Sample records for ac voltage stabilization

  1. High frequency AC power converter for low voltage circuits

    E-Print Network [OSTI]

    Salazar, Nathaniel Jay Tobias

    2012-01-01T23:59:59.000Z

    This thesis presents a novel AC power delivery architecture that is suitable for VHF frequency (50-100MHz) polyphase AC/DC power conversion in low voltage integrated circuits. A complete AC power delivery architecture was ...

  2. Wind Power Plant Voltage Stability Evaluation: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Zhang, Y. C.

    2014-09-01T23:59:59.000Z

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

  3. Strongly nonlinear dynamics of electrolytes in large ac voltages

    E-Print Network [OSTI]

    Hojgaard Olesen, Laurits

    We study the response of a model microelectrochemical cell to a large ac voltage of frequency comparable to the inverse cell relaxation time. To bring out the basic physics, we consider the simplest possible model of a ...

  4. Electrical Circuit Flashover Model of Polluted Insulators under AC Voltage Based on the Arc Root Voltage Gradient Criterion

    E-Print Network [OSTI]

    Yang, Qing

    In order to study the flashover mechanism of polluted insulators under AC voltage, a new arc propagation criterion which is based on an arc root voltage gradient is proposed. This criterion can explain the variation of the ...

  5. Stability issues in IC Low Drop Out voltage regulators

    E-Print Network [OSTI]

    Chava, Krishna Chaitanya

    2002-01-01T23:59:59.000Z

    Performance issues of IC Low Drop Out (LDO) voltage regulators, with specific reference to stability, are discussed in this thesis. Evaluation of existing frequency compensation schemes and their performances across operating loads is presented...

  6. Contribution Allocation for Voltage Stability In Deregulated Power Systems

    E-Print Network [OSTI]

    Contribution Allocation for Voltage Stability In Deregulated Power Systems Garng M. Huang, Senior, stability margin I. INTRODUCTION The deregulated power system is based on transactions; each part Member, IEEE, Kun Men Abstract: With deregulation of power systems, it is of great importance to know who

  7. High voltage stability performance of a gamma ray detection device

    SciTech Connect (OSTI)

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

    2014-02-12T23:59:59.000Z

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

  8. 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.

  9. Measurement based Voltage Stability Monitoring of Power system Garng M. Huang

    E-Print Network [OSTI]

    Measurement based Voltage Stability Monitoring of Power system Garng M. Huang huang Station, TX 77843-3128 Abstract: Many papers discuss the voltage stability assessment of power system. The problem of voltage stability may be simply explained as inability of the power system to provide

  10. 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).

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

    E-Print Network [OSTI]

    to enhance the voltage stability by changing the reactive power distribution in the power system. Authors and operated by some utilities [1,2]. The primary uses of TCSC are to enhance the power system angle stability on the small signal voltage stability for a simple power system with an infinitive bus and a dynamic load

  12. Strategies for Voltage Control and Transient Stability Assessment

    SciTech Connect (OSTI)

    Hiskens, Ian A.

    2013-09-25T23:59:59.000Z

    As wind generation grows, its influence on power system performance will becoming increasingly noticeable. Wind generation di#11;ffers from traditional forms of generation in numerous ways though, motivating the need to reconsider the usual approaches to power system assessment and performance enhancement. The project has investigated the impact of wind generation on transient stability and voltage control, identifying and addressing issues at three distinct levels of the power system: 1) at the device level, the physical characteristics of wind turbine generators (WTGs) are quite unlike those of synchronous machines, 2) at the wind-farm level, the provision of reactive support is achieved through coordination of numerous dissimilar devices, rather than straightforward generator control, and 3) from a systems perspective, the location of wind-farms on the sub-transmission network, coupled with the variability inherent in their power output, can cause complex voltage control issues. The project has sought to develop a thorough understanding of the dynamic behaviour of type-3 WTGs, and in particular the WECC generic model. The behaviour of such models is governed by interactions between the continuous dynamics of state variables and discrete events associated with limits. It was shown that these interactions can be quite complex, and may lead to switching deadlock that prevents continuation of the trajectory. Switching hysteresis was proposed for eliminating deadlock situations. Various type-3 WTG models include control blocks that duplicate integrators. It was shown that this leads to non-uniqueness in the conditions governing steady-state, and may result in pre- and post-disturbance equilibria not coinciding. It also gives rise to a zero eigenvalue in the linearized WTG model. In order to eliminate the anomalous behaviour revealed through this investigation, WECC has now released a new generic model for type-3 WTGs. Wind-farms typically incorporate a variety of voltage control equipment including tapchanging transformers, switched capacitors, SVCs, STATCOMs and the WTGs themselves. The project has considered the coordinated control of this equipment, and has addressed a range of issues that arise in wind-farm operation. The #12;first concerns the ability of WTGs to meet reactive power requirements when voltage saturation in the collector network restricts the reactive power availability of individual generators. Secondly, dynamic interactions between voltage regulating devices have been investigated. It was found that under certain realistic conditions, tap-changing transformers may exhibit instability. In order to meet cost, maintenance, fault tolerance and other requirements, it is desirable for voltage control equipment to be treated as an integrated system rather than as independent devices. The resulting high-level scheduling of wind-farm reactive support has been investigated. In addressing this control problem, several forms of future information were considered, including exact future knowledge and stochastic predictions. Deterministic and Stochastic Dynamic Programming techniques were used in the development of control algorithms. The results demonstrated that while exact future knowledge is very useful, simple prediction methods yield little bene#12;fit. The integration of inherently variable wind generation into weak grids, particularly subtransmission networks that are characterized by low X=R ratios, aff#11;ects bus voltages, regulating devices and line flows. The meshed structure of these networks adds to the complexity, especially when wind generation is distributed across multiple nodes. A range of techniques have been considered for analyzing the impact of wind variability on weak grids. Sensitivity analysis, based on the power-flow Jacobian, was used to highlight sections of a system that are most severely a#11;ffected by wind-power variations. A continuation power flow was used to determine parameter changes that reduce the impact of wind-power variability. It was also used to explore interactions betw

  13. Voltage Stability and Power Quality Issues of Wind Farm with Series Compensation

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Voltage Stability and Power Quality Issues of Wind Farm with Series Compensation T. F. Orchi generator (DFIG) wind farms with series and shunt compensation are analyzed. The voltage source converter of the wind farm are modeled with flicker coefficients as defined by IEC standard 61400 and voltage sag

  14. Voltage, Stability and Diffusion Barrier Differences between Sodium-ion and Lithium-ion Intercalation Materials

    E-Print Network [OSTI]

    Ong, Shyue Ping

    To evaluate the potential of Na-ion batteries, we contrast in this work the difference between Na-ion and Li-ion based intercalation chemistries in terms of three key battery properties—voltage, phase stability and diffusion ...

  15. Supervisory hybrid model predictive control for voltage stability of power networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Supervisory hybrid model predictive control for voltage stability of power networks R.R. Negenborn voltage control problems in electric power networks have stimulated the interest for the imple- mentation dynamics to restore power consumption beyond the capability of the transmission and generation system

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

    E-Print Network [OSTI]

    Schrock, Kenneth C

    2008-01-01T23:59:59.000Z

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

  17. Rotating electrical machines - Part 15: Impulse voltage withstand levels of rotating a.c. machines with form-wound stator coils

    E-Print Network [OSTI]

    International Electrotechnical Commission. Geneva

    1995-01-01T23:59:59.000Z

    Applies to rotating a.c. machines for rated voltages from 3 kV to 15 kV inclusive and incorporating form-wound stator coils. Specifies the rated phase-to-earth impulse voltage withstand levels and the test procedure and voltages to be applied to the main and interturn insulation of sample coils.

  18. Voltage, stability and diffusion barrier differences between sodium-ion and lithium-ion intercalation materials

    E-Print Network [OSTI]

    Ceder, Gerbrand

    Voltage, stability and diffusion barrier differences between sodium-ion and lithium-ion-ion systems. Introduction Rechargeable lithium-ion (Li-ion) batteries1­4 have become a mainstay of the digital), much research has targeted the development and optimization of lithium-ion batteries, in particular

  19. Voltage and Frequency Stability of Weak Power Distribution Networks with Droop-Controlled

    E-Print Network [OSTI]

    Lemmon, Michael

    Voltage and Frequency Stability of Weak Power Distribution Networks with Droop analysis, because of coupled network dynamics. Additionally, droop controlled rotational and electronic DG distribution network coupled with droop-controlled DG's, which are based on both fast inverters and SG

  20. Excitation control for improving transient stability limit and voltage regulation with dynamic loads

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    on the complex nonlinear simulation and the others are based on the linearised power system model. Although control techniques in power systems as one of the most promising application areas; see Bevrani and Hiyama to improve the power system transient stability and voltage regulation in interconnected power systems

  1. Impacts of Large-Scale Wind Generators Penetration on the Voltage Stability of Power Systems

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    development of wind energy tech- nology and the current world-wide status of grid-connected as well as standImpacts of Large-Scale Wind Generators Penetration on the Voltage Stability of Power Systems M. J systems and their dynamic behaviours to identify critical issues that limit the large-scale integration

  2. Voltage Stability and Frequency Synchronization of Weak Power Distribution Networks with Inverter-Based

    E-Print Network [OSTI]

    Lemmon, Michael

    a part of microgrids, are incorporated to improve power quality and reliability when disruptions happen of microgrids [13], together with oth- er generation, storage and load units. These microgrid- s are installedVoltage Stability and Frequency Synchronization of Weak Power Distribution Networks with Inverter

  3. Organic thin film devices with stabilized threshold voltage and mobility, and method for preparing the devices

    DOE Patents [OSTI]

    Nastasi, Michael Anthony; Wang, Yongqiang; Fraboni, Beatrice; Cosseddu, Piero; Bonfiglio, Annalisa

    2013-06-11T23:59:59.000Z

    Organic thin film devices that included an organic thin film subjected to a selected dose of a selected energy of ions exhibited a stabilized mobility (.mu.) and threshold voltage (VT), a decrease in contact resistance R.sub.C, and an extended operational lifetime that did not degrade after 2000 hours of operation in the air.

  4. Power System Stability Using Decentralized Under Frequency and Voltage Load Shedding

    E-Print Network [OSTI]

    Silva, Filipe Faria Da

    not be adaptive to disturbance scale. Besides, due to equality of the frequency throughout the entire power system of Frequency (ROCOF). In order to localize the LS scheme close to the disturbance place, this scheme utilizesPower System Stability Using Decentralized Under Frequency and Voltage Load Shedding Bakhtyar

  5. Stabilization of turbulent lifted jet flames assisted by pulsed high voltage discharge

    SciTech Connect (OSTI)

    Criner, K.; Cessou, A.; Louiche, J.; Vervisch, P. [CORIA UMR 6614 CNRS-Universite et INSA de Rouen, University of Rouen, 76801 Saint Etienne du Rouvray (France)

    2006-01-01T23:59:59.000Z

    To reduce fuel consumption or the pollutant emissions of combustion (furnaces, aircraft engines, turbo-reactors, etc.), attempts are made to obtain lean mixture combustion regimes. These lead to poor stability of the flame. Thus, it is particularly interesting to find new systems providing more flexibility in aiding flame stabilization than the usual processes (bluff-body, stabilizer, quarl, swirl, etc.). The objective is to enlarge the stability domain of flames while offering flexibility at a low energy cost. Evidence is presented that the stabilization of a turbulent partially premixed flame of more than 10 kW can be enhanced by pulsed high-voltage discharges with power consumption less than 0.1% of the power of the flame. The originality of this work is to demonstrate that very effective stabilization of turbulent flames is obtained when high-voltage pulses with very short rise times are used (a decrease by 300% in terms of liftoff height for a given exit jet velocity can be reached) and to provide measurements of minimum liftoff height obtained with discharge over a large range of the stability domain of the lifted jet flame.

  6. On the Configuration of the US Western Interconnection Voltage Stability Boundary

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Vyakaranam, Bharat; Wu, Di; Hou, Zhangshuan; Elbert, Stephen T.; Huang, Zhenyu

    2014-04-01T23:59:59.000Z

    Abstract—Stability limits are considered in power system planning and operations to estimate the available stability margins and, if possible, to maximize the utilization of transmission facilities. These important tasks are influenced by configuration of the stability boundary. The paper introduces a new fast approach to explore the voltage stability boundary of a large system and reveal its detailed multidimensional structure. The 17939-bus U.S. Western Interconnection planning model was used to illustrate the method. Significant peculiarities of the boundary’s configuration were identified, including its nonconvexity, discontinuity, branching and internal singularities (“holes”) that were not known before and could not been found by traditional methods. Experiments using WECC system are performed to evaluate the computation time using different methods. Our results show that the proposed methods are very promising in reducing calculation time and complexity

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

    DOE Patents [OSTI]

    Taubman, Matthew S; Phillips, Mark C

    2014-03-18T23:59:59.000Z

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

  8. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. XX, NO. Y, MONTH 2001 1 Global Transient Stability and Voltage Regulation

    E-Print Network [OSTI]

    Guo, Yi

    and voltage regulator. The designed controller is smooth and robust with respect to di#11;erent transient and voltage regulation are both important properties of power system control, but they are ascribed to di#11 of system behavior. We design in this paper a global controller to co-ordinate the transient stabilizer

  9. Voltage multi-stability in distribution grids with power flow reversal

    E-Print Network [OSTI]

    Hung D. Nguyen; Konstantin Turitsyn

    2014-07-08T23:59:59.000Z

    High levels of penetration of distributed generation and aggressive reactive power compensation with modern power electronics may result in the reversal of active and reactive power flows in future distribution grids. The voltage stability of these operating conditions may be very different from the more traditional power consumption regime. We study the stability characteristics of distribution networks with reversed power flow. After introducing a universal algebraic approach to characterize all the solutions of the power flow equations, we show that new solutions appear in the reversed power flow regime even in the simplest three bus systems. We show that the some of these solutions are stable and the system may exhibit a phenomenon of multistability, where multiple stable equilibria co-exist at the given set of parameters, and the system may converge to an undesirable equilibrium after a disturbance. These predictions are validated with dynamic simulations of two different systems. Under certain conditions the new states are viable and may be characterized by relatively high voltages. Possible approaches towards reactive power/voltage regulation as well as permissible distributed generation capacity in future power systems are proposed and discussed in the end of the paper.

  10. 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

  11. Voltage Stabilization in Microgrids via Quadratic Droop Control John W. Simpson-Porco, Florian Dorfler, and Francesco Bullo

    E-Print Network [OSTI]

    Bullo, Francesco

    -voltage electrical networks equipped with DC/AC inverters ("micro- grids"). It is generally believed that high¨orfler, and Francesco Bullo Abstract-- Motivated by the growing interest in energy tech- nology and smart grid distribution networks, heterogeneously composed of distributed generation, storage, load, and managed

  12. The design of an A-C voltage regulator using a Wein Bridge detector

    E-Print Network [OSTI]

    Brown, Richard True

    1959-01-01T23:59:59.000Z

    ) the regulator would correct for changes in input voltage only, as the detector ie on the input side of the controller. In Figures 1(c) and 1(d) the xegulator would corxect fox' changes in input or load conditions as the detector is placed directly across... the load. Em D Figure 1; Four types of regulator connections. The connections shown in Figures 1(b) and l(d) are limited in that the output is usually less than the input voltage, whereas in Figures 1(a) and 1(c) the controller voltage can buck...

  13. IEEE PES WM Panel on Modeling, Simulation and Applications of FACTS Controllers in Angle and Voltage Stability Studies, Singapore, Jan. 2000 Power Flow and Transient Stability Models of FACTS Controllers

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    power ow and tran- sient stability studies of such system with its controllers. The latter and Voltage Stability Studies, Singapore, Jan. 2000 Power Flow and Transient Stability Models of FACTS|This paper presents transient stability and power ow models of Thyristor ControlledReactor TCR and Voltage

  14. Real Power and Reactive Power Control of a Three-Phase Single-Stage-PV System and PV voltage Stability

    SciTech Connect (OSTI)

    Li, Huijuan [ORNL] [ORNL; Xu, Yan [ORNL] [ORNL; Adhikari, Sarina [ORNL] [ORNL; Rizy, D Tom [ORNL] [ORNL; Li, Fangxing [ORNL] [ORNL; Irminger, Philip [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    Grid-connected photovoltaic (PV) systems with power electronic interfaces can provide both real and reactive power to meet power system needs with appropriate control algorithms. This paper presents the control algorithm design for a three-phase single-stage grid-connected PV inverter to achieve either maximum power point tracking (MPPT) or a certain amount of real power injection, as well as the voltage/var control. The switching between MPPT control mode and a certain amount of real power control mode is automatic and seamless. Without the DC-to-DC booster stage, PV DC voltage stability is an important issue in the control design especially when the PV inverter is operating at maximum power point (MPP) with voltage/var control. The PV DC voltage collapse phenomenon and its reason are discussed. The method based on dynamic correction of the PV inverter output is proposed to ensure PV DC voltage stability. Simulation results of the single-stage PV system during system disturbances and fast solar irradiation changes confirm that the proposed control algorithm for single-stage PV inverters can provide appropriate real and reactive power services and ensure PV DC voltage stability during dynamic system operation and atmospheric conditions.

  15. Stability and electronic properties of carbon in -Al2O3 Jiajie Zhu a,c

    E-Print Network [OSTI]

    Pandey, Ravi

    Stability and electronic properties of carbon in -Al2O3 Jiajie Zhu a,c , K.P. Muthe b , Ravindra China a r t i c l e i n f o Article history: Received 2 July 2013 Received in revised form 8 November and electronic properties of carbon in -Al2O3 are investigated using density functional theory. In the host

  16. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 17, NO. 2, JUNE 2007 3179 Variable Temperature Total AC Loss and Stability

    E-Print Network [OSTI]

    -temperature superconductors, sta- bility, superconducting filaments and wires. I. INTRODUCTION LARGE-SCALE power applications of high temperature superconductors (HTS) are looking more promising with the advances in commercial and increased stability. Both ac losses and stability of HTS materials are functions of temperature, transport

  17. A New Bifurcation Analysis for Power System Dynamic Voltage Stability Studies

    E-Print Network [OSTI]

    a specific system configuration and the operation condition. For a power system, the typical state variables are the time dependent generator voltages (For different generator models, the variables of generator voltages as the variables of the exciter, speed governor and so on; sometimes the dynamics of the load behavior will also

  18. Delocalization of Phase Fluctuations and the Stability of AC Electricity Grids

    E-Print Network [OSTI]

    S. Kettemann

    2015-04-21T23:59:59.000Z

    The energy transition towards an increased supply of renewable energy raises concerns that existing electricity grids, built to connect few centralized large power plants with consumers, may become more difficult to control and stabilized with a rising number of decentralized small scale generators. Here, we aim to study therefore, how local phase fluctuations affect the AC grid stability. To this end, we start from a model of nonlinear dynamic power balance equations. We map them to complex linear wave equations and find stationary solutions for the distribution of phases $\\varphi_i$ at the generator and consumer sites $i$. Next, we derive differential equations for deviations from these stationary solutions. Next, we derive differential equations for deviations from these stationary solutions. Starting with an initially localized phase perturbation, it is found to spread in a periodic grid diffusively throughout the grid. We derive the parametric dependence of diffusion constant $D$. We apply the same solution strategy to general grid topologies and analyse their stability against local fluctuations. The fluctuation remains either localized or becomes delocalized, depending on grid topology and distribution of consumers and generators $P_i$. Delocalization is found to increase the lifetime of phase fluctuations and thereby their influence on grid stability, while localization results in an exponentially fast decay of phase fluctuations at all grid sites.

  19. Nonlinear DSTATCOM controller design for distribution network with distributed generation to enhance voltage stability

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Nonlinear DSTATCOM controller design for distribution network with distributed generation Accepted 19 June 2013 Keywords: Distributed generation Distribution network DSATACOM Partial feedback connected to a distribution network with distributed generation (DG) to regulate the line voltage

  20. Voltage stability of the Puget Sound system under abnormally cold weather conditions

    SciTech Connect (OSTI)

    Jimma, K.M.; Sheehan, M.T. (Puget Sound Power and Light, Bellevue, WA (United States)); Comegys, G.L. (Bonneville Power Administration, Portland, OR (United States)); Miller, N.W.; D'Aquila, R.

    1993-08-01T23:59:59.000Z

    The potential for voltage collapse in the Puget Sound area is analyzed. Shunt and series compensation schemes, as well as undervoltage load shedding, are evaluated. Twenty-five minute time simulations of the Puget Sound area system are presented, showing interaction of load dynamics with LTCs, switched compensation and protective equipment. Results and analysis are relevant to utilities worldwide which must address similar concerns.

  1. Effect of Detailed Power System Models in Traditional and Voltage Stability Constrained

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    problems to improve the accuracy of the results. It is shown in [2] that reactive power limits play], [9], [10], it is demonstrated that reactive power limits play a significant role in voltage collapse of power systems. Therefore, particular attention is placed here to the modeling of reactive power limits

  2. A low voltage and submillisecond-response polymer-stabilized blue phase liquid crystal

    E-Print Network [OSTI]

    Wu, Shin-Tson

    , University of Central Florida, Orlando, Florida 32816, USA 2 JNC Petrochemical Corporation, Ichihara Research-assembly process so that no surfactant (e.g., rubbed polyimide layer) is needed to generate uniform molecular voltage-off state. Alignment-layer-free pro- cess greatly simplifies device fabrication process. Fast

  3. Reactive power management of distribution networks with wind generation for improving voltage stability

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    -loadability Reactive power margin Wind turbine a b s t r a c t This paper proposes static and dynamic VAR planningReactive power management of distribution networks with wind generation for improving voltage February 2013 Available online Keywords: Composite load Distributed generation D-STATCOM Q

  4. Voltage Stability Analysis With Optimum Size and Location Based Synchronous Machine DG

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    scenar- ios for the worldwide energy supply in the future. In Australia CO2 emission from energy is much for loss reduction of the system. This paper also investigates the steady-state and dynamic voltage profile profile of the distribution system. Index Terms--Power loss reduction, distributed generation, optimum

  5. Design of a Solid-State Fast Voltage Compensator for klystron modulators requiring constant AC power consumption

    E-Print Network [OSTI]

    Davide, Aguglia; Philippe, Viarouge; Jerome, Cros

    2015-01-01T23:59:59.000Z

    This paper proposes a novel topological solution for klystron modulators integrating a Fast Voltage Compensator which allows an operation at constant power consumption from the utility grid. This kind of solution is mandatory for the CLIC project under study, which requires several hundreds of synchronously operated klystron modulators for a total pulsed power of 39 GW. The topology is optimized for the challenging CLIC specifications, which require a very precise output voltage flat-top as well as fast rise and fall times (3µs). The Fast Voltage Compensator is integrated in the modulator such that it only has to manage the capacitor charger current and a fraction of the charging voltage. Consequently, its dimensioning power and cost is minimized.

  6. 82 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS, PART 1, VOL. 47, NO. 1, JANUARY 2000 Fig. 5. Output voltage waveform in the closed-loop dc-ac power inverter.

    E-Print Network [OSTI]

    Leuciuc, Adrian

    voltage waveform in the closed-loop dc-ac power inverter. Horizontal scale: 5 ms/div.; vertical scale: 0.2 V/div. Fig. 6. Bode plots of the closed-loop power inverter . Packard 4194A Network Analyzer, Bode that the -3-dB frequency was 205 Hz. IV. CONCLUSION This study demonstrates that a low-frequency dc-ac power

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

    E-Print Network [OSTI]

    Kwak, Sangshin

    2005-08-29T23:59:59.000Z

    Significant advances in modern ac/ac power converter technologies and demands of industries have reached beyond standard ac/ac power converters with voltage-source inverters fed from diode rectifiers. Power electronics converters have been matured...

  8. On Reactive Power Flow and Voltage Stability in Microgrids Basilio Gentile, John W. Simpson-Porco, Florian Dorfler, Sandro Zampieri, and Francesco Bullo

    E-Print Network [OSTI]

    Bullo, Francesco

    ], where an approximate solution to the reactive power flow equations was developed for electrical networksOn Reactive Power Flow and Voltage Stability in Microgrids Basilio Gentile, John W. Simpson-Porco, Florian D¨orfler, Sandro Zampieri, and Francesco Bullo Abstract-- This paper focuses on reactive power

  9. Bonneville Power Administration is investigating wide-area stability and voltage control. The control provides a flexible

    E-Print Network [OSTI]

    Venkatasubramanian, Mani V.

    consists of a ±500-kV, 3100 MW bipolar HVDC link, and a 500-kV AC intertie of 4800 MW capacity. Measures

  10. 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.

  11. E-Print Network 3.0 - acs protein stability Sample Search Results

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

    and Medicine 7 Available online at www.sciencedirect.com Nature and nurture in protein folding and binding Summary: in understanding the regulation of protein stability and...

  12. AbstractDifferent control aspects related to the use of TCSC for stability improvement of power systems are addressed in this

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    of using Flexible AC Transmission system (FACTS) controllers for enhancing power system stability are well1 AbstractDifferent control aspects related to the use of TCSC for stability improvement of power high voltage interconnected system is used to illustrate the ideas presented in the paper. Index TermsStability

  13. Voltage CollapseVoltage Collapse Animation (AC)Animation (AC)

    E-Print Network [OSTI]

    power (or VARs) to their local loads plus VARs to the transmission lines to support the transfer) where the generators, loads and transmission lines interconnect · Transmission lines: lines connecting · Circuit breakers: red boxes · Line flows: arrows on the transmission lines (more easily seen in the last

  14. Optical voltage reference

    DOE Patents [OSTI]

    Rankin, R.; Kotter, D.

    1994-04-26T23:59:59.000Z

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

  15. Abstract--This paper presents the application of FACTS devices for the enhancement of dynamic voltage stability in

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    enabler of the smart grid for the integration of small and medium sized renewable energy into the electricity grids. Multiple mini-grids, connected into the distribution level network, will form new systems in power systems are one of the major concerns in power system planning and operation [8]. If voltage

  16. ac josephson effect: Topics by E-print Network

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

    in the dc mass currents voltage, a high frequency ac voltage is applied across a superconduct- ing Josephson junction, the dc, Dm 22eV, application of a dc voltage produces...

  17. Experimental validation of a high voltage pulse measurement method.

    SciTech Connect (OSTI)

    Cular, Stefan; Patel, Nishant Bhupendra; Branch, Darren W.

    2013-09-01T23:59:59.000Z

    This report describes X-cut lithium niobate's (LiNbO3) utilization for voltage sensing by monitoring the acoustic wave propagation changes through LiNbO3 resulting from applied voltage. Direct current (DC), alternating current (AC) and pulsed voltage signals were applied to the crystal. Voltage induced shift in acoustic wave propagation time scaled quadratically for DC and AC voltages and linearly for pulsed voltages. The measured values ranged from 10 - 273 ps and 189 ps - 2 ns for DC and non-DC voltages, respectively. Data suggests LiNbO3 has a frequency sensitive response to voltage. If voltage source error is eliminated through physical modeling from the uncertainty budget, the sensor's U95 estimated combined uncertainty could decrease to ~0.025% for DC, AC, and pulsed voltage measurements.

  18. Dynamic simulation of voltage collapses

    SciTech Connect (OSTI)

    Deuse, J.; Stubbe, M. (Tractebel, Brussels (Belgium))

    1993-08-01T23:59:59.000Z

    Most of the time the voltage collapse phenomena are studied by means of computer programs designed for the calculation of steady state conditions. But in the real world, the simultaneous occurrences of losses of synchronism, of AVR dynamics or of transformer tap changes call for a full dynamic simulation of voltage phenomena. The present paper shows some examples of dynamic simulations of voltage phenomena using a new general purpose stability program (EUROSTAG), covering in a continuous way the classical fields of transient, mid-term and long-term stability, and also the quasi steady state conditions of a power system.

  19. Non-iterative Voltage Stability

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Vyakaranam, Bharat; Hou, Zhangshuan; Wu, Di; Meng, Da; Wang, Shaobu; Elbert, Stephen T.; Miller, Laurie E.; Huang, Zhenyu

    2014-09-30T23:59:59.000Z

    This report demonstrates promising capabilities and performance characteristics of the proposed method using several power systems models. The new method will help to develop a new generation of highly efficient tools suitable for real-time parallel implementation. The ultimate benefit obtained will be early detection of system instability and prevention of system blackouts in real time.

