most surprisingly, the direction of the current undergoes a sudden reversal above a critical threshold value of laser intensity I_c ~ 3.8*10^13 W/cm2. We trace this switching to the transition from non-linear polarization currents to the tunneling excitation regime. We demonstrate control of the ultrafast currents by the time delay between two laser pulses. We find the ultrafast current control by the non-linear photogalvanic effect to be remarkably robust and insensitive to laser-pulse shape and carrier-envelope phase.

  13. Controlling ultrafast currents by the non-linear photogalvanic effect

    E-Print Network [OSTI]

    Georg Wachter; Shunsuke A. Sato; Christoph Lemell; Xiao-Min Tong; Kazuhiro Yabana; Joachim Burgdörfer

    2015-03-20T23:59:59.000Z

    We theoretically investigate the effect of broken inversion symmetry on the generation and control of ultrafast currents in a transparent dielectric (SiO2) by strong femto-second optical laser pulses. Ab-initio simulations based on time-dependent density functional theory predict ultrafast DC currents that can be viewed as a non-linear photogalvanic effect. Most surprisingly, the direction of the current undergoes a sudden reversal above a critical threshold value of laser intensity I_c ~ 3.8*10^13 W/cm2. We trace this switching to the transition from non-linear polarization currents to the tunneling excitation regime. We demonstrate control of the ultrafast currents by the time delay between two laser pulses. We find the ultrafast current control by the non-linear photogalvanic effect to be remarkably robust and insensitive to laser-pulse shape and carrier-envelope phase.

  14. Investigations of Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics and powders prepared by direct current arc discharge technique

    SciTech Connect (OSTI)

    Li, Shuangbin; Wang, Xiaohan [Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yao, Ying, E-mail: yaoy1125@hotmail.com; Jia, Yongzhong; Xie, Shaolei; Jing, Yan [Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008 (China); Yuzyuk, Yu. I. [Faculty of Physics, Southern Federal University, 5, Zorge str., Rostov-on-Don 344090 (Russian Federation)

    2014-09-01T23:59:59.000Z

    Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics with x ranging from 0 to 1 were prepared by direct current arc discharge technique and studied by means of x-ray diffraction (XRD) and Raman spectroscopy. The cubic-tetragonal ferroelectric phase transition in Ba{sub x}Sr{sub 1?x}TiO{sub 3} ceramics was found to occur at x???0.75. XRD investigation of as-grown BaTiO{sub 3} ceramics revealed co-existence of tetragonal and hexagonal modifications with a small amount of impurity phase BaTi{sub 4}O{sub 9}. No evidences of hexagonal phase were observed in Raman spectra of as-grown BaTiO{sub 3} ceramics, while Raman peaks related to hexagonal phase were clearly observed in the spectrum of fine-grain powders prepared from the same ceramics. A core-shell model for BaTiO{sub 3} ceramics prepared by direct current arc discharge technique is proposed. Absence of the hexagonal phase in any Ba{sub x}Sr{sub 1?x}TiO{sub 3} solid solution with x?

  15. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    DOE Patents [OSTI]

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09T23:59:59.000Z

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  16. 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)

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

    1989-05-01T23:59:59.000Z

    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.

  17. ReHABit : claiming endangered structures in Washington DC to rethink subsidized housing

    E-Print Network [OSTI]

    Fowlkes, Catherine Kuhnle

    2007-01-01T23:59:59.000Z

    There is an affordable housing crisis today in Washington D.C. that is the result of a uniquely complicated history of a capital city and a current economic boom. This thesis responds to that crisis by proposing a new ...

  18. The smoothing transformer, a new concept in dc side harmonic reduction of HVdc schemes

    SciTech Connect (OSTI)

    Enright, W.; Arrillaga, J.; Wood, A.R.; Hidalgo, F.P.

    1996-10-01T23:59:59.000Z

    Direct connection schemes have been a subject of recent investigation, offering operational flexibility and substantial reductions in ac components. In these schemes the use of active dc filters has been suggested to replace the conventional tuned passive filter design. This paper presents the smoothing transformer as a new means for reducing dc harmonics at characteristic and non-characteristic frequencies using only passive components. A realistic smoothing transformer design is examined using the New Zealand HVdc system operating in the direct connection mode. The steady-state and transient performance of the smoothing transformer design is compared with that of the existing dc smoothing reactor and filter bank.

  19. AC and DC power transmission

    SciTech Connect (OSTI)

    Not Available

    1985-01-01T23:59:59.000Z

    The technical and economic assessment of AC and DC transmission systems; long distance transmission, cable transmission, system inter-connection, voltage support, reactive compensation, stabilisation of systems; parallel operation of DC links with AC systems; comparison between alternatives for particular schemes. Design and application equipment: design, testing and application of equipment for HVDC, series and shunt static compensated AC schemes, including associated controls. Installations: overall design of stations and conductor arrangements for HVDC, series and shunt static AC schemes including insulation co-ordination. System analysis and modelling.

  20. A Superconducting transformer system for high current cable testing

    E-Print Network [OSTI]

    Godeke, A.

    2010-01-01T23:59:59.000Z

    A Superconducting Transformer System for High Current CableDC) superconducting transformer system for the high currentsuperconducting cables. The transformer consists of a core-

  1. Effect of energetic electrons on near-wall sheath voltage in the cathode region of a cold cathode direct current discharge

    SciTech Connect (OSTI)

    Blessington, J. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Adams, S. F. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Demidov, V. I. [UES, Inc., 4401 Dayton-Xenia Road, Beavercreek, Ohio 45432 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Williamson, J. M. [Innovative Scientific Solutions, Inc., 2766 Indian Ripple Road, Ohio 45440-3638 (United States)

    2009-10-15T23:59:59.000Z

    It is experimentally demonstrated that energetic electrons originating from the cathode or produced in volumetric processes in the cathode region of a cold cathode direct current discharge can create a large potential drop in the near-wall sheath. This voltage drop may be much greater than kT{sub e}/e (where k is the Boltzmann constant, T{sub e} is the electron temperature, and e is the electron charge). Due to the large near-wall sheath voltage, slow and moderately energetic electrons cannot reach the wall and move toward the anode. Application of additional potentials to the wall can change the amount of energetic electrons reaching the wall. This effect can be used for regulation of the near-cathode plasma and near-wall sheath properties and thus may be useful in technical applications.

  2. Washington, DC,20585

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h JWJLP-~ .

  3. Washington, DC.20585

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h JWJLP-~ .. .

  4. Washington. DC,20585

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h JWJLP-~

  5. Washington. DC.20585'

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h JWJLP-~Department

  6. Washingtori, DC.20585

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h

  7. I ' Washington, DC'

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling CorpNewCF INDUSTRIES,L? . -.HomeDOE F*vSERVICE,'

  8. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    main conclusions about off-grid markets for DC appliances,and power systems. Mature Off-Grid Markets for DC Appliancesapplications include off-grid residential, telecom, remote

  9. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    DC solar-powered DC air-conditioning heat pump produced byRoom Air Conditioners Geothermal Heat Pumps Lighting-efficiency of an air source electric heat-pump water heater

  10. DC systems with transformerless converters

    SciTech Connect (OSTI)

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

    1995-07-01T23:59:59.000Z

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

  11. FEDERAL COMMUNICATIONS COMMISSION Washington, DC

    E-Print Network [OSTI]

    Peha, Jon M.

    1 Before the FEDERAL COMMUNICATIONS COMMISSION Washington, DC GN Docket No. 14-28 In the Matter 15213-3890 peha@cmu.edu July 15, 2014 #12;2 Executive Summary It is important for the Commission situated entity. This policy would particularly benefit new entrepreneurial ventures. The Commission should

  12. Stray current control in rehabilitating rail transit facilities

    SciTech Connect (OSTI)

    Fitzgerald, J.H. III; Bosma, R.; Paladines, F.

    1999-05-01T23:59:59.000Z

    An old Chicago direct current electrified railway yard and shop are being rehabilitated. Modern stray current control techniques are being introduced. Efficient rail operation and safety for the public and operating personnel are paramount. Metra is Chicago's commuter railroad, serving six counties in the metropolitan area. The Electric District, which was electrified in 1926, is a heavy rail system from downtown, serving the south side and suburbs. Operating on the same tracks from Randolph St., to Kensington is America's last electric interurban line, the Chicago South Shore and South Bend Railroad. All trains operate on 1,500-V direct current (DC) propulsion from an overhead catenary system, with the running rails as the negative return.

  13. FC/Battery Power Management for Electric Vehicle Based Interleaved dc-dc Boost Converter Topology

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    FC/Battery Power Management for Electric Vehicle Based Interleaved dc- dc Boost Converter Topology.fr Keywords Fuel cell System (FCS), Electric vehicle, Energy management, Interleaved Boost DC-DC Converter (FC for electric vehicle may not be feasible to satisfy the peak demand changes especially during accelerations

  14. Design and development of a DC-DC converter for a fuel cell inverter system

    E-Print Network [OSTI]

    Gopinath, Rajesh

    2001-01-01T23:59:59.000Z

    This thesis outlines the design and development of a DC-DC converter for a fuel cell inverter application. The proposed DC-DC converter was designed and tested at Texas A&M to meet the specifications laid down for the '2001 Future Energy Challenge...

  15. Analysis and design of a high power dc-dc converter

    E-Print Network [OSTI]

    Husain, Iqbal

    1989-01-01T23:59:59.000Z

    , for example in dc motors, traction motor control, marine hoist~, trolley cars, forklift trucks, mine haulers, dc voltage regulators etc. These choppers can be used for regeneration in the braking mode of a. dc motor pumping energy back to the system.... The elements of a dc-dc SP C are shown in figure 1. 2. The output voltage is usually regulated by pulse width modulation (PAVM) techniques. Input + V, DC Chopper Output V, Control Amp. V, + Ref. Fig. 1. 2 Block diagram of a SPC dc chopper...

  16. Point of collapse and continuation methods for large ac/dc systems

    SciTech Connect (OSTI)

    Canizares, C.A. (Escuela Politecnica Nacional, Quito (Ecuador)); Alvarado, F.L. (Univ. of Wisconsin, Madison, WI (United States))

    1993-02-01T23:59:59.000Z

    This paper describes the implementation of both Point of Collapse (PoC) methods and continuation methods for the computation of voltage collapse points (saddle-node bifurcations) in large ac/dc systems. A comparison of the performance of these methods is presented for real systems of up to 2,158 buses. The paper discusses computational details of the implementation of the PoC and continuation methods, and the unique challenges encountered due to the presence of high voltage direct current (HVDC) transmission, area interchange power control regulating transformers, and voltage and reactive power limits. The characteristics of a robust PoC power flow program are presented, and its application to detection and solution of voltage stability problems is demonstrated.

  17. DC switching regulated power supply for driving an inductive load

    DOE Patents [OSTI]

    Dyer, G.R.

    1983-11-29T23:59:59.000Z

    A dc switching regulated power supply for driving an inductive load is provided. The regulator basic circuit is a bridge arrangement of diodes and transistors. First and second opposite legs of the bridge are formed by first and second parallel-connected transistor arrays, respectively, while the third and fourth legs of the bridge are formed by appropriately connected first and second parallel connected diode arrays, respectively. A dc power supply is connected to the input of the bridge and the output is connected to the load. A servo controller is provided to control the switching rate of the transistors to maintain a desired current to the load. The regulator may be operated in three stages or modes: (1) for current runup in the load, both first and second transistor switch arrays are turned on and current is supplied to the load through both transistor arrays. (2) When load current reaches the desired level, the first switch is turned off, and load current flywheels through the second switch array and the fourth leg diode array connecting the second switch array in series with the load. Current is maintained by alternating between modes 1 and 2 at a suitable duty cycle and switching rate set by the controller. (3) Rapid current rundown is accomplished by turning both switch arrays off, allowing load current to be dumped back into the source through the third and fourth diode arrays connecting the source in series opposition with the load to recover energy from the inductive load.

  18. Graphite electrode DC arc furnace. Innovative technology summary report

    SciTech Connect (OSTI)

    NONE

    1999-05-01T23:59:59.000Z

    The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of feed composition variations on process operating conditions and slag product performance; and collecting mass balance and operating data to support equipment and instrument design.

  19. Disc rotors with permanent magnets for brushless dc motor

    SciTech Connect (OSTI)

    Hawsey, R.A.; Bailery, J.M.

    1992-05-26T23:59:59.000Z

    This patent describes a brushless dc permanent magnet motor for driving an autonomous underwater vehicle. It comprises first and second substantially flat, generally cylindrical stators disposed in side by side relation; a first substantially flat, generally cylindrical rotor; a first shaft connected to the first rotor and a second, concentric shaft connected to the second rotor; and means for providing rotation of the first and second shafts in opposite directions.

  20. Low Cost, High Temperature, High Ripple Current DC Bus Capacitors |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetterEconomy andTerms LoanLos AngelesGuillermo10 DOE1

  1. Ion mass spectrometry investigations of the discharge during reactive high power pulsed and direct current magnetron sputtering of carbon in Ar and Ar/N{sub 2}

    SciTech Connect (OSTI)

    Schmidt, S.; Greczynski, G.; Jensen, J.; Hultman, L. [Thin Film Physics Div., Department of Physics (IFM), Linkoeping University, SE-581 83 (Sweden); Czigany, Zs. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Konkoly Thege Miklos ut 29-33. H-1121 Budapest (Hungary)

    2012-07-01T23:59:59.000Z

    Ion mass spectrometry was used to investigate discharges formed during high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) of a graphite target in Ar and Ar/N{sub 2} ambient. Ion energy distribution functions (IEDFs) were recorded in time-averaged and time-resolved mode for Ar{sup +}, C{sup +}, N{sub 2}{sup +}, N{sup +}, and C{sub x}N{sub y}{sup +} ions. An increase of N{sub 2} in the sputter gas (keeping the deposition pressure, pulse width, pulse frequency, and pulse energy constant) results for the HiPIMS discharge in a significant increase in C{sup +}, N{sup +}, and CN{sup +} ion energies. Ar{sup +}, N{sub 2}{sup +}, and C{sub 2}N{sup +} ion energies, in turn, did not considerably vary with the changes in working gas composition. The HiPIMS process showed higher ion energies and fluxes, particularly for C{sup +} ions, compared to DCMS. The time evolution of the plasma species was analyzed for HiPIMS and revealed the sequential arrival of working gas ions, ions ejected from the target, and later during the pulse-on time molecular ions, in particular CN{sup +} and C{sub 2}N{sup +}. The formation of fullerene-like structured CN{sub x} thin films for both modes of magnetron sputtering is explained by ion mass-spectrometry results and demonstrated by transmission electron microscopy as well as diffraction.

  2. 45nm direct battery DC-DC converter for mobile applications

    E-Print Network [OSTI]

    Bandyopadhyay, Saurav

    2010-01-01T23:59:59.000Z

    Portable devices use Lithium-ion batteries as the energy source due to their high energy density, long cycle life and low memory effects. With the aggressive downscaling of CMOS, it is becoming increasingly difficult to ...

  3. Active dc filter for HVDC systems

    SciTech Connect (OSTI)

    Zhang, W. (Royal Inst. of Tech., Stockholm (Sweden)); Asplund, G.

