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1

Electric current flow through human skin at power frequency voltages  

PubMed Central

Carter, A.O., and Morley R. (1969).Brit. J. industr. Med.,26, 217-223. Electric current flow through human skin at power frequency voltages. Alternating power voltages were applied to small pieces of living skin. Current and voltage were recorded continuously using voltages from 25 V to 250 V. At the lower voltages the skin appeared unaffected, but rapid destruction occurred at the higher voltages. It is concluded that skin impedance, whilst being extremely variable on account of many physical factors, is dependent on voltage and time of application in the range where dangerous electric shock occurs to human beings at power frequencies. PMID:5794946

Carter, A. O.; Morley, R.

1969-01-01

2

The Voltage Stability Research of Ship Electric Power System  

Microsoft Academic Search

Ship electric power system is an independent electric power system, and is important in ships. At present, with the increasing tonnage of ships and more and more ships propelled by electric power, the capacity of generator in a marine power station is getting larger and larger. Because of electric propulsion technology applied by modern marines, the control system of voltage

Fanyinhai Zhaomin

2006-01-01

3

Integrated voltage and reactive power control for all electric ship power systems  

Microsoft Academic Search

All electric ship alternators are connected to a main busbar which feeds all shipboard electric loads. To fulfill power quality requirements of the resulting electrical system, high-performance control of busbar voltage and frequency is needed. Such a task is not of easy accomplishment, due to the complexity of shipboard power station (generators are many and differ by sizes, prime movers,

V. Arcidiacono; S. Castellan; R. Menis; G. Sulligoi

2006-01-01

4

Power Management of Aggregate Electric Water Heater Loads by Voltage Control  

Microsoft Academic Search

This paper discusses a voltage-control strategy for power management of aggregate residential electric water heater (EWH) load. It is shown that by proper control of EWH operating voltage, the aggregate EWH power demand during peak-load hours can be reduced without necessarily sacrificing customers' comfort level.

M. Hashem Nehrir; Runmin Jia; Donald A. Pierre; Donald J. Hammerstrom

2007-01-01

5

Voltage-Distortion Compensation in Electrical Plants Supplying Static Power Converters  

Microsoft Academic Search

Voltage distortion compensation is a problem that must often be tackled in electrical plants supplying nonlinear loads, such as static power converters, both to ensure reliable behavior of apparatus sensible to harmonics and to comply with standard limits. Analysis of the compensation system constituted by harmonic filters and protection reactance is carried out, to clarify their contribution to voltage distortion

Gian Carlo Montanari; Mauro Loggini

1987-01-01

6

System for monitoring the electric power supply system and for voltage and current transients recording  

Microsoft Academic Search

This paper presents a new system for two important applications of digital recording in real time characterisation of electric signals. The first one consists of a digital recorder of the time evolution of voltage signals working in two modes: recording directly the evolution of the signal waveform or the evolution of the main electric parameters: RMS, power components and frequency

E. Aramendi; J. Ruiz; L. Leturiondo; A. Lazcano

1996-01-01

7

Numerical Electric Field Analysis of Power Status Sensor Observing Power Distribution System Taking into Account Voltage Divider Measurement Circuit  

NASA Astrophysics Data System (ADS)

We have proposed and preproducted the voltage-current waveform sensor of resin molded type for measuring the power factor and harmonics in power distribution systems. We have executed numerical electromagnetic analyses using the finite element method to estimate the characteristics and behaviours of the sensor. Although the magnetic field analyses for the current sensor have involved the measurement circuit, the electric field analyses have not included the measurement circuit for measuring voltage waveforms of power lines. In this paper, we describe the electric field analyses with the measurement circuit and prove the insulating strength of the proposed sensor permissible to the use in 22kV power distribution systems.

Kubo, Takuro; Furukawa, Tatsuya; Itoh, Hideaki; Fukumoto, Hisao; Wakuya, Hiroshi; Ohchi, Masashi

8

Electrical safety analysis in low voltage systems with electronic power converters  

Microsoft Academic Search

The widespread use of the power electronic place the problem of the correct operation of the protection system, in order to guarantee the electrical safety for the person in case of indirect contact downstream a converter. The aim of this paper is to estimate the various shapes of voltage and current waves in case of fault in order to give

M. Brenna; F. Iannone; D. Zaninelli

2005-01-01

9

Load insensitive electrical device. [power converters for supplying direct current at one voltage from a source at another voltage  

NASA Technical Reports Server (NTRS)

A class of power converters is described for supplying direct current at one voltage from a source at another voltage. It includes a simple passive circuit arrangement of solid-state switches, inductors, and capacitors by which the output voltage of the converter tends to remain constant in spite of changes in load. The switches are sensitive to the current flowing in the circuit and are employed to permit the charging of capacitance devices in accordance with the load requirements. Because solid-state switches (such as SCR's) may be used with relatively high voltage and because of the inherent efficiency of the invention that permits relatively high switching frequencies, power supplies built in accordance with the invention, together with their associated cabling, can be substantially lighter in weight for a given output power level and efficiency of operation than systems of the prior art.

Schwarz, F. C. (inventor)

1974-01-01

10

Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning  

NASA Technical Reports Server (NTRS)

Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages.

Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

11

Generating Electrical Voltage  

NSDL National Science Digital Library

Teachers' Domain presents this interactive lesson designed to help students "learn how a generator converts mechanical energy into electrical energy. Investigate the principle of magnetic induction by moving a conductor through a magnetic field to see how voltage is generated." The lesson is divided into three major sections: How Do Generators Work?, What Factors Influence Voltage Strength?, and What Determines Voltage Polarity? There are plenty of animations to help students visualize the processes at work in electricity generation. On the site, visitors will also find a supplemental background essay, discussion questions, and standards alignment from Teachers' Domain.

2010-10-06

12

Summary of a Guide for Determining the Maximum Electric Power Station Ground Potential Rise and Induced Voltage from a Power Fault  

Microsoft Academic Search

Difficulties are experienced by telecommunication and protective relay engineers in determining the maximum power station ground potential rise, and\\/or induced voltages. Suitably rated protective devices are required for personnel safety and for the protection and continuity of service of wire line telecommunication facilities entering electrical power stations, or otherwise exposed to the influence of electrical power circuits. This is a

Power Communications

1979-01-01

13

Environmental justice: a contrary finding for the case of high-voltage electric power transmission lines.  

PubMed

Environmental justice is the consideration of whether minority and/or lower-income residents in a geographic area are likely to have disproportionately higher exposures to environmental toxins than those living elsewhere. Such situations have been identified for a variety of factors, such as air pollution, hazardous waste, water quality, noise, residential crowding, and housing quality. This study investigates the application of this concept to high-voltage electric power transmission lines (HVTL), which some perceive as a health risk because of the magnetic fields they generate, and also as esthetically unpleasing. We mapped all 345 kV and higher voltage HVTL in New York State and extracted and summarized proximate US Census sociodemographic and housing characteristic data into four categories on the basis of distances from HVTL. Contrary to our expectation, people living within 2000 ft from HVTL were more likely to be exposed to magnetic fields, white, of higher income, more educated and home owners, than those living farther away, particularly in urban areas. Possible explanations for these patterns include the desire for the open space created by the rights-of-way, the preference for new homes/subdivisions that are often located near HVTL, and moving closer to HVTL before EMFs were considered a risk. This study suggests that environmental justice may not apply to all environmental risk factors and that one must be cautious in generalizing. In addition, it shows the utility of geographical information system methodology for summarizing information from extremely large populations, often a challenge in epidemiology. PMID:19352413

Wartenberg, Daniel; Greenberg, Michael R; Harris, Gerald

2010-05-01

14

Dual voltage electrical system  

SciTech Connect

A dual voltage motor vehicle electrical system is described which consists of an alternating current generator having a polyphase output winding, a polyphase full-wave bridge rectifier comprised of groups of positive and negative diodes, the bridge rectifier having AC input terminals connected to the output winding and having positive and negative direct voltage output terminals, first and second storage batteries connected in series and across the direct voltage output terminals of the bridge rectifier, the negative terminal of one battery and the positive terminal of the other battery being connected to a common junction, a first switchable rectifying circuit connected between the junction and the AC input terminals, the first switchable rectifying circuit when biased conductive and one of the groups of diodes supplying charging current to one of the batteries, a second switchable rectifying circuit connected between the junction and the AC input terminals, the second switchable rectifying circuit when biased conductive and the other group of the diodes supplying charging current to the other battery, means for causing the switchable rectifying circuits to be biased alternately conductive, means for sensing the relative magnitudes of the voltages across the batteries, and means responsive to the difference in the voltages across the batteries for controlling the time periods that the switchable rectifying circuits are biased conductive.

Radomski, T.A.

1987-08-11

15

Electrical aging markers for EPR-based low-voltage cable insulation wiring of nuclear power plants  

NASA Astrophysics Data System (ADS)

This paper presents results of electrical property measurements on EPR-based insulations of low-voltage power cables used in nuclear power plants. The specimens underwent accelerated aging through the simultaneous application of high temperature and gamma-radiation. Mechanical properties and the dielectric response at different frequencies were investigated. Results showed significant variation of the electrical and mechanical properties of aged cables at low frequencies, i.e. lower than 10-2 Hz. In particular, the real and imaginary parts of permittivity increase with aging time, accumulated dose and stress levels applied showing good correlation with elongation at break, which decreases as a function of extent of insulation aging.

Verardi, L.; Fabiani, D.; Montanari, G. C.

2014-01-01

16

Residual voltage of the electrical equipment  

NASA Astrophysics Data System (ADS)

The rapid development of electronic products today, it is a very important part of that electric shock prevention remains the safety design of electronic products. When unplug the electrical equipment, the voltage in each pin of the plug is residual voltage. If residual voltage is too large, it may cause harm to human body, must attach importance to it and precisely measure it. Load of different electrical products lead to different transient voltage changes in sudden power-down, namely the changes in the residual voltage. In this paper, the load on the electrical equipment on the basis of type classification, focusing on the design of their corresponding capacitive load and peak power detection circuit link was simulated, thus arrive at the variation discipline of residual voltage, in order to better protect human safety.

Yuan, Jia; Qian, Xiaoyao; Qian, Jiawei

2010-08-01

17

Static bifurcations in electric power networks: Loss of steady-state stability and voltage collapse  

Microsoft Academic Search

This paper presents an analysis of static stability in electric power systems. The study is based on a model consisting of the classical swing equation characterization for generators and constant admittance, PV bus and\\/or PQ bus load representations which, in general, leads to a semi-explicit (or constrained) system of differential equations. A precise definition of static stability is given and

HARRY G. KWATNY; ARUN K. PASRIJA; LEON Y. BAHAR

1986-01-01

18

High voltage power supply  

NASA Technical Reports Server (NTRS)

A high voltage power supply is formed by three discrete circuits energized by a battery to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. In the first two circuits, the regulator stages are pulse width modulated and include adjustable ressistances for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance for varying the amplitude of a steady signal provided to a third oscillator stage. In the first circuit, the oscillator, formed by a constant current drive network and a tuned resonant network included a step up transformer, is coupled to a second step up transformer which, in turn, supplies an amplified sinusoidal signal to a parallel pair of complementary poled rectifying, voltage multiplier stages to generate the high output voltage.

Ruitberg, A. P.; Young, K. M. (inventors)

1985-01-01

19

High voltage DC power supply  

DOEpatents

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

Droege, Thomas F. (Batavia, IL)

1989-01-01

20

High voltage DC power supply  

DOEpatents

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

Droege, T.F.

1989-12-19

21

Electrical safety for high voltage arrays  

NASA Technical Reports Server (NTRS)

A number of key electrical safety requirements for the high voltage arrays of central station photovoltaic power systems are explored. The suitability of representative industrial DC power switchgear for control and fault protection was evaluated. Included were AC/DC circuit breakers, electromechanical contactors and relays, load interruptors, cold disconnect devices, sectionalizing switches, and high voltage DC fuses. As appropriate, steady state and transient characteristics were analyzed. Failure modes impacting upon operation and maintenance safety were also identified, as were the voltage withstand and current interruption levels.

Marshall, N. A.

1983-01-01

22

Spacecraft high-voltage power supply construction  

NASA Technical Reports Server (NTRS)

The design techniques, circuit components, fabrication techniques, and past experience used in successful high-voltage power supplies for spacecraft flight systems are described. A discussion of the basic physics of electrical discharges in gases is included and a design rationale for the prevention of electrical discharges is provided. Also included are typical examples of proven spacecraft high-voltage power supplies with typical specifications for design, fabrication, and testing.

Sutton, J. F.; Stern, J. E.

1975-01-01

23

High voltage spacecraft electrical systems design  

NASA Technical Reports Server (NTRS)

Factors which must be considered when designing the best and the most cost-effective high-voltage electrical system for a spacecraft are discussed with particular attention given to the EMC considerations, high-voltage power bus, and harnesses. It is emphasized that the use of serial data buses and lines greatly simplify the harness design and weight. Careful attention to the grounding concept and the EMC requirements is necessary for insuring a 'quiet' spacecraft.