  20. Fig. 5. The influence of the network cross-traffic on the ability of the SANET to stabilize the generator's voltage

    E-Print Network [OSTI]

    Branicky, Michael S.

    for dynamical systems simulations. Example: Agent/Plant [2] Third direction: marry a full-fledged network.g., Standard, Power systems, Hydraulics, Pneumatics, Power train) Has commercial and open source simulation the generator's voltage under the varying load. The plots show the line voltage and power for two cases

  1. Voltage balanced multilevel voltage source converter system

    DOE Patents [OSTI]

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

    1997-07-01T23:59:59.000Z

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

  2. 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...

  3. Surface and Structural Stabilities of Carbon Additives in High...

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

    Structural Stabilities of Carbon Additives in High Voltage Lithium Ion Batteries. Surface and Structural Stabilities of Carbon Additives in High Voltage Lithium Ion Batteries....

  4. 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.

  5. 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...

  6. High power impulse magnetron sputtering: Current-voltage-time characteristics indicate the onset of sustained self-sputtering

    E-Print Network [OSTI]

    Anders, Andre; Andersson, Joakim; Ehiasarian, Arutiun

    2008-01-01T23:59:59.000Z

    target voltage starts to slightly droop for higher voltages,1000 V, the actual voltage droops and shows less stability.see a large voltage droop, especially at high current). We

  7. 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.

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

    E-Print Network [OSTI]

    Cañizares, Claudio A.

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

  9. A Matter of Quantum Voltages

    SciTech Connect (OSTI)

    Sellner, Bernhard; Kathmann, Shawn M.

    2014-11-14T23:59:59.000Z

    Voltages inside matter are relevant to crystallization, materials science, biology, catalysis, and aqueous chemistry. Electron holography is able to measure the variation of voltages in matter and modern supercomputers allow the calculation of quantum voltages with practically unlimited spatial and temporal resolution of bulk systems. Of particular interest is the Mean Inner Potential (Vo) - the spatial average of these voltages. Voltages are very sensitive to the distribution of electrons and provide metrics to understand interactions in condensed phases. In the present study, we find excellent agreement with measurements of Vo for vitrified water and salt crystals and demonstrate the impact of covalent and ionic bonding as well as intermolecular/atomic interactions. Furthermore, we predict Vo as well as the fluctuations of these voltages in aqueous NaCl electrolytes and characterize the changes in their behavior as the resolution increases below the size of atoms. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  10. Non-contact current and voltage sensor

    DOE Patents [OSTI]

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

    2014-03-25T23:59:59.000Z

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

  11. Section IV.D.3 for DOE 2013 Annual Report: Novel Phosphazene-based Compounds to Enhance Safety and Stability of Cell Chemistries for High Voltage Applications (INL)

    SciTech Connect (OSTI)

    Kevin L. Gering; Mason K. Harrup; Eric J. Dufek; Sergiy V. Sazhin; Harry W. Rollins; David K. Jamison; Fred F. Stewart; John Burba

    2013-09-01T23:59:59.000Z

    Electrolytes play a central role in performance and aging in most electrochemical systems. As automotive and grid applications place a higher reliance on electrochemical stored energy, it becomes more urgent to have electrolyte components that enable optimal battery performance while promoting battery safety and longevity. Safety remains a foremost concern for widespread utilization of Li-ion technology in electric-drive vehicles, especially as the focus turns to higher voltage systems (5V). This work capitalizes on the long established INL expertise regarding phosphazene chemistry, aimed at battery-viable compounds for electrolytes and electrodes that are highly tolerant to abusive conditions. This report showcases our 2013 work for the DOE applied battery research (ABR) program, wherein testing results are summarized for INL electrolytes and alternative anode materials.

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

    E-Print Network [OSTI]

    of all distribution lines that are controlled by a tap changing source voltage regulator. Several voltage-control primary system with source voltage regulation. Minimum system stability thresholds, system data modeling is mentioned, it refers to using industry accepted distribution system power flow simulation tools

  13. AC Resistance measuring instrument

    DOE Patents [OSTI]

    Hof, Peter J. (Richland, WA)

    1983-01-01T23:59:59.000Z

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument.

  14. AC resistance measuring instrument

    DOE Patents [OSTI]

    Hof, P.J.

    1983-10-04T23:59:59.000Z

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

  15. english 31AC african-amercan studies 17AC history 7B public health 130AC sociology 3AC education 30AC ethnic studies 135AC geography 150AC history 127AC information 142AC psychology 125AC anthropology 2AC american

    E-Print Network [OSTI]

    Alvarez-Cohen, Lisa

    · anthropology 2AC · american studies 10AC · gender and womens studies 50AC · music 26AC · spanish 135AC 50AC · music 26AC · spanish 135AC · sociology 190AC · public policy 117AC · peace and conflict studies 10AC · gender and womens studies 50AC · music 26AC · spanish 135AC · sociology 190AC · public

  16. High Voltage Safety Act

    Broader source: Energy.gov [DOE]

    The purpose of the High Voltage Safety Act is to prevent injury to persons and property and interruptions of utility service resulting from accidental or inadvertent contact with high-voltage...

  17. Automatic voltage imbalance detector

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

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

  18. 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

  19. RESEARCH ARTICLE Interpolation approximation of voltage stability

    E-Print Network [OSTI]

    Tolbert, Leon M.

    ) for reactive power planning Wenjuan Zhang1,2 , Fangxing Li1* and Leon M. Tolbert1,3 1 Department of Electrical.S.A. ABSTRACT Reactive power planning (RPP), or Var planning, is to identify the optimal size and location of reactive power sources. In this paper, first, the previous work using least square method to simplify

  20. System and method for determining stator winding resistance in an AC motor using motor drives

    DOE Patents [OSTI]

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26T23:59:59.000Z

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  1. The EP-4(0) shielding kits: a new approach to protection from induced voltage

    SciTech Connect (OSTI)

    Vorob'ev, A. Yu.; Otmorskii, S. G.; Smekalov, V. V.; Gorozhankina, E. N.; Sosunov, N. N.; Bol'shunov, A. M.

    2011-09-15T23:59:59.000Z

    Problems of safety in work on overhead power lines and the overhead railroad ac contact network under induced voltages are considered. The use of additional individual protection systems is proposed to provide protection from electric shock during such work.

  2. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    DOE Patents [OSTI]

    Gallegos-Lopez, Gabriel (Torrance, CA); Nagashima, James M. (Cerritos, CA); Perisic, Milun (Torrance, CA); Hiti, Silva (Redondo Beach, CA)

    2012-02-14T23:59:59.000Z

    A system is provided for controlling two AC machines. The system comprises a DC input voltage source that provides a DC input voltage, a voltage boost command control module (VBCCM), a five-phase PWM inverter module coupled to the two AC machines, and a boost converter coupled to the inverter module and the DC input voltage source. The boost converter is designed to supply a new DC input voltage to the inverter module having a value that is greater than or equal to a value of the DC input voltage. The VBCCM generates a boost command signal (BCS) based on modulation indexes from the two AC machines. The BCS controls the boost converter such that the boost converter generates the new DC input voltage in response to the BCS. When the two AC machines require additional voltage that exceeds the DC input voltage required to meet a combined target mechanical power required by the two AC machines, the BCS controls the boost converter to drive the new DC input voltage generated by the boost converter to a value greater than the DC input voltage.

  3. Control sensitivity indices for stability analysis of HVdc systems

    SciTech Connect (OSTI)

    Nayak, O.B.; Gole, A.M. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)] [Univ. of Manitoba, Winnipeg, Manitoba (Canada); Chapman, D.G.; Davies, J.B. [Manitoba Hydro, Winnipeg, Manitoba (Canada)] [Manitoba Hydro, Winnipeg, Manitoba (Canada)

    1995-10-01T23:59:59.000Z

    This paper presents a new concept called the ``Control Sensitivity Index`` of CSI, for the stability analysis of HVdc converters connected to weak ac systems. The CSI for a particular control mode can be defined as the ratio of incremental changes in the two system variables that are most relevant to that control mode. The index provides valuable information on the stability of the system and, unlike other approaches, aids in the design of the controller. It also plays an important role in defining non-linear gains for the controller. This paper offers a generalized formulation of CSI and demonstrates its application through an analysis of the CSI for three modes of HVdc control. The conclusions drawn from the analysis are confirmed by a detailed electromagnetic transients simulation of the ac/dc system. The paper concludes that the CSI can be used to improve the controller design and, for an inverter in a weak ac system, the conventional voltage control mode is more stable than the conventional {gamma} control mode.

  4. Abstract--Presented are a methodology and a DFII-based tool for AC-stability analysis of a wide variety of closed-loop

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    variety of closed-loop continuous-time (operational amplifiers and other linear circuits). The methodology loop identification and full- circuit stability analysis, which gives better picture of the circuit use a technique that may be viewed as analogous to time- domain analysis1 of circuit's transfer

  5. Voltage Control Technical Conference

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

    Intro Voltage Control Conference - BPA Active Power Control in Wind Parks - Siemens Interconnection Criteria for Frequency Response Requirements - NERC Model Validation...

  6. 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

  7. Voltage verification unit

    DOE Patents [OSTI]

    Martin, Edward J. (Virginia Beach, VA)

    2008-01-15T23:59:59.000Z

    A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

  8. Local Dynamic Reactive Power for Correction of System Voltage Problems

    SciTech Connect (OSTI)

    Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

    2008-12-01T23:59:59.000Z

    Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.

  9. 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.

  10. 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.

  11. AC Loss Measurements on a 2G YBCO Coil

    SciTech Connect (OSTI)

    Rey, Christopher M [ORNL] [ORNL; Duckworth, Robert C [ORNL] [ORNL; Schwenterly, S W [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES) to continue development of HTS power transformers. For compatibility with the existing power grid, a commercially viable HTS transformer will have to operate at high voltages in the range of 138 kV and above, and will have to withstand 550-kV impulse voltages as well. Second-generation (2G) YBCO coated conductors will be required for an economically-competitive design. In order to adequately size the refrigeration system for these transformers, the ac loss of these HTS coils must be characterized. Electrical AC loss measurements were conducted on a prototype high voltage (HV) coil with co-wound stainless steel at 60 Hz in a liquid nitrogen bath using a lock-in amplifier technique. The prototype HV coil consisted of 26 continuous (without splice) single pancake coils concentrically centered on a stainless steel former. For ac loss measurement purposes, voltage tap pairs were soldered across each set of two single pancake coils so that a total of 13 separate voltage measurements could be made across the entire length of the coil. AC loss measurements were taken as a function of ac excitation current. Results show that the loss is primarily concentrated at the ends of the coil where the operating fraction of critical current is the highest and show a distinct difference in current scaling of the losses between low current and high current regimes.

  12. Time varying voltage combustion control and diagnostics sensor

    DOE Patents [OSTI]

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

    2011-04-19T23:59:59.000Z

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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Mexican Hat, Utah: Text, Appendices A--C. Final report

    SciTech Connect (OSTI)

    NONE

    1988-07-01T23:59:59.000Z

    This Remedial Action Plan (RAP) has been developed to serve a two- fold purpose. It presents the activities proposed by the Department of Energy (DOE) to accomplish long-term stabilization and control of the residual radioactive materials (RRM) from Monument Valley Arizona, and Mexican Hat, Utah, at the Mexican Hat disposal site. It also serves to document the concurrence of both the Navajo Nation and the Nuclear Regulatory Commission (NRC) in the remedial action. This agreement, upon execution by DOE and the Navajo Nation and concurrence by the NRC, becomes Appendix B of the Cooperative Agreement. This document has been structured to provide a comprehensive understanding of the remedial action proposed for the Monument Valley and Mexican Hat sites. It includes specific design and construction requirements for the remedial action. Pertinent information and data are included with reference given to the supporting documents. Appendices A,B, and C are provided as part of this document. Appendix A presents regulatory compliance issues, Appendix B provides details of the engineering design, and Appendix C presents the radiological support plan.

  18. ABBGroup-1-High voltage lab

    E-Print Network [OSTI]

    Basse, Nils Plesner

    oscillations are due to travelling waves in the heating volume. #12;©ABBGroup-9- 3-Sep-07 2. High voltage phase interrupts the injected current, it is stressed by the transient recovery voltage (TRV) oscillating©ABBGroup-1- 3-Sep-07 High voltage lab Research on high voltage gas circuit breakers Nils P. Basse

  19. Electron launching voltage monitor

    DOE Patents [OSTI]

    Mendel, C.W.; Savage, M.E.

    1992-03-17T23:59:59.000Z

    An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors. 5 figs.

  20. Electronic high voltage generator with a high temperature superconducting coil

    SciTech Connect (OSTI)

    Jin, J.X.; Liu, H.K.; Dou, S.X. [Univ. of Wollongong (Australia)] [and others

    1996-12-31T23:59:59.000Z

    A novel method for generating high voltages from a low voltage DC source, by using a capacitor and inductor in a R, L, C resonant circuit has been developed with the consideration of using a high temperature superconducting (HTS) coil. To generate high voltages the polarity of a low voltage battery source is reversed each half resonant cycle, the control being achieved by an electronic switch. Resistance in the circuit limits the voltages that can be built up. By replacing a copper winding inductor with another inductor which has a HTS winding, the magnitude of achievable voltages is substantially increased. A (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+x} multifilament HTS wire is considered in this work to make the superconducting inductor. The high voltages generated are not capable of supplying low impedance loads, however, possible applications of the generator include electrical partial discharge testing and insulation resistance testing. It could also be used as a testing method for the HTS itself with respect to the critical current and AC loss measurement.

  1. Threshold voltage extraction circuit

    E-Print Network [OSTI]

    Hoon, Siew Kuok

    2000-01-01T23:59:59.000Z

    to that of the saturation method. However, instead of fixing Vos ? Vos, the drain current is measured as a function of Vos while Vns is fixed at a constant low voltage of 100mV to ensure operation in the linear MOSFET region. Neglecting channel length modulation effect... transistors are layout next to the DUT of the NMOS and PMOS Vr extraction circuits respectively for extraction of Vr via graphical means. GRAPHICAL METHOD OF THE THRESHOLD-VOLTAGE MEASUREMENT Using the graphical method, the characteristics of 4n versus Vos...

  2. Rotating electrical machines - Part 22: AC generators for reciprocating internal combustion (RIC) engine driven generating sets

    E-Print Network [OSTI]

    International Electrotechnical Commission. Geneva

    1996-01-01T23:59:59.000Z

    Establishes the principal characteristics of a.c. generators under the control of their voltage regulators when used for reciprocating internal combustion engine driven generating sets. Supplements the requirements given in IEC 60034-1.

  3. ac voltage standard: Topics by E-print Network

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

    in the paper can be used in engineering designs. I. INTRODUCTION Piezoelectric Transformers (PT) convert electric power into electric power via a mechanical resonant link....

  4. Adjustable Speed AC Motor Drives-Applications Problems

    E-Print Network [OSTI]

    Enjeti, P.

    Adjustable Speed AC Motor Drives Applications Problems by Dr. P. Enjeti Power Quality Laboratory Department ofElectrical Engineering Texas A&M University College Station, TX 77843 Tel: 409-845-7466 Fax: 409-845-6259 Email..., it generates side effects, some which have been recognized only recently. This paper presents a comprehensive coverage of application issues of PWM inverter controlled ac motor drives which include damage to motor insulation due to reflected voltages caused...

  5. Marine High Voltage Power Conditioning and Transmission System with Integrated Storage DE-EE0003640 Final Report

    SciTech Connect (OSTI)

    Frank Hoffmann, PhD; Aspinall, Rik

    2012-12-10T23:59:59.000Z

    Design, Development, and test of the three-port power converter for marine hydrokinetic power transmission. Converter provides ports for AC/DC conversion of hydrokinetic power, battery storage, and a low voltage to high voltage DC port for HVDC transmission to shore. The report covers the design, development, implementation, and testing of a prototype built by PPS.

  6. System and method for determining stator winding resistance in an AC motor

    DOE Patents [OSTI]

    Lu, Bin (Kenosha, WI); Habetler, Thomas G. (Snellville, GA); Zhang, Pinjia (Atlanta, GA); Theisen, Peter J. (West Bend, WI)

    2011-05-31T23:59:59.000Z

    A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

  7. * jafleeman@aep.com EHV AC and HVDC Transmission Working Together to Integrate Renewable Power

    E-Print Network [OSTI]

    McCalley, James D.

    * jafleeman@aep.com EHV AC and HVDC Transmission Working Together to Integrate Renewable Power J. A current (EHV AC) and high voltage direct current (HVDC) transmission systems and advocates a hybrid as a high capacity platform for system integration. HVDC transmission offers express, efficient delivery

  8. High voltage pulse conditioning

    DOE Patents [OSTI]

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

    1990-01-01T23:59:59.000Z

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

  9. Charge-pump voltage converter

    DOE Patents [OSTI]

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

    2009-11-03T23:59:59.000Z

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

  10. INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS

    E-Print Network [OSTI]

    Kinget, Peter

    INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS Peter Kinget Bell Labs - Lucent Technologies Murray Hill, NJ (USA) Abstract The voltage controlled oscillator (VCO) is a critical sub. We focus on the de- sign of a critical sub-block: the voltage controlled oscillator (VCO). We review

  11. Dynamic performance of a STATCON at an HVDC inverter feeding a very weak AC system

    SciTech Connect (OSTI)

    Zhuang, Y.; Menzies, R.W. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)] [Univ. of Manitoba, Winnipeg, Manitoba (Canada); Nayak, O.B. [HVDC Research Centre, Winnipeg, Manitoba (Canada)] [HVDC Research Centre, Winnipeg, Manitoba (Canada); Turanli, H.M. [Manitoba Hydro, Winnipeg, Manitoba (Canada)] [Manitoba Hydro, Winnipeg, Manitoba (Canada)

    1996-04-01T23:59:59.000Z

    This paper investigates the dynamic performance of the advanced static var compensator or STATCON at a high voltage direct current (HVDC) converter terminal where the ac system has a very low short circuit ratio (SCR). The STATCON is based on a nine-level GTO thyristor inverter. The studies include operating characteristics of the STATCON under various ac and dc disturbances. The simulation results are compared with other types of reactive power compensation options available for such applications. It is shown that the STATCON has clear advantages over the other compensators, in areas such as; fault response time, voltage support ability, and dc recovery, while operating with very weak ac systems.

  12. Incorporating voltage security into the planning, operation and monitoring of restructured electric energy markets

    E-Print Network [OSTI]

    Nair, Nirmal-Kumar

    2006-04-12T23:59:59.000Z

    derived is based on composite market coordination models that have both PoolCo and OpCo transactions, in a shared stressed transmission grid. Our procedure is able to equitably distinguish the impacts of individual transactions on voltage stability...

  13. Prebreakdown and breakdown phenomena in large oil gaps under AC

    SciTech Connect (OSTI)

    Saker, A.; Gournay, P.; Lesaint, O.; Tobazeon, R. [CNRS, Grenoble (France). Lab. d`Electrostatique et de Materiaux Dielectriques; Trinh, N.G. [Inst. de Recherche d`Hydro-Quebec, Varennes, Quebec (Canada); Boisdon, C. [Jeumont-Schneider Transformateurs, Lyon (France)

    1996-12-31T23:59:59.000Z

    This paper presents a study of prebreakdown and breakdown phenomena under AC voltage in mineral oil in large gaps to 60 cm. The investigations presented concern the study of streamers and the measurement of breakdown voltages in rod-plane and sphere-plane gaps. Also, the influence of a contamination by solid particles in the oil has been considered. A specific breakdown mode under AC voltage is evidenced, where bursts of streamers lead to the lowest breakdown fields recorded. Numerical values of the mean field in oil required for direct or burst breakdown modes are derived from the experiments. As a consequence, the great sensitivity to the presence of particles on EHV transformers insulation with large oil gaps is pointed out.

  14. 3.3.3AC Sweep AC . AC

    E-Print Network [OSTI]

    ­. DC ­ AC ­) .( . ­ ,, '­Spice .Spice . : 0 0 E1 PWR(V(%IN+, %IN . )2.3( Etable " . . : 00 V1 0Vdc E2 Pwr(V(%IN+, %IN-),2) ETABLE TABLE = (5

  15. HYBRID CONTROL OF DISTRIBUTED GENERATORS CONNECTED TO WEAK RURAL NETWORKS TO MITIGATE VOLTAGE VARIATION

    E-Print Network [OSTI]

    Harrison, Gareth

    thermal power plants will increase the total and proportion of capacity of Distributed Generation (DG@iee.org; Robin.Wallace@ed.ac.uk ABSTRACT Distributed generators are normally operated in automatic power factor-constrained bi- directional power flow may cause unacceptable voltage fluctuations that would cause generator

  16. Stability measurements of PPL atmospheric pressure arc

    SciTech Connect (OSTI)

    Roquemore, L.; Zweben, S.J. [Princeton Plasma Physics Lab., NJ (United States); Wurden, G.A. [Los Alamos National Lab., NM (United States)

    1997-12-31T23:59:59.000Z

    Experiments on the stability of atmospheric pressure arcs have been started at PPL to understand and improve the performance of arc furnaces used for processing applications in metallurgy and hazardous waste treatment. Previous studies have suggested that the violent instabilities in such arcs may be due to kink modes. A 30 kW, 500 Amp CW DC experimental arc furnace was constructed with a graphite cathode and a molten steel anode. The arc plasma is diagnosed with 4000 frames/sec digital camera, Hall probes, and voltage and current monitors. Under certain conditions, the arc exhibits an intermittent helical instability, with the helix rotating at {approx}600 Hz. The nature of the instability is investigated. A possible instability mechanism is the self-magnetic field of the arc, with saturation occurring due to inhomogeneous heating in a helical arc. The effect of external DC and AC magnetic fields on the instability is investigated. Additionally, arc deflection due to external transverse magnetic field is investigated. The deflection angle is found to be proportional to the applied field, and is in good agreement with a simple model of the {rvec J} x {rvec b} force on the arc jet.

  17. Temperature controlled high voltage regulator

    DOE Patents [OSTI]

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

    2004-04-20T23:59:59.000Z

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

  18. Saving Megawatts with Voltage Optimization

    E-Print Network [OSTI]

    Wilson, T.; Bell, D.

    2010-01-01T23:59:59.000Z

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

  19. Voltage tunable microwave ferrite resonator

    E-Print Network [OSTI]

    Oates, Daniel E.

    A novel method of implementing a tunable resonator using an applied voltage is presented. Stress is used to tune a microstrip resonator fabricated on a polycrystalline ferrite substrate. The stress was applied either ...

  20. ABBGroup-1-High voltage lab

    E-Print Network [OSTI]

    Basse, Nils Plesner

    . GENERATION System voltage: 12-24 kV Rated current: 6000-24000 A Max. short-circuit current: 50-500 kA TRANSMISSION System voltage: 72-800 kV Rated current: 2500-4000 A Max. short-circuit current: 25-63 k. It is designed to protect an electrical circuit from damage caused by overload or short-circuit. A circuit

  1. AC breakdown strength of N2, SF6 and a mixture of N2+SF6 containing a small amount of SF6

    SciTech Connect (OSTI)

    Mardikyan, K.; Kalenderli, O. [Istanbul Technical Univ. (Turkey). Electric-Electronics Faculty; Ersen, O.; Canarslan, E. [Schneider Electric Co., Istanbul (Turkey)

    1996-12-31T23:59:59.000Z

    AC breakdown strengths of N{sub 2}, SF{sub 6} and a mixture of N{sub 2}+SF{sub 6} containing 1% of SF{sub 6} were experimentally studied. For this purpose, 50 Hz AC breakdown voltages in both uniform and non-uniform fields up to a pressure of 400 kPa from 50 kPa were measured. Test results show that the addition of 1% of SF{sub 6} to nitrogen increases the breakdown voltage up to 250 kPa in a non-uniform field. The relative breakdown strength of the mixture with respect to components was also calculated in 50 Hz AC voltage. The analysis of Paschen curves reveals an improvement of 40% in the breakdown strength of mixture in uniform field but in non-uniform fields, the maximum AC breakdown voltage of the mixture is 24% lower than that of pure SF{sub 6}.

  2. Voltage sensing in ion channels: Mesoscale simulations of biological devices

    E-Print Network [OSTI]

    Peyser, Alexander

    2012-01-01T23:59:59.000Z

    Electrical signaling via voltage-gated ion channels depends upon the function of a voltage sensor (VS), identified with the S1-S4 domain in voltage-gated K+ channels. Here we investigate some energetic aspects of the sliding-helix model of the VS using simulations based on VS charges, linear dielectrics and whole-body motion. Model electrostatics in voltage-clamped boundary conditions are solved using a boundary element method. The statistical mechanical consequences of the electrostatic configurational energy are computed to gain insight into the sliding-helix mechanism and to predict experimentally measured ensemble properties such as gating charge displaced by an applied voltage. Those consequences and ensemble properties are investigated for two alternate S4 configurations, \\alpha- and 3(10)-helical. Both forms of VS are found to have an inherent electrostatic stability. Maximal charge displacement is limited by geometry, specifically the range of movement where S4 charges and counter-charges overlap in t...

  3. High-Power Converters and AC Drives IEEE PESC2005 Tutorial

    E-Print Network [OSTI]

    Wu, Bin

    @ee.ryerson.ca http://www.ee.ryerson.ca/~bwu/ 2 High-Power Converters and AC Drives 1. Introduction 2. Cascaded H-Bridge Drives · High-Power Semiconductor Devices High-Power Converters and AC Drives Bin Wu 4High · Multilevel Voltage Source Inverters N dC Cascaded H-bridge (CHB) Inverter dC Two Level Inverter dC Flying

  4. Abstract--This paper investigates how to detect a dynamic voltage collapse situation. The generator and governor dynamics

    E-Print Network [OSTI]

    to an interest in maintaining an optimum, secure and reliable power system operation. One such security issue of the index during the line loss, slow increasing loading and step loading situations. The paper also brings simulations and investigation. Index Terms-- Voltage stability, dynamic voltage collapse, EUROSTAG, security

  5. Frequency stabilization in nonlinear MEMS and NEMS oscillators

    DOE Patents [OSTI]

    Lopez, Omar Daniel; Antonio, Dario

    2014-09-16T23:59:59.000Z

    An illustrative system includes an amplifier operably connected to a phase shifter. The amplifier is configured to amplify a voltage from an oscillator. The phase shifter is operably connected to a driving amplitude control, wherein the phase shifter is configured to phase shift the amplified voltage and is configured to set an amplitude of the phase shifted voltage. The oscillator is operably connected to the driving amplitude control. The phase shifted voltage drives the oscillator. The oscillator is at an internal resonance condition, based at least on the amplitude of the phase shifted voltage, that stabilizes frequency oscillations in the oscillator.

  6. Long term voltage stability analysis for small disturbances

    E-Print Network [OSTI]

    Men, Kun

    2009-05-15T23:59:59.000Z

    that there are three basic patterns: #0;? CBA PPP PPP? , both )Re(EigC and )Re(EigT are positive; when ),( CB PPP? , only )Re(EigT is positive. #0;? BCA PPP PPP? , both )Re(EigC and )Re(EigT are positive; when ),( BC PPP...? , only )Re(EigC is positive. #0;? Bifurcation point A disappears and CB PP PPP? . 3.2.2 PI- regulator Here the parameters of PI-regulator is given as 20or 0.5,5.2 === IIP TTK . Using equations (2...

  7. Coordinated Dynamic Voltage Stabilization based on Model Predictive Control

    E-Print Network [OSTI]

    Kumar, Ratnesh

    is very important for power system operations. This paper presents an approach for optimal coordination and operation [1], [2]. The deregulation of power industry has created an economical incentive to operate power devices, generator reactive power control, transformer tap changer control and load shedding. As shown

  8. Voltage, energy and power in electric circuits

    E-Print Network [OSTI]

    Berzins, M.

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

  9. Voltage Collapse and ODE Approach to Power Flows: Analysis of a Feeder Line with Static Disorder in Consumption/Production

    E-Print Network [OSTI]

    Chertkov, M; Turtisyn, K; Chernyak, V; Lebedev, V

    2011-01-01T23:59:59.000Z

    We consider a model of a distribution feeder connecting multiple loads to the sub-station. Voltage is controlled directly at the head of the line (sub-station), however, voltage anywhere further down the line is subject to fluctuations, caused by irregularities of real and reactive distributed power consumption/generation. The lack of a direct control of voltage along the line may result in the voltage instability, also called voltage collapse - phenomenon well known and documented in the power engineering literature. Motivated by emerging photo-voltaic technology, which brings a new source of renewable generation but also contributes significant increase in power flow fluctuations, we reexamine the phenomenon of voltage stability and collapse. In the limit where the number of consumers is large and spatial variations in power flows are smooth functions of position along the feeder, we derive a set of the power flow Ordinary Differential Equations (ODE), verify phenomenon of voltage collapse, and study the ef...