    1994-01-01T23:59:59.000Z

    This article is a case history of the installation of active dc filters for high-performance, low-cost harmonics filtering at the Lindome converter station in the Konti-Skan 2 HVDC transmission link between Denmark and Sweden. The topics of the article include harmonics, interference, and filters, Lindome active dc filter, active dc filter design, digital signal processor, control scheme, protection and fault monitoring, and future applications.

  4. A Multiphase, Modular, Bidirectional, Triple-Voltage DC-DC Converter Power Systems

    SciTech Connect (OSTI)

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

    2008-01-01T23:59:59.000Z

    Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage [14 V, 42 V, and high voltage (HV)] nets. These will be necessary to accommodate existing 14-V loads as well as efficiently handle new heavy loads at the 42-V net and a traction drive on the HV bus. A low-cost DC-DC converter was proposed for connecting the three voltage nets. It minimizes the number of switches and their associated gate driver components by using two half-bridges and a high-frequency transformer. Another salient feature is that the half bridge on the 42-V bus is also utilized to provide the 14-V bus by operating at duty ratios around an atypical value of 1/3. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft switching. The use of half bridges makes the topology well suited for interleaved multiphase modular configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with an atypical duty ratio on the transformer and a preferred multiphase configuration to minimize capacitor ripple currents.

  5. Analysis of a transformer-less, multi-level DC-DC converter for HVDC operation

    SciTech Connect (OSTI)

    Karady, G.G.; Devarajan, S. [Arizona State Univ., Tempe, AZ (United States)

    1998-12-31T23:59:59.000Z

    HVDC systems require DC step up and DC step down units. The traditional approach is the application of twelve-pulse thyristor bridges with transformers. The developments of fast switching IGBT devices permit the development of transformer-less, multi-level converters. A multi-level circuit was suggested by Limpaecher. This paper presents a detailed simulation of the proposed circuit together with the analysis of its performance. The converter consists of a set of capacitors, air core inductors and solid state switches arranged in a ladder network. In the step-up mode, the closing of solid state switches resonantly charges the capacitors in parallel through an air-cored inductor. Then solid state switches resonantly charges the capacitors in parallel through an air-cored inductor. Then solid state switches connect the capacitors in series and discharge them through an air-core inductor to the load. In the step-down mode the capacitors are charged in series and discharged in parallel. The circuit has three modes of operation in each cycle: charge, inversion, and discharge. The circuit operation is analyzed in each mode using SPICE simulations. The selection of the components is discussed and output voltage regulation is analyzed. The results show that the proposed circuit promises significant reduction of losses, because of the zero current switching. The investment cost is reduced because of the elimination of transformers.

  6. Computer-aided optimization of DC/DC converters for automotive applications

    E-Print Network [OSTI]

    Neugebauer, Timothy C.

    This paper investigates computer-aided optimization of DC/DC converters, with a focus on converters for dual-voltage automotive electrical systems. A new CAD optimization approach based on Monte Carlo search methods is ...

  7. New Architectures for Radio-Frequency DC-DC Power Conversion

    E-Print Network [OSTI]

    Rivas, Juan M.

    This document proposes two new architectures for switched-mode dc–dc power conversion. The proposed architectures enable dramatic increases in switching frequency to be realized while preserving features critical in practice, ...

  8. Optimization of Integrated Transistors for Very High Frequency DC-DC Converters

    E-Print Network [OSTI]

    Sagneri, Anthony D.

    This paper presents a method to optimize integrated lateral double-diffused MOSFET transistors for use in very high frequency (VHF, 30-300 MHz) dc-dc converters. A transistor model valid at VHF switching frequencies is ...

  9. DC to DC power conversion module for the all-electric ship

    E-Print Network [OSTI]

    Gray, Weston L

    2011-01-01T23:59:59.000Z

    The MIT end to end electric ship model is being developed to study competing electric ship designs. This project produced a model of a Power Conversion Module (PCM)- 4, DC-to-DC converter which interfaces with the MIT ...

  10. Reliability Assessment of Fault-Tolerant Dc-Dc Converters for Photovoltaic Applications

    E-Print Network [OSTI]

    Liberzon, Daniel

    Reliability Assessment of Fault-Tolerant Dc-Dc Converters for Photovoltaic Applications Sairaj V in photovoltaic energy processing applications is presented. The proposed approach acknowledges the influence through several case studies. Index Terms-- Markov reliability modeling, photovoltaic systems, power

  11. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    resistance heating and incandescent lighting, the technologyresistance heating or by DC-favoring heat pump technology (technology (electronic fluorescent and LED). Similarly, heating

  12. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    48V DC , depending on battery bank configuration. Lifetime:Characteristics: Lead-acid battery banks are composed ofto produce the desired battery bank voltage. Typical battery

  13. The capacitively coupled converter (C³) for high power DC-DC conversion 

    E-Print Network [OSTI]

    Khan, Shahriar

    1992-01-01T23:59:59.000Z

    THE CAPACITIVELY COUPLED CONVERTER (C3) FOR HIGH POWER DC-DC CONVERSION A Thesis by SHAHRIAR KHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Electrical Engineering THE CAPACITIVELY COUPLED CONVERTER (Cs) FOR HIGH POWER DC-DC CONVERSION A Thesis by SHAHRIAR KHAN Approved as to style and content by: Mehrdad Ehsani (Chair of Committee) Prasad Enjeti...

  14. Digitally Controlled Distributed Multiphase DC-DC Converters Xu Zhang, Luca Corradini and Dragan Maksimovic

    E-Print Network [OSTI]

    Digitally Controlled Distributed Multiphase DC-DC Converters Xu Zhang, Luca Corradini and Dragan, corradin, maksimov}@colorado.edu Abstract -- This paper describes a distributed master-slave multiphase DC V-to-12 V input, 1.3 V, 20 A output two-phase synchronous buck converter. Index Terms-- Multiphase

  15. High Gain Transformerless DC-DC Converters for Renewable Energy Sources

    E-Print Network [OSTI]

    Denniston, Nicholas Aaron

    2011-08-08T23:59:59.000Z

    mode DCM Discontinuous conduction mode EAR Equivalent averaged resistance ESR Equivalent series resistance FC Fuel cell fS Switching frequency HVDC High voltage direct current ix, vx Instantaneous current, voltage of node x Ix, Vx Average....1. Introduction ................................................................................... 59 5.2. Design example and simulation .................................................... 62 5.3. Evaluation of multiple module approach in HVDC converters...

  16. Fault current limiter

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2013-10-08T23:59:59.000Z

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  17. DC-based magnetic field controller

    DOE Patents [OSTI]

    Kotter, D.K.; Rankin, R.A.; Morgan, J.P.

    1994-05-31T23:59:59.000Z

    A magnetic field controller is described for laboratory devices and in particular to dc operated magnetic field controllers for mass spectrometers, comprising a dc power supply in combination with improvements to a Hall probe subsystem, display subsystem, preamplifier, field control subsystem, and an output stage. 1 fig.

  18. DC-based magnetic field controller

    DOE Patents [OSTI]

    Kotter, Dale K. (Shelley, ID); Rankin, Richard A. (Ammon, ID); Morgan, John P,. (Idaho Falls, ID)

    1994-01-01T23:59:59.000Z

    A magnetic field controller for laboratory devices and in particular to dc operated magnetic field controllers for mass spectrometers, comprising a dc power supply in combination with improvements to a hall probe subsystem, display subsystem, preamplifier, field control subsystem, and an output stage.

  19. Multilevel-Dc-Bus Inverter For Providing Sinusoidal And Pwm Electrical Machine Voltages

    DOE Patents [OSTI]

    Su, Gui-Jia [Knoxville, TN

    2005-11-29T23:59:59.000Z

    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.

  20. Aternating current photovoltaic building block

    DOE Patents [OSTI]

    Bower, Ward Issac; Thomas, Michael G.; Ruby, Douglas S.

    2004-06-15T23:59:59.000Z

    A modular apparatus for and method of alternating current photovoltaic power generation comprising via a photovoltaic module, generating power in the form of direct current; and converting direct current to alternating current and exporting power via one or more power conversion and transfer units attached to the module, each unit comprising a unitary housing extending a length or width of the module, which housing comprises: contact means for receiving direct current from the module; one or more direct current-to-alternating current inverters; an alternating current bus; and contact means for receiving alternating current from the one or more inverters.

  1. DC switching regulated power supply for driving an inductive load

    DOE Patents [OSTI]

    Dyer, George R. (Norris, TN)

    1986-01-01T23:59:59.000Z

    A power supply for driving an inductive load current from a dc power supply hrough a regulator circuit including a bridge arrangement of diodes and switching transistors controlled by a servo controller which regulates switching in response to the load current to maintain a selected load current. First and second opposite legs of the bridge are formed by first and second parallel-connected transistor arrays, respectively, while the third and fourth legs of the bridge are formed by appropriately connected first and second parallel connected diode arrays, respectively. The regulator may be operated in three "stages" or modes: (1) For current runup in the load, both first and second transistor switch arrays are turned "on" and current is supplied to the load through both transistor arrays. (2) When load current reaches the desired level, the first switch is turned "off", and load current "flywheels" through the second switch array and the fourth leg diode array connecting the second switch array in series with the load. Current is maintained by alternating between modes 1 and 2 at a suitable duty cycle and switching rate set by the controller. (3) Rapid current rundown is accomplished by turning both switch arrays "off", allowing load current to be dumped back into the source through the third and fourth diode arrays connecting the source in series opposition with the load to recover energy from the inductive load. The three operating states are controlled automatically by the controller.

  2. SPEAR3 LARGE DC MAGNET POWER SUPPLIES

    SciTech Connect (OSTI)

    de Lira, A

    2004-06-23T23:59:59.000Z

    The Stanford Synchrotron Radiation Laboratory (SSRL) has successfully commissioned SPEAR3, its newly upgraded 3-GeV synchrotron light source. First stored beam occurred December 15, 2003 and 100mA operation was reached on January 20, 2004. This paper describes the specification, design, and performance of the SPEAR3 DC magnet large power supplies (LGPS) that consist of tightly-regulated (better than {+-}10 ppm) current sources ranging from 100A to 225A and output powers ranging from 70kW to 135kW. A total of 6 LGPS are in successful operation and are used to power strings of quadrupoles and sextupoles. The LGPS are isolated by a delta/delta-wye 60Hz step-down transformer that provides power to 2 series-connected chopper stages operating phase-shifted at a switching frequency of 18-kHz to provide for fast output response and high efficiency. Also described are outside procurement aspects, installation, in-house testing, and operation of the power supplies.

  3. AVTA: Battery Testing - DC Fast Charging's Effects on PEV Batteries...

    Energy Savers [EERE]

    DC Fast Charging's Effects on PEV Batteries AVTA: Battery Testing - DC Fast Charging's Effects on PEV Batteries The Vehicle Technologies Office's Advanced Vehicle Testing Activity...

  4. Vehicle Technologies Office Merit Review 2014: DC Fast Charging...

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

    DC Fast Charging Effects on Battery Life and EVSE Efficiency and Security Testing Vehicle Technologies Office Merit Review 2014: DC Fast Charging Effects on Battery Life and EVSE...

  5. DC Resistivity Survey (Dipole-Dipole Array) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty EditCalifornia:PowerCER.pngRoofs andCrops Ltd Jump to: navigation, searchDC

  6. DC High School Science Bowl Regionals

    Broader source: Energy.gov [DOE]

    This event is the Washington, D.C. High School Regional competition for the US National Science Bowl. The regional competition is run by the Office of Economic Impact and Diversity, and the...

  7. DC readout experiment in Enhanced LIGO

    E-Print Network [OSTI]

    Fricke, Tobin T

    The two 4 km long gravitational wave detectors operated by the Laser Interferometer Gravitational-wave Observatory (LIGO) were modified in 2008 to read out the gravitational wave channel using the DC readout form of homodyne ...

  8. Catalog of DC Appliances and Power Systems

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    www.lunera.com/. Nextek Power Systems. [cited 2010 Dec];data_files/. DC Power Systems. Wholesale Price List. [citedDUS103927W.pdf. Princeton Power Systems. GTIB-480-100 Grid-

  9. Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking

    SciTech Connect (OSTI)

    Das, Subodh K.

    2006-01-09T23:59:59.000Z

    A successful four-year project on the modeling and optimization of direct chill (DC) casting to reduce ingot cracking has been completed. The project involved close collaboration among private industries, national laboratories, and universities. During the four-year project, 16 quarterly meetings brought the industrial partners and the research team together for discussion of research results and research direction. The industrial partners provided guidance, facilities, and experience to the research team. The research team went to two industrial plants to measure temperature distributions in commercial 60,000-lb DC casting ingot. The collaborative research resulted in several major accomplishments or findings: (1) Surface cracks were shown to be a result of hot tearing rather than cold cracks, as was thought before this project. These cracks form on the surface of a DC cast ingot just above the impingement point of the secondary cooling water jets. The cracks form along dendrite and grain boundaries, where solute and impurity elements are highly segregated. This understanding led to the development of a new technique for determining the mechanical properties in the nonequilibrium mushy zone of alloys and to thermodynamic predictions of the hot tearing propensity of DC cast ingots. (2) The apparent heat transfer coefficient (HTC) at the ingot surface in the water cooling region during DC casting was determined on the basis of temperature measurements in commercial DC casting ingots and an inverse heat transfer analysis. HTCs were calculated as a function of temperature and time, and covered the different regimes of heat transfer expected during DC casting. The calculated values were extrapolated to include the effect of water flow rate. The calculated HTCs had a peak at around 200 C, corresponding to the high heat transfer rates during nucleate boiling, and the profile was consistent with similar data published in the literature. (3) A new method, termed the reheating-cooling method (RCM), was developed and validated for measuring mechanical properties in the nonequilibrium mushy zones of alloys. The new method captures the brittle nature of aluminum alloys at temperatures close to the nonequilibrium solidus temperature, while specimens tested using the reheating method exhibit significant ductility. The RCM has been used for determining the mechanical properties of alloys at nonequilibrium mushy zone temperatures. Accurate data obtained during this project show that the metal becomes more brittle at high temperatures and high strain rates. (4) The elevated-temperature mechanical properties of the alloy were determined. Constitutive models relating the stress and strain relationship at elevated temperatures were also developed. The experimental data fit the model well. (5) An integrated 3D DC casting model has been used to simulate heat transfer, fluid flow, solidification, and thermally induced stress-strain during casting. A temperature-dependent HTC between the cooling water and the ingot surface, cooling water flow rate, and air gap were coupled in this model. An elasto-viscoplastic model based on high-temperature mechanical testing was used to calculate the stress during casting. The 3D integrated model can be used for the prediction of temperature, fluid flow, stress, and strain distribution in DC cast ingots. (6) The cracking propensity of DC cast ingots can be predicted using the 3D integrated model as well as thermodynamic models. Thus, an ingot cracking index based on the ratio of local stress to local alloy strength was established. Simulation results indicate that cracking propensity increases with increasing casting speed. The composition of the ingots also has a major effect on cracking formation. It was found that copper and zinc increase the cracking propensity of DC cast ingots. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks in DC castings from a current level of 5% down to 2%. This could lead to energy savings

  10. American Institute of Aeronautics and Astronautics Active System Identification of a DC-DC Converter Using

    E-Print Network [OSTI]

    American Institute of Aeronautics and Astronautics 1 Active System Identification of a DC and Computer Engineering, UCB 425. #12;American Institute of Aeronautics and Astronautics 2 analysis10

  11. Federal Government Congressional Budget Office, Budget Analysis Division Washington, DC

    E-Print Network [OSTI]

    Shyy, Wei

    Charlotte, NC Gallaher Kazakhstan, Security & Brand Integrity Almaty Oblast, Kazakhstan GMMB Washington, DC

  12. Hydrogen Storage Systems Analysis Working Group Meeting Argonne DC Offices

    E-Print Network [OSTI]

    Hydrogen Storage Systems Analysis Working Group Meeting Argonne DC Offices L'Enfant Plaza, Washington, DC December 4, 2007 SUMMARY REPORT Compiled by Romesh Kumar Argonne National Laboratory Working Group Meeting December 4, 2007 Argonne DC Offices, L'Enfant Plaza, Washington, DC Meeting

  13. Current measurement apparatus

    DOE Patents [OSTI]

    Umans, Stephen D. (Belmont, MA)

    2008-11-11T23:59:59.000Z

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

  14. Direct fabrication of nanopores in a metal foil using focused ion beam with in situ measurements of the penetrating ion beam current

    SciTech Connect (OSTI)

    Nagoshi, Kotaro; Honda, Junki; Sakaue, Hiroyuki; Takahagi, Takayuki; Suzuki, Hitoshi [Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan)

    2009-12-15T23:59:59.000Z

    A through hole with a diameter less than 100 nm was fabricated in an Ag foil using only a focused ion beam (FIB) system and in situ measurements of the penetrating ion beam. During the drilling of the foil by a FIB of Ga{sup +} ions, the transmitted part of the beam was measured with an electrode mounted on the back face of the foil. When the beam current penetrating through the nanopore reached a certain value, irradiation was stopped and the area of the created aperture was measured with a scanning electron microscope. The resulting area was correlated with the current of the penetrating ion beam. This suggests that we can fabricate a nanopore of the desired size by controlling the ion beam via penetrating ion beam measurements. The smallest aperture thus created was circular with diameter of 30 nm.