Stone, R. E.

1993-01-01

24

Output voltage regulation in matrix converter fed power electronic transformer for power systems application in electric ship  

Microsoft Academic Search

The system described in this paper uses three matrix converters and a high frequency transformer to achieve isolation and voltage transformation from primary to secondary side. Two matrix converters produce high frequency voltage across a transformer, with open ended primary. A third matrix converter converts the high frequency chopped voltage to line frequency. The non-idealities such as leakage inductance of

Shabari Nath; K. K. Mohapatra; Ned Mohan

2009-01-01

25

Public Opinions of Building Additional High-Voltage Electric Power Lines  

E-print Network

, and summarizes key findings of the survey. It is hoped that this report will further inform policy makers and interested public and private sector organizations about public opinions regarding the building of new power. Respondents were informed that plans to build additional power lines have been endorsed by both the George W

Tesfatsion, Leigh

26

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

E-print Network

vehicle during both acceleration and regenerative braking. The life cycle of the electric vehicle of which include the use of regenerative braking and load levelling. Regenerative braking is easily electrochemical batteries to store energy during regenerative braking consequently leads to a greatly oversized

Szabados, Barna

27

CPFLOW for Power Tracer and Voltage Monitoring  

E-print Network

Systems Engineering Research Center A National Science Foundation Industry/University Cooperative Research Center since 1996 PSERC #12;Power Systems Engineering Research Center CPFLOW for Power Tracer and Voltage contact: Professor Hsiao-Dong Chiang School of Electrical and Computer Engineering Cornell University 328

28

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

NASA Astrophysics Data System (ADS)

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.

Sulaeman, M. Y.; Widita, R.

2014-09-01

29

Cabine primarie AT/MT dell'ENEL per l'alimentazione dei centri urbani. (ENEL high and medium voltage electrical substations for power supply to urban centers).  

National Technical Information Service (NTIS)

Modular high and medium voltage gas insulated electrical substations are being used by ENEL (Italian Electricity Board) to meet the specific needs of urban centers with special design and sizing constraints of a historical/architectural nature. This paper...

A. Bargigia, C. Boatto, A. Di Mario, N. Fava, S. Sciarra

1991-01-01

30

Low electrical potential anode modified with Fe/ferric oxide and its application in marine benthic microbial fuel cell with higher voltage and power output  

NASA Astrophysics Data System (ADS)

Low voltage and power output limit the widespread application of marine benthic microbial fuel cell (BMFCs). To increase the cell power, a Fe/Ferric oxide modified anode fabricating by electrolytic deposition is reported here. The novel anode has a lower surface contact angle and higher wettability, which favors the adhesion of bacteria. It is firstly demonstrated that the electrical potential of the modified anode is about -775 mV, much lower than that of the plain graphite (about -450 mV). Open circuit potential of BMFC with the modified anode is about 1050 ± 50 mV, while the potential for the plain cells is only 700 ± 50 mV. In comparison with the plain graphite, the modified anode presents a 393-fold exchange current density and a higher kinetic activity. The output power reaches 7.4 × 10-2 mW cm-2, 17.4-fold higher than that of the plain graphite. A composite mechanism of both chemical and microbial enhancement of the modified anode is proposed to explain its excellent electrochemical performance. The modified anode has potential for high-power output cell and novel voltage-booster design to make the BMFC utilization feasibility.

Fu, Yubin; Xu, Qian; Zai, Xuerong; Liu, Yuanyuan; Lu, Zhikai

2014-01-01

31

Reactive power management and voltage control in deregulated power markets  

NASA Astrophysics Data System (ADS)

The research that is the subject of this dissertation is about the management of reactive power and voltage support in the wholesale open access power markets in the United States (US). The purpose of this research is to place decisions about open access market structures, as they relate to reactive power and voltage control, on a logical and consistent economic basis, given the engineering needs of a commercial electric power system. An examination of the electricity markets operating in the US today reveals that current approaches to reactive power management and voltage support are extensions of those based on historical, regulated monopoly electric service. A case for change is built by first looking at the subject of reactive power from an engineering viewpoint and then from an economic perspective. Ultimately, a set of market rules for managing reactive power and voltage support is proposed. The proposal suggests that cost recovery for static and dynamic VARs is appropriately accomplished through the regulated transmission cost of service. Static VAR cost recovery should follow traditional rate recovery methodologies. In the case of dynamic VARs, this work provides a methodology based on the microeconomic theory of the firm for determining such cost. It further suggests that an operational strategy that reduces and limits the use of dynamic VARs, during normal operations, is appropriate. This latter point leads to an increase in the fixed cost of the transmission network but prevents price spikes and short supply situations from affecting, or being affected by, the reactive capability limitations associated with dynamic VARs supplied from synchronous generators. The rules are consistent with a market structure that includes competitive generation and their application will result in the communication of a clear understanding of the responsibilities, related to voltage control, of each type of market entity. In this sense, their application will contribute to the efficient functioning of the wholesale open access markets.

Spangler, Robert G.

32

Electrical Safety In The High Voltage Laboratory  

Microsoft Academic Search

In the process of reevaluating the thoroughness and long-term retention of existing electrical safety training programs at Lawrence Livermore National Lab, a new, intensive training program has been developed. Although it encompasses the electrical safety of utility power it is primarily designed to include the specialized safety issues present in the high energy or pulsed power laboratory. The unique approach

L. B. Gordon; D. L. Counts; W. W. Hofer; C. W. Jordan; A. E. Kirkewoog; B. R. Schleicher

1989-01-01

33

Electrical safety in the high voltage laboratory  

Microsoft Academic Search

In the process of reevaluating the thoroughness and long term retention of existing electrical safety training programs at Lawrence Livermore National Lab, a new, intensive training program was developed. Although it encompasses the electrical safety of utility power it is primarily designed to include the specialized safety issues present in the high energy or pulsed power laboratory. The unique approach

L. B. Gordon; D. L. Counts; W. W. Hofer; C. W. Jordan; A. E. Kirkewoog; B. R. Schleicher

1989-01-01

34

Intense neutron source: high-voltage power supply specifications  

SciTech Connect

This report explains the need for and sets forth the electrical, mechanical and safety specifications for a high-voltage power supply to be used with the intense neutron source. It contains sufficient information for a supplier to bid on such a power supply.

Riedel, A.A.

1980-08-01

35

Adaptive Phase Adjustment Synchronization Method for Source Voltage Distortion in Electric Ship  

E-print Network

Adaptive Phase Adjustment Synchronization Method for Source Voltage Distortion in Electric Ship, the source voltage typically contains some distortion. Specifically, US Navy ship power generators experience such as aeroplanes, vehicles and electric ships. Due to the extensive use of devices with power electronics

Lehman, Brad

36

Critical Voltage for Electrical Degradation of GaN High-Electron Mobility Transistors  

Microsoft Academic Search

We have found that there is a critical drain-to-gate voltage beyond which GaN high-electron mobility transistors start to degrade in electrical-stress experiments. The critical voltage depends on the detailed voltage biasing of the device during electrical stress. It is higher in the OFF state and high-power state than at VDS = 0. In addition, as |VGS| increases, the critical voltage

Jungwoo Joh; JesÚs A. del Alamo

2008-01-01

37

Piezoelectric transformer and modular connections for high power and high voltage power supplies  

NASA Technical Reports Server (NTRS)

A modular design for combining piezoelectric transformers is provided for high voltage and high power conversion applications. The input portions of individual piezoelectric transformers are driven for a single power supply. This created the vibration and the conversion of electrical to electrical energy from the input to the output of the transformers. The output portions of the single piezoelectric transformers are combining in series and/or parallel to provide multiple outputs having different rating of voltage and current.

Vazquez Carazo, Alfredo (Inventor)

2006-01-01

38

Topological properties of high-voltage electrical transmission networks  

Microsoft Academic Search

The topological properties of high-voltage electrical power transmission networks in several UE countries (the Italian 380?kV, the French 400?kV and the Spanish 400?kV networks) have been studied from available data. An assessment of the vulnerability of the networks has been given by measuring the level of damage introduced by a controlled removal of links. Topological studies could be useful to

V. Rosato; S. Bologna; F. Tiriticco

2007-01-01

39

TOPEX electrical power system  

NASA Technical Reports Server (NTRS)

The TOPEX mission requirements which impact the power requirements and analyses are presented. A description of the electrical power system (EPS), including energy management and battery charging methods that were conceived and developed to meet the identified satellite requirements, is included. Analysis of the TOPEX EPS confirms that all of its electrical performance and reliability requirements have been met. The TOPEX EPS employs the flight-proven modular power system (MPS) which is part of the Multimission Modular Spacecraft and provides high reliability, abbreviated development effort and schedule, and low cost. An energy balance equation, unique to TOPEX, has been derived to confirm that the batteries will be completely recharged following each eclipse, under worst-case conditions. TOPEX uses three NASA Standard 50AH Ni-Cd batteries, each with 22 cells in series. The MPS contains battery charge control and protection based on measurements of battery currents, voltages, temperatures, and computed depth-of-discharge. In case of impending battery depletion, the MPS automatically implements load shedding.

Chetty, P. R. K.; Roufberg, Lew; Costogue, Ernest

1991-01-01

40

Powerformers: A breakthrough of high-voltage power generators  

Microsoft Academic Search

This article deals with the powerformer, a new generator that can be directly connected to the transmission network without the need for a step-up transformer. Due to the powerformer's ability to generate electricity at transmission voltage levels, it offers considerable gains with respect to reactive power production and plant efficiency. Hence, a powerformer both facilitates network stability and decreases the

Ibrahim Metwally; R. M. Radwan; A. M. Abou-Elyazied

2008-01-01

41

High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution  

NASA Technical Reports Server (NTRS)

SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses.

Nussberger, A. A.; Woodcock, G. R.

1980-01-01

42

Programmable Multiple-Ramped-Voltage Power Supply  

NASA Technical Reports Server (NTRS)

Ramp waveforms range up to 2,000 V. Laboratory high-voltage power-supply system puts out variety of stable voltages programmed to remain fixed with respect to ground or float with respect to ramp waveform. Measures voltages it produces with high resolution; automatically calibrates, zeroes, and configures itself; and produces variety of input/output signals for use with other instruments. Developed for use with ultraviolet spectrometer. Also applicable to control of electron guns in general and to operation of such diverse equipment used in measuring scattering cross sections of subatomic particles and in industrial electron-beam welders.

Ajello, Joseph M.; Howell, S. K.

1993-01-01

43

46 CFR 111.79-13 - Different voltages and power types.  

Code of Federal Regulations, 2010 CFR

...79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power...

2010-10-01

44

46 CFR 111.79-13 - Different voltages and power types.  

Code of Federal Regulations, 2012 CFR

...79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power...

2012-10-01

45

Power conserving CMOS reference voltage source  

SciTech Connect

This patent describes a power-conserving CMOS reference voltage generation circuit comprising first (101) and second (101') parallel reference voltage sources, coupled to a common ENABLE input, and having a common reference voltage output node (101''), each source including a first, p-channel (102,102') and a second, n-channel (103,103') CMOS transistor series-connected between Vcc and ground. The first and second transistors have respective gates connected at a common gate node (G, G') and respective drains connected to a common drain node (D, D'), characterized in that: the second reference voltage source (101') is of relatively large capacity compared to the first source (101), means (173,107'), responsive to a rising signal edge at the ENABLE input, are provided for temporarily enabling the second source (101'). This shortens the time required to drive the reference voltage at the output node (101'') to a desired level, i.e. enhancing the slew rate of the node, and means (190-194) are provided for interconnecting the common gate nodes (G,G') the common drain nodes (D,D'), and the common output reference voltage output node (101'') in response to a high signal on the ENABLE input and for isolating the nodes from one another in response to a low signal on the ENABLE input, thereby conserving power.

Lee, R.D.

1986-12-09

46

Local Dynamic Reactive Power for Correction of System Voltage Problems  

SciTech Connect

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.

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

2008-12-01

47

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle  

SciTech Connect

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Murty, B.V.

2000-03-21

48

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle  

DOEpatents

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Murty, Balarama Vempaty (West Bloomfield, MI)

2000-01-01

49

Optimal coordinated voltage control for power system voltage stability  

Microsoft Academic Search

An optimal coordinated voltage controller (OCVC) is developed based on the spirit of model predictive control (MPC) method. The OCVC consists of three components, namely a predictor, a control candidate pool, and a selector. It has been used in secondary voltage control (SVC) to coordinate dissimilar control actions at different geographical locations in order to maintain desired voltage profiles in

J. Y. Wen; Q. H. Wu; D. R. Turner; S. J. Cheng; J. Fitch

2004-01-01

50

Peak power bi-directional transfer from high speed flywheel to electrical regulated bus voltage system: A practical proposal for vehicular technology  

SciTech Connect

This paper provides a design outline and implementation procedure for a Secondary Energy Storage Unit (SESU) that can be used to meet the peak energy requirements of an electric vehicle during both acceleration and regenerative braking. The life cycle of the electric vehicle`s batteries can be extended considerably by supplying peak energy requirements from a secondary source. A simulation study was conducted to determine the peak power and energy requirements over the SAE recommended electric vehicle test procedure. A scaled prototype SESU was built using flywheel energy storage, and tests were performed to determine the energy transfer capabilities of a flywheel coupled high speed permanent magnet synchronous machine through the proposed system`s energy storage tank. Results are presented that indicate the necessity of the energy storage tank. An evaluation of the proposed system is also included which indicates the practicality of the system when compared to conventional regenerative control techniques.