  10. Ancillary service details: Voltage control

    SciTech Connect (OSTI)

    Kirby, B.; Hirst, E.

    1997-12-01T23:59:59.000Z

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

  11. High voltage MOSFET switching circuit

    DOE Patents [OSTI]

    McEwan, T.E.

    1994-07-26T23:59:59.000Z

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET. 2 figs.

  12. High voltage MOSFET switching circuit

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  13. Electric power high-voltage transmission lines: Design options, cost, and electric and magnetic field levels

    SciTech Connect (OSTI)

    Stoffel, J.B.; Pentecost, E.D.; Roman, R.D.; Traczyk, P.A.

    1994-11-01T23:59:59.000Z

    This report provides background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist on alternatives in environmental documents. EMF strengths at 0 {+-} 200 ft from centerline were calculated for ac overhead lines, and for 345 and 230-kV ac underground line and for a {+-}450-kV dc overhead line. Compacting and height sensitivity factors were computed for the variation in EMFs when line conductors are moved closer or raised. Estimated costs for the lines are presented and discussed so that the impact of using alternative strategies for reducing EMF strengths and the implications of implementing the strategies can be better appreciated.

  14. Comparison of Two Autonomous AC-DC Converters for Piezoelectric Energy Scavenging Systems

    E-Print Network [OSTI]

    Boyer, Edmond

    - 1 - Comparison of Two Autonomous AC-DC Converters for Piezoelectric Energy Scavenging Systems E Cornaredo, Milan, Italy Abstract - Piezoelectric Energy Scavenging Systems (PESS) are used to convert of the output voltage of these transducers is needed. Since the output power level of the energy transducer can

  15. A/AC.105/C.1/2014/CRP.15 5 February 2014

    E-Print Network [OSTI]

    Schrijver, Karel

    on the Peaceful Uses of Outer Space Scientific and Technical Subcommittee Fifty-first session Vienna, 10 infrastructure, including high voltage electrical transmission systems and pipelines. #12;2 V.14-00677 A/AC.105/C space situational awareness); and potential loss of space-based services, particularly environmental

  16. System and method for monitoring and controlling stator winding temperature in a de-energized AC motor

    DOE Patents [OSTI]

    Lu, Bin (Kenosha, WI); Luebke, Charles John (Sussex, WI); Habetler, Thomas G. (Snellville, GA); Zhang, Pinjia (Atlanta, GA); Becker, Scott K. (Oak Creek, WI)

    2011-12-27T23:59:59.000Z

    A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

  17. High voltage photovoltaic power converter

    DOE Patents [OSTI]

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

    2001-01-01T23:59:59.000Z

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

  18. Dynamic performance of static and synchronous compensators at an HVDC inverter bus in a very weak AC system

    SciTech Connect (OSTI)

    Nayak, O.B.; Gole, A.M. (Univ. of Manitoba, Winnipeg (Canada)); Chapman, D.G.; Davies, J.B. (Manitoba Hydro, Winnipeg (Canada))

    1994-08-01T23:59:59.000Z

    This paper discusses the performance of dynamic voltage control devices at the inverters of very weak ac systems. The types of compensation considered are: (a) static var compensator (SVC), (b) synchronous compensator (SC), (c) a mix of the two and (d) fixed capacitors. Although the primary purpose of these compensators is to control voltage at the ac bus, their dynamic performance during system disturbances is a very important factor. The investigation includes the behavior of the various voltage control options under ac and dc disturbances. The paper shows that the SVC has the fastest response for load rejection type of overvoltages, but can cause serious problems with recovery during undervoltages caused by single phase faults. The CIGRE benchmark model for HVdc control studies has been modified and used in this study. In particular the effect of local load has been included.

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

    DOE Patents [OSTI]

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

    2001-01-01T23:59:59.000Z

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

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

    DOE Patents [OSTI]

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

    2000-01-01T23:59:59.000Z

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

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

    DOE Patents [OSTI]

    Vail III, William Banning; Momii, Steven Thomas

    2003-06-10T23:59:59.000Z

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

  2. 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.

  3. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    DOE Patents [OSTI]

    Gallegos-Lopez, Gabriel (Torrance, CA); Nagashima, James M. (Cerritos, CA); Perisic, Milun (Torrance, CA); Hiti, Silva (Redondo Beach, CA)

    2012-06-05T23:59:59.000Z

    A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

  4. A system for tranmitting low frequency analog signals over ac power lines

    DOE Patents [OSTI]

    Baker, S.P.; Durall, R.L.; Haynes, H.D.

    1987-07-30T23:59:59.000Z

    A system for transmitting low frequency analog signals over ac power lines using FM modulation. A low frequency analog signal to be transmitted is first applied to a voltage-to-frequency converter where it is converted to a signal whose frequency varies in proportion to the analog signal amplitude. This signal is then used to modulate the carrier frequency of an FM transmitter coupled to an ac power line. The modulation signal frequency range is selected to be within the response band of the FM transmitter. The FM modulated carrier signal is received by an FM receiver coupled to the ac power line, demodulated and the demodulated signal frequency is converted by a frequency-to-voltage converter back to the form of the original low frequency analog input signal. 4 figs.

  5. HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

    SciTech Connect (OSTI)

    Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R

    1982-09-01T23:59:59.000Z

    Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.

  6. HTS Conductor Design Issues Including Quench and Stability,

    E-Print Network [OSTI]

    HTS Conductor Design Issues Including Quench and Stability, AC Losses, and Fault Currents M. J objective and technical approach · The purpose of this collaborative R&D project is an investigation of HTS conductor design optimization with emphasis on stability and protection issues for YBCO wires and coils

  7. Low power, scalable multichannel high voltage controller

    DOE Patents [OSTI]

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

    2008-03-25T23:59:59.000Z

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

  8. Low power, scalable multichannel high voltage controller

    DOE Patents [OSTI]

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

    2006-03-14T23:59:59.000Z

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

  9. Dynamic Voltage Regulation Using Distributed Energy Resources

    SciTech Connect (OSTI)

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

    2007-01-01T23:59:59.000Z

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

  10. Voltage Vehicles | 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 YouKizildere IRaghuraji Agro IndustriesTown of Ladoga,planningFlowmeterUtah: Energydba Vision Motor CorpEIAVogtVoltage

  11. Commercialization of Medium Voltage HTS Triax TM Cable Systems

    SciTech Connect (OSTI)

    Knoll, David

    2012-12-31T23:59:59.000Z

    The original project scope that was established in 2007 aimed to install a 1,700 meter (1.1 mile) medium voltage HTS Triax{TM} cable system into the utility grid in New Orleans, LA. In 2010, however, the utility partner withdrew from the project, so the 1,700 meter cable installation was cancelled and the scope of work was reduced. The work then concentrated on the specific barriers to commercialization of HTS cable technology. The modified scope included long-length HTS cable design and testing, high voltage factory test development, optimized cooling system development, and HTS cable life-cycle analysis. In 2012, Southwire again analyzed the market for HTS cables and deemed the near term market acceptance to be low. The scope of work was further reduced to the completion of tasks already started and to testing of the existing HTS cable system in Columbus, OH. The work completed under the project included: • Long-length cable modeling and analysis • HTS wire evaluation and testing • Cable testing for AC losses • Optimized cooling system design • Life cycle testing of the HTS cable in Columbus, OH • Project management. The 200 meter long HTS Triax{TM} cable in Columbus, OH was incorporated into the project under the initial scope changes as a test bed for life cycle testing as well as the site for an optimized HTS cable cooling system. The Columbus cable utilizes the HTS TriaxTM design, so it provided an economical tool for these of the project tasks.

  12. Accepted for publication at IEEE Trans. Power Systems, July 2000, paper No. PE-006PRS (08-2000). Time Dependence of Controls to Avoid Voltage Collapse

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    system model. Keywords: Power system control, voltage stability, voltage collapse, reactive power1 Accepted for publication at IEEE Trans. Power Systems, July 2000, paper No. PE-006PRS (08 is first presented with the help of a simple test system. The time dependence of the control actions

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

    SciTech Connect (OSTI)

    Wohlgemuth, J.

    2013-05-01T23:59:59.000Z

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

  14. Sacramento Area Voltage Support - Environment - Sierra Nevada...

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

    (SMUD), Roseville Electric (Roseville), and the California Independent System Operator (ISO) grid. Western prepared a Sacramento Voltage Support (SVS) Draft Environmental Impact...

  15. Validation of a STATCOM Transient Stability Model through Small-Disturbance Stability Studies

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    . INTRODUCTION Power system operators are constantly striving to keep power networks secure by guaranteeing models. For instance, the TS models proposed for a series of Flexible AC Transmission Systems (FACTS used in small-disturbance stability studies of large, interconnected power grids as well as microgrids

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

    E-Print Network [OSTI]

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

  17. The Constant Voltage Transformer (CVT) for Mitigating Effects of Voltage Sags on Industrial Equipment

    E-Print Network [OSTI]

    Ferraro, R. J.; Osborne, R.; Stephens, R.

    ) an increase in loads that use power electronics in some type of power conversion configuration [1][2]. This paper presents applications of the constant-voltage transformer (CVT) for mitigating the effects of electric service voltage sags on industrial...

  18. Ac-Ac Dual Active Bridge Converter for Solid State Transformer

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    flow. The advantages of direct ac-ac conversion include fewer power conversion stages and minimized single-stage direct ac-ac power conversion to an SST. Fewer conversion stages reduce conduction loss) converter in direct ac-ac power conversion. Like a DAB converter as dc-dc power supply in [5] and [6

  19. Optimal Power Flow Incorporating Voltage Collapse Constraints

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    Optimal Power Flow Incorporating Voltage Collapse Constraints William Rosehart Claudio Ca on the current operating con- ditions is presented. Second, an Optimal Power Flow formulation that incorporates: Voltage Collapse, Optimal Power Flow, Bifur- cations. I. Introduction As open-access market principles

  20. Voltage regulation in linear induction accelerators

    DOE Patents [OSTI]

    Parsons, William M. (Santa Fe, NM)

    1992-01-01T23:59:59.000Z

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

  1. Voltage regulation in linear induction accelerators

    DOE Patents [OSTI]

    Parsons, W.M.

    1992-12-29T23:59:59.000Z

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

  2. REDUCTION OF VOLTAGE VIOLATIONS FROM EMBEDDED GENERATORS

    E-Print Network [OSTI]

    Harrison, Gareth

    , and on the active and reactive power exported from the local busbar. Line power flow is reduced by local demand be used to attempt to maintain voltage. Recent work has considered the use of embedded diesel generators) If the EG tried to meet an excessive demand for reactive power, as voltage continued to fall, the AVR could

  3. Probing spin entanglement by gate-voltage-controlled interference of current correlation in quantum spin Hall insulators

    E-Print Network [OSTI]

    Wei Chen; Z. D. Wang; R. Shen; D. Y. Xing

    2014-05-21T23:59:59.000Z

    We propose an entanglement detector composed of two quantum spin Hall insulators and a side gate deposited on one of the edge channels. For an ac gate voltage, the differential noise contributed from the entangled electron pairs exhibits the nontrivial step structures, from which the spin entanglement concurrence can be easily obtained. The possible spin dephasing effects in the quantum spin Hall insulators are also included.

  4. Electric field and losses at AC self field mode in MF composites

    SciTech Connect (OSTI)

    Fukui, S.; Hlasnik, I.; Tsukamoto, O.; Amemiya, N. (Yokohama National Univ. (Japan)); Polak, M.; Kottman, P. (Slovak Academy of Science, Bratislava (Slovakia). Inst. of Electrical Engineering)

    1994-07-01T23:59:59.000Z

    Studies of the current-voltage characteristics of typical superconducting wires under static and dynamic conditions up to 50 Hz frequency have revealed much higher instantaneous local loss power densities in an external DC magnetic field than those which occur by magnetization in a transverse AC magnetic field. In this paper, the measured loss characteristics are compared with theoretical ones derived from the critical state model, and the self field AC loss are also estimated. Possible errors that can result by applying the critical state model are discussed.

  5. Flexible method for monitoring fuel cell voltage

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

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

  6. Corona and Motor Voltage Interim Report

    SciTech Connect (OSTI)

    Hsu, J.S.

    2005-05-06T23:59:59.000Z

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

  7. ACS | 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-fTriWildcat 1 WindtheEnergySulfonate as aAAB AsiaABEEolicaSection Logo:ACS

  8. ACS Symposium Program

    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. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See the EnergyTAMANG, APIL. A Multilevel224th ACS

  9. Wide-range voltage modulation

    SciTech Connect (OSTI)

    Rust, K.R.; Wilson, J.M.

    1992-06-01T23:59:59.000Z

    The Superconducting Super Collider`s Medium Energy Booster Abort (MEBA) kicker modulator will supply a current pulse to the abort magnets which deflect the proton beam from the MEB ring into a designated beam stop. The abort kicker will be used extensively during testing of the Low Energy Booster (LEB) and the MEB rings. When the Collider is in full operation, the MEBA kicker modulator will abort the MEB beam in the event of a malfunction during the filling process. The modulator must generate a 14-{mu}s wide pulse with a rise time of less than 1 {mu}s, including the delay and jitter times. It must also be able to deliver a current pulse to the magnet proportional to the beam energy at any time during ramp-up of the accelerator. Tracking the beam energy, which increases from 12 GeV at injection to 200 GeV at extraction, requires the modulator to operate over a wide range of voltages (4 kV to 80 kV). A vacuum spark gap and a thyratron have been chosen for test and evaluation as candidate switches for the abort modulator. Modulator design, switching time delay, jitter and pre-fire data are presented.

  10. PH-315 A. La Rosa VOLTAGE-CONTROLLED OSCILLATOR

    E-Print Network [OSTI]

    PH-315 A. La Rosa VOLTAGE-CONTROLLED OSCILLATOR 1. PURPOSE: An integrator and a Schmitt Trigger voltage; hence its name "voltage-controlled oscillator." 2. VOLTAGE-CONTROLLED OSCILLATOR Figure 1 shows voltage. An unusual feature of the circuit is its operation using a single positive supply.1 #12;- + 50k V

  11. Application of GTO voltage source inverter in a hybrid HVDC link

    SciTech Connect (OSTI)

    Zhao, Z.; Iravani, M.R. (Univ. of Toronto, Ontario (Canada). Dept. of Electrical Engineering)

    1994-01-01T23:59:59.000Z

    This paper investigates the application of a GTO voltage source inverter in a two-terminal HVdc link, which is fed at the sending end by a line-commutated rectifier. This type of HVdc link may be applied when power transfer is predominantly unidirectional, especially to a weak ac system. The investigations are based on analytical studies and digital time-domain simulations with the Electro-Magnetic Transient program for DC systems (EMTDC). Control method and protection requirements are studied, together with dynamic behavior of the system following disturbances, e.g. dc fault, ac fault, start-up etc. The studies are aimed at exhibiting the technical feasibility of the proposed HVdc scheme. Need for further studies is pointed out when necessary.

  12. Electro-optical voltage sensor head

    DOE Patents [OSTI]

    Woods, Gregory K. (Idaho Falls, ID)

    1998-01-01T23:59:59.000Z

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

  13. Voltage instability: Mechanisms and control strategies

    SciTech Connect (OSTI)

    Vu, K.T. [ABB Transmission Technology Inst., Raleigh, NC (United States). Power Systems Center] [ABB Transmission Technology Inst., Raleigh, NC (United States). Power Systems Center; Liu, C.C. [Univ. of Washington, Seattle, WA (United States)] [Univ. of Washington, Seattle, WA (United States); Taylor, C.W. [Bonneville Power Administration, Portland, OR (United States)] [Bonneville Power Administration, Portland, OR (United States); Jimma, K.M. [Puget Sound Power and Light Co., Bellevue, WA (United States)] [Puget Sound Power and Light Co., Bellevue, WA (United States)

    1995-11-01T23:59:59.000Z

    One of the main objectives in operating an electric power system is to maintain a proper voltage level throughout a system. Failure to do so can lead to equipment damage and blackout. The article discusses the nonlinear aspects of power systems, with emphasis on voltage instability. It provides an overview of the state-of-the-art on the analysis and control of voltage dynamics. Dynamic mechanisms and control strategies are discussed from both theoretical and practical standpoints. The remedial controls implemented in the Puget Sound region of the Pacific Northwest indicate the practical significance of the research area.

  14. AC system stability analysis and assessment for Shipboard Power Systems 

    E-Print Network [OSTI]

    Qi, Li

    2006-04-12T23:59:59.000Z

    The electric power systems in U.S. Navy ships supply energy to sophisticated systems for weapons, communications, navigation and operation. The reliability and survivability of a Shipboard Power System (SPS) are critical ...

  15. AC system stability analysis and assessment for Shipboard Power Systems

    E-Print Network [OSTI]

    Qi, Li

    2006-04-12T23:59:59.000Z

    The electric power systems in U.S. Navy ships supply energy to sophisticated systems for weapons, communications, navigation and operation. The reliability and survivability of a Shipboard Power System (SPS) are critical to the mission of a Navy...

  16. Modular high voltage power supply for chemical analysis

    DOE Patents [OSTI]

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

    2010-05-04T23:59:59.000Z

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

  17. Modular high voltage power supply for chemical analysis

    SciTech Connect (OSTI)

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

    2007-01-09T23:59:59.000Z

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

  18. Modular high voltage power supply for chemical analysis

    SciTech Connect (OSTI)

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

    2008-07-15T23:59:59.000Z

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

  19. Soft-Switching High-Frequency AC-Link Universal Power Converters with Galvanic Isolation

    E-Print Network [OSTI]

    Amirabadi, Mahshid

    2013-08-07T23:59:59.000Z

    ) direct drive using wound-field synchronous generator [10]. ...................................................................................................... 6 Figure 6 Dc-dc buck-boost converter: (a) configuration, (b) energizing mode (mode 1), (c...) de-energizing mode (mode 2), (d) voltage and current waveforms ........ 12 Figure 7 An alternative representation of the dc-dc buck-boost converter ...................... 13 Figure 8 Dc-dc ac-link buck-boost converter: configuration, behavior...

  20. Voltage Management of Networks with Distributed Generation. 

    E-Print Network [OSTI]

    O'Donnell, James

    2008-01-01T23:59:59.000Z

    At present there is much debate about the impacts and benefits of increasing the amount of generation connected to the low voltage areas of the electricity distribution network. The UK government is under political ...

  1. Electro-optic high voltage sensor

    DOE Patents [OSTI]

    Davidson, James R.; Seifert, Gary D.

    2003-09-16T23:59:59.000Z

    A small sized electro-optic voltage sensor capable of accurate measurement of high voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation. A polarization beam displacer separates the input beam into two beams with orthogonal linear polarizations and causes one linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels effect elliptically polarizes the beam as it travels through the crystal. A reflector redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization. The system may include a detector for converting the output beams into electrical signals and a signal processor for determining the voltage based on an analysis of the output beams.

  2. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1987-11-17T23:59:59.000Z

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

  3. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1987-01-01T23:59:59.000Z

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

  4. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1985-08-05T23:59:59.000Z

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

  5. automatic regulator voltage: Topics by E-print Network

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

    Rouzbahan 2013-01-01 12 Optimal Distributed Voltage Regulation in Power Distribution Networks CERN Preprints Summary: In this paper, we address the problem of voltage...

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

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

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

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

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

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

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

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

    Voltage Fade Issue with Lithium-Manganese-Rich Oxide Cathode Materials Addressing the Voltage Fade Issue with Lithium-Manganese-Rich Oxide Cathode Materials 2012 DOE Hydrogen and...

  9. Summary of Papers 1. P. Sauer and M. Pai, "Power System SteadyState Stability and the Load Flow Jacobian," IEEE

    E-Print Network [OSTI]

    McCalley, James D.

    Summary of Papers 1. P. Sauer and M. Pai, "Power System SteadyState Stability and the Load Flow, "The Continuation Power Flow: A Tool for SteadyState Voltage Stability Analysis," IEEE Transactions of the system to maintain adequate and controllable voltage levels at all system load buses. The main concern

  10. Constant voltage electro-slag remelting control

    DOE Patents [OSTI]

    Schlienger, M.E.

    1996-10-22T23:59:59.000Z

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

  11. Group 3: Humidity, Temperature, and Voltage

    Broader source: Energy.gov [DOE]

    This PowerPoint presentation, focused on humidity, temperature and voltage testing, was originally presented by John Wohlgemuth at the NREL 2013 PV Module Reliability Workshop on Feb. 26-27, 2013 in Denver, CO. It summarizes the activities of a working group chartered to develop accelerated stress tests that can be used as comparative predictors of module life versus stresses associated with humidity, temperature and voltage.

  12. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

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

    1996-01-01T23:59:59.000Z

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

  13. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, G.J.; Roose, L.D.

    1996-04-23T23:59:59.000Z

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed. 13 figs.

  14. Mitigating Voltage Fade in Cathode Materials by Improving the Atomic Level Uniformity of Elemental Distribution

    SciTech Connect (OSTI)

    Zheng, Jianming; Gu, Meng; Genc, Arda; Xiao, Jie; Xu, Pinghong; Chen, Xilin; Zhu, Zihua; Zhao, Wenbo; Pullan, Lee; Wang, Chong M.; Zhang, Jiguang

    2014-04-07T23:59:59.000Z

    Li-rich and Mn-rich (LMR) layered structured materials are very promising cathodes for high-energy lithium-ion batteries. However, their fundamental structure and voltage fading mechanisms are far from being well understood. Here we report the first evidence on the reduced voltage and energy fade of LMR cathode by improving the atomic level spatial distribution of the chemical species. LMR cathode (Li[Li0.2Ni0.2M0.6]O2) prepared by co-precipitation and sol-gel methods are dominated by R-3m phase and show significant Ni-segregation at the surface of the particles. They exhibit large voltage-fade and fast capacity degradation. In contrast, LMR cathode prepared by hydrothermal assisted method is dominated by C2/m phase and minimal Ni-segregation. It also demonstrates much smaller voltage-fade and excellent capacity retention. The fundamental correlation between the atomic level spatial distribution of the chemical species and the functional stability of the materials found in this work also guide the design of other functional materials with enhanced stabilities.

  15. Abstract--This paper reports a method to evaluate composite power system reliability indices incorporating the voltage

    E-Print Network [OSTI]

    3 Abstract--This paper reports a method to evaluate composite power system reliability indices power flow (OPF) computation algorithm, considering the steady state voltage stability margin constraint In the deregulated power systems, reliability evaluation encompassing the system security features has come

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

    E-Print Network [OSTI]

    Boyer, Edmond

    to development of new ecologically favorable methods of decontamination and treatment of waste (household of the most promising directions. The method of plasma pyrolysis and gasification, where at waste processing generation. A high- temperature mineralization is another modern method of toxic and hazardous waste

  17. A nonlinear robust HVDC control for a parallel AC/DC power system

    E-Print Network [OSTI]

    Qu, Zhihua

    A nonlinear robust HVDC control for a parallel AC/DC power system Hongzhi Cai a , Zhihua Qu b. Keywords: Robust control; HVDC; Power system; Stability; Lyapunov method 1. Introduction It has been recognized that, through an HVDC transmission line, fast electronic control can be applied on the DC power

  18. AVTA: Aerovironment AC Level 2 Charging System Testing Results...

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

    Aerovironment AC Level 2 - February 2012 More Documents & Publications AVTA: Clipper Creek AC Level 2 Charging System Testing Results AVTA: Eaton AC Level 2 Charging System...

  19. Distribution System Voltage Performance Analysis for High-Penetration Photovoltaics

    SciTech Connect (OSTI)

    Liu, E.; Bebic, J.

    2008-02-01T23:59:59.000Z

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

  20. Chapter 17. High-Voltage Systems and Dielectric Materials High-Voltage Systems and Dielectric Materials

    E-Print Network [OSTI]

    -Voltage Systems and Dielectric Materials 17-2 RLE Progress Report 152 provides very useful insight into pre-breakdown in high voltage conduction and breakdown phenomena. 1. Mechanisms Behind Positive Streamers and Their Distinct Propagation Modes in Transformer Oil Sponsors This work was supported by ABB Corporate Research

  1. A Charge Pump that Generates Negative High Voltage with Variable Voltage , Eugene Ivanova,

    E-Print Network [OSTI]

    Ayers, Joseph

    A Charge Pump that Generates Negative High Voltage with Variable Voltage Gain Jun Zhaob, , Eugene, Massachusetts 02115, U.S.A. Abstract A cross-coupled structure based charge pump that generates negative high. The proposed negative charge pump is designed to deliver 40 uA with a wide supply range from 2.5V to 5.5V using

  2. 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

  3. Electronic circuit for measuring series connected electrochemical cell voltages

    DOE Patents [OSTI]

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

    2000-01-01T23:59:59.000Z

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

  4. System specification for the plutonium stabilization and packaging system

    SciTech Connect (OSTI)

    NONE

    1996-07-01T23:59:59.000Z

    This document describes functional design requirements for the Plutonium Stabilization and Packaging System (Pu SPS), as required by DOE contract DE-AC03-96SF20948 through contract modification 9 for equipment in Building 707 at Rocky Flats Environmental Technology Site (RFETS).

  5. STABILITY OF PRODUCTION-INVENTORY CONTROL SYSTEMS CONSIDERING INVENTORY SHORTAGES

    E-Print Network [OSTI]

    Venkateswaran, Jayendran

    STABILITY OF PRODUCTION-INVENTORY CONTROL SYSTEMS CONSIDERING INVENTORY SHORTAGES Jayendran@iitb.ac.in) Extended Abstract The modelling and analysis of the production-inventory control systems of manufacturing in inventory levels, production releases, stock-outs; and ultimately affecting the profit of the firm

  6. Compact high voltage solid state switch

    DOE Patents [OSTI]

    Glidden, Steven C.

    2003-09-23T23:59:59.000Z

    A compact, solid state, high voltage switch capable of high conduction current with a high rate of current risetime (high di/dt) that can be used to replace thyratrons in existing and new applications. The switch has multiple thyristors packaged in a single enclosure. Each thyristor has its own gate drive circuit that circuit obtains its energy from the energy that is being switched in the main circuit. The gate drives are triggered with a low voltage, low current pulse isolated by a small inexpensive transformer. The gate circuits can also be triggered with an optical signal, eliminating the trigger transformer altogether. This approach makes it easier to connect many thyristors in series to obtain the hold off voltages of greater than 80 kV.

  7. SiGe BiCMOS Topologies for Low-Voltage Millimeter-Wave Voltage Controlled Oscillators and Frequency Dividers

    E-Print Network [OSTI]

    Voinigescu, Sorin Petre

    SiGe BiCMOS Topologies for Low-Voltage Millimeter-Wave Voltage Controlled Oscillators and Frequency-mail: tod@eecg.toronto.edu Abstract -- BiCMOS topologies for mm-wave voltage- controlled oscillators operation for mm-wave applications. II. BICMOS VOLTAGE-CONTROLLED OSCILLATOR The Colpitts topology

  8. 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.

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

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

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

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

    DOE Patents [OSTI]

    Woods, G.K.; Renak, T.W.

    1999-04-06T23:59:59.000Z

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages is disclosed. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam`s polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured. 18 figs.

  11. Exchange 13/14 www.ed.ac.uk

    E-Print Network [OSTI]

    Herrmann, Samuel

    : Studyabroad@ed.ac.uk Outgoing Students: Sharyn Bennet Email: Erasmus.outgoing@ed.ac.uk Head of Study Abroad

  12. Voltage control on a train system

    DOE Patents [OSTI]

    Gordon, Susanna P.; Evans, John A.

    2004-01-20T23:59:59.000Z

    The present invention provides methods for preventing low train voltages and managing interference, thereby improving the efficiency, reliability, and passenger comfort associated with commuter trains. An algorithm implementing neural network technology is used to predict low voltages before they occur. Once voltages are predicted, then multiple trains can be controlled to prevent low voltage events. Further, algorithms for managing inference are presented in the present invention. Different types of interference problems are addressed in the present invention such as "Interference During Acceleration", "Interference Near Station Stops", and "Interference During Delay Recovery." Managing such interference avoids unnecessary brake/acceleration cycles during acceleration, immediately before station stops, and after substantial delays. Algorithms are demonstrated to avoid oscillatory brake/acceleration cycles due to interference and to smooth the trajectories of closely following trains. This is achieved by maintaining sufficient following distances to avoid unnecessary braking/accelerating. These methods generate smooth train trajectories, making for a more comfortable ride, and improve train motor reliability by avoiding unnecessary mode-changes between propulsion and braking. These algorithms can also have a favorable impact on traction power system requirements and energy consumption.