  15. Direct Catalytic Upgrading of Current Dilute Alcohol Fermentation Streams to Hydrocarbons for Fungible Fuels Presentation for BETO 2015 Project Peer Review

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197E T A *Dingell_to_Bodman_0206.pdfDirect Catalytic

  16. Control of a Fuel-Cell Powered DC Electric Vehicle Motor Federico Zenith

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Control of a Fuel-Cell Powered DC Electric Vehicle Motor Federico Zenith Sigurd Skogestad Introduction Research in fuel cells receives currently a lot of interest. Fuel cells can be used, in different. However, the dynamics of fuel cells has received comparatively less attention. Control of fuel cells

  17. Electrical detection of spin pumping: dc voltage generated by ferromagnetic resonance at ferromagnet/nonmagnet contact

    E-Print Network [OSTI]

    van der Wal, Caspar H.

    Electrical detection of spin pumping: dc voltage generated by ferromagnetic resonance We describe electrical detection of spin pumping in metallic nanostructures. In the spin pumping effect, a precessing ferromagnet attached to a normal metal acts as a pump of spin-polarized current

  18. A DC-DC Converter-Based PEM Fuel Cell System Emulator

    E-Print Network [OSTI]

    Boyer, Edmond

    power supplies. Fuel cell systems are characterized by high costs and complex auxiliary devices still impose some drawbacks: the cost of fuel cell system tests are expensive (e.g., hydrogenA DC-DC Converter-Based PEM Fuel Cell System Emulator Daoud Rezzak, Farid Khoucha, Mohamed

  19. DC's Marble ceiling : urban height and its regulation in Washington, DC

    E-Print Network [OSTI]

    Trueblood, Andrew Tyson

    2009-01-01T23:59:59.000Z

    Washington, DC has a unique urban form that is the result of a century-old law. Through the narrow lens of DC's height limit, I survey a range of topics related to urban height, starting with a review of its history of ...

  20. Wide input range DC-DC converter with digital control scheme

    E-Print Network [OSTI]

    Harfman Todorovic, Maja

    2006-04-12T23:59:59.000Z

    In this thesis analysis and design of a wide input range DC-DC converter is proposed along with a robust power control scheme. The proposed converter and its control is designed to be compatible to a fuel cell power source, which exhibits 2...

  1. Project: Three phase rectifier with low current Student: David Chernya

    E-Print Network [OSTI]

    Supervisor: Prof. Sam Ben-Yaakov Abstract High power DC current has many applications, primarily in heavy industry and, chemical and electrochemical plants. Temporary rectifiers use "static" diode bridges

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

    E-Print Network [OSTI]

    Moores, Gregory Lee

    1998-01-01T23:59:59.000Z

    each flight had caused cracks in the Kapton insulation of the internal wires (Figure 3a). Eventually, through additional handling, these cracks widened enough to allow adjacent conductors to touch forming a short circuit (Figure 3b). This contact may... have been caused by vibration, a tug on the cable or some other mechanical transient because it occurred briefly. When the cable relaxed the conductors separated, drawing an arc (Figure 3c). It was the arc ignition that the astronauts heard...

  3. Understanding S-shaped current-voltage characteristics of organic solar cells: Direct measurement of potential distributions by scanning Kelvin probe

    SciTech Connect (OSTI)

    Saive, Rebecca, E-mail: rebecca.saive@innovationlab.de; Kowalsky, Wolfgang [InnovationLab GmbH, 69115 Heidelberg (Germany) [InnovationLab GmbH, 69115 Heidelberg (Germany); Institut für Hochfrequenztechnik, TU Braunschweig, 38106 Braunschweig (Germany); Kirchhoff-Institute for Physics, Heidelberg University, 69120 Heidelberg (Germany); Mueller, Christian [InnovationLab GmbH, 69115 Heidelberg (Germany) [InnovationLab GmbH, 69115 Heidelberg (Germany); Kirchhoff-Institute for Physics, Heidelberg University, 69120 Heidelberg (Germany); Schinke, Janusz; Lovrincic, Robert [InnovationLab GmbH, 69115 Heidelberg (Germany) [InnovationLab GmbH, 69115 Heidelberg (Germany); Institut für Hochfrequenztechnik, TU Braunschweig, 38106 Braunschweig (Germany)

    2013-12-09T23:59:59.000Z

    We present a comparison of the potential distribution along the cross section of bilayer poly(3-hexylthiophene)/1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C61 (P3HT/PCBM) solar cells, which show normal and anomalous, S-shaped current-voltage (IV) characteristics. We expose the cross sections of the devices with a focussed ion beam and measure them with scanning Kelvin probe microscopy. We find that in the case of S-shaped IV-characteristics, there is a huge potential drop at the PCBM/Al top contact, which does not occur in solar cells with normal IV-characteristics. This behavior confirms the assumption that S-shaped curves are caused by hindered charge transport at interfaces.

  4. Cont. Rot. Rot. DC Cont. Rot. Rot. DC Cont. Rot. Rot. DC Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans

    E-Print Network [OSTI]

    Jackson, Scott A.

    Cont. Rot. Rot. DC Cont. Rot. Rot. DC Cont. Rot. Rot. DC Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans Expected yield per acre2 118 126 39 62 23 149 158 49 70 29

  5. Cont. Rot. Rot. DC Cont. Rot. Rot. DC Cont. Rot. Rot. DC Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans

    E-Print Network [OSTI]

    Cont. Rot. Rot. DC Cont. Rot. Rot. DC Cont. Rot. Rot. DC Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans Corn Corn Beans Wheat Beans Expected yield per acre2 119 127 39 62 23 149 159 49 70 29

  6. Thermal cum DC Camouflage in Duet with Undecorated Natural Materials

    E-Print Network [OSTI]

    Yang, Tian-Zhi; Gao, Dongliang; Wu, Linzhi; Li, Baowen; Thong, John T L; Qiu, Cheng-Wei

    2015-01-01T23:59:59.000Z

    To manipulate various types of physical signals in one single device has long captivated the attention of scientists and engineers. This however is very challenging, if not impossible, even for emerging metamaterials. Up to date, many artificial materials have been proposed, theoretically and (or) experimentally, for manipulating various waves/signals on a one-function-one-device basis. In this work, for the very first time, we employ undecorated natural materials to experimentally demonstrate a simultaneous camouflage for thermal current and electric dc current on the same device. It demonstrates how ingenuity can overcome the limitations of natural material systems without the need for complex decoration to impart inhomogeneous and (or) anisotropic properties, which was previously considered impossible to accomplish except by using metamaterials.

  7. Data:7f1cf63c-cecc-4f01-ae89-a3dc1197b955 | Open Energy Information

    Open Energy Info (EERE)

    cecc-4f01-ae89-a3dc1197b955 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic...

  8. Data:081f0f05-9d4f-4701-b072-4bf5cb7dc11d | Open Energy Information

    Open Energy Info (EERE)

    4bf5cb7dc11d No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2....

  9. Data:781fbb0d-707e-4dc8-9500-3db297f0b065 | Open Energy Information

    Open Energy Info (EERE)

    dc8-9500-3db297f0b065 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic...

  10. Data:9fb9b87b-58b1-4912-bf96-c9dc6f6562f8 | Open Energy Information

    Open Energy Info (EERE)

    12-bf96-c9dc6f6562f8 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic...

  11. Data:B31bb453-f4c3-4047-8339-4dc476e1b0cb | Open Energy Information

    Open Energy Info (EERE)

    339-4dc476e1b0cb No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic...

  12. New Experimental Data in DC745U

    SciTech Connect (OSTI)

    Ortiz-Acosta, Denisse [Los Alamos National Laboratory; Cady, Carl [Los Alamos National Laboratory; Densmore, Crystal [Los Alamos National Laboratory

    2012-06-18T23:59:59.000Z

    The objectives of this project are: (1) study the molecular and mechanical properties of DC745U - (a) DC745U is a silicone elastomer used in several weapons systems, (b) depending on their chemistry and formulation, polymers can be susceptible to damage and failures due to weak chemical linkages and physical interactions, (c) inefficient production processes can generate heterogeneities throughout the material that can contribute negatively to the overall performance and lifetime of the polyer, (d) aging, long-term thermal and radioactive conditions, and mechanical strains can affect the materials network structure and contribute to the degradation of the production; (2) characterization of DC745U materials cured under different conditions to determine possible differences to the polymer structure; and (3) this work is relevant to mission-critical programs and for supporting programmatic work for weapon research.

  13. Simulation of geomagnetic currents induced in a power system by magnetohydrodynamic electromagnetic pulses

    SciTech Connect (OSTI)

    Rackliffe, G.B.; Crouse, J.C.; Legro, J.R.; Kruse, V.J.

    1987-01-01T23:59:59.000Z

    This paper quantifies the quasi-dc currents induced on a power system by a simulated magnetohydrodynamic pulse (MHD-EMP). The determination of the quasi-dc currents is based upon the similarity between the effects of MHD-EMP and the impact of geomagnetic storms. The paper highlights how the methodology to calculate geomagnetic-induced currents from solar storms was modified to calculate the currents induced by a MHD-EMP event. After specification of the MHD-EMP environment and the selection of a power system to study, the quasi-dc currents induced in the power system were calculated.

  14. Development of 500 kV DC PPLP-insulated oil-filled submarine cable

    SciTech Connect (OSTI)

    Fujimori, A. [Kansai Electric Power Co., Inc., Osaka (Japan)] [Kansai Electric Power Co., Inc., Osaka (Japan); Tanaka, T. [Electric Power Development Co., Ltd., Tokyo (Japan)] [Electric Power Development Co., Ltd., Tokyo (Japan); Takashima, H. [Shikoku Electric Power Co., Inc., Kagawa (Japan)] [Shikoku Electric Power Co., Inc., Kagawa (Japan); Imajo, T. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)] [Central Research Inst. of Electric Power Industry, Tokyo (Japan); Hata, R. [Sumitomo Electric Industries, Ltd., Osaka (Japan)] [Sumitomo Electric Industries, Ltd., Osaka (Japan); Tanabe, T. [Furukawa Electric Co., Ltd., Tokyo (Japan)] [Furukawa Electric Co., Ltd., Tokyo (Japan); Yoshida, S. [Fujikura, Ltd., Tokyo (Japan)] [Fujikura, Ltd., Tokyo (Japan); Kakihana, T. [Hitachi Cable, Ltd., Tokyo (Japan)] [Hitachi Cable, Ltd., Tokyo (Japan)

    1996-01-01T23:59:59.000Z

    This paper outlines the development of a 500 kV DC oil-filled submarine cable capable of transmitting 2,800 MW with {+-} 500 kV 2800A bipole system. Polypropylene Laminated Paper (PPL) was employed as the insulation material, which is the worlds first application to DC cables. The conductor size is 3,000 mm{sup 2}, which is the largest size for submarine cables ever put into practical use. Through various fundamental and prototype tests, the cable proved to have excellent electrical characteristics for DC voltage as well as transient overvoltage. The cable and accessories are currently undergoing a long-term accelerated aging test as the final confirmation of their reliability and stability.

  15. Thermoelectric DC conductivities from black hole horizons

    E-Print Network [OSTI]

    Aristomenis Donos; Jerome P. Gauntlett

    2014-10-14T23:59:59.000Z

    An analytic expression for the DC electrical conductivity in terms of black hole horizon data was recently obtained for a class of holographic black holes exhibiting momentum dissipation. We generalise this result to obtain analogous expressions for the DC thermoelectric and thermal conductivities. We illustrate our results using some holographic Q-lattice black holes as well as for some black holes with linear massless axions, in both $D=4$ and $D=5$ bulk spacetime dimensions, which include both spatially isotropic and anisotropic examples. We show that some recently constructed ground states of holographic Q-lattices, which can be either electrically insulating or metallic, are all thermal insulators.

  16. Electric Currents Electric Current

    E-Print Network [OSTI]

    Yu, Jaehoon

    ;Problem 3: At $0.095/kWh, what does it cost to leave a 25W porch light on day and night for a year = 219000 Watt- hour = 219kWh. So, total cost = 219 x$0.095 = $20.8 #12;Problem 4: A 100 W light bulb has of charge per unit time: = . Unit of current: Ampere (A). The purpose of a battery is to produce

  17. High Current Effects in Silicide Films for Sub-0.25 pm VLSI Technologies

    E-Print Network [OSTI]

    to self-heating. Two physical parameters, B and h, associated with DC and pulsed current stress, have been current and self-heating effects [4,5] in these silicides. This paper will present important parameters

  18. Computational study of flow dynamics from a dc arc plasma jet

    E-Print Network [OSTI]

    Juan Pablo Trelles

    2013-03-15T23:59:59.000Z

    Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviations between heavy-species and electron temperatures in the plasma fringes, the development of shear flow instabilities around the jet, the occurrence of localized regions with high electric fields far from the arc, and the formation and evolution of coherent flow structures.