Szabados, B.; Schaible, U.

1998-03-01

51

A high voltage power converter for space astronomy applications  

NASA Technical Reports Server (NTRS)

A dc-dc low-power, high-voltage converter for use in space is described which furnishes a commandable, low-noise dc output in the range of 0 to -7500 V. The converter is suitable for biasing of detectors commonly employed in space astronomy, microchannel plates, photomultipliers, and gas discharge detectors. The converter's reliability has been demonstrated by accelerated life testing under thermal vacuum. The electrical and mechanical design, packaging, layout and fabrication techniques, and tests employed are described.

Ray, David C.; Lampton, Michael L.

1988-01-01

52

Time Evolution of Electrical Degradation under High-Voltage Stress  

E-print Network

Time Evolution of Electrical Degradation under High-Voltage Stress in GaN High Electron Mobility the time evolution of electrical degradation of GaN high electron mobility transistors under high voltage in current collapse and eventually permanent degradation in ID. We also found that the time evolution of gate

del Alamo, Jesús A.

53

Electric power annual 1992  

SciTech Connect

The Electric Power Annual presents a summary of electric utility statistics at national, regional and State levels. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts and the general public with historical data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. ``The US Electric Power Industry at a Glance`` section presents a profile of the electric power industry ownership and performance, and a review of key statistics for the year. Subsequent sections present data on generating capability, including proposed capability additions; net generation; fossil-fuel statistics; retail sales; revenue; financial statistics; environmental statistics; electric power transactions; demand-side management; and nonutility power producers. In addition, the appendices provide supplemental data on major disturbances and unusual occurrences in US electricity power systems. Each section contains related text and tables and refers the reader to the appropriate publication that contains more detailed data on the subject matter. Monetary values in this publication are expressed in nominal terms.

Not Available

1994-01-06

54

Power quality issues with adjustable frequency drives -- Coping with power loss and voltage transient occurrences  

SciTech Connect

The power quality issue is not new to consumers of electrical power. From individual home owners to large industrial complexes, power quality problems can cause eyebrows to raise or bring industrial giants to their knees. Power quality comes in many forms. It can appear in the form of a voltage source which decreases to a small fraction of its normal strength or as a voltage transient, briefly far exceeding its normal value, ready to break down electrical insulation. It can appear as an oscillating voltage or a traveling voltage wave beating against barriers designed as added protection. Defining a single set of rules to control the characteristics of power quality is difficult, since its impact on electrical equipment changes as the characteristics of equipment change. A key to understanding how to cope with power quality issues begins with understanding the nature of electrical products. The nature of any product is defined by how its components are selected and how the designers apply those components. Reviewing design criteria, component selection and product characteristics can provide this basis of understanding.

Murphy, H.G. (Allen-Bradley Co., Mequon, WI (United States))

1993-07-01

55

High-voltage diode photon-coupled pairs in the subunits of automated electric drives  

NASA Astrophysics Data System (ADS)

A system for the phase control of thyristors and a sensor for the voltage at the armature of a dc motor are developed using diode photon-coupled devices as elements for the galvanic decoupling of the power and low-voltage circuits. The exceptional operating characteristics of the devices are demonstrated experimentally, and it is established that high-voltage diode photon-coupled pairs can be used effectively in automated electric drives.

Nosov, Iu. R.; Roizen, S. S.; Sidorov, A. S.

56

Voltage collapse precipitated by the immediate change in stability when generator reactive power limits are encountered  

Microsoft Academic Search

When a generator of a heavily loaded electric power system reaches a reactive power limit, the system can become immediately unstable and a dynamic voltage collapse leading to blackout may follow. The statics and dynamics of this mechanism for voltage collapse are studied by example and by the generic theory of saddle node and transcritical bifurcations. It is shown that

I. Dobson; L. Lu

1992-01-01

57

Electric power annual 1993  

SciTech Connect

This report presents a summary of electric power industry statistics at national, regional, and state levels: generating capability and additions, net generation, fossil-fuel statistics, retail sales and revenue, finanical statistics, environmental statistics, power transactions, demand side management, nonutility power producers. Purpose is to provide industry decisionmakers, government policymakers, analysts, and the public with historical data that may be used in understanding US electricity markets.

Not Available

1994-12-08

58

Automatic Voltage Controllers for South Korean Power System  

Microsoft Academic Search

The paper proposes two automatic voltage controllers for the South Korean power system. Simulation results from detailed Korean power-flow models show that the controllers can provide significant improvements in security, quality and efficiency of power system voltage monitoring and control. Operating within a time scale ranging from tens of seconds to a few minutes, the controllers can act upon voltage

Xing Liu; Vaithianathan Venkatasubramanian; Tae-kyun Kim

2009-01-01

59

Hyperelastic High Voltage Conductor for Electric Drilling  

Microsoft Academic Search

Coiled tubing in combination with a downhole electric drilling motor has many advantages. The rotation speed of the drill bit can be precisely controlled. The electric conductors trans- mit downhole data with high speed and allow logging while drilling. One task within the PDT-COIL project was the integration of electric conductors into the wall of a spoolable fatigue resistant thermoplastic

E. Murtola; S. M. Neuhold; P. Anliker

60

Voltage transformer frequency response. Measuring harmonics in Norwegian 300 kV and 132 kV power systems  

Microsoft Academic Search

Measuring harmonics in high voltage power systems with inductive and in particular capacitive voltage transformers, CVTs, may cause large errors. Test carried out by The Norwegian National Grid Company (Statnett), Bergenshalvoens Kommunale Kraftselskap (BKK) and The Norwegian Electric Power Research Institute (now SINTEF Energy Research) revealed errors from 80% to +1200% (0,2-12 pu) of correct values. Inductive voltage transformers did

H. Seljeseth; E. A. Saethre; T. Ohnstad; I. Lien

1998-01-01

61

Electrical degradation mechanisms of RF power GaAs PHEMTs  

E-print Network

GaAs Pseudomorphic High-Electron Mobility Transistors (PHEMTs) are widely used in RF power applications. Since these devices typically operate at high power levels and under high voltage biasing, their electrical reliability ...

Villanueva, Anita A. (Anita Ariel), 1978-

2007-01-01

62

A novel series connected batteries state of high voltage safety monitor system for electric vehicle application.  

PubMed

Batteries, as the main or assistant power source of EV (Electric Vehicle), are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS), the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application. PMID:24194677

Jiaxi, Qiang; Lin, Yang; Jianhui, He; Qisheng, Zhou

2013-01-01

63

Electric power monthly, June 1988  

SciTech Connect

Total net generation by electric utilities in the United States for the month of June 1988 was 232,183 gigawatthours, 3 percent higher than the amount reported a year ago. Although temperatures (measured by cooling degree days) for June 1988 were 9 percent warmer than normal, they were 3 percent cooler than for June 1987. A large portion of that higher demand for electricity was met by nuclear-powered generation. Net generation from nuclear power during June 1988 (44,079 gigawatthours) was only 1 percent below the record set in January of this year, and 21 percent above that reported in June 1987 (36,560 gigawatthours). The only energy source other than nuclear that reported higher levels of net generation during June 1988 was coal, up 2 percent over the same period last year. Warmer-than-normal temperatures did, however, have an affect on various parts of the country. For example, on Wednesday, June 22, 1988, unseasonably high temperatures forced the Pennsylvania, New Jersey, and Maryland Interconnection (PJM) into a system-wide 5-percent voltage reduction for 2 hours. Contributing to that reduction in voltage was the shutdown of the Three Mile Island, Unit 1, for refueling and the closing of the Peach Bottom Units 2 and 3 by the Nuclear Regulatory Commission. Three Mile Island, Unit 1, normally provides the PJM system with about 800 megawatts while the two Peach Bottom units, combined, provide approximately 2100 megawatts. 10 refs., 1 fig., 27 tabs.

Not Available

1988-09-15

64

Electric and magnetic field sensing for high-voltage applications  

Microsoft Academic Search

Electric and magnetic fields can be measured optically, either directly via Pockels and Faraday effect or indirectly via Piezo effect. In high voltage applications fiber optic sensors are especially attractive for their ability of easy potential separation. For electric fields the Pockels effect in BSO, BGO crystals is mostly read out polarimetrically. The current is mostly measured via the Faraday

Thomas Bosselmann

1997-01-01

65

Electric Power Annual  

EIA Publications

Presents 12 years (2001 - 2012) of national-level data on electricity generating capacity, electricity generation and useful thermal output, fuel receipts, consumption, and emissions. This year's Electric Power Annual has expanded to include several new table series. These include several new annual breakouts of renewable biomass energy sources including wood/wood waste, landfill gas, and biogenic municipal solid waste in Chapter 5 (Consumption of Fossil Fuels); state details of emissions from energy consumption at conventional power plants and combined-heat-and-power plants (Table 9.5); and monthly capacity factors for the past three years and annual capacity factors back to 2008 (Tables 4.8.A. and 4.8.B.)

2013-01-01

66

High frequency AC power converter for low voltage circuits  

E-print Network

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 ...

Salazar, Nathaniel Jay Tobias

2012-01-01

67

Improved detection of electrical activity with a voltage probe based on a voltage-sensing phosphatase  

PubMed Central

One of the most awaited techniques in modern physiology is the sensitive detection of spatiotemporal electrical activity in a complex network of excitable cells. The use of genetically encoded voltage probes has been expected to enable such analysis. However, in spite of recent progress, existing probes still suffer from low signal amplitude and/or kinetics too slow to detect fast electrical activity. Here, we have developed an improved voltage probe named Mermaid2, which is based on the voltage-sensor domain of the voltage-sensing phosphatase from Ciona intestinalis and Förster energy transfer between a pair of fluorescent proteins. In mammalian cells, Mermaid2 permits ratiometric readouts of fractional changes of more than 50% over a physiologically relevant voltage range with fast kinetics, and it was used to follow a train of action potentials at frequencies of up to 150 Hz. Mermaid2 was also able to detect single action potentials and subthreshold voltage responses in hippocampal neurons in vitro, in addition to cortical electrical activity evoked by sound stimuli in single trials in living mice. PMID:23836686

Tsutsui, Hidekazu; Jinno, Yuka; Tomita, Akiko; Niino, Yusuke; Yamada, Yoshiyuki; Mikoshiba, Katsuhiko; Miyawaki, Atsushi; Okamura, Yasushi

2013-01-01

68

Programmable high voltage power supply with regulation confined to the high voltage section  

NASA Technical Reports Server (NTRS)

A high voltage power supply in a dc-dc converter configuration includes a pre-regulator which filters and regulates the dc input and drives an oscillator which applies, in turn, a low voltage ac signal to the low side of a step-up high voltage transformer. The high voltage side of the transformer drives a voltage multiplier which provides a stepped up dc voltage to an output filter. The output voltage is sensed by a feedback network which then controls a regulator. Both the input and output of the regulator are on the high voltage side, avoiding isolation problems. The regulator furnishes a portion of the drive to the voltage multiplier, avoiding having a regulator in series with the load with its attendant, relatively high power losses. This power supply is highly regulated, has low power consumption, a low parts count and may be manufactured at low cost. The power supply has a programmability feature that allows for the selection of a large range of output voltages.

Castell, Karen D. (inventor); Ruitberg, Arthur P. (inventor)

1994-01-01

69

Monitoring and control of voltage stability in power systems  

SciTech Connect

This paper proposes a new technique in controlling voltage instability in power systems. This technique coordinates between the reactive power of excitation systems and that of static var compensators (SVCs). The method starts with the decomposition of system into several voltage control areas (VCAs). When a reactive power deficiency occurs in certain area, excitation systems respond first to supply the required reactive power by increasing reactive generation of synchronous generators to its upper limit. If more reactive power is needed within the specific area to recover voltage instability, a SVC will be inserted by a switching controller in order to achieve the reactive balance. This controller receives an actuating signal when the terminal voltage is still unsatisfactory. By this technique, it is possible to fully utilize the excitation systems reactive power, and to design economic size SVCs to recover voltage instability. The application of the proposed technique on the New-England 39 bus system proves its efficiency in controlling voltage instability.