  13. High Voltage Electrolyte for Lithium Batteries

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

    Argonne's Fluorinated Compounds as High Voltage Electrolytes (HVEs) O O O O O O EC EMC O O O CF CF 3 CF 3 O O O CF 3 F 2 HC C F 2 O F 2 C CF 2 H 6 Code Name Chemical...

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

    SciTech Connect (OSTI)

    Wohlgemuth, J.

    2013-09-01T23:59:59.000Z

    This is a summary of the work of Group 3 of the International PV QA Task Force. Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.

  15. ACS SYMPOSIUM SERIES 966 Rational Environmental

    E-Print Network [OSTI]

    Hammock, Bruce D.

    ACS SYMPOSIUM SERIES 966 Rational Environmental Management of Agrochemicals Risk Assessment-Bayo, Editor Chiha University Sponsored by the ACS Division of Agrochemicals American Chemical Society of agrochemicals : risk assessment, monitoring, and remedial action / Ivan R. Kennedy, editor. ..[et al

  16. Understanding Pound-Drever-Hall locking using voltage controlled radio-frequency oscillators: An undergraduate experiment

    E-Print Network [OSTI]

    Liekhus-Schmaltz, C E

    2011-01-01T23:59:59.000Z

    A senior undergraduate experiment has been developed for learning about frequency stabilization techniques using radio-frequency electronics. The primary objective is to frequency stabilize a voltage controlled oscillator to a cavity resonance at 800 MHz using the Pound-Drever-Hall scheme. This technique is commonly applied to stabilize lasers at optical frequencies, but by using radio-frequency equipment exclusively it is possible to systematically study various aspects of the technique more thoroughly, inexpensively, and free from eye hazards. Students also learn about modular radio-frequency electronics and basic feedback control loops. By varying the temperature of the resonator, the students may determine the thermal expansion coefficients of copper, aluminum, and super invar.

  17. Electro-optic high voltage sensor

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

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

  18. Distribution System Voltage Regulation by Distributed Energy Resources

    SciTech Connect (OSTI)

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

    2014-01-01T23:59:59.000Z

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

  19. Multilevel Cascade H-bridge Inverter DC Voltage Estimation Through Output Voltage Sensing

    E-Print Network [OSTI]

    Tolbert, Leon M.

    system as the inverter power supply may vary. For example, interface of solar panels or fuel cell. The output voltage is then processed by a DSP unit that uses the signals that command the switches

  20. Web https://ms.ecc.utokyo.ac.jp/ (POP) popd.ecc.utokyo.ac.jp

    E-Print Network [OSTI]

    Katsumoto, Shingo

    ; 2 233 #12; (POP) popd.ecc.utokyo.ac.jp SSL995 (IMAP) imapd.ecc.utokyo.ac.jp SSL993 sbmsd.ecc.utokyo.ac.jp SSL465 @ 1. MailHosting D 2. 200MB 400MB 3. POPIMAP IMAPPOP 200MB400MB 3 233 #12;Thunderbird 3 4 233 #12; (POP) popd.ecc.utokyo.ac.jp SSL995 (IMAP) imapd.ecc.utokyo.ac.jp SSL993

  1. A robust coordinated control scheme for HVDC transmission with parallel AC systems

    SciTech Connect (OSTI)

    To, K.W.V.; David, A.K. (Hong Kong Polytechnic (Hong Kong). Dept. of Electrical Engineering); Hammad, A.E. (N.E. Swiss Power Co., Baden (Switzerland))

    1994-07-01T23:59:59.000Z

    This paper introduces a practical control philosophy for HVDC transmission in parallel operation to an AC system with particular emphasis on coordination of both transient and dynamic stability. Systematic development of the control scheme on the basis of on-line identification, optimal control and rule-based bang-optimal coordination principles is presented. Verification tests of the scheme on a physical HVDC/AC system simulator show that the simple control computer algorithm is practical and robust. The controller can successfully distinguish between different system fault severities and adapts its output signals to provide maximum synchronizing torque and ensure optimal damping of power oscillations.

  2. Reactive Support and Voltage Control Service: Key Issues and Challenges

    E-Print Network [OSTI]

    Gross, George

    reactive support and voltage control services. Keywords ­ Competitive Electricity Markets, Reactive PowerReactive Support and Voltage Control Service: Key Issues and Challenges George Gross^, Paolo Marannino° and Gianfranco Chicco* ^ Department of Electrical and Computer Engineering, University

  3. Electrical system architecture having high voltage bus

    DOE Patents [OSTI]

    Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

    2011-03-22T23:59:59.000Z

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  4. Low Voltage White Phosphorescent OLED Achievements

    Broader source: Energy.gov [DOE]

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

  5. High Voltage Electrolyte for Lithium Batteries

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

    5.0E-04 1.0E-03 2 2.2 2.4 2.6 2.8 Voltage (V) dQdV (AhV) 1 st Charge 1.2M LiPF 6 ECEMC 37 1 st Charge 1.0M LiPF 6 TMS1NM3 55 with 2% and 4% VC 1 st Charge 1.0M LiPF 6 TMS...

  6. Electrostatically screened, voltage-controlled electrostatic chuck

    DOE Patents [OSTI]

    Klebanoff, Leonard Elliott (San Ramon, CA)

    2001-01-01T23:59:59.000Z

    Employing an electrostatically screened, voltage-controlled electrostatic chuck particularly suited for holding wafers and masks in sub-atmospheric operations will significantly reduce the likelihood of contaminant deposition on the substrates. The electrostatic chuck includes (1) an insulator block having a outer perimeter and a planar surface adapted to support the substrate and comprising at least one electrode (typically a pair of electrodes that are embedded in the insulator block), (2) a source of voltage that is connected to the at least one electrode, (3) a support base to which the insulator block is attached, and (4) a primary electrostatic shield ring member that is positioned around the outer perimeter of the insulator block. The electrostatic chuck permits control of the voltage of the lithographic substrate; in addition, it provides electrostatic shielding of the stray electric fields issuing from the sides of the electrostatic chuck. The shielding effectively prevents electric fields from wrapping around to the upper or front surface of the substrate, thereby eliminating electrostatic particle deposition.

  7. Electro-optic voltage sensor head

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

  8. Electro-optic voltage sensor head

    DOE Patents [OSTI]

    Crawford, T.M.; Davidson, J.R.; Woods, G.K.

    1999-08-17T23:59:59.000Z

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

  9. Loop-voltage tomography in tokamaks using transient synchrotron radiation

    SciTech Connect (OSTI)

    Fisch, N.J.; Kritz, A.H. (Princeton Univ., NJ (USA). Plasma Physics Lab.; Hunter Coll., New York, NY (USA). Dept. of Physics)

    1989-07-01T23:59:59.000Z

    The loop voltage in tokamaks is particularly difficult to measure anywhere but at the plasma periphery. A brief, deliberate, perturbation of hot plasma electrons, however, produces a transient radiation response that is sensitive to this voltage. We investigate how such a radiation response can be used to diagnose the loop voltage. 24 refs., 6 figs.

  10. Characterized ideal LC circuit Charge, current and voltage vary sinusoidally

    E-Print Network [OSTI]

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    resistance to LC circuit Oscillations become damped Charge, current and voltage still vary sinusoidally Oscillations Draw phasors for voltages of R, C and L at same time t Orient VR, VL, & VC phasors relativeReview Characterized ideal LC circuit Charge, current and voltage vary sinusoidally Added

  11. Accurately measuring current-voltage characteristics of tunnel diodes

    E-Print Network [OSTI]

    Bao, Mingqiang; Wang, Kang L

    2006-01-01T23:59:59.000Z

    of the bias voltage range of oscillations in the I–V curve.and the bias voltage range of oscillation in the I–V curve.or to know the exact voltage range of oscillation in the I–V

  12. DCS1800/WCDMA ADAPTIVE VOLTAGE-CONTROLLED OSCILLATOR

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    DCS1800/WCDMA ADAPTIVE VOLTAGE-CONTROLLED OSCILLATOR Aleksandar Tasiü, Wouter A. Serdijn and John R, an adaptive 2G/3G voltage-controlled oscillator (VCO) is described in this paper. For the DCS1800 operation with this reasoning, an adaptive 2G/3G voltage- controlled oscillator, meant for a dual-standard adaptive front

  13. Selective compensation of voltage harmonics in grid-connected microgrids

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    1 Selective compensation of voltage harmonics in grid-connected microgrids Mehdi Savaghebia , Juan is proposed for selective compensation of main voltage harmonics in a grid- connected microgrid. The aim level. Keywords Distributed Generator (DG); microgrid; grid-connected; voltage harmonics compensation. 1

  14. Structural Optimization of High Voltage Transmission Line Towers considering

    E-Print Network [OSTI]

    Colominas, Ignasi

    Structural Optimization of High Voltage Transmission Line Towers considering Continuum and Discrete/or to common designs largely repeated (e.g. automotive compo- nents), and high voltage transmission towers can than conventional designs of high voltage transmission line towers. The optimization model proposed

  15. System for increasing corona inception voltage of insulating oils

    DOE Patents [OSTI]

    Rohwein, G.J.

    1998-05-19T23:59:59.000Z

    The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil. 5 figs.

  16. Analysis and design of a direct AC to AC matrix converter topology

    E-Print Network [OSTI]

    Choi, Sewan

    1992-01-01T23:59:59.000Z

    - eration. With the advent of the thyristor and more recent devices such as the Metal oxided semiconductor field effect transistor(MOSI'ET), the Insulated gate bipolar transistor(IGBT) and the MOS controlled thyristor(MCT), it has become increas- ingly... commutated devices such as OTO's, IGBT's, IVIOSFET's and MCT's. The principle of forced commutation is used in clirect ac to ac matrix converter which is described in the next section. B. Direct AC to AC Matrix Converter Direct ac to ac matrix converters...

  17. Protecting a HVDC link against accidental isolation from its receiving AC system

    SciTech Connect (OSTI)

    Whitehouse, R.S. (GEC Alsthom Transmission and Distribution Projects Ltd., Stafford (United Kingdom))

    1993-07-01T23:59:59.000Z

    When an HVdc scheme is isolated from its receiving ac system, the inverter may continue to operate, generating its own ac bus voltages; this is defined here as islanding. If islanding is allowed to continue unrestricted, then main circuit components may in some conditions be damaged and it is therefore necessary to provide a suitable protection system. This paper outlines the protection scheme developed for the McNeill Back-to-Back HVdc link in Alberta, Canada, to prevent damage due to islanding while still permitting the link to automatically restart on reclosure of the isolating breaker. Oscillograms showing the protection in operation on both the GEC ALSTHOM HVdc simulator and during tests carried out as part of the commissioning of the McNeill HV dc link are included.

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

    E-Print Network [OSTI]

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

    2014-10-15T23:59:59.000Z

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

  19. Techniques for energy conservation in ac motor-driven systems. Final report

    SciTech Connect (OSTI)

    Mohan, N.

    1981-09-01T23:59:59.000Z

    Techniques for energy conservation of reducing losses in ac motor-driven systems proposed by the technical community in response to surging cost of energy are evaluated and compared. Report objectives are to provide better understanding of underlying principles and to evaluate technical and economic viability of these techniques for various applications. An important aspect considered is the impact on electric utility system in terms of harmonics, power factor of operation, and Electro-Magnetic Interference (EMI). The techniques evaluated are: NASA Power Factor Controller, a simple device for reducing power losses in lightly loaded ac motors; wanlass motor modification, a scheme of reconnecting motor windings with capacitors in series, with the intention of improving the motor efficiencies under all loading conditions; conventional variable frequency solid-state inverters which can control the speed of ac motors by producing adjustable frequency ac voltage, with a significant potential for energy conservation in pumps and air-handling systems; and other variable frequency drives and schemes including cycloconverters, slip-recovery scheme, Exxon Alternating Current Synthesizer, Venturini conversion technique, permanent magnet synchronous motors, and a device called the Phase-Liner. The impact of rapid growth in semiconductors and magnetic materials technologies is also considered.

  20. Study of static reactive power compensators for high-voltage power systems. Final report, May 12, 1981

    SciTech Connect (OSTI)

    Byerly, R.T.; Bennon, R.J.; Taylor, E.R. Jr.; Poznaniak, D.T.

    1981-05-12T23:59:59.000Z

    A general study of the application of static VAR compensators (SVC's) to high-voltage transmission systems has been performed. Considerable emphasis has been placed on improvements to synchronous stability, and it is shown that SVC's can provide significant benefits in terms of damping for unstable modes of oscillation and increases in transient stability limits. This report includes descriptions of static VAR compensators, technical and economic comparisons of different compensators, compensator models for system studies, comprehensive study procedures, study results for two small-scale systems, and guidelines for SVC application.

  1. High voltage power supply. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    NONE

    1996-03-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning high voltage power supply systems and devices. References describe direct and high current power supplies, microprocessor controlled and programmable systems, amplifiers, power supply stabilization, power circuit protection, feedback control, and pulse modulation. Applications cover laser systems, x-ray tubes, electrophoresis, video apparatus, radar and electronic warfare systems, helmet mounted display, and electrosurgery. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  2. High voltage power supply. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    NONE

    1997-06-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning high voltage power supply systems and devices. References describe direct and high current power supplies, microprocessor controlled and programmable systems, amplifiers, power supply stabilization, power circuit protection, feedback control, and pulse modulation. Applications cover laser systems, x-ray tubes, electrophoresis, video apparatus, radar and electronic warfare systems, helmet mounted display, and electrosurgery. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  3. Apparatus for producing voltage and current pulses

    DOE Patents [OSTI]

    Kirbie, Hugh (Los Alamos, NM); Dale, Gregory E. (Los Alamos, NM)

    2010-12-21T23:59:59.000Z

    An apparatus having one or more modular stages for producing voltage and current pulses. Each module includes a diode charging means to charge a capacitive means that stores energy. One or more charging impedance means are connected to the diode charging means to provide a return current pathway. A solid-state switch discharge means, with current interruption capability, is connected to the capacitive means to discharge stored energy. Finally, a control means is provided to command the switching action of the solid-state switch discharge means.

  4. Production of high voltage by ion bombardment

    E-Print Network [OSTI]

    Phinney, Lucas Carter

    2003-01-01T23:59:59.000Z

    . . . 35 FIGIJRE Page 19 I-V curve for the ammeter setup . . 35 20 Diagram of the leakage current test setup . . . . . . 37 21 Voltmeter readings at each high voltage interval . . . . . , 38 CHAPTER I INTRODUCTION Direct energy conversion... streaming into the source There is also a moveable shutter that can stop the beam &om entering the beam line. A Varian VHS-6 diffusion pump is connected at the bottom of the glass cross. Its function is to maintain a vacuum in this part of the accelerator...

  5. Eliminate Voltage Unbalance | 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 YouTube|6721 Federal Register / Vol.6:Energy|Electrifyingof EnergyVoltage

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

    SciTech Connect (OSTI)

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

    1994-02-01T23:59:59.000Z

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

  7. Soft switched high frequency ac-link converter 

    E-Print Network [OSTI]

    Balakrishnan, Anand Kumar

    2009-05-15T23:59:59.000Z

    topology for medium and high power ac-ac, ac-dc and dc-ac applications. An ac-link formed by an inductor-capacitor pair replaces the conventional dc-link. Each leg of the converter is formed by two bidirectional switches. Power transfer from input to output...

  8. IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 55, NO. 4, APRIL 2008 1795 Reaching Criterion of a Three-Phase Voltage-Source

    E-Print Network [OSTI]

    Mazumder, Sudip K.

    is useful for analyzing the global stability of multiphase inverters, potentially leading to advanced of a Three-Phase Voltage-Source Inverter Operating With Passive and Nonlinear Loads and Its Impact on Global functions (CLFs) to analyze the impacts of passive (RL and RC) and nonlinear (diode rectifier) loads

  9. 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.

  10. RHIC spin flipper AC dipole controller

    SciTech Connect (OSTI)

    Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

    2011-03-28T23:59:59.000Z

    The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

  11. Alamouti {yjdong, sky6174}@ccl.snu.ac.kr, jsno@snu.ac.kr, djshin@hanyang.ac.kr

    E-Print Network [OSTI]

    No, Jong-Seon

    @snu.ac.kr, djshin@hanyang.ac.kr (soft-decision-and-forward: SDF) . SDF . Alamouti , . (amplify-and-forward: AF) . , SDF AF . 1. . (source: S-decision-and-forward: SDF) . SDF R S phase, phase 1 phase 2 . Phase 1, S R D , phase 2 R D . , S D

  12. Planar LTCC transformers for high voltage flyback converters.

    SciTech Connect (OSTI)

    Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)

    2007-06-01T23:59:59.000Z

    This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

  13. AC Transit | 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 Future of1 A Strategic Framework for SMRA View from the-1AssessmentAC

  14. ac magnetohydrodynamic microfluidic: Topics by E-print Network

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

    Keywords: electrokinetics, AC Electro-osmosis (ACEO); electrode polarization; microfluidics. 1. Introduction During recent years, AC electro-osmosis (ACEO) has emerged as a...

  15. ac iontophoretic transport: Topics by E-print Network

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

    Keywords: electrokinetics, AC Electro-osmosis (ACEO); electrode polarization; microfluidics. 1. Introduction During recent years, AC electro-osmosis (ACEO) has emerged as a...

  16. AVTA: Clipper Creek AC Level 2 Charging System Testing Results...

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

    electric vehicles. This research was conducted by Idaho National Laboratory. Clipper Creek AC Level 2 - February 2012 More Documents & Publications AVTA: Aerovironment AC Level...

  17. ac traction drives: Topics by E-print Network

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

    Solid State Transformer Engineering Websites Summary: converters as distribution transformers 1. A power electronics-based solid state transformer (SST) providesAc-Ac Dual...

  18. Method for voltage-gated protein fractionation

    DOE Patents [OSTI]

    Hatch, Anson (Tracy, CA); Singh, Anup K. (Danville, CA)

    2012-04-24T23:59:59.000Z

    We report unique findings on the voltage dependence of protein exclusion from the pores of nanoporous polymer exclusion membranes. The pores are small enough that proteins are excluded from passage with low applied electric fields, but increasing the field enables proteins to pass through. The requisite field necessary for a change in exclusion is protein-specific with a correlation to protein size. The field-dependence of exclusion is important to consider for preconcentration applications. The ability to selectively gate proteins at exclusion membranes is also a promising means for manipulating and characterizing proteins. We show that field-gated exclusion can be used to selectively remove proteins from a mixture, or to selectively trap protein at one exclusion membrane in a series.

  19. Voltage controlled MESFET pulse shape generator

    SciTech Connect (OSTI)

    Burkhart, S.C.

    1994-10-26T23:59:59.000Z

    A programmable pulse shape generator capable of producing pulse shapes for Nova and Beamlet has been designed and simulated using the circuit code SPICE. The design utilizes power MESFETS, which are commonly used in microwave amplifiers. The pulse shape is varied by setting a bias voltage on each in a chain of MESFETS with a 200 ps temporal resolution. The electrical pulse then drives an integrated electro-optic modulator similar to what is on Beamlet. Pulse shapes 22 and 25, used on Nova, have been generated by this design. There is no fundamental barrier to making such a pulse generator for use on the National Ignition Facility. In fact, the longer time scales on the NIF pulse will ease the high speed requirements of the pulse shape generator allowing the use of less expensive components. The next step will be to build a prototype circuit for initial testing on Beamlet and Nova.

  20. Submerged Medium Voltage Cable Systems at Nuclear Power Plants...

    Office of Scientific and Technical Information (OSTI)

    Submerged Medium Voltage Cable Systems at Nuclear Power Plants: A Review of Research Efforts Relevant to Aging Mechanisms and Condition Monitoring. Re-direct Destination: In a...

  1. Mitigating Voltage Fade in Cathode Materials by Improving the...

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

    Fade in Cathode Materials by Improving the Atomic Level Uniformity of Elemental Distribution. Mitigating Voltage Fade in Cathode Materials by Improving the Atomic Level...

  2. Nanoscale Morphological and Chemical Changes of High Voltage...

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

    Nanoscale Morphological and Chemical Changes of High Voltage Lithium-Manganese Rich NMC Composite Cathodes with Cycling Friday, August 29, 2014 Renewable energy is critical for the...

  3. active capacitive voltage: Topics by E-print Network

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

    Khoman 5 Discrete Steps in the Capacitance-Voltage Characteristics of GaInNGaN Light Emitting Diode Structures Materials Science Websites Summary: Discrete Steps in the...

  4. Sharp interface and voltage conservation in the ... - Purdue University

    E-Print Network [OSTI]

    2007-07-14T23:59:59.000Z

    electrical wave is anisotropic, and cardiac tissue is made up of cells with heteroge- ... fact that voltage gain or loss due to numerical inaccuracies in the spatial ...

  5. 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.

  6. auxiliary voltage converter: Topics by E-print Network

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

    Voltage Switching inverter working at 20 kHz and an output stage (high frequency transformers, Schottky rectifi ers and output filter... Jrgensen, H E; Dupaquier, A;...

  7. Electrochemical Characterization of Voltage Fade in LMR-NMC cells

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

    the extent of Voltage Fade December 2012 * Establish baseline data on standard materials to facilitate comparison of various datasets March 2013 * Obtain data to determine...

  8. Electrochemical Characterization of Voltage Fade in LMR-NMC cells...

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

    Electrochemical Characterization of Voltage Fade in LMR-NMC cells 2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer...

  9. www.accommodation.salford.ac.uk Accommodation

    E-Print Network [OSTI]

    Romano, Daniela

    sets out the main elements of good management practice. It covers health and safety, maintenancewww.accommodation.salford.ac.uk Accommodation Guide to University and University partner accommodation #12;32 www.accommodation.salford.ac.ukA guide to University and Partner accommodation Welcome

  10. (5202) e-mail: takasaki.midori@ocha.ac.jp (5201) e-mail: iwasaki.ogihara.chizuru@ocha.ac.jp

    E-Print Network [OSTI]

    Matsuzaki, Katsuhiko

    .chika@ocha.ac.jp = (5215) e-mail: schwartz.laure@ocha.ac.jp (5182) e-mail: kanda.yutsuki@ocha.ac.jp (5181) e

  11. Partial Feedback Linearizing Controller Design for a 1 DSTATCOM to Enhance Voltage Stability of

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    to extract maximum power [8]. Moreover, if a wind generator is connected to the distribution network as DG

  12. Impact of Cyber Attacks on Transient Stability of Smart Grids with Voltage Support Devices

    E-Print Network [OSTI]

    Kundur, Deepa

    , Salman Mashayekh, Karen L. Butler-Purry Electrical and Computer Engineering Department Texas A&M University College Station, TX, USA {boboychn, s.mashayekh, klbutler}@tamu.edu Deepa Kundur Electrical. INTRODUCTION In modern power systems, the increasing demand for reliable energy and integration of advanced

  13. Impact of Wind Power Plants on Voltage and Transient Stability of Power Systems

    SciTech Connect (OSTI)

    Muljadi, E.; Nguyen, Tony B.; Pai, M. A.

    2008-09-30T23:59:59.000Z

    A standard three-machine, nine-bus wind power system is studied and augmented by a radially connected wind power plant that contains 22 wind turbine generators.

  14. An improved voltage control on large-scale power system

    SciTech Connect (OSTI)

    Vu, H.; Pruvot, P.; Launay, C.; Harmand, Y. [Electricite de France, Clamart (France). Study and Research Div.] [Electricite de France, Clamart (France). Study and Research Div.

    1996-08-01T23:59:59.000Z

    To achieve a better voltage-var control in the electric power transmission system, different facilities are used. Generators are equipped with automatic voltage regulators to cope with sudden and random changes voltage caused by natural load fluctuations or failures. Other devices like capacitors, inductors, transformers with on load tap changers are installed on the network. Faced with the evolution of the network and operating conditions, electricity utilities are more and more interested in overall and coherent control systems, automatic or not. These systems are expected to coordinate the actions of local facilities for a better voltage control (more stable and faster reaction) inside different areas of the network in case of greater voltage and var variations. They affords besides a better use of existing reactive resources. Also, installation of new devices can be avoided allowing economy of investment. With this frame of mind, EDF has designed a system called Co-ordinated Secondary Voltage Control (CSVC). It`s an automatic closed loop system with a dynamic of a few minutes. It takes into account the network conditions (topology, loads), the voltage limits and the generator operating constraints. This paper presents recent improvements which allow the CSVC to control the voltage profile and different kinds of reactive means on a large-scale power system. Furthermore, this paper presents solution to spread out investment costs over several years, considering a deployment gradually extended.

  15. Measurement of high voltage using Rutherford backscattering spectrometry

    E-Print Network [OSTI]

    Abrego, Celestino Pete

    2007-04-25T23:59:59.000Z

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

  16. A LOW-VOLTAGE TEMPERATURE-STABLE MICROMECHANICAL PIEZOELECTRIC OSCILLATOR

    E-Print Network [OSTI]

    Ayazi, Farrokh

    A LOW-VOLTAGE TEMPERATURE-STABLE MICROMECHANICAL PIEZOELECTRIC OSCILLATOR Reza Abdolvand, Hossein polarization voltages (5-20V) for operation, which complicates the design of the oscillator circuit in today reference oscillator that utilizes a temperature-stable thin- film piezoelectric-on-silicon resonator

  17. Control and Protection Cooperation Strategy for Voltage Instability

    E-Print Network [OSTI]

    Chen, Zhe

    to be transmitted in the weak linked system. On the other hand, the backup protection relays on the transmissionControl and Protection Cooperation Strategy for Voltage Instability Zhou Liu Aalborg University zli are caused by unexpected backup relay operations due to low voltage or overload state caused by post fault

  18. Voltage sensor with fiber Fabry-Perot interferometer

    E-Print Network [OSTI]

    Wann, Been-Huey

    1992-01-01T23:59:59.000Z

    INTRODUCTION. Page II RESEARCH DESCRIPTION. . . A. Optical Fiber Fabry-Perot Interferometer. . . . . B. Piezoelectricity. . C. Modulating Point in 60 Hz Voltage Measurement. . . . . . D. Temperature Control Circuit . . . . 18 . . . 26 III EXPERIMENTAL... PROCEDURES AND RESULTS. . . . . . A. Fabrication of the Optical Fiber Fabry-Perot Interferometer B. Selection of Piezoelectric Materials. C. Implementation of Temperature Control Circuit. . . . D. Experiments of Optical Fiber Voltage Sensor...

  19. Analysis of Voltage Rise Effect on Distribution Network with Distributed

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Analysis of Voltage Rise Effect on Distribution Network with Distributed Generation M. A. Mahmud.hossain@adfa.edu.au, and H.Pota@adfa.edu.au). Abstract: Connections of distributed generation (DG) in distribution networks are increasing. These connections of distributed generation cause voltage rise in the distribution network

  20. CompilerDirected Dynamic Voltage Scaling Based on Program Regions

    E-Print Network [OSTI]

    Kremer, Ulrich

    Compiler­Directed Dynamic Voltage Scaling Based on Program Regions Chung­Hsing Hsu and Ulrich using dynamic voltage scaling. The compiler identifies pro­ gram regions where the CPU can be slowed down without resulting in a significant overall performance loss. For such regions the lowest CPU

  1. Power Grid Voltage Integrity Verification Department of ECE

    E-Print Network [OSTI]

    Najm, Farid N.

    Power Grid Voltage Integrity Verification Maha Nizam Department of ECE University of Toronto devgan@magma-da.com ABSTRACT Full-chip verification requires one to check if the power grid is safe, i.e., if the voltage drop on the grid does not exceed a cer- tain threshold. The traditional simulation-based solution

  2. Longitudinal Stability Calculations

    SciTech Connect (OSTI)

    Blaskiewicz,M.

    2009-01-02T23:59:59.000Z

    Coupled bunch longitudinal stability in the presence of high frequency impedances is considered. A frequency domain technique is developed and compared with simulations. The frequency domain technique allows for absolute stability tests and is applied to the problem of longitudinal stability in RHIC with the new 56 MHz RF system.

  3. E-beam high voltage switching power supply

    DOE Patents [OSTI]

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

    1996-10-15T23:59:59.000Z

    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.