  19. Self-consistent modeling of DC and microwave nitrogen discharges and their afterglows

    SciTech Connect (OSTI)

    Guerra, Vasco [Centro de Fisica dos Plasmas, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)

    2004-12-01T23:59:59.000Z

    This report presents an investigation on the modeling of stationary DC and microwave nitrogen discharges and their afterglows, operating at pressures around one Torr and ionization degrees between 10-7-10-4. The model is based on the self-consistent solutions to the electron Boltzmann equation coupled to the rate balance equations for the most important neutral and charged species, the wave electrodynamics characteristics and the gas thermal balance equation. The results are obtained as a function of the usual discharge operating parameters, namely gas pressure, discharge current or electron density, and tube radius. It is shown that the vibrationally excited molecules play a central role in the whole problem, ensuring a strong link between different kinetics and directly contributing to the mechanisms of dissociation and gas heating. Furthermore, vibrationally excited molecules in high vibration levels are in the origin of the peaks observed in the flowing afterglow for the concentrations of several species, such as N{sub 2}(A {sup 3}{sigma}{sub g}{sup +}), N2(B 3{pi}g), N{sub 2}{sup +}(B {sup 2}{sigma}{sub u}{sup +}) and electrons, which occur downstream from the discharge after a dark zone as a consequence of the V-V up-pumping mechanism.

  20. Ionization tube simmer current circuit

    DOE Patents [OSTI]

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

    1994-01-01T23:59:59.000Z

    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.

  1. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, R.F. Jr.

    1994-12-13T23:59:59.000Z

    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.

  2. DC Wafers | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof EnergyInnovationinConcentratingEnergyCoosaPageEnergy Information NewDBEDC

  3. Optimization of Direct-Injection H2 Combustion Engine Performance...

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

    2010 -- Washington D.C. ace009wallner2010o.pdf More Documents & Publications Optimization of Direct-Injection H2 Combustion Engine Performance, Efficiency, and Emissions H2...

  4. Washington, DC~ZO585

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3uj:'I,\ W C -h JWJLP-~ ..

  5. Design and analysis of a zero-voltage switching scheme for a dc- to-dc converter

    E-Print Network [OSTI]

    Arun, G.

    1992-01-01T23:59:59.000Z

    5S 59 VITA . 65 I. IST OF FICI;RES FIGURE Page Linear versus switch-mode power convers&on Components of a switch-mode dc-to-dc converter 3 A typical dc-to-dc converter system Basic buck converter Basic boost converter Basic buck...-boost converter 7 One leg of a, dc-to-dc converter. Turn-on and turn-off scenartos in switch-mode operation. 16 10 Switching loci in the ur ? ir plane. Circuit for. zero-voltage sw&tching. . Mode 1 17 90 Mode? Mode I Mode 5 oo 93 Typical voltage...

  6. achyrocline satureioides dc: Topics by E-print Network

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

    and DC, microgrid, with its definition as a local grid that comprises distributed generation, energy storage systems to the frequency in the AC bulk grid, the DC voltage in the...

  7. DC Students Flex Their Mental Muscles in Regional Science Bowl...

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

    DC Students Flex Their Mental Muscles in Regional Science Bowl Competition DC Students Flex Their Mental Muscles in Regional Science Bowl Competition February 23, 2015 - 3:12pm...

  8. Halbach array DC motor/generator

    DOE Patents [OSTI]

    Merritt, Bernard T. (Livermore, CA); Dreifuerst, Gary R. (Livermore, CA); Post, Richard F. (Walnut Creek, CA)

    1998-01-01T23:59:59.000Z

    A new configuration of DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An "inside-out" design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then "switched" or "commutated" to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives.

  9. Halbach array DC motor/generator

    DOE Patents [OSTI]

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

    1998-01-06T23:59:59.000Z

    A new configuration of DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An ``inside-out`` design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then ``switched`` or ``commutated`` to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives. 17 figs.

  10. FEDERAL COMMUNICATIONS COMMISSION Washington, DC 20554

    E-Print Network [OSTI]

    Bove Jr., V. Michael

    FCC 96­207 Before the FEDERAL COMMUNICATIONS COMMISSION Washington, DC 20554 In the Matter to the advancement of digital television and related technologies by the Federal Communications Commission, its 617­253­0334, fax 617­258­6264 vmb@media.mit.edu #12; EXECUTIVE SUMMARY The Federal Communications

  11. Quarterly SLUO Executive Committee Meeting February 10, 2010

    E-Print Network [OSTI]

    Wechsler, Risa H.

    trip ­ current atmosphere in DC, message to push, etc. LCLS ­ impression of the current LCLS direction

  12. Energy Training Session for DC Elementary School Teachers

    Broader source: Energy.gov [DOE]

    Are you an elementary school teacher in Washington, DC, looking for creative ideas to introduce energy curriculum to your students?

  13. High pressure, high current, low inductance, high reliability sealed terminals

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN) [Oak Ridge, TN; McKeever, John W. (Oak Ridge, TN) [Oak Ridge, TN

    2010-03-23T23:59:59.000Z

    The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

  14. Geothermal Energy: Current abstracts

    SciTech Connect (OSTI)

    Ringe, A.C. (ed.)

    1988-02-01T23:59:59.000Z

    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)

  15. Anomalous - viscosity current drive

    DOE Patents [OSTI]

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

    1988-01-01T23:59:59.000Z

    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.

  16. Aalborg Universitet Hierarchical Control for Multiple DC Microgrids Clusters

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Hierarchical Control for Multiple DC Microgrids Clusters Shafiee, Qobad Control for Multiple DC Microgrids Clusters. I E E E Transactions on Energy Conversion. General rights, J. C. Vasquez, and J. M. Guerrero, "Hierarchical Control for Multiple DC-Microgrids Clusters," IEEE

  17. Transportation YOU 2013 DC Youth Summit WTS Transportation YOU

    E-Print Network [OSTI]

    Minnesota, University of

    Transportation YOU 2013 DC Youth Summit WTS Transportation YOU CTS Research Conference May 21, 2014 Lisa Rasmussen, WTS / Kimley-Horn and Associates, Inc #12;Transportation YOU 2013 DC Youth SummitTransportation YOU 2013 DC Youth Summit Agenda What is Transportation YOU? Transportation YOU ­ WTS Local Chapter

  18. D.C. Water Resources Research Center Annual Technical Report

    E-Print Network [OSTI]

    D.C. Water Resources Research Center Annual Technical Report FY 2007 D.C. Water Resources Research of the District of Columbia (DC) Water Resources Research Institute (the Institute) for the period of March 1 relevant water resources research results and transfer information to assist policy makers and residents

  19. Low Power DC-DC Converters and a Low Quiescent Power High PSRR Class-D Audio Amplifier

    E-Print Network [OSTI]

    Torres, Joselyn

    2013-12-03T23:59:59.000Z

    High-performance DC-DC voltage converters and high-efficient class-D audio amplifiers are required to extend battery life and reduce cost in portable electronics. This dissertation focuses on new system architectures and design techniques...

  20. Low Power DC-DC Converters and a Low Quiescent Power High PSRR Class-D Audio Amplifier 

    E-Print Network [OSTI]

    Torres, Joselyn

    2013-12-03T23:59:59.000Z

    High-performance DC-DC voltage converters and high-efficient class-D audio amplifiers are required to extend battery life and reduce cost in portable electronics. This dissertation focuses on new system architectures and design techniques...

  1. Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking

    SciTech Connect (OSTI)

    Das, S.K.; Ningileri, S.; Long, Z.; Saito, K.; Khraisheh, M.; Hassan, M.H.; Kuwana, K.; Han, Q.; Viswanathan, S.; Sabau, A.S.; Clark, J.; Hyrn, J. (ANL)

    2006-08-15T23:59:59.000Z

    Approximately 68% of the aluminum produced in the United States is first cast into ingots prior to further processing into sheet, plate, extrusions, or foil. The direct chill (DC) semi-continuous casting process has been the mainstay of the aluminum industry for the production of ingots due largely to its robust nature and relative simplicity. Though the basic process of DC casting is in principle straightforward, the interaction of process parameters with heat extraction, microstructural evolution, and development of solidification stresses is too complex to analyze by intuition or practical experience. One issue in DC casting is the formation of stress cracks [1-15]. In particular, the move toward larger ingot cross-sections, the use of higher casting speeds, and an ever-increasing array of mold technologies have increased industry efficiencies but have made it more difficult to predict the occurrence of stress crack defects. The Aluminum Industry Technology Roadmap [16] has recognized the challenges inherent in the DC casting process and the control of stress cracks and selected the development of 'fundamental information on solidification of alloys to predict microstructure, surface properties, and stresses and strains' as a high-priority research need, and the 'lack of understanding of mechanisms of cracking as a function of alloy' and 'insufficient understanding of the aluminum solidification process', which is 'difficult to model', as technology barriers in aluminum casting processes. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks from the current level of 5% to 2%. Decreasing stress crack incidence is important for improving product quality and consistency as well as for saving resources and energy, since considerable amounts of cast metal could be saved by eliminating ingot cracking, by reducing the scalping thickness of the ingot before rolling, and by eliminating butt sawing. Full-scale industrial implementation of the results of the proposed research would lead to energy savings in excess of 6 trillion Btu by the year 2020. The research undertaken in this project aimed to achieve this objective by a collaboration of industry, university, and national laboratory personnel through Secat, Inc., a consortium of aluminum companies. During the four-year project, the industrial partners and the research team met in 16 quarterly meetings to discuss research results and research direction. The industrial partners provided guidance, facilities, and experience to the research team. The research team went to two industrial plants to measure temperature distributions in commercial 60,000-lb DC casting ingot production. The project focused on the development of a fundamental understanding of ingot cracking and detailed models of thermal conditions, solidification, microstructural evolution, and stress development during the initial transient in DC castings of the aluminum alloys 3004 and 5182. The microstructure of the DC casting ingots was systematically characterized. Carefully designed experiments were carried out at the national laboratory and university facilities as well as at the industrial locations using the industrial production facilities. The advanced computational capabilities of the national laboratories were used for thermodynamic and kinetic simulations of phase transformation, heat transfer and fluid flow, solidification, and stress-strain evolution during DC casting. The achievements of the project are the following: (1) Identified the nature of crack formation during DC casting; (2) Developed a novel method for determining the mechanical properties of an alloy at the nonequilibrium mushy zone of the alloy; (3) Measured heat transfer coefficients (HTCs) between the solidifying ingot and the cooling water jet; (4) Determined the material constitutive model at high temperatures; and (5) Developed computational capabilities for the simulation of cracking formation in DC casting ingot. The models and the database de

  2. Directives Tools

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

    Useful links and resources for Directives Writers, Directives Point of Contact (DPCs), Subject Matter Experts (SMEs), and Draft Directive Reviewers.

  3. Generating expansion model incorporating compact DC power flow equations

    SciTech Connect (OSTI)

    Nderitu, D.G.; Sparrow, F.T.; Yu, Z. [Purdue Inst. for Interdisciplinary Engineering Studies, West Lafayette, IN (United States)

    1998-12-31T23:59:59.000Z

    This paper presents a compact method of incorporating the spatial dimension into the generation expansion problem. Compact DC power flow equations are used to provide real-power flow coordination equations. Using these equations the marginal contribution of a generator to th total system loss is formulated as a function of that generator`s output. Incorporating these flow equations directly into the MIP formulation of the generator expansion problem results in a model that captures a generator`s true net marginal cost, one that includes both the cost of generation and the cost of transport. This method contrasts with other methods that iterate between a generator expansion model and an optimal power flow model. The proposed model is very compact and has very good convergence performance. A case study with data from Kenya is used to provide a practical application to the model.

  4. Possible temperature control DC switch effect between two superconductors

    E-Print Network [OSTI]

    Tian De Cao

    2011-08-11T23:59:59.000Z

    The lifetime of an electron pair could not be unlimited long, on the basis of this, we suggest a model. The model means that the movements of charge carriers in a superconductor should have three forms: the single-electron movement, the single-pair movement, and the revolving around the mass center of two electrons in a pair. Thus the current in a superconductor has three possible parts. Similarly, there should be three possible effects in a SIS junction: the tunneling of single electron, the tunneling of single pair, and the pair-forming following the pair-breaking. This paper will discuss these problems and present a possible temperature control DC switch effect between two superconductors.

  5. Discharging a DC bus capacitor of an electrical converter system

    DOE Patents [OSTI]

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

    2014-10-14T23:59:59.000Z

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  6. GNP NanocompositeDirect current resistivity

    E-Print Network [OSTI]

    Collins, Gary S.

    in polycarbonate composite for improved static dissipation rate Michelle Tsui1, Bin Li2, Jianying Ji2, Michael cast on glass panel · 0.03-0.05 mm thickness for testing Casting Sample Preparation Polycarbonate (PC, but are strong insulators and prone to ESD Conductive filler added to polymer decreases static dissipation rate

  7. Ocean indicators Current knowledge and future directions

    E-Print Network [OSTI]

    -016-00) Hatchery Wild #12;Spatial distribution is stock-specific #12;Steelhead R2 = 0.68 Group A with 1-year lag R2 of mechanistic understanding · Plugging in to management #12;Managing for Harvest Egg take Escapement (hatchery

  8. Pacific Direct Current Intertie (PDCI) Upgrade Project

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPO Website Directory PPPOLarson.Cheryl Aand

  9. Modeling a short dc discharge with thermionic cathode and auxiliary anode

    SciTech Connect (OSTI)

    Bogdanov, E. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation) [St. Petersburg State University, St. Petersburg 199034 (Russian Federation); University ITMO, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); Demidov, V. I. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation) [St. Petersburg State University, St. Petersburg 199034 (Russian Federation); West Virginia University, Morgantown, West Virginia 26506 (United States); Kaganovich, I. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Koepke, M. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A. [St. Petersburg State University, St. Petersburg 199034 (Russian Federation)] [St. Petersburg State University, St. Petersburg 199034 (Russian Federation)

    2013-10-15T23:59:59.000Z

    A short dc discharge with a thermionic cathode can be used as a current and voltage stabilizer, but is subject to current oscillation. If instead of one anode two anodes are used, the current oscillations can be reduced. We have developed a kinetic model of such a discharge with two anodes, where the primary anode has a small opening for passing a fraction of the discharge current to an auxiliary anode. The model demonstrates that the current-voltage relationship of the discharge with two anodes is characterized everywhere by positive slope, i.e., positive differential resistance. Therefore, the discharge with two anodes is expected to be stable to the spontaneous oscillation in current that is induced by negative differential resistance. As a result, such a discharge can be used in an engineering application that requires stable plasma, such as a current and voltage stabilizer.

  10. DC side filters for multiterminal HVDC systems

    SciTech Connect (OSTI)

    Shore, N.L.; Adamson, K.; Bard, P. [and others] [and others

    1996-10-01T23:59:59.000Z

    Multiterminal HVDC systems present challenges in the specification and design of suitable dc side filtering. This document examines the existing experience and addresses the particular technical problems posed by multiterminal systems. The filtering requirements of small taps are discussed, as is the potential use of active filters. Aspects of calculation and design are considered and recommendations made to guide the planners and designers of future multiterminal schemes.

  11. Demonstration of Cathode Emittance Dominated High Bunch Charge Beams in a DC gun-based Photoinjector

    E-Print Network [OSTI]

    Gulliford, Colwyn; Bazarov, Ivan; Dunham, Bruce; Cultrera, Luca

    2015-01-01T23:59:59.000Z

    We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (greater than or equal to 100 pC) beams produced in the DC gun-based Cornell Energy Recovery Linac Photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittance measured at 9-9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs (ERLs) and Free Electron Lasers (FELs).