Sallam, A.A.; Aboul-Ela, M.E.; Elaraby, E.E. [Suez Canal Univ., Port-Said (Egypt)

1995-12-31

70

A Regional Demand Forecast by NN Method for Distributed Autonomous Voltage and Reactive Power Control System  

NASA Astrophysics Data System (ADS)

This paper describes technology required for advanced intelligent voltage and reactive secondary control systems enabling co-ordination of voltage control between main and local power systems. Firstly, the paper describes the general structure of a power system control and the concept of a proposed autonomous voltage and reactive power control system. Then, the paper comments on the inadequate behavior of voltage and reactive power control systems, such as up-and-down fluctuations, which sometimes occur during off-peak load times, and explains the reasons for voltage fluctuations. The capacity of distributed generation is increasing in accordance with deregulation of electric supply. In order to enhance voltage stability of power system, the voltage control system requires the more detail information and data of its local network systems, such as local demand forecast, distributed generation and characteristics of power systems. The paper briefly describes two previously developed intelligent component functions, namely, flexible feed forward control to prevent voltage fluctuation, and on-line acquisition of voltage characteristics by neural network technology. The paper describes local demand forecasting one or two hours in advance by the NN method. This method is also applicable to the forecast of the total demand of a power system.

Suzuki, Osamu; Wu, Guohong; Minakawa, Tamotsu

71

Large autonomous spacecraft electrical power system (LASEPS)  

NASA Technical Reports Server (NTRS)

NASA - Marshall Space Flight Center is creating a large high voltage electrical power system testbed called LASEPS. This testbed is being developed to simulate an end-to-end power system from power generation and source to loads. When the system is completed it will have several power configurations, which will include several battery configurations. These configurations are: two 120 V batteries, one or two 150 V batteries, and one 250 to 270 V battery. This breadboard encompasses varying levels of autonomy from remote power converters to conventional software control to expert system control of the power system elements. In this paper, the construction and provisions of this breadboard are discussed.

Dugal-Whitehead, Norma R.; Johnson, Yvette B.

1992-01-01

72

Plasma Membrane Voltage Changes during Nanosecond Pulsed Electric Field Exposure  

PubMed Central

The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60 ns and maximum field strengths of ?100 kV/cm (100 V/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal resolution of 5 ns was achieved by the excitation of this dye with a tunable laser pulse. The laser pulse was synchronized with the applied electric field to record images at times before, during, and after exposure. When exposing the Jurkat cells to a pulse, the voltage across the membrane at the anodic pole of the cell reached values of 1.6 V after 15 ns, almost twice the voltage level generally required for electroporation. Voltages across the membrane on the side facing the cathode reached values of only 0.6 V in the same time period, indicating a strong asymmetry in conduction mechanisms in the membranes of the two opposite cell hemispheres. This small voltage drop of 0.6–1.6 V across the plasma membrane demonstrates that nearly the entire imposed electric field of 10 V/?m penetrates into the interior of the cell and every organelle. PMID:16513782

Frey, W.; White, J. A.; Price, R. O.; Blackmore, P. F.; Joshi, R. P.; Nuccitelli, R.; Beebe, S. J.; Schoenbach, K. H.; Kolb, J. F.

2006-01-01

73

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

SciTech Connect

This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.

Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

2008-03-03

74

NSTX Electrical Power Systems  

SciTech Connect

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physic Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The design of the NSTX electrical power system was tailored to suit the available infrastructure and electrical equipment on site. Components were analyzed to verify their suitability for use in NSTX. The total number of circuits and the location of the NSTX device drove the major changes in the Power system hardware. The NSTX has eleven (11) circuits to be fed as compared to the basic three power loops for TFTR. This required changes in cabling to insure that each cable tray system has the positive and negative leg of cables in the same tray. Also additional power cabling had to be installed to the new location. The hardware had to b e modified to address the need for eleven power loops. Power converters had to be reconnected and controlled in anti-parallel mode for the Ohmic heating and two of the Poloidal Field circuits. The circuit for the Coaxial Helicity Injection (CHI) System had to be carefully developed to meet this special application. Additional Protection devices were designed and installed for the magnet coils and the CHI. The thrust was to making the changes in the most cost-effective manner without compromising technical requirements. This paper describes the changes and addition to the Electrical Power System components for the NSTX magnet systems.

A. Ilic; E. Baker; R. Hatcher; S. Ramakrishnan; et al

1999-12-16

75

E-beam high voltage switching power supply  

DOEpatents

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

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

1996-01-01

76

Transmission Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage Power-lines for Broadband Communications  

E-print Network

Transmission Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage Power of Electrical Engineering, Center for Information & Communications Technology Research (CICTR) University Park with 70% of standard annealed copper conductivity. Originally designed for power delivery rather than

Kavehrad, Mohsen

77

Copper wire theft and high voltage electrical burns  

PubMed Central

High voltage electrical burns are uncommon. However in the midst of our economic recession we are noticing an increasing number of these injuries. Copper wire is a valuable commodity with physical properties as an excellent conductor of electricity making it both ubiquitous in society and prized on the black market. We present two consecutive cases referred to the National Burns Unit who sustained life threatening injuries from the alleged theft of high voltage copper wire and its omnipresence on an international scale. PMID:25356371

Francis, Eamon C; Shelley, Odhran P

2014-01-01

78

Voltage-current-power meter for photovoltaic solar arrays  

NASA Technical Reports Server (NTRS)

A meter is disclosed for measuring the voltage, current, and power (VIP) parameters of a photovoltaic solar array, or array module, under sunlight operating conditions utilizing a variable load connected across the array and controlled by a voltage regulator which responds to the difference between the output voltage of the array and a programmed test voltage from a source which generates a single ramp voltage for measuring and recording current as a function of voltage, repeated ramp voltages at a high rate for peak output measurements or a DC voltage for VIP measurements at selected points on the I-V characteristic curve of the array. The voltage signal from a current sensing element, such as a shunt resistor in series with the variable load, is compared with the output current of a reference solar cell to provide a normalizing signal to be added to the signal from the current-sensing element in order to provide a record of array current as a function of array voltage, i.e., for all load conditions from short circuit to open circuit. As the normalized current is thus measured, an analog multiplier multiplies the array voltage and normalized current to provide a measurement of power. Switches are provided to selectively connect the power, P, current, I, or voltage, V, to a meter, directly or through a peak detector. At the same time any one of the parameters V, I and P may be recorded as a function of any other parameter.

Ross, Ronald G. (Inventor)

1979-01-01

79

High voltage power condition systems powered by flux compression generators  

NASA Astrophysics Data System (ADS)

Compact, high-gain magnetic flux compressors (FCGs) are convenient sources of substantial energy for plasma-physics and electron-beam-physics experiments, but the need for high-voltage, fast-rising pulses is difficult to meet directly with conventional generators. While a variety of novel concepts employing simultaneous, axially-detonated explosive systems are under development, power-conditioning systems based on fuse opening switches and high-voltage transformers constitute another approach that complements the fundamental size, weight, and configuration of the small helical flux compressor. In this paper, we consider first a basic inductive store/opening switch circuit and the implications associated with, specifically, a fuse opening switch and an FCG energy source. We develop a general solution to a transformer/opening switch circuit---which also includes (as a special case) the direct inductive store/opening switch circuit (without transformer) and we report results of one elementary experiment demonstrating the feasibility of the approach.

Reinovsky, R. E.; Lindemuth, I. R.; Vorthman, J. E.

80

A high power density high voltage distributed power system for pulse power applications  

Microsoft Academic Search

In this paper, a high-density high-voltage distributed power system for pulse power applications is designed and implemented. Different topologies are evaluated for two power stages. According to pulse load condition, system power density is optimized through the tradeoff between power loss and magnetic component size. High power density and high efficiency are verified by the experimental result

Bing Lu; Yarig Qiu; Chuanyun Wang; Yonghan Kang; Juanjuan Sun; Wei Dong; Francisco Canales; Peter Barbosa; Ming Xu; Fred C. Lee; Richard Gean; Wesley C. Tipton; Damian Urciuoli

2005-01-01

81

Electric power emergency handbook  

SciTech Connect

The Emergency Electric Power Administration's Emergency Operations Handbook is designed to provide guidance to the EEPA organization. It defines responsibilities and describes actions performed by the government and electric utilities in planning for, and in operations during, national emergencies. The EEPA Handbook is reissued periodically to describe organizational changes, to assign new duties and responsibilities, and to clarify the responsibilities of the government to direct and coordinate the operations of the electric utility industry under emergencies declared by the President. This Handbook is consistent with the assumptions, policies, and procedures contained in the National Plan for Emergency Preparedness. Claimancy and restoration, communications and warning, and effects of nuclear weapons are subjects covered in the appendices.

Labadie, J.R.

1980-09-01

82

Medium power voltage multipliers with a large number of stages  

NASA Technical Reports Server (NTRS)

Voltage multiplier techniques were extended at medium power levels to larger multiplication ratios. A series of DC-DC converters were built, with from 20 to 45 stages and with power levels up to 100 watts. Maximum output voltages were about 10,000 volts.

Harrigill, W. T.; Myers, I. T.

1978-01-01

83

Medium power voltage multipliers with a large number of stages  

NASA Technical Reports Server (NTRS)

Voltage multiplier techniques are extended at medium power levels to larger multiplication ratios. A series of dc-dc converters were built, with from 20 to 45 stages and with power levels up to 100 watts. Maximum output voltages were about 10,000 volts.

Harrigill, W. T.; Myers, I. T.

1978-01-01

84

Conceptual definition of a high voltage power supply test facility  

NASA Technical Reports Server (NTRS)

NASA Lewis Research Center is presently developing a 60 GHz traveling wave tube for satellite cross-link communications. The operating voltage for this new tube is - 20 kV. There is concern about the high voltage insulation system and NASA is planning a space station high voltage experiment that will demonstrate both the 60 GHz communications and high voltage electronics technology. The experiment interfaces, requirements, conceptual design, technology issues and safety issues are determined. A block diagram of the high voltage power supply test facility was generated. It includes the high voltage power supply, the 60 GHz traveling wave tube, the communications package, the antenna package, a high voltage diagnostics package and a command and data processor system. The interfaces with the space station and the attached payload accommodations equipment were determined. A brief description of the different subsystems and a discussion of the technology development needs are presented.

Biess, John J.; Chu, Teh-Ming; Stevens, N. John

1989-01-01

85

Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devices  

E-print Network

This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an ...

Fallier, William F. (William Frederick)

2007-01-01

86

High voltage power supply with modular series resonant inverters  

DOEpatents

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

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

1995-07-18

87

Electrical Power Devices Cooling Technique.  

National Technical Information Service (NTIS)

The apparatus for cooling a high power electrical transformer and electrical motors uses thermally conductive material interleaved between the turn layers of a high power transformer and iron core laminates to provide a low resistant thermal path to ambie...

E. Sines

1999-01-01

88

Electric power monthly, February 1994.  

National Technical Information Service (NTIS)

The Electric Power Monthly (EMP) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie...

1994-01-01

89

Electric power monthly, October 1993.  

National Technical Information Service (NTIS)

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie...

1993-01-01

90

Electric power monthly, January 1994.  

National Technical Information Service (NTIS)

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie...

1994-01-01

91

Mobile electric power  

SciTech Connect

Analytic Power has proven the feasibility of a mobile electric power unit in the form of a hydride fueled ion-exchange membrane (IEM) fuel cell stack. We have over 5 years experience building and testing IEM fuel cells. The power section of a 350 watt fuel cell stack weighs 4.65 pounds based on our five cell sub-stack component weights. The composite stack structure is fabricated from two components; a unitized flow field and catalyzed membrane. The lightweight unitized flow field concept was proven in the first three months of the contract. A single unit flow field weighs 0.155 pounds and can seal to 60 psi. The single cell catalyzed Nafion membrane exceeded our performance goal of 0.6 volts at 100 ASF. Stack performance points were 0.42 volts at 113 ASF and .75 volts at 96 asf.

Bloomfield, V.J.; Bloomfield, D.P.; Johnson, B.Q.

1992-01-30

92

Insulation Requirements of High-Voltage Power Systems in Future Spacecraft  

NASA Technical Reports Server (NTRS)

The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

Qureshi, A. Haq; Dayton, James A., Jr.