  4. E-beam high voltage switching power supply

    DOE Patents [OSTI]

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

    1996-01-01T23:59:59.000Z

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

  5. Salt tectonics driven by differential sediment loading: Stability analysis and finite element experiments

    E-Print Network [OSTI]

    Beaumont, Christopher

    1 Salt tectonics driven by differential sediment loading: Stability analysis and finite element University of Leeds Leeds LS2 9JT United Kingdom e-mail: lykke@earth.leeds.ac.uk Short running title: Salt salt layer drives salt deformation and has a significant impact on the structural evolution

  6. HVDC Control Strategies to Improve Transient Stability in Interconnected Power Systems

    E-Print Network [OSTI]

    Boyer, Edmond

    HVDC Control Strategies to Improve Transient Stability in Interconnected Power Systems J. Hazra Dpt of Li`ege, Belgium, dernst@ulg.ac.be Abstract--This paper presents three HVDC modulation strate- gies flow settings through the HVDC-links. The proposed techniques are tested on the IEEE 24-Bus reliability

  7. Phase Behavior and Emulsion Stability of the Aot/Decane/ Water/NaCl System at Very Low Volume Fractions of Oil

    E-Print Network [OSTI]

    Yithanllili Bastidas; Lisset Hernaandez; Issarly Rivas; Kareem Rahn-Chique; German Urbina-Villalba

    2014-10-09T23:59:59.000Z

    The stability of a ternary system composed of decane/water/Aerosol-OT and salt is revisited. Phase diagrams and emulsions similar in composition to those previously studied by Hofman and Stein [Hofman, 1991] were made. Ac- cording to our results, and contrary to the common experience, these systems exhibit a maximum of stability very close to the balance zone.

  8. www.mmu.ac.uk/careers Careers & Employability Service

    E-Print Network [OSTI]

    .mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www.jobs.ac.uk · www.Findamasters.com · www.mmu.ac.uk/careers PG Professional/Vocational courses: Courses to allow you to enter certain professions Courses involve lectures for the first two terms then a research project for the final term (often finishing after

  9. Low-voltage gas-discharge device

    DOE Patents [OSTI]

    Kovarik, V.J.; Hershcovitch, A.; Prelec, K.

    1982-06-08T23:59:59.000Z

    An electronic device of the type wherein current flow is conducted by an ionized gas comprising a cathode of the type heated by ionic bombardment, an anode, means for maintaining a predetermined pressure in the region between the anode and the cathode and means for maintaining a field in the region is described. The field, which is preferably a combined magnetic and electric field, is oriented so that the mean distance traveled by electrons before reaching the anode is increased. Because of this increased distance traveled electrons moving to the anode will ionize a large number of gas atoms, thus reducing the voltage necessary to initiate gas breakdown. In a preferred embodiment the anode is a main hollow cathode and the cathode is a smaller igniter hollow cathode located within and coaxial with the main hollow cathode. An axial magnetic field is provided in the region between the hollow cathodes in order to facilitate gas breakdown in that region and initiate plasma discharge from the main hollow cathode.

  10. Spark-safe low-voltage detonator

    DOE Patents [OSTI]

    Lieberman, Morton L. (Albuquerque, NM)

    1989-01-01T23:59:59.000Z

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

  11. Bonfire-safe low-voltage detonator

    DOE Patents [OSTI]

    Lieberman, Morton L. (Albuquerque, NM)

    1990-01-01T23:59:59.000Z

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

  12. Bonfire-safe low-voltage detonator

    DOE Patents [OSTI]

    Lieberman, M.L.

    1988-07-01T23:59:59.000Z

    A column of explosive in a low-voltage detonator which makes it bonfire-safe includes a first layer of an explosive charge of CP, or a primary explosive, and a second layer of a secondary organic explosive charge, such as PETN, which has a degradation temperature lower than the autoignition temperature of the CP or primary explosives. The first layer is composed of a pair of increments disposed in a bore of a housing of the detonator in an ignition region of the explosive column and adjacent to and in contact with an electrical ignition device at one end of the bore. The second layer is composed of a plurality of increments disposed in the housing bore in a transition region of the explosive column next to and in contact with the first layer on a side opposite from the ignition device. The first layer is loaded under a sufficient high pressure, 25 to 40 kpsi, to achieve ignition, whereas the second layer is loaded under a sufficient low pressure, about 10 kpsi, to allow occurrence of DDT. Each increment of the first and second layers has an axial length-to-diameter ratio of one-half. 2 figs.

  13. Integrated, Low Voltage, DynamicallyIntegrated, Low Voltage, Dynamically Adaptive BuckAdaptive Buck--Boost ConverterBoost Converter

    E-Print Network [OSTI]

    Rincon-Mora, Gabriel A.

    Improvement in battery life Low voltage Single cell operation (Li-ion/NiCd/NiMH/Fuel Cell) Integrated frequency 1 MHz ± 20% Closed-loop bandwidth 50 kHz 1-dB step change response time 20 µsec Full-load efficiency 90 % Control signal Output voltageTpower_change Tresponse Time 1 dB Typical transient response

  14. Analysis and synthesis of HVDC controls for robust stability of power systems

    SciTech Connect (OSTI)

    Venkataraman, S.; Khammash, M.H.; Vittal, V. [Iowa State Univ., Ames, IA (United States). Dept. of Electrical Engineering and Computer Engineering] [Iowa State Univ., Ames, IA (United States). Dept. of Electrical Engineering and Computer Engineering

    1995-11-01T23:59:59.000Z

    High Voltage DC (HVDC) links have controllable characteristics with potential for affecting system stability. This paper follows the robustness methodology procedure to analyze the stability robustness of HVDC controls in power systems over a range of operating conditions. A novel method to design power system controllers using the robustness methodology is also proposed. Numerical results for a sample test-system are obtained and compared with those obtained by conventional techniques.

  15. 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.

  16. 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.

  17. Electro-optic voltage sensor with beam splitting

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

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

  18. Electro-optic voltage sensor with Multiple Beam Splitting

    DOE Patents [OSTI]

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

    2000-01-01T23:59:59.000Z

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

  19. Spark-safe low-voltage detonator

    DOE Patents [OSTI]

    Lieberman, M.L.

    1988-07-01T23:59:59.000Z

    A column of explosive in a low-voltage detonator which makes it spark-safe includes an organic secondary explosive charge of HMX in the form of a thin pad disposed in a bore of a housing of the detonator in an ignition region of the explosive column and adjacent to an electrical ignition device at one end of the bore. The pad of secondary charge has an axial thickness within the range of twenty to thirty percent of its diameter. The explosive column also includes a first explosive charge of CP disposed in the housing bore in the ignition region of the explosive column next to the secondary charge pad on a side opposite from the ignition device. The first CP charge is loaded under sufficient pressure, 25 to 40 kpsi, to provide mechanical confinement of the pad of secondary charge and physical coupling thereof with the ignition device. The explosive column further includes a second explosive charge of CP disposed in the housing bore in a transition region of the explosive column next to the first CP charge on a side opposite from the pad of secondary charge. The second CP charge is loaded under sufficient pressure, about 10 kpsi, to allow occurrence of DDT. The first explosive CP charge has an axial thickness within the range of twenty to thirty percent of its diameter, whereas the second explosive CP charge contains a series of increments (nominally 4), each of which has an axial thickness-to-diameter ratio of one to two. 2 figs.

  20. Progress Toward a Stabilization and Preconditioning Protocol for Polycrystalline Thin-Film Photovoltaic Modules

    SciTech Connect (OSTI)

    del Cueto, J. A.; Deline, C. A.; Rummel, S. R.; Anderberg, A.

    2010-08-01T23:59:59.000Z

    Cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS) thin-film photovoltaic (PV) modules can exhibit substantial variation in measured performance depending on prior exposure history. This study examines the metastable performance changes in these PV modules with the goal of establishing standard preconditioning or stabilization exposure procedures to mitigate measured variations prior to current-voltage (IV) measurements.

  1. Aalborg Universitet Frequency Stability of Hierarchically Controlled Hybrid Photovoltaic-Battery-

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    sharing among PV voltage source inverters (VSIs), while injecting the dispatched power to the main grid as well. However, the different resources with conventional constant P/Q and P/V controls coexisting. Further, frequency stability analysis is presented based on small signal models of the hybrid PV

  2. A First-Principles Approach to Studying the Thermal Stability of Oxide Cathode Materials

    E-Print Network [OSTI]

    Ceder, Gerbrand

    the thermal stability of rechargeable lithium batteries, it is important to understand the thermal degradation to be effective in predicting a wide variety of materials properties, including the intercalation voltage,1 Li shown that the self-interaction present in LDA and GGA, which is responsible for the underestimation

  3. Small-Signal Stability Assessment of Active Distribution Networks with Dynamic Loads

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    the flow of power and the voltage profiles of the system and these profiles are different for different types of loads [3]. In addition to the power flow at and around N. K. Roy, H. R. Pota, and T. F. OrchiSmall-Signal Stability Assessment of Active Distribution Networks with Dynamic Loads N. K. Roy

  4. Nanosecond pulsed electric fields (nsPEFs) low cost generator design using power MOSFET and Cockcroft-Walton multiplier circuit as high voltage DC source

    SciTech Connect (OSTI)

    Sulaeman, M. Y.; Widita, R. [Department of Physics, Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Bandung (Indonesia)

    2014-09-30T23:59:59.000Z

    Purpose: Non-ionizing radiation therapy for cancer using pulsed electric field with high intensity field has become an interesting field new research topic. A new method using nanosecond pulsed electric fields (nsPEFs) offers a novel means to treat cancer. Not like the conventional electroporation, nsPEFs able to create nanopores in all membranes of the cell, including membrane in cell organelles, like mitochondria and nucleus. NsPEFs will promote cell death in several cell types, including cancer cell by apoptosis mechanism. NsPEFs will use pulse with intensity of electric field higher than conventional electroporation, between 20–100 kV/cm and with shorter duration of pulse than conventional electroporation. NsPEFs requires a generator to produce high voltage pulse and to achieve high intensity electric field with proper pulse width. However, manufacturing cost for creating generator that generates a high voltage with short duration for nsPEFs purposes is highly expensive. Hence, the aim of this research is to obtain the low cost generator design that is able to produce a high voltage pulse with nanosecond width and will be used for nsPEFs purposes. Method: Cockcroft-Walton multiplier circuit will boost the input of 220 volt AC into high voltage DC around 1500 volt and it will be combined by a series of power MOSFET as a fast switch to obtain a high voltage with nanosecond pulse width. The motivation using Cockcroft-Walton multiplier is to acquire a low-cost high voltage DC generator; it will use capacitors and diodes arranged like a step. Power MOSFET connected in series is used as voltage divider to share the high voltage in order not to damage them. Results: This design is expected to acquire a low-cost generator that can achieve the high voltage pulse in amount of ?1.5 kV with falltime 3 ns and risetime 15 ns into a 50? load that will be used for nsPEFs purposes. Further detailed on the circuit design will be explained at presentation.

  5. Emerging Polymer-Stabilized Blue Phase Liquid Crystal Display Jin Yan, Hui-Cheng Cheng, Linghui Rao, Takahiro Ishinabe and Shin-Tson Wu

    E-Print Network [OSTI]

    Wu, Shin-Tson

    Emerging Polymer-Stabilized Blue Phase Liquid Crystal Display Jin Yan, Hui-Cheng Cheng, Linghui Rao, FL 32816, USA ABSTRACT Polymer-stabilized blue-phase liquid crystals hold great potential for future display applications. Some technical challenges, such as blue-phase temperature range, operation voltage

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

    DOE Patents [OSTI]

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

    1993-01-19T23:59:59.000Z

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

  7. Three phase AC motor controller

    DOE Patents [OSTI]

    Vuckovich, Michael (Elizabeth, PA); Wright, Maynard K. (Bethel Park, PA); Burkett, John P. (South Huntington Township, Westmoreland County, PA)

    1984-03-20T23:59:59.000Z

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  8. Bouncing of a droplet on a superhydrophobic surface in AC electrowetting

    E-Print Network [OSTI]

    Lee, Seung Jun; Kang, Kwan Hyoung

    2009-01-01T23:59:59.000Z

    We introduce a droplet-jumping phenomenon on a superhydrophobic surface driven by the resonant AC electrowetting. The resonant electrical actuation enables a droplet to accumulate sufficient surface energy for jumping, and superhydrophobic surface minimizes adhesion and hysteresis effects. They provide the effective energy conversion from the surface energy to the kinetic energy and improve the stability and the reproducibility of the droplet jumping. The controlled droplet jumping made by the resonant AC electrowetting could place another milestone in digital microfluidics by establishing a potential way to realize the three-dimensional droplet manipulation based on the conventional single plate EWOD configurations. This abstract is related to a fluid dynamics video for the gallery of fluid motion 2009.

  9. Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    coupling (PCC). Unbalance compensation is achieved by proper control of distributed generators (DGs unbalance. Keywords-distributed generation; microgrid; secondary control; voltage unbalance compensation I. INTRODUCTION Distributed Generators (DGs) may be connected individually to the utility grid or be integrated

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

    SciTech Connect (OSTI)

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

    2009-02-01T23:59:59.000Z

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

  11. An Adaptive Voltage Control Algorithm with Multiple Distributed Energy

    SciTech Connect (OSTI)

    Li, Huijuan [University of Tennessee, Knoxville (UTK); Li, Fangxing [ORNL; Adhikari, Sarina [ORNL; Xu, Yan [ORNL; Rizy, D Tom [ORNL; Kueck, John D [ORNL

    2009-01-01T23:59:59.000Z

    Distributed energy resources (DE) with power electronics (PE) interfaces with the right control are capable of providing reactive power related ancillary services. Voltage regulation in particular has drawn much attention. In this paper the challenges to control multiple DEs to regulate the local voltage in distribution systems is addressed and a decentralized adaptive voltage control method is proposed. The simulation results in different system conditions show that this adaptive voltage control method is capable of satisfying the fast response speed requirement without causing oscillation or instability of the system. Since this method has high tolerance to the shortage of the system parameters and can be widely adaptive to the variable operation situations of the power systems, it is very suited for the utility application.

  12. Operation of buck regulator with ultra-low input voltage

    E-Print Network [OSTI]

    Harris, Cory Angelo

    2014-01-01T23:59:59.000Z

    Based on the LTC3621 and LTC3624, the designed buck regulator proposed in this thesis aims to lower the allowed input voltage and increase efficiency compared to the original part without making significant changes to ...

  13. High-voltage air-core pulse transformers

    SciTech Connect (OSTI)

    Rohwein, G. J.

    1981-01-01T23:59:59.000Z

    General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)

  14. IEEE 342 Node Low Voltage Networked Test System

    SciTech Connect (OSTI)

    Schneider, Kevin P.; Phanivong, Phillippe K.; Lacroix, Jean-Sebastian

    2014-07-31T23:59:59.000Z

    The IEEE Distribution Test Feeders provide a benchmark for new algorithms to the distribution analyses community. The low voltage network test feeder represents a moderate size urban system that is unbalanced and highly networked. This is the first distribution test feeder developed by the IEEE that contains unbalanced networked components. The 342 node Low Voltage Networked Test System includes many elements that may be found in a networked system: multiple 13.2kV primary feeders, network protectors, a 120/208V grid network, and multiple 277/480V spot networks. This paper presents a brief review of the history of low voltage networks and how they evolved into the modern systems. This paper will then present a description of the 342 Node IEEE Low Voltage Network Test System and power flow results.

  15. Design & Fabrication of a High-Voltage Photovoltaic Cell

    SciTech Connect (OSTI)

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

    2012-09-05T23:59:59.000Z

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

  16. Unravelling the Performance Degradation Mechanisms in High-voltage...

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

    Unravelling the Performance Degradation Mechanisms in High-voltage Lithium-ion Battery Composite Oxide Electrodes Apr 11 2014 02:00 PM - 03:00 PM Debasish Mohanty, ORNL, Oak Ridge...

  17. Voltage Dependent Charge Storage Modes and Capacity in Subnanometer Pores

    SciTech Connect (OSTI)

    Qiao, Rui [Clemson University; Meunier, V. [Rensselaer Polytechnic Institute (RPI); Huang, Jingsong [ORNL; Wu, Peng [ORNL; Sumpter, Bobby G [ORNL

    2012-01-01T23:59:59.000Z

    Using molecular dynamics simulations, we show that charge storage in subnanometer pores follows a distinct voltage-dependent behavior. Specifically, at lower voltages, charge storage is achieved by swapping co-ions in the pore with counterions in the bulk electrolyte. As voltage increases, further charge storage is due mainly to the removal of co-ions from the pore, leading to a capacitance increase. The capacitance eventually reaches a maximum when all co-ions are expelled from the pore. At even higher electrode voltages, additional charge storage is realized by counterion insertion into the pore, accompanied by a reduction of capacitance. The molecular mechanisms of these observations are elucidated and provide useful insight for optimizing energy storage based on supercapacitors.

  18. Modeling the operating voltage of liquid metal battery cells

    E-Print Network [OSTI]

    Newhouse, Jocelyn Marie

    2014-01-01T23:59:59.000Z

    A one-dimensional, integrative model of the voltage during liquid metal battery operation has been developed to enhance the understanding of performance at the cell level. Two liquid metal batteries were studied: Mg-Sb for ...

  19. IMPACT OF DYNAMIC VOLTAGE SCALING (DVS) ON CIRCUIT OPTIMIZATION

    E-Print Network [OSTI]

    Esquit Hernandez, Carlos A.

    2010-01-16T23:59:59.000Z

    Circuit designers perform optimization procedures targeting speed and power during the design of a circuit. Gate sizing can be applied to optimize for speed, while Dual-VT and Dynamic Voltage Scaling (DVS) can be applied to optimize for leakage...

  20. IMPACT OF DYNAMIC VOLTAGE SCALING (DVS) ON CIRCUIT OPTIMIZATION 

    E-Print Network [OSTI]

    Esquit Hernandez, Carlos A.

    2010-01-16T23:59:59.000Z

    Circuit designers perform optimization procedures targeting speed and power during the design of a circuit. Gate sizing can be applied to optimize for speed, while Dual-VT and Dynamic Voltage Scaling (DVS) can be applied ...

  1. Prediction of flashover voltage of non-ceramic insulators under contaminated conditions

    E-Print Network [OSTI]

    Prediction of flashover voltage of non-ceramic insulators under contaminated conditions S ABSTRACT This paper describes the development of a theoretical model to predict flashover voltage

  2. Control of Grid Connected AC-DC Converters with Minimized DC Link Capacitance under Unbalanced Grid Voltage Condition

    E-Print Network [OSTI]

    Lehn, Peter W.

    Winkelnkemper2 manfred.winkelnkemper @ch.abb.com 1 University of Toronto 10 Kings College Road Toronto, ON, M5S

  3. Abstract--This paper discusses modelling of high voltage AC underground cables. For long cables, when crossbonding points

    E-Print Network [OSTI]

    Bak, Claus Leth

    is with Manitoba HVDC Research Centre, R3J 3W1 Winnipeg, Canada (e-mail: Jeewantha@hvdc.ca ) C. L. Bak

  4. TPWRD-00683-2009 1 Abstract--With the increasing use of high-voltage AC cables at

    E-Print Network [OSTI]

    Silva, Filipe Faria Da

    System Operator, Energinet.dk. F. F. da Silva is a PhD student at the Institute of Energy Technology of Energy Technology, Aalborg University, 9220 Aalborg, Denmark (e-mail: clb@iet.aau.dk). U. S. Gudmundsdottir is a PhD student at the Institute of Energy Technology, Aalborg University, 9220 Aalborg, Denmark

  5. Electrodic voltages accompanying stimulated bioremediation of a uranium-contaminated aquifer

    SciTech Connect (OSTI)

    Williams, K.H.; N'Guessan, A.L.; Druhan, J.; Long, P.E.; Hubbard, S.S.; Lovley, D.R.; Banfield, J.F.

    2009-11-15T23:59:59.000Z

    The inability to track the products of subsurface microbial activity during stimulated bioremediation has limited its implementation. We used spatiotemporal changes in electrodic potentials (EP) to track the onset and persistence of stimulated sulfate-reducing bacteria in a uranium-contaminated aquifer undergoing acetate amendment. Following acetate injection, anomalous voltages approaching -900 mV were measured between copper electrodes within the aquifer sediments and a single reference electrode at the ground surface. Onset of EP anomalies correlated in time with both the accumulation of dissolved sulfide and the removal of uranium from groundwater. The anomalies persisted for 45 days after halting acetate injection. Current-voltage and current-power relationships between measurement and reference electrodes exhibited a galvanic response, with a maximum power density of 10 mW/m{sup 2} during sulfate reduction. We infer that the EP anomalies resulted from electrochemical differences between geochemically reduced regions and areas having higher oxidation potential. Following the period of sulfate reduction, EP values ranged from -500 to -600 mV and were associated with elevated concentrations of ferrous iron. Within 10 days of the voltage decrease, uranium concentrations rebounded from 0.2 to 0.8 {mu}M, a level still below the background value of 1.5 {mu}M. These findings demonstrate that EP measurements provide an inexpensive and minimally invasive means for monitoring the products of stimulated microbial activity within aquifer sediments and are capable of verifying maintenance of redox conditions favorable for the stability of bioreduced contaminants, such as uranium.

  6. Measuring Helical FCG Voltage with an Electric Field Antenna

    SciTech Connect (OSTI)

    White, A D; Anderson, R A; Javedani, J B; Reisman, D B; Goerz, D A; Ferriera, A J; Speer, R D

    2011-08-01T23:59:59.000Z

    A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach.

  7. Image-line voltage controlled oscillators and grating antennas

    E-Print Network [OSTI]

    Kirk, Alexander MacDonald

    1991-01-01T23:59:59.000Z

    IMAGE-LINE VOLTAGE CONTROLLED OSCILLATORS AND GRATING ANTENNAS A Thesis by ALEXANDER MacDONALD KIRK Submitted to the Office of Graduate Studies of Texas ABM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1991 Major Subject: Electrical Engineering IMAGE-LINE VOLTAGE CONTROLLED OSCILLATORS AND GRATING ANTENNAS A Thesis by ALEXANDER MacDONALD KIRK Approved as to style and content by: Kai Chang (Chair of Committee) Robert D. Nevels...

  8. Sinusoidal voltage controlled oscillators using operational transconductance amplifiers

    E-Print Network [OSTI]

    Hoyle Passano, Javier Joaquin

    1985-01-01T23:59:59.000Z

    SINUSOIDAI. VOLTAGE CONTROLLED OSCILLATORS I. SING OPERATIONAL TRANSCONDUCTANCE AMPLIFIERS A Thesis JAVIFB . IOAQUIN HOYI. K I'ASSANO Suhndtted to the Graduate College ol' 'I'exes A8cM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1985 Major Subject: Electrical Engineering SINUSOIDAL VOLTAGE CONTROLLED OSCILLATORS USING OPERATIONAI, TRANSCONDUCTANCE AMPLIFIERS A Thesis by JAVIER JOAQUIN HOYLE PASSANO Approved as to style and content by: o...

  9. Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells

    DOE Patents [OSTI]

    Delnick, F.M.

    1993-04-13T23:59:59.000Z

    Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl[sub 2] and SO[sub 2]Cl[sub 2] electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl[sub 2] and Li/SO[sub 2]Cl[sub 2] batteries.

  10. Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells

    DOE Patents [OSTI]

    Delnick, Frank M. (Albuquerque, NM)

    1993-01-01T23:59:59.000Z

    Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl.sub.2 and SO.sub.2 Cl.sub.2 electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl.sub.2 and Li/SO.sub.2 Cl.sub.2 batteries.

  11. Corrosion/Fragmentation of Layered Composite Cathode and Related Capacity/Voltage Fading during Cycling Process

    SciTech Connect (OSTI)

    Zheng, Jianming; Gu, Meng; Xiao, Jie; Zuo, Pengjian; Wang, Chong M.; Zhang, Jiguang

    2013-06-26T23:59:59.000Z

    Pristine and cycled layered structure cathode of Li[Li0.2Ni0.2M0.6]O2 samples are characterized by aberration-corrected scanning transmission electron microscopy and electron energy loss spectroscopy. These analyses provide new insights on capacity/voltage fading mechanism of Li[Li0.2Ni0.2M0.6]O2. Sponge-like structure and fragment pieces were found on the surface of cathode after cycling. Mn2+ species and reduced Li content in the fragments caused significant capacity loss. These results also reveal the functional mechanism of surface coatings, e.g. AlF3, which can protect the electrode from etching by acidic species in the electrolyte, suppress cathode degradation and improve long-term cycling stability.

  12. Electrochemical Performance and Stability of the Cathode for Solid Oxide Fuel Cells. I. Cross Validation of Polarization Measurements by Impedance Spectroscopy and Current-Potential Sweep

    SciTech Connect (OSTI)

    Zhou, Xiao Dong; Pederson, Larry R.; Templeton, Jared W.; Stevenson, Jeffry W.

    2009-12-09T23:59:59.000Z

    The aim of this paper is to address three issues in solid oxide fuel cells: (1) cross-validation of the polarization of a single cell measured using both dc and ac approaches, (2) the precise determination of the total areal specific resistance (ASR), and (3) understanding cathode polarization with LSCF cathodes. The ASR of a solid oxide fuel cell is a dynamic property, meaning that it changes with current density. The ASR measured using ac impedance spectroscopy (low frequency interception with real Z´ axis of ac impedance spectrum) matches with that measured from a dc IV sweep (the tangent of dc i-V curve). Due to the dynamic nature of ASR, we found that an ac impedance spectrum measured under open circuit voltage or on a half cell may not represent cathode performance under real operating conditions, particularly at high current density. In this work, the electrode polarization was governed by the cathode activation polarization; the anode contribution was negligible.

  13. High voltage electrical amplifier having a short rise time

    DOE Patents [OSTI]

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

    1991-01-01T23:59:59.000Z

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

  14. Voltage-controllable generator of pure spin current: A three-terminal model

    SciTech Connect (OSTI)

    Ma, Zheng; Wu, Reng-Lai; Yu, Ya-Bin, E-mail: apybyu@hnu.edu.cn; Wang, Miao [School of Physics and Electronics, Hunan University, Changsha 410082 (China)

    2014-07-28T23:59:59.000Z

    Three-terminal devices have been frequently proposed to generate the pure spin current. However, the controllability and stability of pure spin current still needs to be improved. In this paper, a three-terminal device, composed of a ferromagnetic metallic lead and two nonmagnetic semiconductor leads coupled with a quantum dot, is employed to study the properties of electron spin transport. The results show that when the external voltage on one of nonmagnetic semiconductor leads is adjusted to a proper range, a pure spin current plateau or a fully spin-polarized current plateau appears in another nonmagnetic semiconductor lead. In a wide range of external voltage, the pure spin current or the spin-polarized current is kept unchanged. Since the change of temperature may considerably influence the spin-polarization of current and is inevitable actually, we studied the corresponding compensation to keep the pure spin current unchanged. Furthermore, the effect of device parameters on the pure spin current is also investigated.

  15. Low frequency AC waveform generator

    DOE Patents [OSTI]

    Bilharz, Oscar W. (Scotia, NY)

    1986-01-01T23:59:59.000Z

    Low frequency sine, cosine, triangle and square waves are synthesized in circuitry which allows variation in the waveform amplitude and frequency while exhibiting good stability and without requiring significant stabilization time. A triangle waveform is formed by a ramped integration process controlled by a saturation amplifier circuit which produces the necessary hysteresis for the triangle waveform. The output of the saturation circuit is tapped to produce the square waveform. The sine waveform is synthesized by taking the absolute value of the triangular waveform, raising this absolute value to a predetermined power, multiplying the raised absolute value of the triangle wave with the triangle wave itself and properly scaling the resultant waveform and subtracting it from the triangular waveform itself. The cosine is synthesized by squaring the triangular waveform, raising the triangular waveform to a predetermined power and adding the squared waveform raised to the predetermined power with a DC reference and subtracting the squared waveform therefrom, with all waveforms properly scaled. The resultant waveform is then multiplied with a square wave in order to correct the polarity and produce the resultant cosine waveform.

  16. Variations on stability

    E-Print Network [OSTI]

    Ruben Minasian; Alessandro Tomasiello

    2002-05-07T23:59:59.000Z

    We explore the effects of non-abelian dynamics of D-branes on their stability and introduce Hitchin-like modifications to previously-known stability conditions. The relation to brane-antibrane systems is used in order to rewrite the equations in terms of superconnections and arrive at deformed vortex equations.

  17. Variations on stability

    E-Print Network [OSTI]

    Minasian, R; Minasian, Ruben; Tomasiello, Alessandro

    2001-01-01T23:59:59.000Z

    We explore the effects of non-abelian dynamics of D-branes on their stability and introduce Hitchin-like modifications to previously-known stability conditions. The relation to brane-antibrane systems is used in order to rewrite the equations in terms of superconnections and arrive at deformed vortex equations.