  12. Stray currents -- Generation, interference effects and control

    SciTech Connect (OSTI)

    Nikolakakos, S. [Raytheon Engineers and Constructors, Inc., Lyndhurst, NJ (United States)

    1998-12-31T23:59:59.000Z

    Stray currents, mostly known for their detrimental corrosion affects on the underground structures, can be effectively controlled by the implementation of specific measures at both the source of generation and at the affected structure(s). This paper discusses the most serious sources of stray current generation, the resulting problems and the numerous control methods that can be utilized to minimize corrosion and safety problems. Safety concerns associated with dc power systems are also discussed.

  13. Method of measuring the dc electric field and other tokamak parameters

    DOE Patents [OSTI]

    Fisch, Nathaniel J. (Princeton, NJ); Kirtz, Arnold H. (Princeton Junction, NJ)

    1992-01-01T23:59:59.000Z

    A method including externally imposing an impulsive momentum-space flux to perturb hot tokamak electrons thereby producing a transient synchrotron radiation signal, in frequency-time space, and the inference, using very fast algorithms, of plasma parameters including the effective ion charge state Z.sub.eff, the direction of the magnetic field, and the position and width in velocity space of the impulsive momentum-space flux, and, in particular, the dc toroidal electric field.

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

    E-Print Network [OSTI]

    Yancey, Billy Ferrall

    2011-08-08T23:59:59.000Z

    With the ever-growing developments of sustainable energy sources such as fuel cells, photovoltaics, and other distributed generation, the need for a reliable power conversion system that interfaces these sources is in great demand. In order...

  15. DC-DC Converter Topology Assessment for Large Scale Distributed Photovoltaic Plant Architectures

    SciTech Connect (OSTI)

    Mohammed S. Agamy; Maja Harfman-Todorovic; Ahmed Elasser; Juan A. Sabate; Robert L. Steigerwald; Yan Jiang; Somasundaram Essakiappan

    2011-07-01T23:59:59.000Z

    Distributed photovoltaic (PV) plant architectures are emerging as a replacement for the classical central inverter based systems. However, power converters of smaller ratings may have a negative impact on system efficiency, reliability and cost. Therefore, it is necessary to design converters with very high efficiency and simpler topologies in order not to offset the benefits gained by using distributed PV systems. In this paper an evaluation of the selection criteria for dc-dc converters for distributed PV systems is performed; this evaluation includes efficiency, simplicity of design, reliability and cost. Based on this evaluation, recommendations can be made as to which class of converters is best fit for this application.

  16. Inductorless DC-AC Cascaded H-bridge Multilevel Boost Inverter for Electric/Hybrid Electric Vehicle

    E-Print Network [OSTI]

    Tolbert, Leon M.

    boost inverter for EV and HEV applications. Currently available power inverter systems for HEVs use a DC and EV need a traction motor and a power inverter to drive the traction motor. The power inverter is the key part of a HEV or EV. The requirements of the power inverter include high peak power and low

  17. KAUAI CEANNEL CURRENTS THESIS SUBMITTED TO TEE GRADUATE

    E-Print Network [OSTI]

    Luther, Douglas S.

    from August L95, through Novem ber 1966. Direct current measurements were made by a Savonius current

  18. Induced Currents, Eddy Currents and

    E-Print Network [OSTI]

    Tobar, Michael

    Lecture 11 Induced Currents, Eddy Currents and Maxwell's Equations 1 Faraday Disk Dynamo F = q Eddy Currents We have learnt that changing magnetic fields can induce electric fields in conductors 108 ms-1 16 #12;In this lecture and the next Eddy Currents: We have covered Sect. 29

  19. A Bi-Directional DC-DC Converter with Minimum Energy Storage Elements Leon M. Tolbert1,3

    E-Print Network [OSTI]

    Tolbert, Leon M.

    and ambient thermal conditions controls the engine to run at its most efficient operating point. The variable. Military mobile electric generators are designed to operate in a temperature range from -45°C to 60°C envelope when these units are not run near full load; therefore, running the engine at variable speed

  20. DC Breakdown Experiments with Iridium Cathode

    E-Print Network [OSTI]

    Profatilova, Iaroslava; Korsback, Anders; Muranaka, Tomoko; Wuensch, Walter

    2015-01-01T23:59:59.000Z

    Electrical breakdown occurring in rf accelerating structures is one of the major disruptions of the accelerated beam in CLIC. At CERN, as complements to rf facilities, DC-spark systems have been used to study breakdown properties of many candidate materials for making rf components. In this note, measurements of conditioning speed, breakdown field and field enhancement factor of iridium are presented comparing with previously tested materials. The average breakdown field after conditioning reached 238 MV/m, which places iridium next to copper. By comparison with results and properties of other metals, the low breakdown field of iridium could be explained by its face-centred-cubic crystal structure.

  1. User:Dc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTri Global Energy LLCEnergy) RedirectCwebber Jump to: navigation,DbowersDc

  2. Dc's blog | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOE Facility Database DataDatatechnicNew Jersey: Energy ResourcesDc's blog Home

  3. XL-DC/Mark V Options You can customize the XL-DC and Mark V

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    administrator with the NTP Time Server Protocol, network status, and statistics. This feature implements SNMP. XL-DC Mark V Network Time Server Telecommunications Interface Frequency Measurement STD Time Interface Low Phase Noise Output Network Interface Loss of Lock Alarm STD Programmable Pulse Output

  4. A Reachability-Based Method for Large-Signal Behavior Verification of DC-DC Converters

    E-Print Network [OSTI]

    Liberzon, Daniel

    -loop, large-signal system behavior verification, and iv) switching detail modeling. In open-loop, large´inguez-Garc´ia, Member, IEEE Abstract--A method for large-signal behavior verification of power electronics DC behavior verification, lengthy time-domain simula- tions are conducted to analyze the system response

  5. Development of a 55 kW 3X DC-DC Converter for HEV Systems

    E-Print Network [OSTI]

    Tolbert, Leon M.

    converter and a traction motor to drive the vehicle. In most commercial HEV systems, the power converter one of the hottest parts in the system. Hence, with the trend of higher coolant temperatures, those-dc converter and the continuous control of the modulation index of the inverter, it is sufficient to operate

  6. Energy Challenge Two: The WeatherizeDC Campaign | Department...

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

    economic and environmental justice by creating clean energy career opportunities for people who need them most. The DC Project applies cutting-edge organizing tools and tactics...

  7. assisted dc magnetron: Topics by E-print Network

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

    resistivity exceeding 1020 .cm 2. However, native defects (most Mekki, Abdelkarim 23 Optimization of DC reactive magnetron sputtering deposition process for efficient YSZ...

  8. DC Bus Capacitor Manufacturing Facility for Electric Drive Vehicles...

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

    0 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C. apearravt028boan2010...

  9. ac to dc converters: Topics by E-print Network

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

    to use solid state Inverters(DC to AC converters) to have a variable voltage, fixed or variable frequency power source available for industrial applications. With advancements...

  10. PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL

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

    PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL LABORATORIES Jay Johnson 1 , Birger Pahl 2 , Charles Luebke 2 , Tom Pier 2 , Theodore Miller 3 , Jason Strauch 1 ,...

  11. Identifying semiconductors by d.c. ionization conductivity

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    expected from high-Z semiconductor detectors? ,” IEEE Transand binary compound semiconductors and insulators,” J PhysIdentifying Semiconductors by D.C. Ionization Conductivity

  12. DC Resistivity Survey (Wenner Array) At Mt Princeton Hot Springs...

    Open Energy Info (EERE)

    2008 - 2010 Usefulness useful DOE-funding Unknown Exploration Basis Determination of groundwater flux patterns Notes Researchers measured DC resistivity and produced 12 resistivity...

  13. Electric current locator

    DOE Patents [OSTI]

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

    2012-02-07T23:59:59.000Z

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

  14. Data:1c3e5e8d-4a78-4492-9dc2-82c4f9b4918a | Open Energy Information

    Open Energy Info (EERE)

    dc2-82c4f9b4918a No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic...

  15. Design and analysis of a zero-voltage switching scheme for a dc- to-dc converter 

    E-Print Network [OSTI]

    Arun, G.

    1992-01-01T23:59:59.000Z

    DESIGN AND ANALYSIS OF A ZERO-VOLTAGE SSVITCHING SCFIE'. tIE FOR A DC-TO-DC CONVERTER A Thesis by G. ARUN Submitted to the Office of Graduate Studies of Texas ARM 1. niversity in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Electrical Engineering DESIGN AND ANALYSIS OE A ZERO-VOLTAGE SWITCHING SCHEME I'OR A DC-TO-DC CONVERTER A Thesis by G. AR(tN Approved as to style and content by: P. Enjeti (Chair of Cornrnitteel C...

  16. Parallel 3D Finite Element Numerical Modelling of DC Electron Guns

    SciTech Connect (OSTI)

    Prudencio, E.; Candel, A.; Ge, L.; Kabel, A.; Ko, K.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; /SLAC

    2008-02-04T23:59:59.000Z

    In this paper we present Gun3P, a parallel 3D finite element application that the Advanced Computations Department at the Stanford Linear Accelerator Center is developing for the analysis of beam formation in DC guns and beam transport in klystrons. Gun3P is targeted specially to complex geometries that cannot be described by 2D models and cannot be easily handled by finite difference discretizations. Its parallel capability allows simulations with more accuracy and less processing time than packages currently available. We present simulation results for the L-band Sheet Beam Klystron DC gun, in which case Gun3P is able to reduce simulation time from days to some hours.

  17. Current Rusume

    E-Print Network [OSTI]

    2015-02-09T23:59:59.000Z

    Research Interest Rough paths theory, Stochastic differential equations, ... I am currently working on a problem about stochastic analysis on Riemannian folia-.

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

    E-Print Network [OSTI]

    Lemieux, Guy

    SoC Energy Savings = Reduce+Reuse+Recycle: A Case Study Using a 660MHz DC-DC Converter, mehdia, samad, prp, shahriar } @ ece.ubc.ca Abstract ­ This paper advocates `reduce, reuse, recycle to emphasize reuse and recycling as well. We design a DC-DC buck converter to demonstrate the 3 techniques

  19. Dynamic microscopic theory of fusion using DC-TDHF

    SciTech Connect (OSTI)

    Umar, A. S.; Oberacker, V. E.; Keser, R.; Maruhn, J. A.; Reinhard, P.-G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States); RTE University, Science and Arts Faculty, Department of Physics, 53100, Rize (Turkey); Institut fuer Theoretische Physik, Goethe-Universitaet, D-60438 Frankfurt am Main (Germany); Institut fur Theoretische Physik, Universitat Erlangen, D-91054 Erlangen (Germany)

    2012-10-20T23:59:59.000Z

    The density-constrained time-dependent Hartree-Fock (DC-TDHF) theory is a fully microscopic approach for calculating heavy-ion interaction potentials and fusion cross sections below and above the fusion barrier. We discuss recent applications of DC-TDHF method to fusion of light and heavy systems.

  20. ELECTROMAGNETIC RADIATION FROM A STRONG DC ELECTRIC FIELD

    E-Print Network [OSTI]

    Guedel, Manuel

    ELECTROMAGNETIC RADIATION FROM A STRONG DC ELECTRIC FIELD Manuel G¨udel 1 and Donat G. Wentzel 2 1 accelerated by a strong dc electric field show not only very efficient generation of beam waves but also emission of o­mode radiation. We present a set of particle simulations for which we study the behavior

  1. Read-out electronics for DC squid magnetic measurements

    DOE Patents [OSTI]

    Ganther, Jr., Kenneth R. (Olathe, KS); Snapp, Lowell D. (Independence, MO)

    2002-01-01T23:59:59.000Z

    Read-out electronics for DC SQUID sensor systems, the read-out electronics incorporating low Johnson noise radio-frequency flux-locked loop circuitry and digital signal processing algorithms in order to improve upon the prior art by a factor of at least ten, thereby alleviating problems caused by magnetic interference when operating DC SQUID sensor systems in magnetically unshielded environments.

  2. National Small Business Federal Contracting Summit-DC Fall Conference

    Broader source: Energy.gov [DOE]

    The 2014 National Small Business Federal Contracting Summit - DC Fall Conference is presented jointly by the National Association of Small Business Contractors (the Supplier Council of The American Small Business Chamber of Commerce) and the U.S. Women's Chamber of Commerce in Washington DC.

  3. DC, AC and advanced EV propulsion systems

    SciTech Connect (OSTI)

    O'Neil, W.

    1983-08-01T23:59:59.000Z

    Battery development and liquid fuel availability and cost are still the pacing factors in wide scale electric vehicle introduction. Propulsion systems also require technical development, however, if electric vehicles are to be acceptable in the marketplace in competition against ICE vehicles. Eaton Corporation has undertaken a program designed to identify and investigate three broad types of propulsion systems in identical test vehicles on the same test track under conditions as similar as possible. Characteristics of dc, ac and advanced systems are compared to date, and projections of anticipated results and further work are provided. The compelling advantages of multiple mechanical ratios in EV propulsion systems are reviewed. An emerging, but less obvious, advantage is higher overall system efficiency.

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

    SciTech Connect (OSTI)

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

    2007-12-31T23:59:59.000Z

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

  5. Stray current interference control for HVDC earth currents

    SciTech Connect (OSTI)

    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

    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.

  6. Modeling and simulation, and their validation of three-phase transformers with three legs under DC bias

    SciTech Connect (OSTI)

    Fuchs, E.F.; You, Y.; Roesler, D.J. [Univ. of Colorado, Boulder, CO (United States)] [Univ. of Colorado, Boulder, CO (United States)

    1999-04-01T23:59:59.000Z

    This paper proposes a new model for three-phase transformers with three legs with and without tank under DC bias based on electric and magnetic circuit theory. For the calculation of the nonsinusoidal no-load currents, a combination of time and frequency domains is used. The analysis shows that (1) asymmetric three-phase transformers with three legs generate magnetizing currents with triplen harmonics not being of the zero-sequence type. (2) The wave shapes of the three magnetizing currents of (asymmetric) transformers are dependent on the phase sequence. (3) The magnetic history of transformer magnetization -- due to residual magnetization and hysteresis of the tank -- cannot be ignored if a DC bias is present and the magnetic influence of the tank is relatively strong, e.g., for oil-cooled transformers. (4) Symmetric three-phase transformers with three legs generate no-load currents without triplen harmonics. (5) The effects of DC bias currents (e.g., reactive power demand, harmonic distortion) can be suppressed employing symmetric three-phase transformers with three legs including tank. Measurements corroborate computational results; thus this nonlinear model is valid and accurate.

  7. Abstract --A systematic framework for reliability assessment and fault-tolerant design of multiphase dc-dc

    E-Print Network [OSTI]

    Liberzon, Daniel

    reliability. Index Terms--Markov reliability modeling, maximum power point tracking, photovoltaics, switch1 Abstract -- A systematic framework for reliability assessment and fault-tolerant design of multiphase dc-dc converters deployed in photovoltaic applications is presented. System-level steady

  8. 3X DC-DC Multiplier/Divider for HEV Systems Wei Qian, Fang Z. Peng, Miaosen Shen

    E-Print Network [OSTI]

    Tolbert, Leon M.