1995-01-01

93

Analysis of the most appropriate electrical architecture and communication bus for the new dual voltage 14\\/42 V system  

Microsoft Academic Search

In this paper we analyze the advantages and disadvantages of the basic electrical architecture of the dual voltage 14\\/42 V system for vehicles proposed up to date. Certain functions of management of the electrical power and protection of the electrical system are also discussed such as the circuit protection, battery management system and fusing. In our analysis of circuit protection

Javier MaixC Altes; Ernest Gil Dolcet; B. P. Solorzano

2002-01-01

94

Human Factors Aspects of Power System Voltage Visualizations Douglas A. Wiegmann Aaron M. Rich Thomas J. Overbye Yan Sun  

E-print Network

Human Factors Aspects of Power System Voltage Visualizations Douglas A. Wiegmann Aaron M. Rich with the human factors aspects of using color contours to visualize electric power system bus voltage magnitude utility, with restructuring they are increasingly inadequate. This paper presents results of human factors

95

Bidirectional power electronic transformer based compact dynamic voltage restorer  

Microsoft Academic Search

In this paper a dynamic voltage restorer (DVR) circuit with a bi-directional power electronic transformer (PET) structure is proposed to correct input utility voltage distortions on a sensitive load. This DVR-PET contains full-bridge DC-link inverter (FBDCI), high frequency isolating transformer (HFIT), cyclo-converter and output filter. A phase shift modulation (PSM) control scheme is used to regulate compensation voltage. The proper

S. H. Hosseini; M. B. B. Sharifian; M. Sabahi; A. Y. Goharrizi; G. B. Gharehpetian

2009-01-01

96

ELECTRICAL POWER SYSTEM HEALTH MANAGEMENT  

Microsoft Academic Search

One of the most critical systems in any aerospace vehicle is the electrical power system. Comprised of energy generation, energy storage, power distribution, and power management, the electrical power system (EPS) is relied upon by every major subsystem for proper operation. In order to meet the safety requirements of aeronautics and space systems - and provide for their reliability, maintainability,

Robert M. Button; Amy Chicatelli

97

Power Balance Theory Based Voltage and Frequency Control for IAG in Wind Power Generation  

Microsoft Academic Search

This paper deals with an application of the power balance theory in a voltage and frequency controller (VFC) of an autonomous wind power generation using an isolated asynchronous generator (IAG) feeding three-phase four wire loads. The reference generator currents are estimated using the power balance theory to control the voltage and frequency of IAG system. Three-leg voltage source converter (VSC)

Bhim Singh; Shailendra Sharma

2009-01-01

98

Power electronics in electric utilities: Static var compensators  

Microsoft Academic Search

This paper deals with dynamic var compensation of electric power systems, applying power electronics for reactive power generation and control. After an overview of the emergence and status of modern, solid-state var compensators in utility and industrial applications, the first part of the paper explains how dynamic var compensation increases transmittable power by providing voltage support, transient stability improvement, and

L. Gyugyi

1988-01-01

99

Electric power processing, distribution, management and energy storage  

NASA Technical Reports Server (NTRS)

Power distribution subsystems are required for three elements of the SPS program: (1) orbiting satellite, (2) ground rectenna, and (3) Electric Orbiting Transfer Vehicle (EOTV). Power distribution subsystems receive electrical power from the energy conversion subsystem and provide the power busses rotary power transfer devices, switchgear, power processing, energy storage, and power management required to deliver control, high voltage plasma interactions, electric thruster interactions, and spacecraft charging of the SPS and the EOTV are also included as part of the power distribution subsystem design.

Giudici, R. J.

1980-01-01

100

Power-aware soft error hardening via selective voltage scaling  

Microsoft Academic Search

Nanoscale integrated circuits are becoming increasingly sensitive to radiation-induced transient faults (soft errors) due to current technology scaling trends, such as shrinking feature sizes and reducing supply voltages. Soft errors, which have been a significant concern in memories, are now a main factor in reliability degradation of logic circuits. This paper presents a power-aware methodology using dual supply voltages for

Kai-chiang Wu; Diana Marculescu

2008-01-01

101

Electrical Power Generation Using Piezoelectric Crystal  

E-print Network

Abstract- The usefulness of most high technology devices such as cell phones, computers, and sensors is limited by the storage capacity of batteries. In the future, these limitations will become more pronounced as the demand for wireless power outpaces battery development which is already nearly optimized. Thus, new power generation techniques are required for the next generation of wearable computers, wireless sensors, and autonomous systems to be feasible. Piezoelectric materials are excellent power generation devices because of their ability to couple mechanical and electrical properties. For example, when an electric field is applied to piezoelectric a strain is generated and the material is deformed. Consequently, when a piezoelectric is strained it produces an electric field; therefore, piezoelectric materials can convert ambient vibration into electrical power. Piezoelectric materials have long been used as sensors and actuators; however their use as electrical generators is less established. A piezoelectric power generator has great potential for some remote applications such as in vivo sensors, embedded MEMS devices, and distributed networking. Developing piezoelectric generators is challenging because of their poor source characteristics (high voltage, low current, high impedance) and relatively low power output. This paper presents a theoretical analysis to increase the piezoelectric power generation that is verified with experimental results. Index Terms-Piezoelectric materials, piezoelectricity, power generation, PZT ceramics.

unknown authors

102

A Field Study of Lightning Surges Propagating through Low-voltage Electric Appliances  

NASA Astrophysics Data System (ADS)

In today's highly information-based society, lightning damage has a significant impact on an increasing number of electric appliances such as personal computers and facsimile machines. Lightning surge protection devices for electric appliances are on the market and concern for lightning protection has been increasing, but there are still many unknown aspects of lightning surges that propagate into residences. To provide effective lightning protection measures, clarification of surge propagation patterns is needed. The Tokyo Electric Power Company has observed the patterns of lightning surge propagation into houses using lightning surge waveform detectors installed at ordinary residences and obtained data on 30 lightning surge current waveforms between 2008 and 2009. This paper discusses various aspects of lightning surge currents propagating into low-voltage appliances, including home electric appliances, based on the lightning surge current waveform data obtained from lightning observations. The result revealed the patterns of lightning surge currents propagating into the ground and lines of low-voltage appliances.

Ishii, Tsunayoshi; Sakamoto, Yoshiki; Oguchi, Shuichi; Okabe, Shigemitsu

103

Systematically study on the static power-angle characteristics of a high voltage cable-wound generator prototype  

Microsoft Academic Search

High voltage cable-wound generator is a new kind of generator, which can be directly connected to the power grid. Basing on the fundamental theories of electrical machinery, the expressions of power-angle characteristics of high voltage cable-wound generator prototype with excitation regulator and without excitation regulator are deduced in this paper. Combining with the parameters of a high voltage cable-wound generator

Tao Dajun; Ge Baojun; Lv Yanling; Zhang Zhiqiang

2009-01-01

104

The Fifth Northwest Electric Power  

E-print Network

demand for electricity, hydro conditions, and forced outages of major power plants. Other uncer- taintiesThe Fifth Northwest Electric Power and Conservation Plan #12;#12;1 Background The Northwest electricity for many years. But by the 1960s, increased demand led energy planners to believe that hydropower

105

Very-high-frequency low-voltage power delivery  

E-print Network

Power conversion for the myriad low-voltage electronic circuits in use today, including portable electronic devices, digital electronics, sensors and communication circuits, is becoming increasingly challenging due to the ...

Li, Wei, Ph. D. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

2013-01-01

106

High Voltage AC Power Transmission Lines and Communications Receiver Sites.  

National Technical Information Service (NTIS)

A short discussion of the effects of the Electromagnetic Interference (EMI) radiated from High Voltage AC (HVAC) Power Transmission lines on HF Communications Receivers is followed by the description of a method for choosing communications receiver sites ...

F. R. Hill

1976-01-01

107

Power converter design for a fuel cell electric vehicle  

Microsoft Academic Search

This research is developed the electric vehicle by the fuel cell. Between fuel cell source and motor controller, we add new power converter, offer steady output voltage to motor controller and drive the direct current hub motor. Converter not only offers steady output voltage but it also combines with coupling inductance technology to battery charger. Besides offers energy to drive

Van-Tsai Liu; Jia-Wei Hong; Kuo-Ching Tseng

2010-01-01

108

High efficiency LDMOS power FET for low voltage wireless communications  

Microsoft Academic Search

High efficiency, high gain power transistors are required to meet RF performance and output specifications as new generation portable communication products move towards lower voltage operations. A low cost, high efficiency silicon MOSFET using RFLDMOS (LV2) technology was developed in Motorola to operate at 3.4-12.5 V drain voltages. The LV2 device can deliver 70% power added efficiency with 12 dB

G. Ma; W. Burger; C. Dragon; T. Gillenwater

1996-01-01

109

Voltage regulator dissipates minimal power and functions as a voltage divider  

NASA Technical Reports Server (NTRS)

Regulator requires minimum amount of power for voltage division and it is not required continuously. The only power loss, except for regulating purposes, is that needed to provide for imbalances in load current requirements. For balanced loads, only leakage current flows through regulating transistors.

Hester, H. B.

1971-01-01

110

Practical medium voltage converter topologies for high power applications  

Microsoft Academic Search

Multilevel power conversion has been receiving increasing attention in the past few years for high power applications. Numerous topologies and modulation strategies have been introduced and studied extensively for utility and drive applications in the recent literature. These converters are suitable in high voltage and high power applications due to their ability to synthesize waveforms with better harmonic spectrum and

Peter K. Steimer; Madhav D. Manjrekar

2001-01-01

111

E-beam high voltage switching power supply  

DOEpatents

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

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

1997-01-01

112

Results of an electrical power system fault study  

NASA Technical Reports Server (NTRS)

NASA-Marshall conducted a study of electrical power system faults with a view to the development of AI control systems for a spacecraft power system breadboard. The results of this study have been applied to a multichannel high voltage dc spacecraft power system, the Large Autonomous Spacecraft Electrical Power System (LASEPS) breadboard. Some of the faults encountered in testing LASEPS included the shorting of a bus an a falloff in battery cell capacity.

Dugal-Whitehead, Norma R.; Johnson, Yvette B.

1992-01-01

113

NASCAP modelling of high-voltage power system interactions with space charged-particle environments  

NASA Technical Reports Server (NTRS)

A simple space power system operating in geosynchronous orbit was analyzed. This system consisted of two solar array wings and a central body. Each solar array wing was considered to be divided into three regions operating at 2000 volts. The center body was considered to be an electrical ground with the array voltages both positive and negative relative to ground. The system was analyzed for both a normal environment and a moderate geomagnetic substorm environment. Initial results indicate a high probability of arcing at the interconnects on the negative operating voltage wing. The dielectric strength of the substrate may be exceeded giving rise to breakdown in the bulk of the material. The geomagnetic substorm did not seem to increase the electrical gradients at the interconnects on the negative operating voltage wing but did increase the gradients on the positive operating voltage wing which could result in increased coupling current losses.

Stevens, N. J.; Roche, J. C.; Mandell, M. J.

1979-01-01

114

Current and voltage monitors on a pulsed-power accelerator “Gamma-1”  

NASA Astrophysics Data System (ADS)

There is presented a system of registering electric parameters of high-current pulsed electron accelerator “Gamma-1” its output electric power being 1.5 TW. The accelerator system of registration makes it possible to register in a single time scale the voltage pulses with the amplitude up to 3 MV, current pulses with the amplitude up to 1 MA and duration from several nanoseconds to a microsecond. Into the system of registration there are included two-step resistive voltage dividers, capacitive voltage divider, Rogowski coils, sectionalized Rogowski coils, B-dots, shunts, transmission line, attenuators, oscilloscopes, program system. The program system is aimed at reading, transmitting and processing information from oscilloscopes on the archival computer and provides interaction with database of current and voltage sensors, cables and filters. For each registration session the system also forms a map of experiment where system configuration and experiment parameters are presented.

Zavyalov, N. V.; Gordeev, V. S.; Grishin, A. V.; Puchagin, S. Yu.; Strabykin, K. V.; Kalashnikov, D. A.; Mansurov, D. O.; Moiseevskikh, M. A.; Majornikova, V. L.; Kozachek, A. V.; Mikhailov, E. S.; Kalashnikov, D. A.; Kozachek, A. V.

2014-08-01

115

30 CFR 56.12071 - Movement or operation of equipment near high-voltage power lines.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12071 Movement or operation of equipment near high-voltage power lines. When equipment must be moved or...

2013-07-01

116

Experimental and numerical investigations into high-voltage pulsed DC electric fields for enhancing CE chip performance  

Microsoft Academic Search

This paper presents a simple method to enhance the separation efficiency of DNA biosamples in a chip-based capillary electrophoresis system utilizing high-voltage pulsed DC electric fields. Since the average power consumption is reduced by the pulse electric fields, the Joule heating effect is significantly reduced. The experimental and numerical investigations commence by separating a mixed sample comprising two fluorescences with

Jing-Hui Wang; Meng-Ku Chi; Lung-Ming Fu; Che-Hsin Lin

2009-01-01

117

Mobile Power Distribution Unit for High Voltages.  

National Technical Information Service (NTIS)

The patent describes a rail-mounted three-phase mobile open distribution unit operating on 220 KV mounted on transportable platforms and containing a power transformer, disconnector units, separator units, a shorting switch, and dischargers. In order to r...