  18. Homological stabilizer codes

    SciTech Connect (OSTI)

    Anderson, Jonas T., E-mail: jonastyleranderson@gmail.com

    2013-03-15T23:59:59.000Z

    In this paper we define homological stabilizer codes on qubits which encompass codes such as Kitaev's toric code and the topological color codes. These codes are defined solely by the graphs they reside on. This feature allows us to use properties of topological graph theory to determine the graphs which are suitable as homological stabilizer codes. We then show that all toric codes are equivalent to homological stabilizer codes on 4-valent graphs. We show that the topological color codes and toric codes correspond to two distinct classes of graphs. We define the notion of label set equivalencies and show that under a small set of constraints the only homological stabilizer codes without local logical operators are equivalent to Kitaev's toric code or to the topological color codes. - Highlights: Black-Right-Pointing-Pointer We show that Kitaev's toric codes are equivalent to homological stabilizer codes on 4-valent graphs. Black-Right-Pointing-Pointer We show that toric codes and color codes correspond to homological stabilizer codes on distinct graphs. Black-Right-Pointing-Pointer We find and classify all 2D homological stabilizer codes. Black-Right-Pointing-Pointer We find optimal codes among the homological stabilizer codes.

  19. Stabilized radio frequency quadrupole

    DOE Patents [OSTI]

    Lancaster, Henry D. (Orinda, CA); Fugitt, Jock A. (Berkeley, CA); Howard, Donald R. (Danville, CA)

    1984-01-01T23:59:59.000Z

    A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

  20. E-beam high voltage switching power supply

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

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

  1. E-beam high voltage switching power supply

    DOE Patents [OSTI]

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

    1997-03-11T23:59:59.000Z

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

  2. Cinema 16 Collection / A.C. Killip (collector)

    E-Print Network [OSTI]

    Handy, Todd C.

    Cinema 16 Collection / A.C. Killip (collector) University of British Columbia Archives #12;Table;Collection Description Cinema 16 Collection / A.C. Killip (collector). ­ 1961-1970. 1.5 cm of textual records

  3. WASEDAUNIVERSITY http://www.sci.waseda.ac.jp

    E-Print Network [OSTI]

    Kasahara, Hironori

    ://www.cse.sci.waseda.ac.jp/ http://www.ase.sci.waseda.ac.jp/ http://www.waseda.jp/ips/ http://www.waseda.jp/weee/ INDEX 2014 5

  4. Concept of Quasi-Capacitive Tapping of Bipolar Voltage-Controlled Oscillators

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    Concept of Quasi-Capacitive Tapping of Bipolar Voltage-Controlled Oscillators Aleksandar Tasic the active part of the oscillator and the LC-tank, as proposed in this paper, the voltage swing over the tank of high- performance bipolar voltage-controlled oscillators (VCO's). As the voltage-controlled oscillators

  5. Neurocomputing 69 (2006) 10621065 Dependence of the spike-triggered average voltage on

    E-Print Network [OSTI]

    Gerstner, Wulfram

    2006-01-01T23:59:59.000Z

    .V. All rights reserved. Keywords: Spike-triggered voltage; h-current; Damped voltage oscillations 1 oscillations. The model comprises a variable v for the membrane voltage, with time-scale tv and a secondNeurocomputing 69 (2006) 1062­1065 Dependence of the spike-triggered average voltage on membrane

  6. Requirements for a Standard Test to Rate the Durability of PV Modules at System Voltage (Presentation)

    SciTech Connect (OSTI)

    Hacke, P.; Terwilliger, K.; Glick, S.; Kempe, M.; Kurtz, S.; Bennett, I.; Kloos, M.

    2011-02-01T23:59:59.000Z

    Degradation modes in photovoltaic modules under system bias voltage stress are described and classified.

  7. DATE04 SPECIAL SECTION Overhead-conscious voltage selection for dynamic

    E-Print Network [OSTI]

    Marchal, Loris

    combination with dynamic voltage scaling indispensable for energy-efficient designs in the foreseeable future

  8. Radio-Frequency Interference (RFI) From Extra-High-Voltage (EHV) Transmission Lines

    E-Print Network [OSTI]

    Ellingson, Steven W.

    -current (HVAC) transmission lines; high-voltage direct-current (HVDC) transmission lines will be addressed

  9. Voltage control in pulsed system by predict-ahead control

    DOE Patents [OSTI]

    Payne, A.N.; Watson, J.A.; Sampayan, S.E.

    1994-09-13T23:59:59.000Z

    A method and apparatus for predict-ahead pulse-to-pulse voltage control in a pulsed power supply system is disclosed. A DC power supply network is coupled to a resonant charging network via a first switch. The resonant charging network is coupled at a node to a storage capacitor. An output load is coupled to the storage capacitor via a second switch. A de-Q-ing network is coupled to the resonant charging network via a third switch. The trigger for the third switch is a derived function of the initial voltage of the power supply network, the initial voltage of the storage capacitor, and the present voltage of the storage capacitor. A first trigger closes the first switch and charges the capacitor. The third trigger is asserted according to the derived function to close the third switch. When the third switch is closed, the first switch opens and voltage on the node is regulated. The second trigger may be thereafter asserted to discharge the capacitor into the output load. 4 figs.

  10. STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE

    E-Print Network [OSTI]

    STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE MECH-14A NA7.5.13 Distributed Energy Storage DX AC DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION

  11. www.pet.hw.ac.uk 1 Private and Confidential

    E-Print Network [OSTI]

    Painter, Kevin

    www.pet.hw.ac.uk 1 Private and Confidential Application for MSc Courses - Supplementary Information of Exam Grade Attained Subjects taken at `O' level or equivalent with grades #12;www.pet.hw.ac.uk 2 of principal & subsidiary subjects Please leave blank for Institute Use #12;www.pet.hw.ac.uk 3 Employment Dates

  12. www.strath.ac.uk THIS IS YOUR

    E-Print Network [OSTI]

    Mottram, Nigel

    Building Lorna Bennet SBS Exchange Co-ordinator Michele French SBS Exchange Secretary 01 | Contents 03 Building erkan.oterkus@strath.ac.uk Lorna Bennet Strathclyde Business School Level 2, Sir William Duncan Building lorna.bennet@strath.ac.uk www.strath.ac.uk | 06 #12;Key Dates www

  13. Thermal Stabilization Blend Plan

    SciTech Connect (OSTI)

    RISENMAY, H.R.

    2000-05-02T23:59:59.000Z

    This Blend Plan documents the feed material items that are stored in 2736-2 vaults, the 2736-ZB 638 cage, the 192C vault, and the 225 vault that will be processed through the thermal stabilization furnaces. The purpose of thermal stabilization is to heat the material to 1000 degrees Celsius to drive off all water and leave the plutonium and/or uranium as oxides. The stabilized material will be sampled to determine the Loss On Ignition (LOI) or percent water. The stabilized material must meet water content or LOI of less than 0.5% to be acceptable for storage under DOE-STD-3013-99 specifications. Out of specification material will be recycled through the furnaces until the water or LOI limits are met.

  14. Voltage Impacts of Utility-Scale Distributed Wind

    SciTech Connect (OSTI)

    Allen, A.

    2014-09-01T23:59:59.000Z

    Although most utility-scale wind turbines in the United States are added at the transmission level in large wind power plants, distributed wind power offers an alternative that could increase the overall wind power penetration without the need for additional transmission. This report examines the distribution feeder-level voltage issues that can arise when adding utility-scale wind turbines to the distribution system. Four of the Pacific Northwest National Laboratory taxonomy feeders were examined in detail to study the voltage issues associated with adding wind turbines at different distances from the sub-station. General rules relating feeder resistance up to the point of turbine interconnection to the expected maximum voltage change levels were developed. Additional analysis examined line and transformer overvoltage conditions.

  15. A study of temperature compensating circuits for voltage references which use negative temperature coefficient zener diodes

    E-Print Network [OSTI]

    Coleman, Spencer Delano

    1961-01-01T23:59:59.000Z

    Character- istics in Breakdown Region . 13 3f. 1N 751 Zener Diode Voltage vs Current Character- istics in Breakdown Region . 14 3g, lN752 Zener Diode Voltage vs Current Character- istics in Breakdown Region 15 4a. 1N746 Zener Diode Ambient Temperature... vs Voltage Characteristics in Breakdown Region. . . . . . . . . . 16 4b. IN747 Zener Diode Ambient Temperature vs Voltage Characteristics in Breakdown Region. . . . . . . . . . 17 4c. 1N748 Zener Diode Ambient Temperature vs Voltage...

  16. Low frequency ac waveform generator

    DOE Patents [OSTI]

    Bilharz, O.W.

    1983-11-22T23:59:59.000Z

    Low frequency sine, cosine, triangle and square waves are synthesized in circuitry which allows variation in the waveform amplitude and frequency while exhibiting good stability and without requiring significant stablization time. A triangle waveform is formed by a ramped integration process controlled by a saturation amplifier circuit which produces the necessary hysteresis for the triangle waveform. The output of the saturation circuit is tapped to produce the square waveform. The sine waveform is synthesized by taking the absolute value of the triangular waveform, raising this absolute value to a predetermined power, multiplying the raised absolute value of the triangle wave with the triangle wave itself and properly scaling the resultant waveform and subtracting it from the triangular waveform to a predetermined power and adding the squared waveform raised to the predetermined power with a DC reference and subtracting the squared waveform therefrom, with all waveforms properly scaled. The resultant waveform is then multiplied with a square wave in order to correct the polarity and produce the resultant cosine waveform.

  17. Chapter 24: Alternating-Current Circuits 2. The voltage in the European wall socket oscillates between the positive and negative peak voltages, resulting in an rms

    E-Print Network [OSTI]

    Kioussis, Nicholas

    1 Chapter 24: Alternating-Current Circuits 2. The voltage in the European wall socket oscillates 240 V 340 VV V 6. A light bulb dissipates power as the voltage oscillates across its filament.0 V 1.32 A 15.2 V I X 13. An oscillating voltage drives an alternating current through a capacitor

  18. Low-voltage ultra-low-poweranalog IC design -djmamic translinearcircuits 1.3.1 1.3 Low-voltage ultra-low-power analog IC design

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    Low-voltage ultra-low-poweranalog IC design -djmamic translinearcircuits 1.3.1 1.3 Low-voltage ultra-low-power analog IC design -dynamic translinear circuits 0 (rg G x m .- E . . . . . a r, a" P, 44' s" +N m - _ c o3 #12;Low-voltage ultra-low-power analog IC design -dynamic translinear circuits I

  19. Bulk power system voltage phenomena -III: Voltage stability, security & control, Davos, Switzerland, August 1994 THE IRRELEVANCE OF LOAD DYNAMICS FOR THE LOADING MARGIN

    E-Print Network [OSTI]

    Dobson, Ian

    instability [11]. Therefore it is useful to compute the location of fold bifurcations of power system models and their sensitivities depend only on the static parts of dynamic power system models. For example, a dynamic power dynamic power system models to be properly understood, the computation of loading mar- gin and its

  20. High voltage switch triggered by a laser-photocathode subsystem

    DOE Patents [OSTI]

    Chen, Ping; Lundquist, Martin L.; Yu, David U. L.

    2013-01-08T23:59:59.000Z

    A spark gap switch for controlling the output of a high voltage pulse from a high voltage source, for example, a capacitor bank or a pulse forming network, to an external load such as a high gradient electron gun, laser, pulsed power accelerator or wide band radar. The combination of a UV laser and a high vacuum quartz cell, in which a photocathode and an anode are installed, is utilized as triggering devices to switch the spark gap from a non-conducting state to a conducting state with low delay and low jitter.

  1. Effects of Distributed Energy Resources on Conservation Voltage Reduction (CVR)

    SciTech Connect (OSTI)

    Singh, Ruchi; Tuffner, Francis K.; Fuller, Jason C.; Schneider, Kevin P.

    2011-10-10T23:59:59.000Z

    Conservation Voltage Reduction (CVR) is one of the cheapest technologies which can be intelligently leveraged to provide considerable energy savings. The addition of renewables in the form of distributed resources can affect the entire power system, but more importantly, affects the traditional substation control schemes at the distribution level. This paper looks at the effect on energy consumption, peak load reduction, and voltage profile changes due to the addition of distributed generation in a distribution feeder using combinations of volt var control. An IEEE 13-node system is used to simulate the various cases. Energy savings and peak load reduction for different simulation scenarios are compared.

  2. Distinctly Ambitious www.hw.ac.uk

    E-Print Network [OSTI]

    Painter, Kevin

    , Duncan Hand at the James Watt Institute for High Value Manufacturing led a team to apply laser-based manufacturing processes to the production of dental products. The project led to the development of a laserDistinctly Ambitious www.hw.ac.uk Laser Machining #12;Cutting-edge engineering technology for laser

  3. Physics and contentswww.manchester.ac.uk

    E-Print Network [OSTI]

    engineering, science and bioscience research councils. As a postgraduate student at The UniversityPhysics and Astronomy #12;contentswww.manchester.ac.uk 12 The University of Manchester 2 Physics to be part of The University of Manchester. If you choose to be a postgraduate student here you can join us

  4. Four-Channel Differential AC Amplifier

    E-Print Network [OSTI]

    Kleinfeld, David

    to amplify cellular neurophysiological signals in applications requiring high gain, high input impedance, low://www.a-msystems.com General Description Instrument Features The Four-Channel Differential AC Amplifier Model 1700 is designed noise, high common-mode rejection, and powerline interference rejection. Typical applications include

  5. AC Losses of Prototype HTS Transmission Cables

    SciTech Connect (OSTI)

    Demko, J.A.; Dresner, L.; Hughey, R.L.; Lue, J.W.; Olsen, S.K.; Sinha, U.; Tolbert, J.C.

    1998-09-13T23:59:59.000Z

    Since 1995 Southwire Company and Oak Ridge National Laboratory (ORNL) have jointly designed, built, and tested nine, l-m long, high temperature superconducting (HTS) transmission cable prototypes. This paper summarizes the AC loss measurements of five of the cables not reported elsewhere, and compares the losses with each other and with theory developed by Dresner. Losses were measured with both a calorimetric and an electrical technique. Because of the broad resistive transition of the HTS tapes, the cables can be operated stably beyond their critical currents. The AC losses were measured in this region as well as below critical currents. Dresner's theory takes into account the broad resistive transition of the HTS tapes and calculates the AC losses both below and above the critical current. The two sets of AC 10SS data agree with each other and with the theory quite welL In particular, at low currents of incomplete penetration, the loss data agree with the theoretical prediction of hysteresis loss based on only the outer two Iayers carrying the total current.

  6. 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.

  7. Improving the dynamic performance of a complex AC/DC system by HVDC control modifications

    SciTech Connect (OSTI)

    Hammad, A.E. (ABB Power Systems, Baden (CH)); Gagnon, J. (Hydro Quebec, Montreal (CA)); McCallum, D. (IREQ, Montreal (CA))

    1990-10-01T23:59:59.000Z

    The power system of Hydro-Quebec has a peak load of approximately 27 GW. The great distance between the production sites and the load centers introduces stability limitations, which is the reason why the Quebec grid cannot be economically synchronized (through ac transmission with limited capacity) with the U.S. northeastern network. Power exports are therefore dependent on the use of HVDC links of which Hydro-Quebec now possesses five, for a capacity of over 2600 MW. Such a capacity will again soon increase. At the moment, the Chateauguay scheme has the largest HVDC capacity. It transfers 1000 MW by means of two Back-to-Back converter blocks. Various automatic control systems are installed on the Chateauguay scheme owing to the fact that a single circuit of a 765 kV ac line transmits the output of both the HVDC converter stations as well as the output from Beauharnois hydro generating station. Such controls have performed satisfactorily since 1984. However, a remarkable improvement of the overall ac/dc system dynamic performance can be gained by making certain modifications in some of these HVDC system controls. This paper presents the salient features of such control modifications, currently under consideration, using the results of an investigation by digital and analogue simulations that demonstrate the achieved improvements.

  8. Truthful Complex-valued Knapsack Problem and Discrete Optimization in A/C Electrical Grid

    E-Print Network [OSTI]

    Chau, Chi-Kin

    2012-01-01T23:59:59.000Z

    Since efficient power allocation is a critical requirement for smart grid, we study an important basic setting -- "knapsack problem with selfish users", whereby we design a mechanism to find a utility-maximizing allocation for a group of users with inelastic demands, such that users truthfully reveal their private utility information. As a departure from the traditional setting, complex-valued entities (e.g. power, voltage, and current) are common in A/C electrical grid. There were only few results in the literature concerning complex-valued entities for discrete optimization, because they are substantially more challenging. In this paper, we introduce a non-trivial generalization of knapsack problem with a complex-valued constraint on A/C power, which casts fundamental insight to discrete optimization for smart grid. We provide results of approximability (the existence of a (1/2- e-approximation algorithm) and inapproximability (the absence of FPTAS unless P = NP) for a class of complex-valued knapsack probl...

  9. AC Resonant charger with charge rate unrelated to primary power frequency

    DOE Patents [OSTI]

    Watson, Harold (Torrance, CA)

    1982-01-01T23:59:59.000Z

    An AC resonant charger for a capacitive load, such as a PFN, is provided with a variable repetition rate unrelated to the frequency of a multi-phase AC power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.

  10. Low Cost Fabrication of 2G Wires for AC Applications

    SciTech Connect (OSTI)

    Kodenkandath, T.; List, F.A., III

    2005-09-15T23:59:59.000Z

    Ink-jet printing has been demonstrated as an adaptable technology for printing YBCO filaments using a Metal Organic (MO) YBCO precursor. The technology was demonstrated using AMSC's proprietary metal organic TFA-based YBCO precursor and a commercial piezoelectric print-head on RABiTS templates. Filaments with a width of 100 um and spacing of 200 um were successfully printed, decomposed and processed to YBCO. Critical currents of {approx} 200 A/cm-w were achieved in a series of filaments with a 2 mm width. The single nozzle laboratory printer used in the Phase 1 program is capable of printing {approx} 100 um wide single filaments at a rate of 8-10 cm/sec. The electrical stabilization of filaments with a Ag ink was also evaluated using ink-jet printing. The overall objective of the Phase 1 Project was the evaluation and demonstration of inkjet-printing for depositing YBCO filaments on textured templates (RABiTS, IBAD, ISD, etc. substrates) with properties appropriate for low loss ac conductors. Goals of the Phase 1 program included development of an appropriate precursor ink, demonstration of the printing process, processing and characterization of printed YBCO filaments and evaluation of the process for further development.

  11. Improving ac motor efficiency with fuzzy logic energy optimizer

    SciTech Connect (OSTI)

    Spiegel, R.J.; Chappell, P.J.; Cleland, J.G.

    1994-08-01T23:59:59.000Z

    The paper discusses EPA's research program to develop fuzzy-logic-based energy optimizers for alternating-current (AC) induction motors driven by Adjustable Speed Drives (ASDs). The technical goals of the program are to increase the efficiency of ASD/motor combinations (especially when operating at off-rated torque/speed conditions), develop a generic controller for energy optimization that can be applied to a wide range of motors and ASDs regardless of size and application, and develop a controller for energy optimization that can eliminate the requirement for tachometer or encoder feedback, and still maintain the stability and response of closed-loop control. Electric motors use over 60% of the electrical power generated in the U.S. The U.S. population of approximately 1 billion motors use over 1700 billion kWh per year. Over 140 million new motors are sold each year. A review of the U.S. motor population reveals that 90% of the motors are less than 1 hp (fractional motors) in size, but use less than 10% of the electricity consumed by motors. More that 80% of the electricity used by motors is consumed by less than 1% of the motor population (motors greater than 20 hp). Thus, it is clear that large energy savings from improvement in motor efficiency could be achieved from a relatively small motor population.

  12. Way to reduce arc voltage losses in hybrid thermionic converters

    SciTech Connect (OSTI)

    Tskhakaya, V.K.; Yarygin, V.I.

    1982-03-01T23:59:59.000Z

    Experimental results are reported concerning the output and emission characteristics of the arc and hybrid regimes in a plane-parallel thermionic converter with Pt--Zr--O electrode pair. It is shown that arc voltage losses can be reduced to values below those obtainable in ordinary arc thermionic converters.

  13. Standby Voltage Scaling for Reduced Power B. Calhoun, A. Chandrakasan

    E-Print Network [OSTI]

    Calhoun, Benton H.

    Engineering Massachusetts Institute of Technology, Cambridge, MA Abstract Lowering VDD during standby mode leakage, gate leakage, GIDL, and forward biased diode leak- age[2]. At the 0.13 m technology node to pinch in the rail voltages during standby[5]. The quantity and sizes of the devices used in the diode

  14. Current isolating epitaxial buffer layers for high voltage photodiode array

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

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

  15. Power Management Unit A digitalized Embedded Linear Voltage Regulator for

    E-Print Network [OSTI]

    Wichmann, Felix

    Climate Control Cooling FAN Park Distance Control Adaptive Cruise Control Night Vision Blindspot Detection cost More expensive mask cost More sensitive to radiation Higher leakage current Lower voltage headroom) System CostsSystem Costs Si-Area, Test Time, Package (# of pins) Development Cost/ Time to market

  16. THREE DIMENSIONAL VISUALIZATIONS FOR POWER SYSTEM CONTINGENCY ANALYSIS VOLTAGE DATA

    E-Print Network [OSTI]

    that the power systems are now often operated closer to their limits to maximum transmission system utilizationTHREE DIMENSIONAL VISUALIZATIONS FOR POWER SYSTEM CONTINGENCY ANALYSIS VOLTAGE DATA Y. Sun IEEE security assessment is critical for detecting underlying problems in a power system. More frequent CA

  17. Enhanced Archaerhodopsin Fluorescent Protein Voltage Yiyang Gong1,2*

    E-Print Network [OSTI]

    Ferrari, Silvia

    Enhanced Archaerhodopsin Fluorescent Protein Voltage Indicators Yiyang Gong1,2* , Jin Zhong Li1 by nearly three-fold in comparison to Arch-D95N. Citation: Gong Y, Li JZ, Schnitzer MJ (2013) Enhanced; Published June 19, 2013 Copyright: © 2013 Gong et al. This is an open-access article distributed under

  18. Topical Review Voltage Dependence of the Na/K Pump

    E-Print Network [OSTI]

    Gadsby, David

    Topical Review Voltage Dependence of the Na/K Pump R.F. Rakowski1 , D.C. Gadsby2 , P. De Weer3 1, Philadelphia, PA 19104, USA Received: 2 August 1996/Revised: 13 September 1996 Introduction Whether Na/K pump & Rakowski, 1988). While it follows from first principles that the rate of net forward Na/K pumping must

  19. Electrodic voltages accompanying stimulated bioremediation of a uraniumcontaminated aquifer

    E-Print Network [OSTI]

    Hubbard, Susan

    the accumulation of dissolved sulfide and the removal of uranium from groundwater. The anomalies persisted for 45. Within 10 days of the voltage decrease, uranium concentrations rebounded from 0.2 to 0.8 mM, a level of bioreduced contaminants, such as uranium. Citation: Williams, K. H., A. L. N'Guessan, J. Druhan, P. E. Long

  20. Voltage Sequence Control Based High-Current Rectifier System

    E-Print Network [OSTI]

    Paderborn, Universität

    of transformer. A passive filter is added at the primary side to achieve power factor improvement over the range of output voltage. This scheme is optimized to determine optimum turns ratio of the transformer and optimum not enforce unity power factor operation and guidelines provided by harmonic standards such as IEEE-519

  1. Ultra-compact Marx-type high-voltage generator

    DOE Patents [OSTI]

    Goerz, David A. (Brentwood, CA); Wilson, Michael J. (Modesto, CA)

    2000-01-01T23:59:59.000Z

    An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

  2. Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids Mehdi@et.aau.dk Abstract-- The concept of microgrid hierarchical control is presented, recently. In this paper, a hierarchical scheme which includes primary and secondary control levels is proposed for islanded microgrids

  3. Energy Efficient Datapath Scheduling using Multiple Voltages and Dynamic Clocking

    E-Print Network [OSTI]

    Mohanty, Saraju P.

    consumption of a device has to be minimum to increase battery life, the energy-delay- product hasEnergy Efficient Datapath Scheduling using Multiple Voltages and Dynamic Clocking Saraju P. Mohanty clocking in a co-ordinated manner in order to reduce energy consumption of datapath circuits. In dynamic

  4. Smart Grid Voltage Sag Detection using Instantaneous Features Extraction

    E-Print Network [OSTI]

    Boyer, Edmond

    encountered power quality disturbances. Index Terms--Smart grid, voltage sag detection, power quality (PQ as the generation system is moved nearby the distribution level and this is achieved by using a set of micro grids grids are their availability, reliability, and profitability; in order to fulfill power demand according

  5. Energy Efficiency in Low Voltage Hall Thrusters Jerry L. Ross

    E-Print Network [OSTI]

    King, Lyon B.

    Energy Efficiency in Low Voltage Hall Thrusters Jerry L. Ross Lyon B. King Energy efficiency/s of xenon. Acceleration and current efficiencies were compared to thrust efficiency over a range of magnet coil current values of 0 A - 2.5 A. Acceleration efficiencies were obtained with a 4-grid Retarding

  6. Memory Power Management via Dynamic Voltage/Frequency Scaling

    E-Print Network [OSTI]

    McGaughey, Alan

    years. In the data center environment, thermal management and power budgeting have become significant transitions [10, 23], or scal- ing active server power proportionally to load [2]. In this paper, we focusMemory Power Management via Dynamic Voltage/Frequency Scaling Howard David, Chris Fallin§, Eugene

  7. Memory Power Management via Dynamic Voltage/Frequency Scaling

    E-Print Network [OSTI]

    Mutlu, Onur

    years. In the data center environment, thermal management and power budgeting have become significant sleep transitions [10, 23], or scal- ing active server power proportionally to load [2]. In this paperMemory Power Management via Dynamic Voltage/Frequency Scaling Howard David, Chris Fallin§, Eugene

  8. Field Optimization of Three Dimensional High Voltage C. Trinitis

    E-Print Network [OSTI]

    Stamatakis, Alexandros

    Field Optimization of Three Dimensional High Voltage Equipment C. Trinitis Lehrstuhl f The goal of finding an optimal electric field strength distribution for arbitrary three di­ mensional­ cal optimization algorithm. The package ob­ tained from these three components is then able

  9. 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

  10. 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

  11. Addition and subtraction of spin pumping voltages in magnetic hybrid structures

    SciTech Connect (OSTI)

    Azevedo, A., E-mail: aac@df.ufpe.br; Alves Santos, O.; Cunha, R. O.; Rezende, S. M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Rodríguez-Suárez, R. [Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile)

    2014-04-14T23:59:59.000Z

    We report an investigation of the spin pumping voltage generated in bilayers of ferromagnetic/normal metal in which the ferromagnetic layer is yttrium iron garnet or Permalloy and the normal-metal layer is Pt or Ta. We also investigated a special case in which the voltage is detected in single layer of Permalloy under ferromagnetic resonance condition. It is shown that the spin pumping voltage generated in metallic bilayers have contributions from both layers and the resulting voltage depends on the relative signs of charge currents generated by the inverse spin Hall effect. For instance, the spin pumping voltage generated in Ta has the same sign as the one generate in single layer of Permalloy, but contrary to the voltage generated in Pt. When the voltage is measured in shunted metallic bilayers, the resulting voltage can be a sum or a subtraction of the voltages generated in both layers.

  12. Stabilized PV system

    DOE Patents [OSTI]

    Dinwoodie, Thomas L. (Piedmont, CA)

    2002-12-17T23:59:59.000Z

    A stabilized PV system comprises an array of photovoltaic (PV) assemblies mounted to a support surface. Each PV assembly comprises a PV module and a support assembly securing the PV module to a position overlying the support surface. The array of modules is circumscribed by a continuous, belt-like perimeter assembly. Cross strapping, extending above, below or through the array, or some combination of above, below and through the array, secures a first position along the perimeter assembly to at least a second position along the perimeter assembly thereby stabilizing the array against wind uplift forces. The first and second positions may be on opposite sides on the array.