    -dc converter, this converter can have three output/input voltage ratios with smooth transition. The control motor to drive the vehicle. The power converter could be just a traditional inverter or a dc, the inductor is bulky, heavy, costly, and always one of the hottest components. With the trend of higher

  9. Annual Meeting of Energy Recovery Council, W hi DC D b 3 2011Washington DC, December 3. 2011

    E-Print Network [OSTI]

    Columbia University

    Annual Meeting of Energy Recovery Council, W hi DC D b 3 2011Washington DC, December 3. 2011 to the recyclers (e.g. metal smelters; secondary paper mills).(e.g. metal smelters; secondary paper mills). All, recovery (called WastetoEnergy; WTE) gy, , y ( gy; ) · All countries (and communities) who rely on WTE also

  10. This document is the preprint version of the paper: L. Meng, T. Dragicevic, J.M. Guerrero, and J.C. Vasquez, "Stability constrained efficiency optimization for droop controlled dc-dc conversion

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    .C. Vasquez, "Stability constrained efficiency optimization for droop controlled dc-dc conversion system, Austria, Nov 2013. Stability Constrained Efficiency Optimization for Droop Controlled DC-DC Conversion a hierarchical control in a droop-controlled dc-dc conversion system with special focus on improving system

  11. Inverted end-Hall-type low-energy high-current gaseous ion source

    SciTech Connect (OSTI)

    Oks, E. M.; Vizir, A. V.; Shandrikov, M. V.; Yushkov, G. Yu.; Grishin, D. M.; Anders, A.; Baldwin, D. A. [High Current Electronics Institute, Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); 4Wave, Inc., Sterling, Virginia 20166 (United States)

    2008-02-15T23:59:59.000Z

    A novel approach to low-energy, high-current, gaseous ion beam generation was explored and an ion source based on this technique has been developed. The source utilizes a dc high-current (up to 20 A) gaseous discharge with electron injection into the region of ion generation. Compared to the conventional end-Hall ion source, the locations of the discharge anode and cathode are inverted: the cathode is placed inside the source and the anode outside, and correspondingly, the discharge current is in the opposite direction. The discharge operates in a diverging axial magnetic field, similar to the end-Hall source. Electron generation and injection is accomplished by using an additional arc discharge with a ''cold'' (filamentless) hollow cathode. Low plasma contamination is achieved by using a low discharge voltage (avoidance of sputtering), as well as by a special geometric configuration of the emitter discharge electrodes, thereby filtering (removing) the erosion products stemming from the emitter cathode. The device produces a dc ion flow with energy below 20 eV and current up to 2.5 A onto a collector of 500 cm{sup 2} at 25 cm from the source edge, at a pressure {>=}0.02 Pa and gas flow rate {>=}14 SCCM. The ion energy spread is 2 to 3 eV (rms). The source is characterized by high reliability, low maintenance, and long lifetime. The beam contains less than 0.1% of metallic ions. The specific electric energy consumption is 400 eV per ion registered at the collector. The source operates with noble gases, nitrogen, oxygen, and hydrocarbons. Utilizing biasing, it can be used for plasma sputtering, etching, and other ion technologies.

  12. Implementing the DC Mode in Cosmological Simulations with Supercomoving Variables

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gnedin, Nickolay Y.; Kravtsov, Andrey V.; Rudd, Douglas H.

    2011-06-02T23:59:59.000Z

    As emphasized by previous studies, proper treatment of the density fluctuation on the fundamental scale of a cosmological simulation volume - the 'DC mode' - is critical for accurate modeling of spatial correlations on scales ~> 10% of simulation box size. We provide further illustration of the effects of the DC mode on the abundance of halos in small boxes and show that it is straightforward to incorporate this mode in cosmological codes that use the 'supercomoving' variables. The equations governing evolution of dark matter and baryons recast with these variables are particularly simple and include the expansion factor, and hence the effect of the DC mode, explicitly only in the Poisson equation.

  13. Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and

    E-Print Network [OSTI]

    Shaw, Leah B.

    Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films magnetic field. We study the interaction behavior of YBCO thin films in an ac transport current and a dc the calibrated field profiles. The current density evolution in YBCO thin films is studied by TRMOI as a function

  14. Control method for peak power delivery with limited DC-bus voltage

    DOE Patents [OSTI]

    Edwards, John; Xu, Longya; Bhargava, Brij B.

    2006-09-05T23:59:59.000Z

    A method for driving a neutral point-clamped multi-level voltage source inverter supplying a synchronous motor is provided. A DC current is received at a neutral point-clamped multi-level voltage source inverter. The inverter has first, second, and third output nodes. The inverter also has a plurality of switches. A desired speed of a synchronous motor connected to the inverter by the first second and third nodes is received by the inverter. The synchronous motor has a rotor and the speed of the motor is defined by the rotational rate of the rotor. A position of the rotor is sensed, current flowing to the motor out of at least two of the first, second, and third output nodes is sensed, and predetermined switches are automatically activated by the inverter responsive to the sensed rotor position, the sensed current, and the desired speed.

  15. Radiofrequency amplifier based on a dc superconducting quantum interference device

    DOE Patents [OSTI]

    Hilbert, Claude (Berkeley, CA); Martinis, John M. (Berkeley, CA); Clarke, John (Berkeley, CA)

    1986-01-01T23:59:59.000Z

    A low noise radiofrequency amplifier (10), using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID (11) and an input coil (12) are maintained at superconductivity temperatures in a superconducting shield (13), with the input coil (12) inductively coupled to the superconducting ring (17) of the dc SQUID (11). A radiofrequency signal from outside the shield (13) is applied to the input coil (12), and an amplified radiofrequency signal is developed across the dc SQUID ring (17) and transmitted to exteriorly of the shield (13). A power gain of 19.5.+-.0.5 dB has been achieved with a noise temperature of 1.0.+-.0.4 K. at a frequency of 100 MHz.

  16. Radiofrequency amplifier based on a dc superconducting quantum interference device

    DOE Patents [OSTI]

    Hilbert, C.; Martinis, J.M.; Clarke, J.

    1984-04-27T23:59:59.000Z

    A low noise radiofrequency amplifer, using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID and an input coil are maintained at superconductivity temperatures in a superconducting shield, with the input coil inductively coupled to the superconducting ring of the dc SQUID. A radiofrequency signal from outside the shield is applied to the input coil, and an amplified radiofrequency signal is developed across the dc SQUID ring and transmitted to exteriorly of the shield. A power gain of 19.5 +- 0.5 dB has been achieved with a noise temperature of 1.0 +- 0.4 K at a frequency of 100 MHz.

  17. Thermoelectric DC conductivities with momentum dissipation from higher derivative gravity

    E-Print Network [OSTI]

    Long Cheng; Xian-Hui Ge; Zu-Yao Sun

    2015-04-28T23:59:59.000Z

    We present a mechanism of momentum relaxation in higher derivative gravity by adding linear scalar fields to the Gauss-Bonnet theory. We analytically computed all of the DC thermoelectric conductivities in this theory by adopting the method given by Donos and Gauntlett in [arXiv:1406.4742]. The results show that the DC electric conductivity is not a monotonic function of the effective impurity parameter $\\beta$: in the small $\\beta$ limit, the DC conductivity is dominated by the coherent phase, while for larger $\\beta$, pair creation contribution to the conductivity becomes dominant, signaling an incoherent phase. In addition, the DC heat conductivity is found independent of the Gauss-Bonnet coupling constant.

  18. National Science Bowl Brings Best and Brightest to DC

    Broader source: Energy.gov [DOE]

    The National Science Bowl Finals in Washington D.C. April 27 to 30 pit 113 high and middle school teams against one another answering questions Jeopardy-style about biology, chemistry, earth science, physics, astronomy, and math.

  19. Reactive DC magnetron sputtering of ultrathin superconducting niobium nitride films

    E-Print Network [OSTI]

    Dane, Andrew E. (Andrew Edward)

    2015-01-01T23:59:59.000Z

    DC reactive magnetron sputtering was used to deposit few-nanometer-thick films of niobium nitride for fabrication of superconducting devices. Over 1000 samples were deposited on a variety of substrates, under various chamber ...

  20. Current Titles

    SciTech Connect (OSTI)

    Various

    2006-06-01T23:59:59.000Z

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

  1. Manika Prasad is currently Associate Professor of Petroleum Engineering at the Colorado School of Mines. She directs the O-CLASSH (Organic, Clay, Sand, Shale) research group and the

    E-Print Network [OSTI]

    of Mines. She directs the O-CLASSH (Organic, Clay, Sand, Shale) research group and the co interested to understand how the ant-sized phenomena control elephant-sized features. She has published

  2. Analysis and design of a saturable reactor assisted soft-switching full-bridge dc-dc converter

    SciTech Connect (OSTI)

    Hamada, Satoshi (Sansha Electric Manufacturing Co., Ltd., Osaka (Japan)); Nakaoka, Mutsuo (Kobe Univ. (Japan). Dept. of Electrical and Electronics Engineering)

    1994-05-01T23:59:59.000Z

    Analysis and design considerations for a saturable reactor assisted soft-switching full-bridge dc-dc converter are presented. The converter has advantages such as low switching losses with no substantial increase in conduction losses, wide load range, and constant frequency operation. To show how to utilize the analysis results, a 350-W, 500-kHz converter is chosen as a design example. The results are verified experimentally on a prototype converter.

  3. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

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

    1995-08-08T23:59:59.000Z

    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.

  4. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

    Bogaty, John M. (Lombard, IL); Clifft, Benny E. (Park Forest, IL); Bollinger, Lowell M. (Downers Grove, IL)

    1995-01-01T23:59:59.000Z

    A beam current limiter 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.

  5. Reid Rosnick/DC/USEPA/US 10/25/2012 11:54 AM

    E-Print Network [OSTI]

    EPA-694 Reid Rosnick/DC/USEPA/US 10/25/2012 11:54 AM To Philip Egidi cc bcc Subject Re: Subpart W Pennsylvania Ave., NW Washington, DC 20460 202.343.9563 rosnick.reid@epa.gov -----Philip Egidi/DC/USEPA/US wrote: ----- To: Reid Rosnick/DC/USEPA/US@EPA From: Philip Egidi/DC/USEPA/US Date: 10/25/2012 11:41AM Cc

  6. Data:Cd13dc44-d0d6-46f0-bb39-fb84b30f7517 | Open Energy Information

    Open Energy Info (EERE)

    Cd13dc44-d0d6-46f0-bb39-fb84b30f7517 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading......

  7. Data:5ccaa7a7-0863-44b5-98fe-1e44dc285b01 | Open Energy Information

    Open Energy Info (EERE)

    ccaa7a7-0863-44b5-98fe-1e44dc285b01 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading......

  8. Lab 4 -Motor Constants and Sensor Calibration Consider a DC servo motor which is connected to a power supply. The motor inertia is Jm. The rotational

    E-Print Network [OSTI]

    Stanford University

    Lab 4 - Motor Constants and Sensor Calibration PRE-LAB Consider a DC servo motor which is connected to a power supply. The motor inertia is Jm. The rotational damping in the motor is bm. The motor produces a torque Tm = Kmi where Km is the motor's torque constant and i is the current from the power supply. a

  9. Directives System

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

    1998-01-30T23:59:59.000Z

    The Department of Energy (DOE) Directives System is the means by which DOE policies, requirements, and responsibilities are developed and communicated throughout the Department. Directives are used to inform, direct, and guide employees in the performance of their jobs, and to enable employees to work effectively within the Department and with agencies, contractors, and the public. Cancels: DOE O 251.1, DOE M 251.1-1

  10. Gain, directionality and noise in microwave SQUID amplifiers: Input-output approach

    E-Print Network [OSTI]

    Archana Kamal; John Clarke; Michel Devoret

    2012-06-20T23:59:59.000Z

    We present a new theoretical framework to analyze microwave amplifiers based on the dc SQUID. Our analysis applies input-output theory generalized for Josephson junction devices biased in the running state. Using this approach we express the high frequency dynamics of the SQUID as a scattering between the participating modes. This enables us to elucidate the inherently nonreciprocal nature of gain as a function of bias current and input frequency. This method can, in principle, accommodate an arbitrary number of Josephson harmonics generated in the running state of the junction. We report detailed calculations taking into account the first few harmonics that provide simple semi-quantitative results showing a degradation of gain, directionality and noise of the device as a function of increasing signal frequency. We also discuss the fundamental limits on device performance and applications of this formalism to real devices.

  11. The 100,000 amp dc power supply for a staged hadron collider superferric magnet

    SciTech Connect (OSTI)

    Hays, Steven L.; Claypool, Bradley; Foster, G.William; /Fermilab

    2005-09-01T23:59:59.000Z

    A 1.5 volt 100,000 amp DC switcher power supply was developed for testing a superferric magnet string at FNAL. This supply was used during testing as both the ramping supply and holding supply powering a single magnet load with a total load resistance of 0.7{micro} Ohms. The supply consists of ten paralleled switcher cells, powered by a 400 volt/600 Amp DC power supply. Each cell consists of an IGBT H-bridge driving a step-down transformer at a switching frequency of 2 kHz. The transformer has an effective turns ratio of 224:1. The secondary consists of 32 parallel single-turn full wave rectifier windings. The rectification is done with 64 Shottky diodes. Each cell is rated at 1.5 volts/10,000 amps. During this test each cell was operated as a constant power source without load current or field feedback. This paper will describe the design of the switcher cell and control system used during testing. We will also describe the next level of improvements to the current feedback system to improve the ramp control.

  12. Current Trends, DC, 3/24-28/03Progress towards Energy Supported by

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    development · Recent NSTX research progress · FESAC: fusion net electrical output in 35 years · Near New Mexico U Wash U Wisc UKAEA Fusion Hiroshima U HIST Kyushu Tokai U Niigata U Tsukuba U U Tokyo

  13. A Completely Modular Power Converter for High-Power High-Current DC Applications

    E-Print Network [OSTI]

    Paderborn, Universität

    and filter components. Reliability and availability are other important requirements from the power converter connection of semiconductor devices, however, several centralized components (filters, transformer etc.) are used, which lead to multiple failure modes. Replacement of these large power components is both time

  14. The War of the Currents: AC vs. DC Power | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartmentTest for PumpingThe Facts onDepartmentThe Sun andDepartment

  15. 2012 IEEE. Reprinted, with permission, from B.J. Williamson, M.A. Redfern and R.K. Aggarwal, Project Edison: SMART-DC, IEEE PES Innovative Smart Grid Technologies (ISGT-EUROPE 2011) December 2011. This material is posted here with permission of the IEEE.

    E-Print Network [OSTI]

    Burton, Geoffrey R.

    of a DC network. Demand offsetting using the flexibility of energy storage has been demonstrated with real Tesla and Thomas Edison came head-to-head in `The War of the Currents'. Tesla is generally considered

  16. Characterization of the PvdS-regulated promoter motif in Pseudomonas syringae pv. tomato DC3000 reveals

    E-Print Network [OSTI]

    Myers, Chris

    Characterization of the PvdS-regulated promoter motif in Pseudomonas syringae pv. tomato DC3000S, a group IV sigma factor encoded by Pseudomonas syringae pv. tomato DC3000 (DC3000), a plant pathogen, 2002; Potvin et al., 2008). The model plant pathogen Pseudomonas syringae pv. tomato DC3000 (DC3000

  17. DESIGN OF A DC/RF PHOTOELECTRON GUN.

    SciTech Connect (OSTI)

    YU,D.NEWSHAM,Y.SMIRONOV,A.YU,J.SMEDLEY,J.SRINIVASAN RAU,T.LEWELLEN,J.ZHOLENTS,A.