B. M. Gamburg, D. A. Myslin, K. S. Bessonov

1972-01-01

118

Electrical actuation of electrically conducting and insulating droplets using ac and dc voltages  

NASA Astrophysics Data System (ADS)

Electrical actuation of liquid droplets at the microscale offers promising applications in the fields of microfluidics and lab-on-chip devices. Much prior research has targeted the electrical actuation of electrically conducting liquid droplets using dc voltages (classical electrowetting). Electrical actuation of conducting droplets using ac voltages and the actuation of insulating droplets (using dc or ac voltages) has remained relatively unexplored. This paper utilizes an energy-minimization-based analytical framework to study the electrical actuation of a liquid droplet (electrically conducting or insulating) under ac actuation. It is shown that the electromechanical regimes of classical electrowetting, electrowetting under ac actuation and insulating droplet actuation can be extracted from the generic electromechanical actuation framework, depending on the electrical properties of the droplet, the underlying dielectric layer and the frequency of the actuation voltage. This paper also presents experiments which quantify the influence of the ac frequency and the electrical properties of the droplet on its velocity under electrical actuation. The velocities of droplets moving between two parallel plates under ac actuation are experimentally measured; these velocities are then related to the actuation force on the droplet which is predicted by the electromechanical model developed in this work. It is seen that the droplet velocities are strongly dependent on the frequency of the ac actuation voltage; the cut-off ac frequency, above which the droplet fails to actuate, is experimentally determined and related to the electrical conductivity of the liquid. This paper then analyzes and directly compares the various electromechanical regimes for the actuation of droplets in microfluidic applications.

Kumari, N.; Bahadur, V.; Garimella, S. V.

2008-10-01

119

Performance Comparison of Voltage Stability Indices for Weak Bus Identification in Power Systems  

NASA Astrophysics Data System (ADS)

Voltage collapse event is identified as complex and localized in nature but its effect is extensive once occurred. The vital effect of voltage collapse would be the total system collapse or blackouts which would cost a large loss to utility companies. Eventually, on- line monitoring of power system stability has become an important factor for electric power utilities. The last utmost option to avert voltage collapse incident from occurring is by the implementation of under voltage load shedding scheme. The identification of location for load shedding is the main motivation of the study. The weakest bus in a power system is identified as the location for load shedding. This location is obtained using voltage stability index Ld. The performance and effectiveness of Ld index is compared with Fast Voltage Stability Index (FVSI) and Le Index. The results obtained indicate that Ld Index can be used to identify the weak bus in a power system and consequently for the placement of UVLS relays in a power system network.

Verayiah, R.; Mohamed, A.; Shareef, H.; Zainal Abidin, I. Hj

2013-06-01

120

Small disturbance voltage stability evaluation of power systems  

Microsoft Academic Search

Loading of today power systems continuously increases especially in the developed countries and liberalized electricity markets. On the other hand, operating points of a power system are acceptable in the feasible region usually surrounded by the borders of different stabilities. Power system instability is critical for all participants of the electricity market. Determination of different stability margins can result in

Nima Amjady; Mohammad Reza Ansari

2008-01-01

121

Electric power 2007  

SciTech Connect

Subjects covered include: power industry trends - near term fuel strategies - price/quality/delivery/opportunity; generating fleet optimization and plant optimization; power plant safety and security; coal power plants - upgrades and new capacity; IGCC, advanced combustion and CO{sub 2} capture technologies; gas turbine and combined cycle power plants; nuclear power; renewable power; plant operations and maintenance; power plant components - design and operation; environmental; regulatory issues, strategies and technologies; and advanced energy strategies and technologies. The presentations are in pdf format.

NONE

2007-07-01

122

Review on partial discharge detection techniques related to high voltage power equipment using different sensors  

NASA Astrophysics Data System (ADS)

When operating an equipment or a power system at the high voltage, problems associated with partial discharge (PD) can be tracked down to electromagnetic emission, acoustic emission or chemical reactions such as the formation of ozone and nitrous oxide gases. The high voltage equipment and high voltage installation owners have come to terms with the need for conditions monitoring the process of PD in the equipments such as power transformers, gas insulated substations (GIS), and cable installations. This paper reviews the available PD detection methods (involving high voltage equipment) such as electrical detection, chemical detection, acoustic detection, and optical detection. Advantages and disadvantages of each method have been explored and compared. The review suggests that optical detection techniques provide many advantages in the consideration of accuracy and suitability for the applications when compared to other techniques.

Yaacob, M. M.; Alsaedi, M. A.; Rashed, J. R.; Dakhil, A. M.; Atyah, S. F.

2014-12-01

123

Review on partial discharge detection techniques related to high voltage power equipment using different sensors  

NASA Astrophysics Data System (ADS)

When operating an equipment or a power system at the high voltage, problems associated with partial discharge (PD) can be tracked down to electromagnetic emission, acoustic emission or chemical reactions such as the formation of ozone and nitrous oxide gases. The high voltage equipment and high voltage installation owners have come to terms with the need for conditions monitoring the process of PD in the equipments such as power transformers, gas insulated substations (GIS), and cable installations. This paper reviews the available PD detection methods (involving high voltage equipment) such as electrical detection, chemical detection, acoustic detection, and optical detection. Advantages and disadvantages of each method have been explored and compared. The review suggests that optical detection techniques provide many advantages in the consideration of accuracy and suitability for the applications when compared to other techniques.

Yaacob, M. M.; Alsaedi, M. A.; Rashed, J. R.; Dakhil, A. M.; Atyah, S. F.

2014-09-01

124

Global Transient Stability and Voltage Regulation for Power Systems  

Microsoft Academic Search

This paper concems the global control of power systems. It arises from the practical concem that transient stability and voltage regulation are both important properties of power system control, but they are ascribed to different model descriptions and relate to different stages of system operation (i.e., transient period and post-transient period, respectively). Earlier control results deal with the two problems

Y. Guo; D. J. Hill; Y. Wang

2001-01-01

125

Global transient stability and voltage regulation for power systems  

Microsoft Academic Search

Summary form only given as follows. This paper is concerned with the global control of power systems. It arises from the practical concern that transient stability and voltage regulation are both important properties of power system control, but they are ascribed to different model descriptions and relate to different stages of system operation (i.e. transient period and post-transient period respectively).

Yi Guo; D. J. Hill; Youyi Wang

2002-01-01

126

Global transient stability and voltage regulation for power systems  

Microsoft Academic Search

This paper concerns the global control of power systems. It arises from the practical concern that transient stability and voltage regulation are both important properties of power system control, but they are ascribed to different model descriptions and relate to different stages of system operation (i.e., transient period and post-transient period respectively). Earlier control results deal with the two problems

Yi Guo; David J. Hill; Youyi Wang

2001-01-01

127

Electrical power generating system  

NASA Astrophysics Data System (ADS)

An alternating current power generation system adopted to inject power in an already powered power line is discussed. The power generating system solves to adjustably coup an induction motor, as a generator, to an ac power line wherein the motor and power line are connected through a triac. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced. The principal application will be for windmill powered generation.

Nola, F. J.

1981-03-01

128

STC-DBS Electrical Power Subsystem  

SciTech Connect

The design of the STC-DBS (Satellite Television Corporation - Direct Broadcast Satellite) Electrical Power Subsystem presently under development at RCA Astro-Electronics is highlighted. To efficiently satisfy the payload power requirements, which are dominated by three 220W TWTAs, while at the same time permitting maximum use of already qualified designs, a dual bus system was selected. The payload bus, which operates during non-eclipse periods, is a shunt-regulated solar array bus at 100 volts. The housekeeping bus is regulated at 35.5 volts when sunlit and varies with the battery voltage during eclipse.

Peck, S.R.; Callen, P.; Pierce, P.; Wylie, T.

1984-08-01

129

Electric-Power System Simulator  

NASA Technical Reports Server (NTRS)

Shows different combinations of generation, storage, and load components: display, video monitor with keyboard input to microprocessor, and video monitor for display of load curves and power generation. Planning tool for electric utilities, regulatory agencies, and laymen in understanding basics of electric-power systems operation.

Caldwell, R. W.; Grumm, R. L.; Biedebach, B. L.

1984-01-01

130

A proposal for electric power plant for future ICE powered vehicles  

Microsoft Academic Search

There is growing realization that the present electrical power plant in vehicles is nearing the limits of its capability. Vehicle electrical charging system capability has continually increased to meet the demands of higher electrical and electronic content to the extent that alternators for high line vehicles are now rated to well over 100 Amps. This paper proposes a dual voltage

John M. Miller; Patrick J. McCleer; L. J. Giacoletto

1996-01-01

131

High-voltage Milberger slip slide power conditioner  

NASA Astrophysics Data System (ADS)

A high-voltage converter circuit uses a slip slide power conditioner to reduce non-monotonic non-linearities in the converter output signal is disclosed. The slip slide power conditioner includes: a choke feed dc circulator; two radio frequency (RF) power pumps; a phase detector; a phase controller; and a combiner. The choke feed dc circulator receives the dc input signal and produces therefrom two voltage output signals which are each sent to one of the two RF power pumps. The two RF power pumps produce two out-of-phase square wave output signals which are algebraically combined in the combiner to form an output signal whose amplitude is a function of phase difference. The phase detector and phase controller sample this output signal and adjust the phase of the two power pumps to remove non-linearities due to secondary ranging (resonance) that beats with harmonics of their square wave signals.

Jones, Franklin B.

1986-08-01

132

Voltage controllable power factor corrector based inductive coupling power transfer system  

Microsoft Academic Search

This paper proposed a novel inductive coupling power transfer (ICPT) topology to improve the power factor, output voltage regulation and efficiency. The proposed ICPT is mainly constructed by a voltage controllable power factor corrector (VC-PFC) and a LLC resonant circuit. Additionally, the series compensation and series-parallel compensation are used in the primary and the secondary sides of the coupling transformer

Liang-Rui Chen; Hai-Wen Chang; Chia-Hsuan Wu; Chung-Ming Young; Neng-Yi Chu

2012-01-01

133

Voltage biasing, cyclic voltammetry, & electrical impedance spectroscopy for neural interfaces.  

PubMed

Electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measure properties of the electrode-tissue interface without additional invasive procedures, and can be used to monitor electrode performance over the long term. EIS measures electrical impedance at multiple frequencies, and increases in impedance indicate increased glial scar formation around the device, while cyclic voltammetry measures the charge carrying capacity of the electrode, and indicates how charge is transferred at different voltage levels. As implanted electrodes age, EIS and CV data change, and electrode sites that previously recorded spiking neurons often exhibit significantly lower efficacy for neural recording. The application of a brief voltage pulse to implanted electrode arrays, known as rejuvenation, can bring back spiking activity on otherwise silent electrode sites for a period of time. Rejuvenation alters EIS and CV, and can be monitored by these complementary methods. Typically, EIS is measured daily as an indication of the tissue response at the electrode site. If spikes are absent in a channel that previously had spikes, then CV is used to determine the charge carrying capacity of the electrode site, and rejuvenation can be applied to improve the interface efficacy. CV and EIS are then repeated to check the changes at the electrode-tissue interface, and neural recordings are collected. The overall goal of rejuvenation is to extend the functional lifetime of implanted arrays. PMID:22395095

Wilks, Seth J; Richner, Tom J; Brodnick, Sarah K; Kipke, Daryl R; Williams, Justin C; Otto, Kevin J

2012-01-01

134

Electric Field Analysis of the Insulation Structure of Power Transformer  

Microsoft Academic Search

Electric field and dielectric conditions were analysed in an oil immersed power transformer. The particularity of the transformer’s design we are dealing with is an attempt to eliminate the stress-control ring above the low voltage (LV) winding. Using the finite element method (FEM) we analysed the steady state electric field that suited conditions during dielectric test with a separate AC

Danilo Makuc; Juso Ikanovi?; Konrad Lenasi

135

Electric Power Monthly  

EIA Publications

Provides monthly statistics at the state, Census division, and U.S. levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold.

2014-01-01

136

Characteristics of pulsed power generator by versatile inductive voltage adder  

NASA Astrophysics Data System (ADS)

A pulsed power generator by inductive voltage adder, versatile inductive voltage adder (VIVA-I), which features a high average potential gradient (2.5 MV/m), was designed and is currently in operation,. It was designed to produce an output pulse of 4 MV/60 ns by adding 2 MV pulses in two-stages of induction cells, where amorphous cores are installed. As a pulse forming line, we used a Blumlein line with the switching reversed, where cores are automatically biased due to the presence of prepulse. Good reproducibility was obtained even in the absence of the reset pulse. Within [similar]40% of full charge voltage, pulsed power characteristics of Marx generator, pulse forming line (PFL), transmission line (TL), and induction cells were tested for three types of loads; open-circuit, dummy load of liquid (CuSO4) resistor, and electron beam diode. In the open-circuit test, [similar]2.0 MV of output voltage was obtained with good reproducibility. Dependences of output voltage on diode impedances were evaluated by using various dummy loads, and the results were found as expected. An electron-beam diode was operated successfully, and [similar]18 kA of beam current was obtained at the diode voltage of [similar]1 MV.

Yatsui, Kiyoshi; Shimiya, Kouichi; Masugata, Katsumi; Shigeta, Masao; Shibata, Kazuhiko

2005-10-01

137

Electrical power generating system  

NASA Astrophysics Data System (ADS)

A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

Nola, F. J.