  13. THE ACS NEARBY GALAXY SURVEY TREASURY

    SciTech Connect (OSTI)

    Dalcanton, Julianne J.; Williams, Benjamin F.; Rosema, Keith; Gogarten, Stephanie M.; Christensen, Charlotte; Gilbert, Karoline; Hodge, Paul [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Seth, Anil C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dolphin, Andrew [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Holtzman, Jon [Department of Astronomy, New Mexico State University, Box 30001, 1320 Frenger St., Las Cruces, NM 88003 (United States); Skillman, Evan D.; Weisz, Daniel [Department of Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States); Cole, Andrew [School of Mathematics and Physics, University of Tasmania, Hobart, Tasmania (Australia); Girardi, Leo [Osservatorio Astronomico di Padova - INAF, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Karachentsev, Igor D. [Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnji Arkhyz, Karachai-Circessia Republic 369167 (Russian Federation); Olsen, Knut [NOAO, National Optical Astronomy Observatory 950 N. Cherry Ave., Tucson, AZ 85719 (United States); Freeman, Ken [Mount Stromlo Observatory, Research School of Astronomy and Astrophysics, The Australian National Univ., ACT 0200 (Australia); Gallart, Carme [Inst. de AstrofIsica de Canarias, VIa Lactea, s/n, 38200 La Laguna, Tenerife (Spain); Harris, Jason [Steward Observatory, Univ. of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); De Jong, Roelof S. [Space Telescope Science Inst., 3700 San Martin Dr., Baltimore, MD 21218 (United States)], E-mail: jd@astro.washington.edu, E-mail: ben@astro.washington.edu, E-mail: krosema@astro.washington.edu, E-mail: stephanie@astro.washington.edu, E-mail: christensen@astro.washington.edu, E-mail: fabio@astro.washington.edu, E-mail: trq@astro.washington.edu, E-mail: aseth@cfa.harvard.edu (and others)

    2009-07-15T23:59:59.000Z

    The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D < 4 Mpc). The survey volume encompasses 69 galaxies in diverse environments, including close pairs, small and large groups, filaments, and truly isolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of {approx}10{sup 4} in luminosity and star formation rate. The survey data consist of images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST), supplemented with archival data and new Wide Field Planetary Camera 2 (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. The new wide field imaging in ANGST reaches median 50% completenesses of m {sub F475W} = 28.0 mag, m {sub F606W} = 27.3 mag, and m {sub F814W} = 27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). The deep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometric catalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.

  14. ac-driven atomic quantum motor

    E-Print Network [OSTI]

    A. V. Ponomarev; S. Denisov; P. Hanggi

    2009-06-09T23:59:59.000Z

    We invent an ac-driven quantum motor consisting of two different, interacting ultracold atoms placed into a ring-shaped optical lattice and submerged in a pulsating magnetic field. While the first atom carries a current, the second one serves as a quantum starter. For fixed zero-momentum initial conditions the asymptotic carrier velocity converges to a unique non-zero value. We also demonstrate that this quantum motor performs work against a constant load.

  15. Method and apparatus for stabilizing pulsed microwave amplifiers

    DOE Patents [OSTI]

    Hopkins, Donald B. (Sacramento, CA)

    1993-01-01T23:59:59.000Z

    Phase and amplitude variations at the output of a high power pulsed microwave amplifier arising from instabilities of the driving electron beam are suppressed with a feed-forward system that can stabilize pulses which are too brief for regulation by conventional feedback techniques. Such variations tend to be similar during successive pulses. The variations are detected during each pulse by comparing the amplifier output with the low power input signal to obtain phase and amplitude error signals. This enables storage of phase and amplitude correction signals which are used to make compensating changes in the low power input signal during the following amplifier output pulse which suppress the variations. In the preferred form of the invention, successive increments of the correction signals for each pulse are stored in separate channels of a multi-channel storage. Sequential readout of the increments during the next pulse provides variable control voltages to a voltage controlled phase shifter and voltage controlled amplitude modulator in the amplifier input signal path.

  16. Method and apparatus for stabilizing pulsed microwave amplifiers

    DOE Patents [OSTI]

    Hopkins, D.B.

    1993-01-26T23:59:59.000Z

    Phase and amplitude variations at the output of a high power pulsed microwave amplifier arising from instabilities of the driving electron beam are suppressed with a feed-forward system that can stabilize pulses which are too brief for regulation by conventional feedback techniques. Such variations tend to be similar during successive pulses. The variations are detected during each pulse by comparing the amplifier output with the low power input signal to obtain phase and amplitude error signals. This enables storage of phase and amplitude correction signals which are used to make compensating changes in the low power input signal during the following amplifier output pulse which suppress the variations. In the preferred form of the invention, successive increments of the correction signals for each pulse are stored in separate channels of a multi-channel storage. Sequential readout of the increments during the next pulse provides variable control voltages to a voltage controlled phase shifter and voltage controlled amplitude modulator in the amplifier input signal path.

  17. Direct amplitude detuning measurement with ac dipole

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

    White, S.; Maclean, E.; Tomás, R.

    2013-07-01T23:59:59.000Z

    In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of the accelerator. Assessing and understanding these effects in experiments is essential to confirm the accuracy of the magnetic model and improve the machine performance. A direct measurement of the machine nonlinearities can be obtained by characterizing the dependency of the tune as a function of the amplitude of oscillations (usually defined as amplitude detuning). The conventional technique is to excite the beam to large amplitudes with a single kick and derive the tune from turn-by-turn data acquired with beam position monitors. Although this provides a very precise tune measurement it has the significant disadvantage of being destructive. An alternative, nondestructive way of exciting large amplitude oscillations is to use an ac dipole. The perturbation Hamiltonian in the presence of an ac dipole excitation shows a distinct behavior compared to the free oscillations which should be correctly taken into account in the interpretation of experimental data. The use of an ac dipole for direct amplitude detuning measurement requires careful data processing allowing one to observe the natural tune of the machine; the feasibility of such a measurement is demonstrated using experimental data from the Large Hadron Collider. An experimental proof of the theoretical derivations based on measurements performed at injection energy is provided as well as an application of this technique at top energy using a large number of excitations on the same beam.

  18. Stability and Complexity in

    E-Print Network [OSTI]

    Landweber, Laura

    and complexity of a commu- nity of interacting plants and animals, following the food web as a clue. Contrary in power. Stability and Complexity in Model Ecosystems played a key role in introducing nonlinear thinking, and current threats to biodiversity have made questions about the role of ecosystem complexity

  19. Stabilized chromium oxide film

    DOE Patents [OSTI]

    Garwin, Edward L. (Los Altos, CA); Nyaiesh, Ali R. (Palo Alto, CA)

    1988-01-01T23:59:59.000Z

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  20. Stabilized chromium oxide film

    DOE Patents [OSTI]

    Nyaiesh, A.R.; Garwin, E.L.

    1986-08-04T23:59:59.000Z

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150A are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  1. Tetraphenylborate Solids Stability Tests

    SciTech Connect (OSTI)

    Walker, D.D. [Westinghouse Savannah River Company, AIKEN, SC (United States); Edwards, T.B.

    1997-12-19T23:59:59.000Z

    Tetraphenylborate solids provide a potentially large source of benzene in the slurries produced in the In-Tank Precipitation process. The stability of the solids is an important consideration in the safety analysis of the process and we desire an understanding of the factors that influence the rate of conversion of the solids to benzene.

  2. Irradiation Stability of Carbon Nanotubes

    E-Print Network [OSTI]

    Aitkaliyeva, Assel

    2010-01-14T23:59:59.000Z

    were used in experiments, and several defect characterization techniques were applied to characterize the damage. Development of dimensional changes of carbon nanotubes in microscopes operated at accelerating voltages of 30 keV revealed that binding...

  3. Interline photovoltaic (I-PV) power plants for voltage unbalance compensation

    E-Print Network [OSTI]

    Moawwad, Ahmed

    This paper proposes a stationary-frame control method for voltage unbalance compensation using Interline Photovoltaic (I-PV) power system. I-PV power systems are controlled to compensate voltage unbalance autonomously. The ...

  4. Novel techniques for fault location, voltage profile calculation and visualization of transients

    E-Print Network [OSTI]

    Evrenosoglu, Cansin Yaman

    2009-05-15T23:59:59.000Z

    techniques of voltage profiles along transmission lines. A simple yet effective approach to accurately and rapidly obtain the voltage profile along a transmission line during fault transients is presented. The objective of the presented method is to eliminate...

  5. A low-voltage zero-crossing-based delta-sigma analog-to-digital converter

    E-Print Network [OSTI]

    Guyton, Matthew C. (Matthew Christopher)

    2010-01-01T23:59:59.000Z

    A zero-crossing-based (ZCB) switched-capacitor technique is presented for operation under low power supply voltages without gate boosting. Voltage ramp generators maintain common-mode level at each integrator output. ...

  6. Dynamic photorefractivity guided by single-pulse voltage

    SciTech Connect (OSTI)

    Agashkov, A. V., E-mail: agashkov@inel.bas.net.by; Kovalev, A. A. [National Academy of Sciences of Belarus, Institute of Electronics (Belarus); Parka, J. [Military University of Technology, Institute of Applied Physics (Poland)

    2008-03-15T23:59:59.000Z

    The dynamic photorefractivity in a cell with photoconducting orienting layers, filled with a nematic liquid crystal (LC) 6CHBT and a mixture of anthraquinone dyes AD1 and AD2, has been investigated. The single-pulse mode, in which the polarity and amplitude of a dc electric field applied to an LC cell are switched for a fixed time interval, has been used. The scheme of dynamic self-diffraction of low-power laser beams was used in the experiment. The dependences of the width and intensity of diffraction pulses on the bias and switching voltages have been investigated. It is established that the width and intensity of the diffraction pulse arising after initial voltage recovery depends also on the switching pulse width. At the optimal width of the control pulse, the diffraction efficiency increases by two orders of magnitude.

  7. Analysis of Solar Cell Quality Using Voltage Metrics: Preprint

    SciTech Connect (OSTI)

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

    2012-06-01T23:59:59.000Z

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

  8. Evaluation of Conservation Voltage Reduction (CVR) on a National Level

    SciTech Connect (OSTI)

    Schneider, Kevin P.; Fuller, Jason C.; Tuffner, Francis K.; Singh, Ruchi

    2010-09-29T23:59:59.000Z

    Conservation Voltage Reduction (CVR) is a reduction of energy consumption resulting from a reduction of feeder voltage. While there have been numerous CVR systems deployed in North America there has been little substantive analytic analysis of the effect; the majority of the published results are based on empirical field measurements. Since these results are based on empirical measurements it is difficult to extrapolate how this technology will behave on the various types of distribution feeders found throughout the nation. This report has utilized the Taxonomy of Prototypical feeder developed under the Modern Grid Initiative (MGI), now the Modern Grid Strategy (MGS), in order to estimate the benefits of CVR on multiple distribution feeder types. This information will then be used to determine an estimate of the national benefits of a wide scale deployment of CVR.

  9. A frequency-domain transient stability criterion for normal contingencies

    SciTech Connect (OSTI)

    Marceau, R.J.; Rizzi, J.C. [Ecole Polytechnique de Montreal, Quebec (Canada). Dept. of Electrical Engineering] [Ecole Polytechnique de Montreal, Quebec (Canada). Dept. of Electrical Engineering; Mailhot, R. [Hydro-Quebec, Montreal, Quebec (Canada)] [Hydro-Quebec, Montreal, Quebec (Canada)

    1995-08-01T23:59:59.000Z

    In a previous paper, a simple frequency-domain stability criterion was proposed for networks near the stability limit subjected to a 3-phase fault with no loss of line. The criterion can be summarized as follows: if a system is stable, the phase angle of the Fourier transform of a network`s transient voltage response exhibits a clockwise polar plot behavior at all buses (i.e. for increasing frequency); if the system is unstable, it exhibits a counterclockwise behavior in at least one location. Though these results are of interest, the criterion would be of greater practical use in mechanizing dynamic security analysis if it could be extended to the types of contingencies actually used in security analysis, namely normal contingencies. Normal contingencies are commonly defined as the loss of any element in a power system, either spontaneously or preceded by a fault, and such changes in topology impact post-contingency steady-state voltages in addition to their transient behavior. The present paper shows how such cases can be treated, thereby extending the applicable range of the criterion to normal contingencies.

  10. Low Voltage Reversible Electrowetting Exploiting Lubricated Polymer Honeycomb Substrates

    E-Print Network [OSTI]

    Edward Bormashenko; Roman Pogreb; Yelena Bormashenko; Roman Grynyov; Oleg Gendelman

    2014-06-16T23:59:59.000Z

    Low-voltage electrowetting-on-dielectric scheme realized with lubricated honeycomb polymer surfaces is reported. Polycarbonate honeycomb reliefs manufactured with the breath-figures self-assembly were impregnated with silicone and castor oils. The onset of the reversible electrowetting for silicone oil impregnated substrates occurred at 35 V, whereas for castor oil impregnated ones it took place at 80 V. The semi-quantitative analysis of electrowetting of impregnated surfaces is proposed.

  11. Magnetic shielding of Hall thrusters at high discharge voltages

    SciTech Connect (OSTI)

    Mikellides, Ioannis G., E-mail: Ioannis.G.Mikellides@jpl.nasa.gov; Hofer, Richard R.; Katz, Ira; Goebel, Dan M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-08-07T23:59:59.000Z

    A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700?V (I{sub sp}???2000–2700?s) at 6?kW, and 800?V (I{sub sp} ? 3000) at 9?kW. At 6?kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300?V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed maximum erosion rates in the range of 300–700?V are found not to exceed 10{sup ?2}?mm/kh. Such rates are ?3 orders of magnitude less than those observed in the unshielded version of the same thruster at 300?V. At 9?kW and 800?V, saturation of the magnetic circuit did not allow for precisely the same magnetic shielding topology as that employed during the 6-kW operation since this thruster was not designed to operate at this condition. Consequently, the maximum erosion rate at the inner wall is found to be ?1 order of magnitude higher (?10{sup ?1}?mm/kh) than that at 6?kW. At the outer wall, the ion energy is found to be below the sputtering yield threshold so no measurable erosion is expected.

  12. Dependence of effective internal field of congruent lithium niobate on its domain configuration and stability

    SciTech Connect (OSTI)

    Das, Ranjit, E-mail: ranjitdas.in@gmail.com, E-mail: souvik2cat@gmail.com, E-mail: srirajib@yahoo.com; Ghosh, Souvik, E-mail: ranjitdas.in@gmail.com, E-mail: souvik2cat@gmail.com, E-mail: srirajib@yahoo.com; Chakraborty, Rajib, E-mail: ranjitdas.in@gmail.com, E-mail: souvik2cat@gmail.com, E-mail: srirajib@yahoo.com [Department of Applied Optics and Photonics, University of Calcutta, JD-2, Sector III, Salt Lake, Kolkata 700098 (India)

    2014-06-28T23:59:59.000Z

    Congruent lithium niobate is characterized by its internal field, which arises due to defect clusters within the crystal. Here, it is shown experimentally that this internal field is a function of the molecular configuration in a particular domain and also on the stability of that particular configuration. The measurements of internal field are done using interferometric technique, while the variation of domain configuration is brought about by room temperature high voltage electric field poling.

  13. NREL Certifies First All-Quantum-Dot Photovoltaic Cell; Demonstrates Stability, Performance (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-02-01T23:59:59.000Z

    Researchers at the National Renewable Energy Laboratory (NREL) have certified the first all-quantum-dot photovoltaic cell, which was based on lead sulfide and demonstrated reasonable quantum dot solar cell performance for an initial efficiency measurement along with good stability. The certified open-circuit voltage of the quantum dot cell is greater than that possible from bulk lead sulfide because of quantum confinement.

  14. Linear inductive voltage adders (IVA) for advanced hydrodynamic radiography

    SciTech Connect (OSTI)

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

    1998-09-01T23:59:59.000Z

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

  15. 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.

  16. Advanced Gate Drive for the SNS High Voltage Converter Modulator

    SciTech Connect (OSTI)

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

    2009-05-07T23:59:59.000Z

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

  17. Thermally-induced voltage alteration for integrated circuit analysis

    DOE Patents [OSTI]

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

    2000-01-01T23:59:59.000Z

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

  18. Thermally-induced voltage alteration for analysis of microelectromechanical devices

    DOE Patents [OSTI]

    Walraven, Jeremy A. (Albuquerque, NM); Cole, Jr., Edward I. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A thermally-induced voltage alteration (TIVA) apparatus and method are disclosed for analyzing a microelectromechanical (MEM) device with or without on-board integrated circuitry. One embodiment of the TIVA apparatus uses constant-current biasing of the MEM device while scanning a focused laser beam over electrically-active members therein to produce localized heating which alters the power demand of the MEM device and thereby changes the voltage of the constant-current source. This changing voltage of the constant-current source can be measured and used in combination with the position of the focused and scanned laser beam to generate an image of any short-circuit defects in the MEM device (e.g. due to stiction or fabrication defects). In another embodiment of the TIVA apparatus, an image can be generated directly from a thermoelectric potential produced by localized laser heating at the location of any short-circuit defects in the MEM device, without any need for supplying power to the MEM device. The TIVA apparatus can be formed, in part, from a scanning optical microscope, and has applications for qualification testing or failure analysis of MEM devices.

  19. Impact of Compiler Optimizations on Voltage Droops and Reliability of an SMT, Multi-Core Processor

    E-Print Network [OSTI]

    John, Lizy Kurian

    Impact of Compiler Optimizations on Voltage Droops and Reliability of an SMT, Multi-Core Processor unreliable operation in microprocessors. Voltage droops due to di/dt effects have been studied in the past, however no prior work studies the effect of compiler optimizations on voltage droops. Past work has

  20. Analysis of Instruction-level Vulnerability to Dynamic Voltage and Temperature Variations

    E-Print Network [OSTI]

    Gupta, Rajesh

    and supply voltage droops [2]. Static process variations can sometimes be mitigated through binning of dynamic variation from environmental and workload changes include supply voltage droops and temperature changes. Voltage droops result from abrupt changes in the switching activity, inducing large current

  1. October 6, 2006 V. Ghazikhanian 1 TOF Low Voltage System Review

    E-Print Network [OSTI]

    Llope, William J.

    TOF Low Voltage Power System. The TOF low voltage system is based on the Wiener PL512 low noise, high45 plugs #12;October 6, 2006 V. Ghazikhanian Tray Low Voltage Power System. Totalof120 the plot of the dark current data on slide]. The DC power will be transmitted via DC transmission lines

  2. An earth-isolated optically coupled wideband high voltage probe powered by ambient light

    E-Print Network [OSTI]

    Bellan, Paul M.

    An earth-isolated optically coupled wideband high voltage probe powered by ambient light Xiang Zhai) An earth-isolated optically coupled wideband high voltage probe powered by ambient light Xiang Zhaia online 9 October 2012) An earth-isolated optically-coupled wideband high voltage probe has been developed

  3. Parameter Variation Analysis for Voltage Controlled Oscillators in Phase-Locked Loops

    E-Print Network [OSTI]

    Moon, Un-Ku

    Parameter Variation Analysis for Voltage Controlled Oscillators in Phase-Locked Loops Igor Vytyaz), the oscillation frequency of a voltage-controlled oscillator (VCO) is specified by the reference frequency on the oscillation frequency as the PLL adjusts the control voltage to keep the frequency unchanged. More importantly

  4. 1. ABSTRACT A 1.4-GHz LC voltage-controlled oscillator has

    E-Print Network [OSTI]

    Lee, Thomas H.

    1. ABSTRACT A 1.4-GHz LC voltage-controlled oscillator has been implemented in a MOSIS 0.5-µm CMOS integrated, low noise, low power voltage-controlled oscillator (VCO). For higher quality receivers, an LC the overall phase noise. In this paper, we present such an LC voltage-controlled oscillator fabricated through

  5. EFFECTS OF SUBSTRATE ON PHASE-NOISE OF BIPOLAR VOLTAGE-CONTROLLED OSCILLATORS

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    EFFECTS OF SUBSTRATE ON PHASE-NOISE OF BIPOLAR VOLTAGE-CONTROLLED OSCILLATORS Aleksandar Tasic predict a dramatically different performance of the oscillators, being different phase-noise, voltage of quasi-tapped bipolar voltage-controlled oscillators [2], phase- noise being of most interest. Contrary

  6. Fast Optimization of Nano-CMOS Voltage-Controlled Oscillator using Polynomial Regression and Genetic Algorithm

    E-Print Network [OSTI]

    Mohanty, Saraju P.

    Fast Optimization of Nano-CMOS Voltage-Controlled Oscillator using Polynomial Regression in a current-starved 50nm voltage-controlled oscillator (VCO). Accurate polynomial-regression based models have-CMOS), Voltage-Controlled Oscillator (VCO). 1. Introduction Digital design exploration and optimization is highly

  7. CONCEPT OF FREQUENCY-TRANSCONDUCTANCE TUNING OF BIPOLAR VOLTAGE-CONTROLLED OSCILLATORS

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    CONCEPT OF FREQUENCY-TRANSCONDUCTANCE TUNING OF BIPOLAR VOLTAGE-CONTROLLED OSCILLATORS Aleksandar-transconductance tuning, introduced in this paper, offers the possibility for voltage-controlled oscillators to trade-tank, the loop-gain, the voltage swing and the phase-noise of the oscillator are changed as well

  8. Understanding Pound-Drever-Hall locking using voltage controlled radio-frequency oscillators: An undergraduate experiment

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Understanding Pound-Drever-Hall locking using voltage controlled radio-frequency oscillators. The three main pieces of equipment are a commercial voltage controlled oscillator, a resonating cavity of the voltage controlled oscillator. The cavity resonance is then observed by scanning the frequency

  9. The vertical voltage termination technique characterizations of single die multiple 600V power

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    The vertical voltage termination technique ­ characterizations of single die multiple 600V power.grenoble-inp.fr Abstract-- Deep trench terminations are commonly known as a technique to achieve ideal breakdown voltages for high voltage devices. This paper presents the use of deep trench terminations as an original concept

  10. Low-Voltage Ride-Through Techniques for DFIG-Based Wind Turbines

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Low-Voltage Ride-Through Techniques for DFIG-Based Wind Turbines: State-of-the-Art Review deals with low-voltage ride-through (LVRT) capability of wind turbines (WTs) and in particular those as to index some emerging solutions. Index Terms--Wind turbine, doubly-fed induction generator, low voltage

  11. Voltage-Sensitivity of Motoneuron NMDA Receptor Channels Is Modulated by Serotonin in the Neonatal Rat Spinal Cord

    E-Print Network [OSTI]

    Manitoba, University of

    isolated in tetrodotoxin, induces nonlinear membrane behavior that results in voltage oscillations which generate rhythmic voltage oscillations in the presence of NMDA and synaptic blockade (with tetrodotoxin application induces neither voltage oscillations (in synaptically isolated motoneurons) nor locomotor network

  12. AUV {gslee, sbahk}@netlab.snu.ac.kr

    E-Print Network [OSTI]

    Bahk, Saewoong

    AUV , {gslee, sbahk}@netlab.snu.ac.kr Transmission Power Control in Cluster AUV (CH) AUV . 1 . 1. 2. 3 . AUV CH (Buoy

  13. University Policy No.: AC1145 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1145 Classification: Academic and Students Approving Authority, interdisciplinary programs, divisions, and the library) will undergo a review every five to seven years

  14. University Policy No.: AC1150 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1150 Classification: Academic and Students TEACHING, portfolios, references, library resources, laboratories and equipment) related to the subject matter

  15. WASEDAUNIVERSITY http://www.sci.waseda.ac.jp/research/

    E-Print Network [OSTI]

    Kasahara, Hironori

    ://www.ase.sci.waseda.ac.jp/ http://www.waseda.jp/ips/ http://www.waseda.jp/weee/ INDEX 2015 5 2 31http

  16. ac conductivity studies: Topics by E-print Network

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

    Last updated 8 Plotkin, Joshua B. 40 Study of supplementary controls for embedded HVDC links in a AC power system. Open Access Theses and Dissertations Summary: ??This...

  17. ac line conditioners: Topics by E-print Network

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

    of lines . ..2 Main Terasoma, Tomohide 83 Study of supplementary controls for embedded HVDC links in a AC power system. Open Access Theses and Dissertations Summary: ??This...

  18. ac losses: Topics by E-print Network

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

    23 24 25 Next Page Last Page Topic Index 1 Transport AC loss in high temperature superconducting coils University of Cambridge - Dspace Summary: 's electromagnetic properties and...

  19. Stability of Coupling Algorithms

    E-Print Network [OSTI]

    Akkasale, Abhineeth

    2012-07-16T23:59:59.000Z

    of Committee, K. B. Nakshatrala Committee Members, Steve Suh J. N. Reddy Head of Department, Dennis O?Neal May 2011 Major Subject: Mechanical Engineering iii ABSTRACT Stability of Coupling Algorithms. (May 2011) Abhineeth Akkasale, B.E., Bangalore... step. iv To Amma and Anna v ACKNOWLEDGMENTS First and foremost, I thank Dr. Kalyana B. Nakshatrala for being an incredible advisor and for his time and patience in constantly guiding me through my research. I am indebted to him for his guidance...

  20. Simplex stability Dhruv Mubayi

    E-Print Network [OSTI]

    Mubayi, Dhruv

    Simplex stability Dhruv Mubayi Reshma Ramadurai November 5, 2008 Abstract A d-simplex that contains no d-simplex. We prove that if |G| (1 - o(1)) n-1 k-1 , then there is a vertex x of G such that the Ai's form a d-simplex, and A contains an element of j=iAj for each i. This generalizes, in asymptotic

  1. Codeword Stabilized Quantum Codes

    E-Print Network [OSTI]

    Andrew Cross; Graeme Smith; John A. Smolin; Bei Zeng

    2007-09-27T23:59:59.000Z

    We present a unifying approach to quantum error correcting code design that encompasses additive (stabilizer) codes, as well as all known examples of nonadditive codes with good parameters. We use this framework to generate new codes with superior parameters to any previously known. In particular, we find ((10,18,3)) and ((10,20,3)) codes. We also show how to construct encoding circuits for all codes within our framework.

  2. AVTA Voltec AC Level 1 and Level 2 Charging Systems Testing Results...

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

    Eaton AC Level 2 Charging System Testing Results AVTA: Aerovironment AC Level 2 Charging System Testing Results AVTA: Siemens-VersiCharge AC Level 2 Charging System Testing Results...

  3. A 3-phase AC to AC matrix converter using the Venturini method 

    E-Print Network [OSTI]

    Dabbousi, Rami M. Osama

    2002-01-01T23:59:59.000Z

    ]. 2. 1 Mathematical Description The input voltages are: V, -& ?? VI costs;t 21t V. =V cos(ot. t- ? ) i2 I i V. =V cos(to t+ ? ) 2tt i3 I where, oh is the input frequency The converter output current is sinusoidal: I t ? Io cos(toot+ ttto) 2...' I =I cos(to t ? +0 ) 02 0 o 3 2tt I 3 Io cos(toot + + t ) 0 0 where, to, is the output frequency 11 Consequently, the matrix equation representation for both the voltage and current is as follows: V, (t) =M(t)V, . (t) I, . (1) = M(t)'I. (1...

  4. AC power | Princeton Plasma Physics Lab

    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 3,625 1,006 492 742EnergyOnItemResearch >InternshipDepartmentNeutrino-Induced1 TEMPERATUREii ABSTRACT ThisAC

  5. Shape Bifurcation of a Spherical Dielectric Elastomer Balloon under the Actions of Internal Pressure and Electric Voltage

    E-Print Network [OSTI]

    Xudong Liang; Shengqiang Cai

    2015-05-29T23:59:59.000Z

    Under the actions of internal pressure and electric voltage, a spherical dielectric elastomer balloon usually keeps a sphere during its deformation, which has also been assumed in many previous studies. In this article, using linear perturbation analysis, we demonstrate that a spherical dielectric elastomer balloon may bifurcate to a non-spherical shape under certain electromechanical loading conditions. We also show that with a non-spherical shape, the dielectric elastomer balloon may have highly inhomogeneous electric field and stress/stretch distributions, which can lead to the failure of the system. In addition, we conduct stability analysis of the dielectric elastomer balloon in different equilibrium configurations by evaluating its second variation of free energy under arbitrary perturbations. Our analyses indicate that under pressure-control and voltage-control mode, non-spherical deformation of the dielectric elastomer balloon is energetically unstable. However, under charge-control or ideal gas mass-control mode, non-spherical deformation of the balloon is energetically stable.

  6. adjustable speed ac: Topics by E-print Network

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

    of Input Voltage Sag and Unbalance on DC Link Inductor and Capacitor Stress in Adjustable Speed Drives Renewable Energy Websites Summary: 's transition into single-phase operation,...

  7. ac adjustable speed: Topics by E-print Network

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

    of Input Voltage Sag and Unbalance on DC Link Inductor and Capacitor Stress in Adjustable Speed Drives Renewable Energy Websites Summary: 's transition into single-phase operation,...

  8. AVTA: Siemens-VersiCharge AC Level 2 Charging System Testing...

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

    Siemens-VersiCharge AC Level 2 Charging System Testing Results AVTA: Siemens-VersiCharge AC Level 2 Charging System Testing Results The Vehicle Technologies Office's Advanced...

  9. AVTA: GE Energy WattStation AC Level 2 Charging System Testing...

    Energy Savers [EERE]

    2012 More Documents & Publications AVTA: Aerovironment AC Level 2 Charging System Testing Results AVTA: GE Smart Grid Capable AC Level 2 Testing Results AVTA: Siemens-VersiCharge...