    2003-05-12T23:59:59.000Z

    An integrated dc/rf photoelectron gun produces a low-emittance beam by first rapidly accelerating electrons at a high gradient during a short ({approx}1 ns), high-voltage pulse, and then injecting the electrons into an rf cavity for subsequent acceleration. Simulations show that significant improvement of the emittance appears when a high field ({approx} 0.5-1 GV/m) is applied to the cathode surface. An adjustable dc gap ({le} 1 mm) which can be integrated with an rf cavity is designed for initial testing at the Injector Test Stand at Argonne National Laboratory using an existing 70-kV pulse generator. Plans for additional experiments of an integrated dc/rf gun with a 250-kV pulse generator are being made.

  18. 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.

  19. Analysis of dc harmonics using the three-pulse model for the intermountain power project HVDC transmission

    SciTech Connect (OSTI)

    Dickmander, D.L.; Peterson, K.J.

    1989-04-01T23:59:59.000Z

    The harmonic analysis of the dc-side of an HVDC line transmission requires realistic models of the converters, the dc line, and other relevant equipment. These models must include all important paths for harmonic current, and appropriate sources of harmonic voltage generation. The classical converter modeling technique has been demonstrated to be insufficient in field measurements and analysis of the harmonic spectra found on recent HVDC line transmission. For this reason, a new model of the converter bridge which takes into account the major stray capacitances in the converter (the three-pulse model) has been developed, and is described in detail elsewhere. This paper presents comparisons between the classical and three-pulse calculations for the Intermountain Power Project (IPP) HVDC transmission. The calculation results from the three-pulse model agree favorably with the harmonics found in field measurements.

  20. A Digitally Implemented Photovoltaic Simulator with a Double Current Mode Controller

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    -DC converter-based photovoltaic (PV) simulator which emulates the output characteristics of a real solar panel data and a double current mode controller that regulates output current is implemented. In particular, the PV simulator designed is portable and has a maximum output power of 85W. The control

  1. D.C. | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof EnergyInnovationinConcentratingEnergyCoosaPage EditCrystalsolapprovalCzech SunD.C.

  2. Department.,of Energy Washington; DC'

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling CorpNew 1325.8. (8-89)p, .'Dear Mr.FILE&,of

  3. A direct AC-to-DC converter topology with high-frequency isolation

    E-Print Network [OSTI]

    Sulistyono, Widodo

    1994-01-01T23:59:59.000Z

    disadvantages of the conventional approach are: it requires relatively large input ac filter components, requires two stages of rectification and of de filtering (i.e., at the front-end and output rectifiers), and exhibit poor overall input power factor...

  4. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    the market, in fact, the battery-storage inverter describedalong with 22 kWh of battery storage. This study by Baek etpower, but the cost of battery storage per unit of load

  5. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    average residential electricity consumption by end-use inaverage residential electricity consumption by end-use inU.S. residential electricity consumption for 2010 for 32

  6. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    into today’s PV-system inverters and is therefore omittedinterviewed. c Today’s PV-system inverter minus the MPPT,of today’s new PV-system string inverters. b Represents best

  7. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    to the battery, and the percentage of excess PV power thatbattery charging capacity to excess PV. ..37], local battery storage for building-sited PV, if handled

  8. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    Battery Backup (AC-House) ..Battery Backup (AC-House) .Inverter without Battery Backup (AC-House) Description Grid-

  9. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    are the dominant energy storage technology used with suchutilizing energy storage and other enabling technologies.

  10. Optimizing Energy Savings from Direct-DC in U.S. Residential Buildings

    E-Print Network [OSTI]

    Garbesi, Karina

    2012-01-01T23:59:59.000Z

    heat pump technologies where applicable models exist (electric water heaters,Heat Pumps for AC Electric Clothes Dryers Electric Secondary Space Heaters Dishwashers Electric Water Heaters (

  11. BEAM DYNAMICS SIMULATIONS FOR A DC GUN BASED INJECTOR FOR PERL...

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

    DC gun. The schematic layout of a PERL DC gun based injector and its preliminary beam dynamics are presented in this paper. The transverse and longitudinal emittance of photo-...

  12. Analysis of Fe Nanoparticles Using XPS Measurements Under D.C...

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

    Fe Nanoparticles Using XPS Measurements Under D.C. or Pulsed-Voltage Bias. Analysis of Fe Nanoparticles Using XPS Measurements Under D.C. or Pulsed-Voltage Bias. Abstract: The...

  13. If you reside in WASHINGTON, DC - MD -VA - WV your salary will...

    National Nuclear Security Administration (NNSA)

    If you are employed in the WASHINGTON, DC Metropolitan Area (D.C., Baltimore, Northern VA, Eastern WV, and Southern PA) your salary will range from: Pay Band Pay Plan(s) Minimum...

  14. Energy Secretary Moniz's Remarks at CSIS in Washington D.C. on...

    Energy Savers [EERE]

    Moniz's Remarks at CSIS in Washington D.C. on Energy Security 40 Years after the Embargo - As Delivered Energy Secretary Moniz's Remarks at CSIS in Washington D.C. on Energy...

  15. U.S. Department of Energy - Washington, DC | Department of Energy

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

    Photovoltaic System at the Forrestal Building in Washington, DC The U.S. Department of Energy (DOE) is housed in the Forrestal Building in Washington, DC. A photovoltaic (PV)...

  16. Electrostatic coalescence system with independent AC and DC hydrophilic electrodes

    DOE Patents [OSTI]

    Hovarongkura, A. David (Arlington, VA); Henry, Jr., Joseph D. (Morgantown, WV)

    1981-01-01T23:59:59.000Z

    An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

  17. DC WRRC Report No. 126 GROUND WATER RESOURCE ASSESSMENT STUDY

    E-Print Network [OSTI]

    District of Columbia, University of the

    DRILLING AND FIELD OPERATIONS REPORT FOR THE GROUP A WELLS D.C. WATER RESOURCES RESEARCH CENTER University No. 126 GROUND WATER RESOURCE ASSESSMENT STUDY FOR THE DISTRICT OF COLUMBIA WELL DRILLING AND FIELDDC WRRC Report No. 126 GROUND WATER RESOURCE ASSESSMENT STUDY FOR THE DISTRICT OF COLUMBIA WELL

  18. D.C. Water Resources Research Center Annual Technical Report

    E-Print Network [OSTI]

    and among agencies, universities, and other area researchers; and to support the development and Guidelines under the Water Resources Development Act, and other federal spending and activities relatedD.C. Water Resources Research Center Annual Technical Report FY 2009 D.C. Water Resources Research

  19. EE443L Lab 2: Modeling a DC Motor Introduction

    E-Print Network [OSTI]

    Wedeward, Kevin

    and add conversion factors. Copy the LabVIEW VI lab2.vi and its associated subVI Altera the four conversion factors. Motor voltage is measured with a voltage divider to ensure DAQ card analog: The DC motor is a common actuator in control systems that converts electrical energy into rotational

  20. DC Optimal Power Flow: Uniqueness and Chee Wei Tan

    E-Print Network [OSTI]

    Tan, Chee Wei

    and are computationally fast for practical smart power grids. I. BACKGROUND The Optimal Power Flow (OPF) problem network. The DC-OPF can be practically important in a smart grid, where there are renewables, e.g., solar implications on how algorithms can be designed to solve the OPF in a smart grid. Different from prior work

  1. D.C. Water Resources Research Institute Annual Technical Report

    E-Print Network [OSTI]

    projects that address the three components of integrated urban water system: storm water runoff and sewer developing and maintaining new environmental quality testing and modeling tools to advance water researchD.C. Water Resources Research Institute Annual Technical Report FY 2013 D.C. Water Resources

  2. Natural Gas Pipeline Leaks Across Washington, DC Robert B. Jackson,,,

    E-Print Network [OSTI]

    Jackson, Robert B.

    Natural Gas Pipeline Leaks Across Washington, DC Robert B. Jackson,,, * Adrian Down, Nathan G increased in recent decades, but incidents involving natural gas pipelines still cause an average of 17 fatalities and $133 M in property damage annually. Natural gas leaks are also the largest anthropogenic

  3. High Voltage DC Transmission 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    1 High Voltage DC Transmission 1.0 Introduction HVDC has been applied in electric power systems for many years now. Figure 1 illustrates worldwide many of the HVDC applications [1]. Fig. 1 ABB provides a webpage which summarizes HVDC projects by type and capacity or by commissioning year [2]. Wikipedia [3

  4. High Voltage DC Transmission 2 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    1 High Voltage DC Transmission 2 1.0 Introduction Interconnecting HVDC within an AC system requires on use of switching devices collectively referred to in the HVDC community as valves. Valves may be non. Fig. 1 There have been three types of devices for implementing HVDC converter circuits: mercury

  5. WASHINGTON TECHNICAL INSTITUTE WASHINGTON, D.C. 20008

    E-Print Network [OSTI]

    District of Columbia, University of the

    WASHINGTON TECHNICAL INSTITUTE WASHINGTON, D.C. 20008 WRRC REPORT NO. 9 CHARACTERIZATION-379, as amended. Agreement No. 14-34-0001-6066 Water Resources Research Center Washington Technical Institute Analysis of Composite Samples Before Concentration............ 16 5. Organic Losses During Concentration

  6. Reprint & Copyright by Aerospace Medical Association, Washington, DC

    E-Print Network [OSTI]

    Reprint & Copyright ©by Aerospace Medical Association, Washington, DC TECHNICAL NOTE Reflectance.EPICS Biomedical Engineering and Science Institute and Department of Electrical and Computer Engineering, Drexel and pulsatile and mean Doppler velocities were examined as predictors of impending peripheral light loss (PLL

  7. Building Scale DC Microgrids Chris Marnay, Steven Lanzisera, Michael Stadler, and Judy Lai

    E-Print Network [OSTI]

    of building loads are either native DC, such as electronics and compact fluorescent and light emitting diode

  8. Interviews in Washington, DC for Albert Einstein Fellowship Semi-Finalists

    Broader source: Energy.gov [DOE]

    Selected semi-finalists in the Albert Einstein Distinguished Educator Fellowship are invited to DC for interviews.

  9. Control of a Fuel-Cell Powered DC Electric Vehicle Motor

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Control of a Fuel-Cell Powered DC Electric Vehicle Motor Federico Zenith Sigurd Skogestad Meeting, 2005 www.ntnu.no Federico Zenith, Sigurd Skogestad, Control of a Fuel-Cell Powered DC Electric Vehicle Motor #12;2 Outline 1) Control of Fuel Cells--Status 2) Dynamic Modelling of Fuel Cells 3) DC

  10. FLATNESS BASED CONTROL OF A BUCK-CONVERTER DRIVEN DC MOTOR

    E-Print Network [OSTI]

    Knobloch,Jürgen

    FLATNESS BASED CONTROL OF A BUCK-CONVERTER DRIVEN DC MOTOR Felix Antritter ,1 Peter Maurer Johann on the circuit and control design of a buck converter driven DC motor. The steps of design, as for example objective: tracking control of the DC motor's shaft angular velocity. The dynamic system composed from

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

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    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

  12. A Noise-Shaped Switched-Capacitor DC-DC Voltage Regulator A. Rao, W.McIntyre 1

    E-Print Network [OSTI]

    Moon, Un-Ku

    -dc converter with fractional gains. The charge pump used to convert the input voltage acts as a D/A converter the inductive conversion topology has been the standard solution to providing a constant and stable voltage from a battery. With the continued shrinking of the hand-held devices as cell phones, PDA's, pagers and laptops

  13. 164 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 1, JANUARY 2006 A Digitally Controlled DC/DC Converter

    E-Print Network [OSTI]

    Popovic, Zoya

    164 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 1, JANUARY 2006 A Digitally Controlled DC of power, dynamic control of the drain supply voltage has been proposed [1]­[6]. The technique of adjusting-loop implementation of the RFPA power control through the drain supply voltage. The ob- jectives are to improve

  14. Current balancing for battery strings

    DOE Patents [OSTI]

    Galloway, James H. (New Baltimore, MI)

    1985-01-01T23:59:59.000Z

    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.

  15. DC CICC retrofit magnet preliminary design, software development and analysis report

    SciTech Connect (OSTI)

    Myatt, R.L.; Marston, P.G.

    1992-02-10T23:59:59.000Z

    The proposed retrofit coil is made of superconducting Cable-in-Conduit Conductor (CICC). The coils are designed to produce a nominal vertical field of 4.5 tesla within the MHD channel based on a nominal current density of 13.05 MA/m{sup 2}. The coils are supported within a case, or so-called constant tension strap. When the magnet is energized, the electromagnetic J {times} B body forces push the winding pack laterally outward and vertically towards the machine's midplane, thus putting the strap in tension. The end turns add axial tension to the conductor (a condition which is not simulated by this 2-D model of the midlength cross section). A sketch of the magnet system and structure is shown in Fig. 1.0-1. The purpose of this report is to describe the progress made in the design and analysis of the DC CICC retrofit magnet, and to outline the proposed next step.

  16. DC CICC retrofit magnet preliminary design, software development and analysis report. Quarterly progress report

    SciTech Connect (OSTI)

    Myatt, R.L.; Marston, P.G.

    1992-01-01T23:59:59.000Z

    The proposed retrofit coil is made of superconducting Cable-in-Conduit Conductor (CICC). The coils are designed to produce a nominal vertical field of 4.5 tesla within the MHD channel based on a nominal current density of 13.05 MA/m{sup 2}. The coils are supported within a case, or so-called constant tension strap. When the magnet is energized, the electromagnetic J x B body forces push the winding pack laterally outward and vertically towards the machine`s midplane, thus putting the strap in tension. The end turns add axial tension to the conductor (a condition which is not simulated by this 2-D model of the midlength cross section). A sketch of the magnet system and structure is shown in Fig. 1.0--1. The purpose of this report is to describe the progress made in the design and analysis of the DC CICC retrofit magnet.

  17. Dependence of plasma characteristics on dc magnetron sputter parameters

    SciTech Connect (OSTI)

    Wu, S.Z. [Recording Media Operation, Seagate Technology, 47010 Kato Road, Fremont, California 94538 (United States)

    2005-10-15T23:59:59.000Z

    Plasma discharge characteristics of a dc magnetron system were measured by a single Langmuir probe at the center axis of the dual-side process chamber. Plasma potential, floating potential, electron and ion densities, and electron temperature were extracted with varying dc power and gas pressure during sputter deposition of a metal target; strong correlations were shown between these plasma parameters and the sputter parameters. The electron density was controlled mostly by secondary electron generation in constant power mode, while plasma potential reflects the confinement space variation due to change of discharge voltage. When discharge pressure was varied, plasma density increases with the increased amount of free stock molecules, while electron temperature inversely decreased, due to energy-loss collision events. In low-pressure discharges, the electron energy distribution function measurements show more distinctive bi-Maxwellian distribution, with the fast electron temperature gradually decreases with increased gas pressure.