1983-06-01

138

Electrical power generating system  

NASA Technical Reports Server (NTRS)

A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

Nola, F. J. (inventor)

1983-01-01

139

Voltage security considerations in an open power market  

Microsoft Academic Search

The deregulation of the electric power industry in Europe is the major issue nowadays. The new environment raises questions concerning all sectors of the electric power industry. Nevertheless, the transmission system is the key point in market development since it puts constraints to the market operation due to technical requirements. Especially, in systems having weak connections among areas, congestion problems

J. Kabouris; C. D. Vournas; S. Efstathiou; G. A. Manos; G. C. Contaxis

2000-01-01

140

Voltages induced on a power distribution line by overhead cloud lightning  

NASA Technical Reports Server (NTRS)

Voltages induced by overhead cloud lightning on a 448 m open circuited power distribution line and the corresponding north-south component of the lightning magnetic field were simultaneously measured at the NASA Kennedy Space Center during the summer of 1986. The incident electric field was calculated from the measured magnetic field. The electric field was then used as an input to the computer program, EMPLIN, that calculated the voltages at the two ends of the power line. EMPLIN models the frequency domain field/power coupling theory found, for example, in Ianoz et al. The direction of the source, which is also one of the inputs to EMPLIN, was crudely determined from a three station time delay technique. The authors found reasonably good agreement between calculated and measured waveforms.

Yacoub, Ziad; Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

141

Electrical power systems for Mars  

NASA Technical Reports Server (NTRS)

Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

Giudici, Robert J.

1986-01-01

142

Electrical power systems for Mars  

NASA Astrophysics Data System (ADS)

Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

Giudici, Robert J.

1986-05-01

143

Feasibility of electric power transmission by DC superconducting cables  

Microsoft Academic Search

The electrical characteristics of dc superconducting cables of two power ratings were studied: 3 GW and 500 MW. Two designs were considered for each of the two power ratings. In the first design, the SUPPLY stream of the cryogen is surrounded by the high-voltage high-temperature superconductor cylinder. The RETURN stream of the cryogen is on the grounded side of the

Pritindra Chowdhuri; Chandralekha Pallem; Jonathan A Demko; Michael J Gouge

2005-01-01

144

Avalanche behavior of low-voltage power MOSFETs  

Microsoft Academic Search

This letter addresses the behavior of low voltage power MOSFETs under avalanche, with a paralleling point of view. It is shown that during avalanche, up-to-date technology MOSFET transistors exhibit a resistance far in excess of their on-state resistance (RDSon). A novel test setup is proposed to measure \\

Cyril Buttay; Tarek Ben Salah; Dominique Bergogne; Bruno Allard; Hervé Morel; Jean-Pierre Chante

2004-01-01

145

Wireless transfer of electric power  

E-print Network

In this dissertation, I describe the design and construction of a system which can transfer electric power wirelessly. This is accomplished using inductive, near-field, non-radiative coupling between self-resonant copper ...

Moffatt, Robert Alexander

2009-01-01

146

Electric Power Annual, 1986.  

National Technical Information Service (NTIS)

Sharply lower petroleum prices in 1986 from 1985 led to increased net generation by petroleum-fired plants and less gas-fired generation. Nuclear-powered generation capability increased in 1986, resulting in increased nuclear-powered net generation. These...

1987-01-01

147

Online Assessment of Voltage Stability in Power Systems with PMUs  

NASA Astrophysics Data System (ADS)

Abstract: For the assessment of voltage instability which comprises the detection of voltage instability and identification of critical buses, two indices namely, system wide Qtax, and bus-specific qtax, are proposed. The Qtax, based on the sensitivity of the reactive power injections to the loading in the system provides early detection of impending voltage instability. The computed qtax indices identify the critcal buses among the load buses in the system. The identified critical buses provided optimal lacations for the corrective control actions for averting voltage instability. Additionally, for voltage stability monitoring, determining the poing of exhaustion of the reactive reserves in system is also crucial. This is addressed by proposed Q-Monitoring Index (QMI), which is the ratio of the reactive component of the source current to the sink current that flows through the adjacent transmission line. These proposed indices together can provide early indication to impending voltage instability. This has been illustrated on IEEE-39 bus system. The reactive support on identified critical buses results in maximum increase in the loadability of the system.

Chitare, Prasad Bhagwat; Murthy Balijepalli, V. S. K.; Khaparde, S. A.

2013-05-01

148

Optimally scaled low-voltage vertical power MOSFETs for high-frequency power conversion  

Microsoft Academic Search

The systematic optimization of low-voltage silicon power MOSFET technology is described. It is shown that device scaling using advanced fabrication technologies can result in nearly optimal performance from low-voltage silicon power MOSFETs. The details discussed include: (1) system impact; (2) unit cell optimization; (3) device and process modeling; (4) fabrication technology development; and (5) performance results. The device technologies optimized

K. Shenai

1990-01-01

149

Low-Power Low-Voltage Current Readout Circuit for Inductively Powered Implant System  

Microsoft Academic Search

Low voltage and low power are two key requirements for on-chip realization of wireless power and data telemetry for applications in biomedical sensor instrumentation. Batteryless operation and wireless telemetry facilitate robust, reliable, and longer lifetime of the implant unit. As an ongoing research work, this paper demonstrates a low-power low-voltage sensor readout circuit which could be easily powered up with

Mohammad R. Haider; Syed K. Islam; Salwa Mostafa; Mo Zhang; Taeho Oh

2010-01-01

150

Evaluation of high temperature dielectric films for high voltage power electronic applications  

NASA Technical Reports Server (NTRS)

Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200 C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250 C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200 C. However, above 200 C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.

Suthar, J. L.; Laghari, J. R.

1992-01-01

151

Trading speed for low power by choice of supply and threshold voltages  

Microsoft Academic Search

The trading of speed for low power consumption in CMOS VLSI by using the supply voltage and the threshold voltage as variables was investigated. It is shown that it is desirable to minimize the supply voltage for minimizing the power consumption. The lower bound of the supply voltage and the possible decrease in power consumption without speed loss were investigated

Dake Liu; Christer Svensson

1993-01-01

152

30 CFR 75.812 - Movement of high-voltage power centers and portable transformers; permit.  

Code of Federal Regulations, 2010 CFR

...of high-voltage power centers and portable transformers; permit. 75...of high-voltage power centers and portable transformers; permit. [Statutory Provisions] Power centers and portable transformers shall be...

2010-07-01

153

Power quality measurements performed on a low-voltage grid equipped with two wind turbines  

Microsoft Academic Search

The power quality of a low-voltage grid with two wind turbines is investigated. Slow voltage variations as well as transients and harmonics are measured and analysed. Furthermore, the spectrum of the power is determined so that the presence of periodic power components can be investigated. Although periodic power fluctuations reaching 10% of the rated power are registered, voltage variations are

T. Thiringer

1996-01-01

154

Electrical Power Trade-Offs  

NASA Technical Reports Server (NTRS)

Electrical power trade studies were initiated in September 1982 supporting the Space Station Systems Definition activity. Responsibility for performing the electrical power trade studies (Power Data Base) was divided between the NASA Centers. Center representatives and their respective subjects are identified in the accompanying chart. The data base material was used to conduct a general storage trade study. When the results appeared to favor the flywheel option, effort was focused on a comparative flywheel investigation wherein a range of flywheel performance and cost possibilities was compared with optimistic projections of competing options.

Giudici, B.

1983-01-01

155

Electrical Properties and Power Considerations of a Piezoelectric Actuator  

NASA Technical Reports Server (NTRS)

This paper assesses the electrical characteristics of piezoelectric wafers for use in aeronautical applications such as active noise control in aircraft. Determination of capacitive behavior and power consumption is necessary to optimize the system configuration and to design efficient driving electronics. Empirical relations are developed from experimental data to predict the capacitance and loss tangent of a PZT5A ceramic as nonlinear functions of both applied peak voltage and driving frequency. Power consumed by the PZT is the rate of energy required to excite the piezoelectric system along with power dissipated due to dielectric loss and mechanical and structural damping. Overall power consumption is thus quantified as a function of peak applied voltage and driving frequency. It was demonstrated that by incorporating the variation of capacitance and power loss with voltage and frequency, satisfactory estimates of power requirements can be obtained. These relations allow general guidelines in selection and application of piezoelectric actuators and driving electronics for active control applications.

Jordan, T.; Ounaies, Z.; Tripp, J.; Tcheng, P.

1999-01-01

156

Voltage Drop  

NSDL National Science Digital Library

The first site with information on voltage drop is provided by Power and System Innovations on their Frequently Asked Questions: Voltage Drop (1) page. Visitors can read what voltage drop is, what causes it, what happens as a result of it, and what the maximum recommended voltage drop is. The second site, Basics of Electricity (2), is part of General Electric's Lighting for Business Web site. Through descriptions and illustrations, the site explains what voltage drop is and gives examples of how it is calculated using Ohm's law. The next site is a lab worksheet that is part of a class from the Electrical and Computer Engineering Department of Montana State University called Voltage Drop in Cables (3). The objective of the lesson is to determine the internal resistance of an extension cord and choose the proper wire size for a particular application. Students are given an explanation of the procedure and a number of questions to answer related to the exercise. The Oregon Building Congress offers the Lesson Plans (4) Web site and the downloadable Voltage Drop educational activity. The lesson, which is suggested to be contained within a unit on formulas and solving literal equations, explores the concept of voltage drop that is encountered in basic wiring. The fifth site entitled Explanation of Voltage Drop in a Series Circuit (5) is offered by the Horizons Electronic Lesson Plan Resource. The page describes voltage drop as an electronic concept, gives a formula determining voltage drop, provides a schematic that helps illustrate the concept, and offers a quiz and answer sheet. Next, from electrician.com, is the online Voltage Drop Calculator (6). Users input the type and size of wire being used, the voltage and phase, circuit length, and amp load to calculate voltage drop and several other parameters. The seventh site, entitled The Hazards of Voltage Drop (7), is provided within the Electrical Construction Maintenance Web site. The page describes how electrical equipment can overheat or even power down if it operates below its voltage rating. It also provides a thorough explanation of how to determine the load's operating voltage. The last site, maintained by Williamson Labs (8), is a comprehensive learning site called Elementary Electricity. Visitors will find a wealth of information here, including fun descriptions, graphics, and animations on all aspects of electricity including voltage drop.

157

Voltage and power relationships in lithium-containing solar cells.  

NASA Technical Reports Server (NTRS)

Photovoltaic characteristics have been measured on a large number of crucible-grown lithium-containing solar cells irradiated by 1-MeV electrons to fluences ranging from 3 x 10 to the 13th power to 3 x 10 to the 15th power electrons per sq cm. These measurements have established empirical relationships between cell photovoltaic parameters and lithium donor density gradient. Short-circuit current and maximum power measured immediately after irradiation decrease logarithmically with lithium gradient. Open-circuit voltage increases logarithmically with lithium gradient both immediately after irradiation and after recovery, the degree of recovery being strongly gradient-dependent at high fluence. As a result, the maximum power and the power at 0.43 V after recovery from 3 x 10 to the 15th power electrons per sq cm increase with increasing lithium gradient.

Faith, T. J.

1972-01-01

158

Oceans and electrical power  

Microsoft Academic Search

The first part of this paper focused on the potential energy that could be extracted from salinity an'd thermal differences in the oceans; possibilities of converting marine biomass into an energy source were likewise examined. Closest to implementation are apparently schemes to harness thermal differences and wave energy. Tidal power is already producing energy in France, U.S.S.R. and China. Of

Roger H. Charlier

1982-01-01

159

Software control program for 25 kW breadboard testing. [spacecraft power supplies; high voltage batteries  

NASA Technical Reports Server (NTRS)

A data acquisition software program developed to operate in conjunction with the automated control system of the 25 kW PM Electric Power System Breadboard Test facility is described. The proram provides limited interactive control of the breadboard test while acquiring data and monitoring parameters, allowing unattended continuous operation. The breadboard test facility has two positions for operating separate configurations. The main variable in each test setup is the high voltage Ni-Cd battery.

Pajak, J. A.

1981-01-01

160

Finding Market Power in Electric Power Markets  

Microsoft Academic Search

As part of the regulatory review of electric utility mergers in the United States, the Federal Energy Regulatory Commission requires utilities to submit market power studies. The Commission has specified a detailed method for calculating market concentration in these studies.This paper shows that one can simulate the actual price effects from the merger by using similar data and models. Using

John Morris

2000-01-01

161

Module Two: Voltage; Basic Electricity and Electronics Individualized Learning System.  

ERIC Educational Resources Information Center

In this module the student will study and learn what voltage is, how it is generated, what AC (alternating current) and DC (direct current) are and why both kinds are needed, and how to measure voltages. The module is divided into six lessons: EMF (electromotive force) from chemical action, magnetism, electromagnetic induction, AC voltage, the…

Bureau of Naval Personnel, Washington, DC.

162

Nuclear electric power sources  

NASA Technical Reports Server (NTRS)

Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

Singh, J. J.

1978-01-01

163

Power supply with feedback circuit for limiting output voltage  

SciTech Connect

This patent describes a elf-resonating power supply for controlling operation of an electrostatic air cleaner cell, a transformer having a primary winding and first and second secondary windings; a first transistor connected in series with the primary winding, the first secondary winding being effective to successively bias the first transistor on and off, the second secondary winding being effective to provide an output voltage to the cell; and feedback circuit means having first and second circuit portion.