  10. 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.

  11. business.cardiff.ac.uk Cardiff Business sChool

    E-Print Network [OSTI]

    Davies, Christopher

    business.cardiff.ac.uk Cardiff Business sChool MBa PrograMMes #12;01 business.cardiff.ac.ukWhy Cardiff Business School?01 Why Cardiff Business sChool? We are accredited by the Association to Advance Collegiate Schools of Business (AACSB International), a leading hallmark of business school excellence. We

  12. www.swansea.ac.uk/artsandhumanities Arts and Humanities

    E-Print Network [OSTI]

    Martin, Ralph R.

    dissertation or design a research project of their own (with 10,000 word report) which draws on issues Email: rhys.jones@swansea.ac.uk www.swansea.ac.uk/mediastudies/admissions - The Potter Guide to Higher relations, humanities, social science, computer science or related background. Professionals interested

  13. www.mmu.ac.uk/careers Careers & Employability Service

    E-Print Network [OSTI]

    ;www.mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www: Courses to allow you to enter certain professions Courses that build your skills in a new area Examples · MRes (taught prep for further research) These usually involve lectures for the first two terms

  14. Methods, systems and apparatus for controlling third harmonic voltage when operating a multi-space machine in an overmodulation region

    SciTech Connect (OSTI)

    Perisic, Milun; Kinoshita, Michael H; Ranson, Ray M; Gallegos-Lopez, Gabriel

    2014-06-03T23:59:59.000Z

    Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.

  15. Solid State AC Motor Drives - Conservation Perspectives 

    E-Print Network [OSTI]

    Mohan, N.; Ferraro, R. J.

    1982-01-01T23:59:59.000Z

    Figure 4. Voltage and Current Waveforms. It may be useful to discuss the mechanism by which this concept results in energy savings. Prudent design of a machine requires that the motor losses be a minimum near the rated output condition when... range at constant torque, a 548 ESL-IE-82-04-106 Proceedings from the Fourth Industrial Energy Technology Conference, Houston, TX, April 4-7, 1982 (a) I '--- "'" oJ I I ReClifiCoiion;:mo;:;rsion I Fiilered I I I Load ~Reclifitotion J 1 Current...

  16. Solid State AC Motor Drives - Conservation Perspectives

    E-Print Network [OSTI]

    Mohan, N.; Ferraro, R. J.

    1982-01-01T23:59:59.000Z

    sources of electromagnetic interference and their wid~spread use may result in interference with the ne~rby com munication circuits and Power Line Communi?ations (PLC ). EPRI ACTIVITIES RE: HARMONICS The study of harmonics and electrical noise... generated by solid-state control devices ~s been underway at EPRI since the mid 1970's. A ~ecent EPRI project (6) investigated the techniqubs to minimize the generation of harmonics and t~e effects of current and voltage surges on the utili~y distri...

  17. Adaptive Nonlinear Control of Induction Motors through AC/DC/AC A. El Fadili*1

    E-Print Network [OSTI]

    Boyer, Edmond

    in a satisfactory way. First, a nonlinear model of the whole controlled system is developed within the Park be tightly regulated; (iii) the power factor correction (PFC) w.r.t. the power supply net must be performed control objectives (motor speed tracking, rotor flux regulation, DC link voltage regulation and unitary

  18. Abstract--In this paper, we present the voltage build up process and the terminal voltage control of an isolated wind

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Abstract-- In this paper, we present the voltage build up process and the terminal voltage control that when capacitors are connected across the stator terminals of an induction machine, driven in the stator will continue to grow until steady-state condition is reached [2, 3]. However, self excitation has

  19. Induction of nuclear fission by high-voltage application

    E-Print Network [OSTI]

    Hirokazu Maruyama

    2007-11-20T23:59:59.000Z

    In nuclear power generation, fissile materials are mainly used. For example, $U^{235}$ is fissile and therefore quite essential for use of nuclear energy. However, the material $U^{235}$ has very small natural abundance less than 1 %. We should seek possibility of utilizing fissionable materials such as $U^{238}$ because natural abundance of such fissionable materials is generally much larger than fissile ones. In this paper, we show that thermal neutrons with vanishing kinetic energy can induce nuclear fission when high voltage is applied to fissionable materials. To obtain this result, we use the liquid-drop model for nuclei. Finally, we propose how fissionable materials can be utilized.

  20. Worldwide reliability surveys of high voltage circuit breakers

    SciTech Connect (OSTI)

    Heising, C.R.

    1995-05-01T23:59:59.000Z

    This article reports on the results of two CIGRE 13.06 Working Group worldwide surveys of the reliability of high voltage circuit breakers, 63 kV and above. The first inquiry included 78,000 breaker-years of ``in service data`` from 102 utilities in 22 countries during the years 1974--1977 and included all interrupting technologies. The second inquiry included 70,708 breaker-years from 132 utilities in 22 countries for the years 1988--1991 and only included single-pressure SF6 breakers, because this is what most utilities are now buying. Thirty-one US utilities submitted data.

  1. 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.

  2. 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.

  3. Outdoor PV Module Degradation of Current-Voltage Parameters: Preprint

    SciTech Connect (OSTI)

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

    2012-04-01T23:59:59.000Z

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

  4. Self-monitoring high voltage transmission line suspension insulator

    DOE Patents [OSTI]

    Stemler, Gary E. (Vancouver, WA); Scott, Donald N. (Vancouver, WA)

    1981-01-01T23:59:59.000Z

    A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

  5. Light-induced voltage alteration for integrated circuit analysis

    DOE Patents [OSTI]

    Cole, E.I. Jr.; Soden, J.M.

    1995-07-04T23:59:59.000Z

    An apparatus and method are described for analyzing an integrated circuit (IC). The invention uses a focused light beam that is scanned over a surface of the IC to generate a light-induced voltage alteration (LIVA) signal for analysis of the IC. The LIVA signal may be used to generate an image of the IC showing the location of any defects in the IC; and it may be further used to image and control the logic states of the IC. The invention has uses for IC failure analysis, for the development of ICs, for production-line inspection of ICs, and for qualification of ICs. 18 figs.

  6. Low Voltage Cables Market Analysis | 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 Jump to: navigation, searchOf KilaueaInformation Other4Q07) WindLow Voltage Cables Market Analysis

  7. Low Voltage Cables Market Trends | 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 Jump to: navigation, searchOf KilaueaInformation Other4Q07) WindLow Voltage Cables Market

  8. Low Voltage Cables Market size | 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 Jump to: navigation, searchOf KilaueaInformation Other4Q07) WindLow Voltage Cables MarketLow

  9. Low Voltage Cables Market | 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 Jump to: navigation, searchOf KilaueaInformation Other4Q07) WindLow Voltage Cables MarketLowLow

  10. HIGH-VOLTAGE SPINEL AND POLYANION CATHODES | 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 YourTransport(Fact Sheet), GeothermalGrid Integration0-1HAWAI'I CLEANDepartmentDOEHIGH-VOLTAGE

  11. Chassis stabilization system

    DOE Patents [OSTI]

    Claxton, Gerald L. (Fresno, CA)

    1999-01-01T23:59:59.000Z

    A stabilizing suspension system is provided for vehicles carrying telescopic booms or aerial work platforms having a fixed axle and a oscillating axle. Hydraulic cylinders are connected to each end of the oscillating axle, each cylinder being capable of extending and retracting. An off level sensor senses the angle of tilt of the chassis in both left and right directions and, when a predetermined threshold of tilt has been detected, the hydraulic cylinder on the downhill side of the chassis is locked against retracting, but is free to move in the downhill direction to allow the downhill wheel to remain in contact with the ground.

  12. Personal Web Archive: E-mail: waka@iplab.cs.tsukuba.ac.jp, {shizuki,jiro}@cs.tsukuba.ac.jp

    E-Print Network [OSTI]

    Tanaka, Jiro

    Personal Web Archive: Web E-mail: waka@iplab.cs.tsukuba.ac.jp, {shizuki,jiro}@cs.tsukuba.ac.jp Web Web Web Web Web Web Personal Web Archive Personal Web Archive: Support System for Browsing the Versions of Web Page Ryota WAKAMATSU Buntarou SHIZUKI Jiro TANAKA Graduate School of Systems

  13. Safe-commutation principle for direct single-phase AC-AC converters for use in audio power

    E-Print Network [OSTI]

    and G, expressed as very low total harmonic distortion + noise (THD+N) levels and supplemented. SIngle Conversion stage AMplifier (SICAM) is the next im- portant evolutionary step in designing-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source

  14. An accurate continuous calibration system for high voltage current transformer

    SciTech Connect (OSTI)

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

    2011-02-15T23:59:59.000Z

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

  15. Bi-directional power control system for voltage converter

    DOE Patents [OSTI]

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

    1999-05-11T23:59:59.000Z

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

  16. Bi-directional power control system for voltage converter

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

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

  17. Experiment and Simulation of Dynamic Voltage Regulation in Multiple Distributed Energy Resources Systems

    SciTech Connect (OSTI)

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

    2007-01-01T23:59:59.000Z

    Distributed energy (DE) resources are power sources located near load centers and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide reactive power (along with active power) locally for dynamic voltage regulation. In this paper, a synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Developed voltage control schemes for the inverter and the synchronous condenser are presented. Experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously although the dynamic response of the inverter is much faster than the synchronous condenser. In a system with multiple DEs performing local voltage regulation, the interaction between the DEs is studied. The simulation results show the relationship between the voltages in the system and the reactive power required for the voltage regulation. Also, integrated voltage regulation (multiple DEs performing voltage regulation) can increase the voltage regulation capability of DEs and reduce the capital and operating costs.

  18. Over Voltage in a Multi-sectioned Solenoid during a Quenching

    SciTech Connect (OSTI)

    Guo, Xinglong; Wang, Li; Pan, Heng; Wu, Hong; Liu, Xiaokun; Chen, Anbin; Green, M.A.; Xu, F.Y.

    2009-06-21T23:59:59.000Z

    Accurate analysis of over voltage in the superconducting solenoid during a quench is one of the bases for quench protection system design. Classical quench simulation methods can only give rough estimation of the over voltage within a magnet coil. In this paper, for multi-sectioned superconducting solenoid, based on the classical assumption of ellipsoidal normal zone, three-dimension al temperature results are mapped to the one-dimension of the wire, the temperature distribution along the wire and the resistances of each turn are obtained. The coil is treated as circuit comprised of turn resistances, turn self and mutual inductances. The turn resistive voltage, turn inductive voltage, and turn resultant voltage along the wire are calculated. As a result, maximum internal voltages, the layer-to-layer voltages and the turn-to-turn voltages are better estimated. Utilizing this method, the over voltage of a small solenoid and a large solenoid during quenching have been studied. The result shows that this method can well improve the over voltage estimate, especially when the coil is larger.

  19. Abstract--This paper investigates the effect of Thyristor Controlled Series Capacitor (TCSC) on the voltage stability

    E-Print Network [OSTI]

    , by incorporating TCSC, is then brought about by two case studies. For comparison purposes the results as obtained distribution. Some numerical cases are presented to discuss the effects of TCSC that is expected when of the approach in security based reliability studies for systems having control components like TCSC. Index Terms

  20. DECENTRALIZED CONTROL ARCHITECTURE FOR COUPLING MICROGRIDS INTO DISTRIBUTION NETWORKS 1 Task 1: Coupling Low-Voltage Microgrids into

    E-Print Network [OSTI]

    Lemmon, Michael

    DECENTRALIZED CONTROL ARCHITECTURE FOR COUPLING MICROGRIDS INTO DISTRIBUTION NETWORKS 1 Task 1: Coupling Low-Voltage Microgrids into Mid-Voltage Distribution Systems Zhao Wang, Student Member, IEEE-voltage (LV) microgrids. At the same time, reactive power is dispatched coordinatively so that voltage

  1. Electric fields effect on liftoff and blowoff of nonpremixed laminar jet flames in a coflow

    SciTech Connect (OSTI)

    Kim, M.K.; Ryu, S.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2010-01-15T23:59:59.000Z

    The stabilization characteristics of liftoff and blowoff in nonpremixed laminar jet flames in a coflow have been investigated experimentally for propane fuel by applying AC and DC electric fields to the fuel nozzle with a single-electrode configuration. The liftoff and blowoff velocities have been measured by varying the applied voltage and frequency of AC and the voltage and the polarity of DC. The result showed that the AC electric fields extended the stabilization regime of nozzle-attached flame in terms of jet velocity. As the applied AC voltage increased, the nozzle-attached flame was maintained even over the blowout velocity without having electric fields. In such a case, a blowoff occurred directly without experiencing a lifted flame. While for the DC cases, the influence on liftoff was minimal. There existed three different regimes depending on the applied AC voltage. In the low voltage regime, the nozzle-detachment velocity of either liftoff or blowoff increased linearly with the applied voltage, while nonlinearly with the AC frequency. In the intermediate voltage regime, the detachment velocity decreased with the applied voltage and reasonably independent of the AC frequency. At the high voltage regime, the detachment was significantly influenced by the generation of discharges. (author)

  2. 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.

  3. IMPROVED ROOF STABILIZATION TECHNOLOGIES

    SciTech Connect (OSTI)

    M.A. Ebadian, Ph.D.

    1999-01-01T23:59:59.000Z

    Many U.S. Department of Energy (DOE) remediation sites have performed roof repair and roof replacement to stabilize facilities prior to performing deactivation and decommissioning (D&D) activities. This project will review the decision criteria used by these DOE sites, along with the type of repair system used for each different roof type. Based on this information, along with that compiled from roofing experts, a decision-making tool will be generated to aid in selecting the proper roof repair systems. Where appropriate, innovative technologies will be reviewed and applied to the decision-making tool to determine their applicability. Based on the results, applied research and development will be conducted to develop a method to repair these existing roofing systems, while providing protection for the D and D worker in a cost-efficient manner.

  4. Laser controlled flame stabilization

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Thomas, Matthew E. (Huntsville, AL)

    2001-01-01T23:59:59.000Z

    A method and apparatus is provided for initiating and stabilizing fuel combustion in applications such as gas turbine electrical power generating engines and jet turbine engines where it is desired to burn lean fuel/air mixtures which produce lower amounts of NO.sub.x. A laser induced spark is propagated at a distance from the fuel nozzle with the laser ignitor being remotely located from the high temperature environment of the combustion chamber. A laser initiating spark generated by focusing high peak power laser light to a sufficiently tight laser spot within the fuel to cause the ionization of air and fuel into a plasma is unobtrusive to the flow dynamics of the combustion chamber of a fuel injector, thereby facilitating whatever advantage can be taken of flow dynamics in the design of the fuel injector.

  5. Pulsed voltage electrospray ion source and method for preventing analyte electrolysis

    DOE Patents [OSTI]

    Kertesz, Vilmos (Knoxville, TN); Van Berkel, Gary (Clinton, TN)

    2011-12-27T23:59:59.000Z

    An electrospray ion source and method of operation includes the application of pulsed voltage to prevent electrolysis of analytes with a low electrochemical potential. The electrospray ion source can include an emitter, a counter electrode, and a power supply. The emitter can include a liquid conduit, a primary working electrode having a liquid contacting surface, and a spray tip, where the liquid conduit and the working electrode are in liquid communication. The counter electrode can be proximate to, but separated from, the spray tip. The power system can supply voltage to the working electrode in the form of a pulse wave, where the pulse wave oscillates between at least an energized voltage and a relaxation voltage. The relaxation duration of the relaxation voltage can range from 1 millisecond to 35 milliseconds. The pulse duration of the energized voltage can be less than 1 millisecond and the frequency of the pulse wave can range from 30 to 800 Hz.

  6. Bright and fast voltage reporters across the visible spectrum via electrochromic FRET (eFRET)

    E-Print Network [OSTI]

    Zou, Peng; Douglass, Adam D; Hochbaum, Daniel R; Brinks, Daan; Werley, Christopher A; Harrison, D Jed; Campbell, Robert E; Cohen, Adam E

    2014-01-01T23:59:59.000Z

    We present a palette of brightly fluorescent genetically encoded voltage indicators (GEVIs) with excitation and emission peaks spanning the visible spectrum, sensitivities from 6 - 10% Delta F/F per 100 mV, and half-maximal response times from 1 - 7 ms. A fluorescent protein is fused to an Archaerhodopsin-derived voltage sensor. Voltage-induced shifts in the absorption spectrum of the rhodopsin lead to voltage-dependent nonradiative quenching of the appended fluorescent protein. Through a library screen, we identified linkers and fluorescent protein combinations which reported neuronal action potentials in cultured rat hippocampal neurons with a single-trial signal-to-noise ratio from 6.6 to 11.6 in a 1 kHz imaging bandwidth at modest illumination intensity. The freedom to choose a voltage indicator from an array of colors facilitates multicolor voltage imaging, as well as combination with other optical reporters and optogenetic actuators.

  7. Understanding and Improving High Voltage Vacuum Insulators for Microsecond Pulses

    SciTech Connect (OSTI)

    Javedani, J B; Goerz, D A; Houck, T L; Lauer, E J; Speer, R D; Tully, L K; Vogtlin, G E; White, A D

    2007-03-05T23:59:59.000Z

    High voltage insulation is one of the main areas of pulsed power research and development, and dielectric breakdown is usually the limiting factor in attaining the highest possible performance in pulsed power devices. For many applications the delivery of pulsed power into a vacuum region is the most critical aspect of operation. The surface of an insulator exposed to vacuum can fail electrically at an applied field more than an order or magnitude below the bulk dielectric strength of the insulator. This mode of breakdown, called surface flashover, imposes serious limitations on the power flow into a vacuum region. This is especially troublesome for applications where high voltage conditioning of the insulator and electrodes is not practical and for applications where relatively long pulses, on the order of several microseconds, are required. The goal of this project is to establish a sound fundamental understanding of the mechanisms that lead to surface flashover, and then evaluate the most promising techniques to improve vacuum insulators and enable high voltage operation at stress levels near the intrinsic bulk breakdown limits of the material. The approach we proposed and followed was to develop this understanding through a combination of theoretical and computation methods coupled with experiments to validate and quantify expected behaviors. In this report we summarize our modeling and simulation efforts, theoretical studies, and experimental investigations. The computational work began by exploring the limits of commercially available codes and demonstrating methods to examine field enhancements and defect mechanisms at microscopic levels. Plasma simulations with particle codes used in conjunction with circuit models of the experimental apparatus enabled comparisons with experimental measurements. The large scale plasma (LSP) particle-in-cell (PIC) code was run on multiprocessor platforms and used to simulate expanding plasma conditions in vacuum gap regions. Algorithms were incorporated into LSP to handle secondary electron emission from dielectric materials to enable detailed simulations of flashover phenomenon. Theoretical studies were focused on explaining a possible mechanism for anode initiated surface flashover that involves an electron avalanche process starting near the anode, not a mechanism involving bulk dielectric breakdown. Experiments were performed in Engineering's Pulsed Power Lab using an available 100-kV, 10-{micro}s pulse generator and vacuum chamber. The initial experiments were done with polyethylene insulator material in the shape of a truncated cone cut at +45{sup o} angle between flat electrodes with a gap of 1.0 cm. The insulator was sized so there were no flashovers or breakdowns under nominal operating conditions. Insulator flashover or gap closure was induced by introducing a plasma source, a tuft of velvet, in proximity to the insulator or electrode.

  8. Optimal design of AC filter circuits in HVDC converter stations

    SciTech Connect (OSTI)

    Saied, M.M.; Khader, S.A. [Kuwait Univ. (Kuwait). Electrical and Computer Engineering Dept.

    1995-12-31T23:59:59.000Z

    This paper investigates the reactive power as well as the harmonic conditions on both the valve and the AC-network sides of a HVDC converter station. The effect of the AC filter circuits is accurately modeled. The program is then augmented by adding an optimization routine. It can identify the optimal filter configuration, yielding the minimum current distortion factor at the AC network terminals for a prespecified fundamental reactive power to be provided by the filter. Several parameter studies were also conducted to illustrate the effect of accidental or intentional deletion of one of the filter branches.

  9. Systems and methods for process and user driven dynamic voltage and frequency scaling

    DOE Patents [OSTI]

    Mallik, Arindam (Evanston, IL); Lin, Bin (Hillsboro, OR); Memik, Gokhan (Evanston, IL); Dinda, Peter (Evanston, IL); Dick, Robert (Evanston, IL)

    2011-03-22T23:59:59.000Z

    Certain embodiments of the present invention provide a method for power management including determining at least one of an operating frequency and an operating voltage for a processor and configuring the processor based on the determined at least one of the operating frequency and the operating voltage. The operating frequency is determined based at least in part on direct user input. The operating voltage is determined based at least in part on an individual profile for processor.

  10. High-speed, sub-pull-in voltage MEMS switching.

    SciTech Connect (OSTI)

    Spahn, Olga Blum; Brewer, Steven; Olsson, Roy H.; Bogart, Gregory R.; Luck, David L.; Watts, Michael R.; Shaw, Michael J.; Nielson, Gregory N.; Resnick, Paul James; Tigges, Christopher P.; Grossetete, Grant David

    2008-01-01T23:59:59.000Z

    We have proposed and demonstrated MEMS switching devices that take advantage of the dynamic behavior of the MEMS devices to provide lower voltage actuation and higher switching speeds. We have explored the theory behind these switching techniques and have demonstrated these techniques in a range of devices including MEMS micromirror devices and in-plane parallel plate MEMS switches. In both devices we have demonstrated switching speeds under one microsecond which has essentially been a firm limit in MEMS switching. We also developed low-loss silicon waveguide technology and the ability to incorporate high-permittivity dielectric materials with MEMS. The successful development of these technologies have generated a number of new projects and have increased both the MEMS switching and optics capabilities of Sandia National Laboratories.

  11. (Insulating materials and large high voltage electric systems)

    SciTech Connect (OSTI)

    Dale, S.J.

    1990-09-18T23:59:59.000Z

    The traveler attended the 33rd Session of CIGRE (The International Conference on Large High Voltage Electric Systems in Paris, France) as a US technical expert advisor the Study Committee 15, Insulating Materials. Over 200 papers were discussed, contributed from over 45 countries at the conference on all aspects of electric power generation and transmission. Of special interest was a panel session on superconducting technology for electric power systems and the participation on a new task force on the electrical insulation at cryogenic temperatures. Significant insight was gained into the development of superconducting power technologies in Europe and Japan. CIGRE has set up a committee to follow the development in research on the biological effects of electric and magnetic fields. The traveler also visited the Centre for Electric Power Engineering at the University of Strathclyde, Glasgow, Scotland and discussed research on degradation of polymeric cable insulation and gas insulated equipment. 5 refs.

  12. DIII-D ICRF high voltage power supply regulator upgrade

    SciTech Connect (OSTI)

    Cary, W.P.; Burley, B.L.; Grosnickle, W.H.

    1997-11-01T23:59:59.000Z

    For reliable operation and component protection, of the 2 MW 30--120 MHz ICRF Amplifier System on DIII-D, it is desirable for the amplifier to respond to high VSWR conditions as rapidly as possible. This requires a rapid change in power which also means a rapid change in the high voltage power supply current demands. An analysis of the power supply`s regulator dynamics was needed to verify its expected operation during such conditions. Based on this information it was found that a new regulator with a larger dynamic range and some anticipation capability would be required. This paper will discuss the system requirements, the as-delivered regulator performance, and the improved performance after installation of the new regulator system. It will also be shown how this improvement has made the amplifier perform at higher power levels more reliably.

  13. Effect of high-voltage nanosecond pulses on complex plasmas

    SciTech Connect (OSTI)

    Pustylnik, M. Y.; Ivlev, A. V.; Thomas, H. M.; Morfill, G. E. [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, 85741 Garching (Germany); Vasilyak, L. M.; Vetchinin, S. P.; Polyakov, D. N.; Fortov, V. E. [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, 125412 Moscow (Russian Federation)

    2009-11-15T23:59:59.000Z

    Influence of high-voltage (1-11 kV) pulses of nanosecond (20 ns) duration on microparticles levitating in a rf plasma is studied. It is shown that the pulses produce significant influence on the plasma, causing perturbations with the relaxation time of the order of 10{sup -4} s. This time is sufficient for the microparticle to acquire significant kinetic energy. Application of repetitive pulses leads to the vertical oscillations of the microparticles. Clusters, consisting of small number of microparticles, exhibit parametric instabilities of horizontal modes under the effect of repetitive pulses. It was shown that the parametric instability is caused by the vertical oscillations of the microparticles in the nonuniform environment of the sheath.

  14. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    SciTech Connect (OSTI)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01T23:59:59.000Z

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  15. Nanowire-based ternary transistor by threshold-voltage manipulation

    SciTech Connect (OSTI)

    Han, Junebeom; Lim, Taekyung; Bong, Jihye; Seo, Keumyoung; Ju, Sanghyun, E-mail: shju@kgu.ac.kr [Department of Physics, Kyonggi University, Suwon, Gyeonggi-Do 443-760 (Korea, Republic of); Kim, Sunkook [Department of Electronics and Radio Engineering, Kyung Hee University, Yongin, Gyeonggi-Do 446-701 (Korea, Republic of)

    2014-04-07T23:59:59.000Z

    We report on a ternary device consisting of two nanowire channels that have different threshold voltage (V{sub th}) values and show that three current stages can be produced. A microscale laser-beam shot was utilized to selectively anneal the nanowire channel area to be processed, and the amount of V{sub th} shift could be controlled by adjusting the laser wavelength. Microscale laser annealing process could control V{sub th} of the individual nanowire transistors while maintaining the other parameters the constant, such as the subthreshold slope, on–off current ratio, and mobility. This result could provide a potential for highly integrated and high-speed ternary circuits.

  16. Probabilistic Vulnerability Assessment Based on Power Flow and Voltage Distribution

    SciTech Connect (OSTI)

    Ma, Jian; Huang, Zhenyu; Wong, Pak C.; Ferryman, Thomas A.

    2010-04-30T23:59:59.000Z

    Risk assessment of large scale power systems has been an important problem in power system reliability study. Probabilistic technique provides a powerful tool to solve the task. In this paper, we present the results of a study on probabilistic vulnerability assessment on WECC system. Cumulant based expansion method is applied to obtain the probabilistic distribution function (PDF) and cumulative distribution function (CDF) of power flows on transmission lines and voltage. Overall risk index based on the system vulnerability analysis is calculated using the WECC system. The simulation results based on WECC system is used to demonstrate the effectiveness of the method. The methodology can be applied to the risk analysis on large scale power systems.

  17. High voltage design structure for high temperature superconducting device

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D. (Rexford, NY)

    2008-05-20T23:59:59.000Z

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

  18. System and method for floating-substrate passive voltage contrast

    DOE Patents [OSTI]

    Jenkins, Mark W. (Albuquerque, NM); Cole, Jr., Edward I. (Albuquerque, NM); Tangyunyong, Paiboon (Albuquerque, NM); Soden, Jerry M. (Placitas, NM); Walraven, Jeremy A. (Albuquerque, NM); Pimentel, Alejandro A. (Albuquerque, NM)

    2009-04-28T23:59:59.000Z

    A passive voltage contrast (PVC) system and method are disclosed for analyzing ICs to locate defects and failure mechanisms. During analysis a device side of a semiconductor die containing the IC is maintained in an electrically-floating condition without any ground electrical connection while a charged particle beam is scanned over the device side. Secondary particle emission from the device side of the IC is detected to form an image of device features, including electrical vias connected to transistor gates or to other structures in the IC. A difference in image contrast allows the defects or failure mechanisms be pinpointed. Varying the scan rate can, in some instances, produce an image reversal to facilitate precisely locating the defects or failure mechanisms in the IC. The system and method are useful for failure analysis of ICs formed on substrates (e.g. bulk semiconductor substrates and SOI substrates) and other types of structures.

  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. PVREG - A photovoltaic voltage regulation investigation tool: Program reference manual

    SciTech Connect (OSTI)

    Garrett, D.L.; Sims, T.R.; Jones, R.A.; Jeter, S.M.

    1989-06-01T23:59:59.000Z

    This manual provides information for installing and maintaining the computer program PVREG, a program developed to study the impact of distributed photovoltaic systems on the voltage regulation of distribution systems. The manual describes installation on the Apollo workstation or the IBM PC-AT (or compatible), but the instructions and code description should be general enough to assist installation on other computers, also. The manual assumes that the user is well acquainted with the computer on which the program is to operate and with the operating system of that computer. The manual describes the program structure and models in detail and provides step-by-step installation instructions for both the Apollo and AT-compatible computers. 9 figs., 11 tabs.