  18. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

    2002-01-01T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  19. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  20. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng; Lai, Jih-Sheng

    2001-04-03T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  1. Multilevel cascade voltage source inverter with separate DC sources

    DOE Patents [OSTI]

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

    1997-06-24T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

  2. This document is a preprint of the paper: L. Meng, T. Dragicevic, J.M. Guerrero, and J.C Vasquez, "Optimization with system damping restoration for droop controlled dc-dc converters," in

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    , "Optimization with system damping restoration for droop controlled dc-dc converters," in Proc. IEEE Energy Restoration for Droop Controlled DC-DC Converters Lexuan Meng, Tomislav Dragicevic, Josep M. Guerrero, Juan C systems and uninterruptable power supply systems. Droop control along with virtual resistance (VR

  3. Alternating current long range alpha particle detector

    DOE Patents [OSTI]

    MacArthur, D.W.; McAtee, J.L.

    1993-02-16T23:59:59.000Z

    An alpha particle detector, utilizing alternating currents, which is capable of detecting alpha particles from distinct sources. The use of alternating currents allows use of simpler ac circuits which, in turn, are not susceptible to dc error components. It also allows the benefit of gas gain, if desired. In the invention, a voltage source creates an electric field between two conductive grids, and between the grids and a conductive enclosure. Air containing air ions created by collision with alpha particles is drawn into the enclosure and detected. In some embodiments, the air flow into the enclosure is interrupted, creating an alternating flow of ions. In another embodiment, a modulated voltage is applied to the grid, also modulating the detection of ions.

  4. USCOMM-WB-DC PRELIMZNARY REPORT OH HURRICANE DAISY

    E-Print Network [OSTI]

    QC 945.2 .D3 H8 1958 c.2 #12;#12;USCOMM-WB-DC #12;PRELIMZNARY REPORT OH HURRICANE DAISY AWGUST 24-29, 1958 Hurricane "Daisy", intense but small in area, was detected as a tropical storm about 300 miles into a hurricane on August 25. A u g u s t 27 it drifted very slowly northward. coast increased. the Atlantic off

  5. Operation of a test bed axial-gap brushless DC rotor with a superconducting stator

    SciTech Connect (OSTI)

    McKeever, J.W.; Sohns, C.W.; Schwenterly, S.W.; Young, R.W. Sr.; Campbell, V.W.; Hickey, M.H.; Ott, G.W. [Oak Ridge National Lab., TN (United States); Bailey, J.M. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-12-31T23:59:59.000Z

    A variable-speed axial-gap motor with a stator consisting of four liquid helium cooled superconducting electromagnets (two pole pairs) was built and proof tested up to 608 rpm in November 1990 as a tool for joint industry-laboratory evaluation of coils fabricated from high-temperature oxide superconductors. A second rotor was fabricated with improved material, winding configuration, and wire type, and the drive system was modified to eliminate current spiking. The modified motor was characterized to design speed, 188 rad/s (1800 rpm), to acquire a performance baseline for future comparison with that of high-temperature superconducting (HTS) wire. As it becomes commercially available, HTS wire will replace the low-temperature electromagnet wire in a stator modified to control wire temperatures between 4 K and 77 K. Measurements of the superconducting electromagnetic field and locked rotor torque as functions of cryocurrent and dc current through two phases of the rotor, respectively, provided data to estimate power that could be developed by the rotor. Back emf and parasitic mechanical and electromagnetic drag torques were measured as functions of angular velocity to calculate actual rotor power developed and to quantify losses, which reduce the motor`s efficiency. A detailed measurement of motor power at design speed confirmed the developed power equation. When subsequently operated at the 33-A maximum available rotor current, the motor delivered 15.3 kW (20.5 hp) to the load. In a final test, the cryostat was operated at 2500 A, 200 A below its critical current. At rotor design current of 60 A and 2500 A stator current, the extrapolated developed power would be 44.2 kW (59.2 hp) with 94% efficiency.

  6. DC and RF Measurements of Serial Bi-SQUID Arrays

    E-Print Network [OSTI]

    Prokopenko, G V; de Escobar, A Leese; Taylor, B; de Andrade, M C; Berggren, S; Longhini, P; Palacios, A; Nisenoff, M; Fagaly, R L

    2012-01-01T23:59:59.000Z

    SQUID arrays are promising candidates for low profile antennas and low noise amplifier applications. We present the integrated circuit designs and results of DC and RF measurements of the wideband serial arrays based on integration of linear bi-SQUID cells forming a Superconducting Quantum Interference Filter (bi-SQUID SQIF). Various configurations of serial arrays designs are described. The measured linearity, power gain, and noise temperature are analyzed and compared. The experimental results are matched to results of mathematical modeling. A serial bi-SQUID SQIF arrays are mounted into a coplanar waveguide (CPW) and symmetrically grounded to corresponding sides of CPW. The RF output comes out from the central common line, which is also used for DC biasing and forms a symmetrical balanced output. The signal and DC flux biasing line is designed as coplanar lines passed in parallel over each bi-SQUID cell in a bidirectional fashion concentrating magnetic flux inside of each cell. Serial bi-SQUID SQIF arrays ...

  7. Abstract -This paper presents the coordinated control of distributed energy storage systems (DESSs) in DC micro-grids.

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    ) in DC micro-grids. In order to balance the state-of-charge (SoC) of each energy storage unit (ESU--Droop control; distributed energy storage system (DESS); DC micro-grids; state-of-charge (SoC) I. INTRODUCTION and more popularity [1]. Nowadays DC micro-grids are becoming more attractive with the raise of DC power

  8. Optimal Demand Response in DC Distribution Networks Hamed Mohsenian-Rad, Member, IEEE and Ali Davoudi, Member, IEEE

    E-Print Network [OSTI]

    Mohsenian-Rad, Hamed

    such as photovoltaic systems are essentially DC sources. Battery storage devices are also easier H. Mohsenian

  9. New leading/trailing edge modulation strategies for two-stage AC/DC PFC adapters to reduce DC-link capacitor ripple current

    E-Print Network [OSTI]

    Sun, Jing

    2007-09-17T23:59:59.000Z

    -link capacitor is one of the largest because it should keep the output voltage with low ripple. Also, the size of this capacitor is penalized due to the universal line voltage application. Synchronization through employing leading edge modulation for the first...

  10. 1428 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 23, NO. 3, MAY 2008 Digital Average Current-Mode Controller for DCDC

    E-Print Network [OSTI]

    controls the output power, while an internal (fast) loop controls the current. This paper introduces a digital average current mode controller for dc power supplies in PVD applica- tions. The controller control loop enable opera- tion over wide ranges of output power and voltage. The proposed control

  11. High-current, fast-switching transistor development

    SciTech Connect (OSTI)

    Hower, P.L.

    1981-03-15T23:59:59.000Z

    Work that shows how the results obtained under a previous contract (NAS3-18916) have been applied to a larger-diameter (33-mm) transistor are described. An improved base contact for equalizing the base-emitter voltage at high currents has been developed along with an improved emitter contact preform which increases the silicon area available for current conduction. The electrical performance achieved is consistent with the proposed optimum design. The device design, wafer-processing techniques, and various measurements which include forward SOA, dc characteristics, and switching times are described.

  12. The capacitively coupled converter (C³) for high power DC-DC conversion

    E-Print Network [OSTI]

    Khan, Shahriar

    1992-01-01T23:59:59.000Z

    A&M University. A combination of inherent capacitive commutation and gate turn-off switching devices (MCT, GTO, and ZTO) allows zero current switching, and reduces the switching losses to a minimum. This converter is capable of a wide ratio... to implement these switches and the power capability of the transistor can be increased manifold. If a high frequency capability is desired to reduce the sizes of the reactive elements, high power gate turn-off devices, such as the GTO, ZTO, or the MCT may...

  13. Electrospray Diagnostics by Fourier Analysis of Current Oscillations and Fast Imaging

    E-Print Network [OSTI]

    Vertes, Akos

    Electrospray Diagnostics by Fourier Analysis of Current Oscillations and Fast Imaging Lida Parvin of the spray voltage, liquid flow rate, and composition. Most Fourier spectra indicated a strong dc component, a low-frequency branch at low flow rates and applied voltages, and a high- frequency branch

  14. ANALYSIS OF ELECTRIC CURRENT HELICITY IN ACTIVE REGIONS ON THE BASIS OF VECTOR MAGNETOGRAMS

    E-Print Network [OSTI]

    Yurchyshyn, Vasyl

    can suggest that the build up of large­scale currents in an active region due to small­scale of Sciences, Beijing 100080, China Abstract. The problem of (dc) magnetic field energy build up in the solar seemingly can occur in any active region, the energy build up mechanism must be easy accessible for all

  15. Direct-Current Resistivity At Central Nevada Seismic Zone Region...

    Open Energy Info (EERE)

    Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoreticalcomputer simulation tests of various methods on eight hypothetical 'model' basing-and-range...

  16. Direct-Current Resistivity Survey At Valles Caldera - Redondo...

    Open Energy Info (EERE)

    structure in the reservoir region. Some of the data were reinterpreted using K508 computer models, and interpretations from the various surveys were compared for consistency of...

  17. Direct-Current Resistivity Survey At Walker-Lane Transitional...

    Open Energy Info (EERE)

    Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoreticalcomputer simulation tests of various methods on eight hypothetical 'model' basing-and-range...

  18. Direct-Current Resistivity Survey At Northern Basin & Range Region...

    Open Energy Info (EERE)

    Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoreticalcomputer simulation tests of various methods on eight hypothetical 'model' basing-and-range...

  19. Direct-Current Resistivity Survey At Nw Basin & Range Region...

    Open Energy Info (EERE)

    Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoreticalcomputer simulation tests of various methods on eight hypothetical 'model' basing-and-range...

  20. Direct-Current Resistivity Survey At Central Nevada Seismic Zone...

    Open Energy Info (EERE)

    Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoreticalcomputer simulation tests of various methods on eight hypothetical 'model' basing-and-range...

  1. Cooling efficiency of a brushless direct current stand fan

    E-Print Network [OSTI]

    Yang, Bin; Schiavon, Stefano; Sekhar, Chandra; Cheong, David; Tham, Kwok Wai; Nazaroff, William W

    2015-01-01T23:59:59.000Z

    eq (°C) Front Side Fig. 4. Cooling effect comparison betweenmanikin distance. 3.1.2. Cooling Fan Efficiency (CFE) indexdevices [41-42]. Local cooling for front and side fan-

  2. CAPTURING TAGGED RED SALMON WITH PULSED DIRECT CURRENT

    E-Print Network [OSTI]

    the electrodes were forced to move towards the positive electrode, placed in slack water 3 feet deep close pressing problems now facing biologists working on research and man- agement of our salmon resources. Red

  3. Direct-Current Resistivity Survey At Cove Fort Area (Warpinski...

    Open Energy Info (EERE)

    The project at Cove FortSulphurdale in Utah, T26S R67W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale...

  4. Direct-Current Resistivity Survey At Cove Fort Area - Vapor ...

    Open Energy Info (EERE)

    The project at Cove FortSulphurdale in Utah, T26S R67W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale...

  5. Direct-Current Resistivity Survey At Lightning Dock Area (Warpinski...

    Open Energy Info (EERE)

    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...

  6. Cooling efficiency of a brushless direct current stand fan

    E-Print Network [OSTI]

    Yang, Bin; Schiavon, Stefano; Sekhar, Chandra; Cheong, David; Tham, Kwok Wai; Nazaroff, William W

    2014-01-01T23:59:59.000Z

    refrigeration and Air-Conditioning Engineers (ANSI/ASHRAErefrigeration and Air-Conditioning Engineers. [46] Gagge AP,than compressor-based air conditioning. To evaluate the

  7. Cooling efficiency of a brushless direct current stand fan

    E-Print Network [OSTI]

    Yang, Bin; Schiavon, Stefano; Sekhar, Chandra; Cheong, David; Tham, Kwok Wai; Nazaroff, William W

    2015-01-01T23:59:59.000Z

    refrigeration and Air-Conditioning Engineers (ANSI/ASHRAErefrigeration and Air-Conditioning Engineers. [46] Gagge AP,than compressor-based air conditioning. To evaluate the

  8. Direct-Current Resistivity Survey At Cove Fort Area - Vapor ...

    Open Energy Info (EERE)

    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...

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

    Open Energy Info (EERE)

    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...

  10. Direct-Current Resistivity Survey At Cove Fort Area (Warpinski...

    Open Energy Info (EERE)

    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...

  11. Direct-Current Resistivity At Beowawe Hot Springs Area (Garg...

    Open Energy Info (EERE)

    Philip E. Wannamaker, Jim Combs (2007) Use Of Electrical Surveys For Geothermal Reservoir Characterization- Beowawe Geothermal Field Additional References Retrieved from...

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

    Open Energy Info (EERE)

    Philip E. Wannamaker, Jim Combs (2007) Use Of Electrical Surveys For Geothermal Reservoir Characterization- Beowawe Geothermal Field Additional References Retrieved from...

  13. Direct-Current Resistivity Survey At Dixie Valley Geothermal...

    Open Energy Info (EERE)

    Research Program Update - Fiscal Year 2004 B. M. Kennedy, M. C. van Soest (2006) a Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Additional...

  14. Sandia National Laboratories: photovoltaic direct-current arc...

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

    Program Goals IndustryCollaboration FutureCollaborations Publications Contacts Photovoltaic (PV) arc-faults can lead to fires, damage property, and threaten the safety of...

  15. Current Directions in Psychological 20(6) 400406

    E-Print Network [OSTI]

    Barrett, Lisa Feldman

    and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0963721411429125 http://cdps.sagepub.com Charles, wide-eyed expression) evolved to express certain internal mental states (e.g., fear) and that humans scien- tific papers casually state that expressions are innate and uni- versally recognized. Research

  16. Cooling efficiency of a brushless direct current stand fan

    E-Print Network [OSTI]

    Yang, Bin; Schiavon, Stefano; Sekhar, Chandra; Cheong, David; Tham, Kwok Wai; Nazaroff, William W

    2015-01-01T23:59:59.000Z

    orientations for 24 °C dry-bulb temperature, fan speedchamber under four dry-bulb temperatures (24, 26, 28, and 30CFE index is influenced by dry-bulb temperature, fan speed

  17. Cooling efficiency of a brushless direct current stand fan

    E-Print Network [OSTI]

    Yang, Bin; Schiavon, Stefano; Sekhar, Chandra; Cheong, David; Tham, Kwok Wai; Nazaroff, William W

    2015-01-01T23:59:59.000Z

    a tropical analysis. Energy Build 1995; 23: 63-70. [8] Aynsley R. Saving energy with indoor air movement. Int JSchiavon S, Melikov AK. Energy saving and improved comfort

  18. Direct-Current Resistivity Survey At Mauna Loa Southwest Rift...

    Open Energy Info (EERE)

    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....

  19. Direct Biological Conversion of Electrical Current into Methane by

    E-Print Network [OSTI]

    produced from renewable energy sources (such as wind, solar, or biomass) into a biofuel (methane) as well. Revised manuscript received March 5, 2009. Accepted March 6, 2009. New sustainable methods are needed to produce renewable energy carriers that can be stored and used for transportation, heating, or chemical

  20. Current Delegations by Functional Area - DOE Directives, Delegations, and

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContract Management Fermi Site OfficeCoursePublic SafetyTRANSCOM