Kniepkamp, D.I.

1992-06-23

164

Skylab technology electrical power system  

NASA Technical Reports Server (NTRS)

The solar array/battery power systems for the Skylab vehicle were designed to operate in a solar inertial pointing mode to provide power continuously to the Skylab. Questions of power management are considered, taking into account difficulties caused by the reduction in power system performance due to the effects of structural failure occurring during the launching process. The performance of the solar array of the Apollo Telescope Mount Power System is discussed along with the Orbital Workshop solar array performance and the Airlock Module power conditioning group performance. A list is presented of a number of items which have been identified during mission monitoring and are recommended for electrical power system concepts, designs, and operation for future spacecraft.

Woosley, A. P.; Smith, O. B.; Nassen, H. S.

1974-01-01

165

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

E-print Network

Voltage and Frequency Stability of Weak Power Distribution Networks with Droop to improve power quality and reliability of power grids. These DG's, however, may cause voltage and frequency with rated power level (stressful). Weak networks complicate voltage stability and frequency synchronization

Lemmon, Michael

166

Power-Efficient Pulse Width Modulation DC/DC Converters with Zero Voltage Switching Control  

E-print Network

voltage ripple and the speed of the voltage comparators which has shown to introduce new low-frequency General Terms Design. Keywords DC/DC conversion, zero voltage switching. 1. INTRODUCTION Power consumptionPower-Efficient Pulse Width Modulation DC/DC Converters with Zero Voltage Switching Control Changbo

He, Lei

167

A fractional open circuit voltage based maximum power point tracker for photovoltaic arrays  

Microsoft Academic Search

In this paper a fractional open circuit voltage based maximum power point tracker (MPPT) for photovoltaic (PV) arrays is proposed. The fractional open circuit voltage based MPPT utilizes the fact that the PV array voltage corresponding to the maximum power exhibits a linear dependence with respect to array open circuit voltage for different irradiation and temperature levels. This method is

J. Ahmad

2010-01-01

168

High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices  

NASA Technical Reports Server (NTRS)

A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

2014-01-01

169

Introduction to Electric Power Systems  

NSDL National Science Digital Library

This fine course is offered as a welcome addition to MIT's OpenCourseWare initiative. The materials from this version of "Introduction to Electric Power Systems" are from the iteration taught by Professor James Kirtley in Spring 2011. On the site, visitors can look over the syllabus, the course calendar, readings, assignments, and quizzes. The topics covered here include load flow, power electric motor drives, and polyphase networks. The site also includes a number of problem sets, along with their accompanying solutions. Visitors can look over the readings and provide feedback on the course to the site administrators.

Kirtley, James L.

2011-01-01

170

Electric Power annual 1996: Volume II  

SciTech Connect

This document presents a summary of electric power industry statistics. Data are included on electric utility retail sales of electricity, revenues, environmental information, power transactions, emissions, and demand-side management.

NONE

1997-12-01

171

High-efficiency power amplifier using dynamic power-supply voltage for CDMA applications  

Microsoft Academic Search

Efficiency and linearity of the microwave power amplifier are critical elements for mobile communication systems. This paper discusses improvements in system efficiency that are obtainable when a DC-DC converter is used to convert available battery voltage to an optimal supply voltage for the output RF amplifier. A boost DC-DC converter with an operating frequency of 10 MHz is demonstrated using

Gary Hanington; Pin-Fan Chen; Peter M. Asbeck; Lawrence E. Larson

1999-01-01

172

Current injection gate drive circuit for controlling the turn-off characteristic of low voltage power MOSFETs with high current ratings  

Microsoft Academic Search

In battery fed power trains with power converters like in lift trucks or electrical passenger cars the battery voltage varies substantially between charching and discharching and for full loaded and empty battery status. For gate drive circuit design and MOSFET selection the overvoltage at turn-off affected by the induced voltages at the stray inductances in the commutation path and the

Bjoern Wittig; Friedrich W. Fuchs

2010-01-01

173

Solid-Body Fuse Developed for High- Voltage Space Power Missions  

NASA Technical Reports Server (NTRS)

AEM Incorporated has completed the development, under a NASA Glenn Research Center contract, of a solid-body fuse for high-voltage power systems of satellites and spacecraft systems. High-reliability fuses presently defined by MIL-PRF-23419 do not meet the increased voltage and amperage requirements for the next generation of spacecraft. Solid-body fuses exhibit electrical and mechanical attributes that enable these fuses to perform reliably in the vacuum and high-vibration and -shock environments typically present in spacecraft applications. The construction and screening techniques for solid-body fuses described by MIL-PRF-23419/12 offer an excellent roadmap for the development of high-voltage solid-body fuses.

Dolce, James L.; Baez, Anastacio N.

2001-01-01

174

Multi-objective Optimal Power Flows to Evaluate Voltage Security Costs in Power Networks  

E-print Network

of the network, the incorporation of voltage collapse criteria and tools in the operation of power systems optimization methods to determine optimal control parameters that maximize load mar- gins and thus avoid

Cañizares, Claudio A.

175

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

E-print Network

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 ...

Moawwad, Ahmed

176

Transmission rights and market power on electric power networks  

E-print Network

We analyze whether and how the allocation of transmission rights associated with the use of electric power networks affects the behavior of electricity generators and electricity consumers with market power. We consider ...

Joskow, Paul L.

2000-01-01

177

Electric Power Network Decision Effects  

Microsoft Academic Search

Electric power networks pose design decision complexities characteristic of other large engineered systems. A great number of decisions must be made by many decision-makers, some decisions are made in a sequential manner over very long time periods, objectives compete, a large number of feasible solutions exist, and one decision-maker's actions can impact others, whose reactions in turn can affect the

Steven R. Harper; Deborah L. Thurston

2009-01-01

178

Voltage and Reactive Power Control Taking into Account of Economy and Security by using Tabu Search  

NASA Astrophysics Data System (ADS)

Due to deregulation of electric power market, the several power transactions and the distributed generators will increase year by year. The power flow in power system will vary increasingly more complex and more uncertain by them. So it is difficult for Voltage and reactive power(Q) Control (VQC) to sustain the adequate voltages in the power system. On the other hand, the economy and security are requested for power system operation and control under the competitive environment. The optimization algorithm is effective to satisfy these trade-off problem. The optimization of VQC traces the combinational optimization problem with shunt devices, transformer tap and generator terminal voltage. Tabu Search (TS), which is one of meta-heuristic approaches, is suitable for the optimization problem of VQC. Because it is able to deal with the discrete variables such as shunt devices easily and it needs few tuning parameters. In this paper, in order to realize flexible VQC which responds to the uncertain power flow with competitive environment, we propose the optimization of VQC with TS algorithm taking into account of both economy and security. The security is considered as the minimization of generator reactive outputs and transformer tap positions difference from the neutral. Moreover, the novel neighborhood condition setting focused on the control interference between voltage control equipments is applied to minimizing the objective function. It is confirmed by several numerical simulations using IEEE 14 and 57 bus system that the proposed scheme is able to ensure the security and to find the useful optimal solution efficiently.

Nakachi, Yoshiki; Kato, Atsushi; Ukai, Hiroyuki

179

Series capacitor combined with power system stabilizer for enhancement of power-systems voltage synchronous stability  

Microsoft Academic Search

The paper presents a nonlinear dynamic controller for a combination of static series capacitor compensation and power system stabilizer, for enhancement of both voltage and transient stability of power system. The proposed controller implements speed deviation signal and generator terminal current deviation signal. The proposed scheme is validated using a sample single machine infinite bus power system loaded by a

A. M. Sharaql; M. Z. El-Sadek; F. N. Abd-Elbar; A. M. Hemeida

2000-01-01

180

High voltage insulation of bushing for HTS power equipment  

NASA Astrophysics Data System (ADS)

For the operation of high temperature superconducting (HTS) power equipments, it is necessary to develop insulating materials and high voltage (HV) insulation technology at cryogenic temperature of bushing. Liquid nitrogen (LN2) is an attractive dielectric liquid. Also, the polymer insulating materials are expected to be used as solid materials such as glass fiber reinforced plastic (GFRP), polytetra-fluoroethylene (PTFE, Teflon), Silicon (Si) rubber, aromatic polyamide (Nomex), EPDM/Silicon alloy compound (EPDM/Si). In this paper, the surface flashover characteristics of various insulating materials in LN2 are studied. These results are studied at both AC and impulse voltage under a non-uniform field. The use of GFRP and Teflon as insulation body for HTS bushing should be much desirable. Especially, GFRP is excellent material not only surface flashover characteristics but also mechanical characteristics at cryogenic temperature. The surface flashover is most serious problem for the shed design in LN2 and operation of superconducting equipments.

Kim, Woo-Jin; Choi, Jae-Hyeong; Kim, Sang-Hyun

2012-12-01

181

Static reactive power compensators for high-voltage power systems. Final report  

SciTech Connect

A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high voltage as (HVAC) systems. The static var system is defined as a form of reactive power compensator. The general need for reactive power compensation in HVAC systems is discussed, and the static var system is compared to other devices utilized to provide reactive power compensation. Examples are presented of applying SVS for specific functions, such as the prevention of voltage collapse. The operating principles of commercially available SVS's are discussed in detail. The perormance and active power loss characteristics of SVS types are compared.

Not Available

1981-04-01

182

An electrically powered binary star?  

E-print Network

We propose a model for stellar binary systems consisting of a magnetic and a non-magnetic white-dwarf pair which is powered principally by electrical energy. In our model the luminosity is caused by resistive heating of the stellar atmospheres due to induced currents driven within the binary. This process is reminiscent of the Jupiter-Io system, but greatly increased in power because of the larger companion and stronger magnetic field of the primary. Electrical power is an alternative stellar luminosity source, following on from nuclear fusion and accretion. We find that this source of heating is sufficient to account for the observed X-ray luminosity of the 9.5-min binary RX J1914+24, and provides an explanation for its puzzling characteristics.

Kinwah Wu; Mark Cropper; Gavin Ramsay; Kazuhiro Sekiguchi

2001-11-19

183

Electric power monthly, October 1993  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1993-10-20

184

High voltage electrical burn injuries in teenage children: case studies with similarities (an Indian perspective).  

PubMed

From 1992 to 2012, a total of 911 paediatric burns were admitted and treated at Kanchi Kamakoti Childs Trust Hospital Intensive Burn Care Unit, of these 28 children had suffered electrical injuries and burns. 7 teenagers suffered high voltage electrical burn injuries: 2 were involved in train accidents which caused fatal electrical injuries, and 5 had electrical burn injuries caused by similar types of accidents, requiring Paediatric Intensive Care Unit (PICU) care, repeated surgeries and extensive rehabilitation. A common factor among these latter 5 patients was that they were injured by overhead high electrical voltage cables. Their management was labour intensive and highly costly. In this report, the type of accident, the electrical voltage that produced burns and the treatment details are elaborated. Findings included similarities in age and type of accident, and failure to implement safety procedures and apply standard norms of high voltage transmission feeder lines. PMID:24563637

Mathangi Ramakrishnan, K; Babu, M; Mathivanan; Ramachandran, B; Balasubramanian, S; Raghuram, K

2013-09-30

185

High voltage electrical burn injuries in teenage children: case studies with similarities (an indian perspective)  

PubMed Central

Summary From 1992 to 2012, a total of 911 paediatric burns were admitted and treated at Kanchi Kamakoti Childs Trust Hospital Intensive Burn Care Unit, of these 28 children had suffered electrical injuries and burns. 7 teenagers suffered high voltage electrical burn injuries: 2 were involved in train accidents which caused fatal electrical injuries, and 5 had electrical burn injuries caused by similar types of accidents, requiring Paediatric Intensive Care Unit (PICU) care, repeated surgeries and extensive rehabilitation. A common factor among these latter 5 patients was that they were injured by overhead high electrical voltage cables. Their management was labour intensive and highly costly. In this report, the type of accident, the electrical voltage that produced burns and the treatment details are elaborated. Findings included similarities in age and type of accident, and failure to implement safety procedures and apply standard norms of high voltage transmission feeder lines. PMID:24563637

Mathangi Ramakrishnan, K.; Babu, M.; Mathivanan; Ramachandran, B.; Balasubramanian, S.; Raghuram, K.

2013-01-01

186

Electric power annual 1995. Volume II  

SciTech Connect

This document summarizes pertinent statistics on various aspects of the U.S. electric power industry for the year and includes a graphic presentation. Data is included on electric utility retail sales and revenues, financial statistics, environmental statistics of electric utilities, demand-side management, electric power transactions, and non-utility power producers.

NONE

1996-12-01

187

Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems  

NASA Astrophysics Data System (ADS)

Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions.

Béthoux, O.; Cathelin, J.

2010-12-01

188

Manned spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward a growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented. Significant challenges different from Space Shuttle, innovative concepts and ideas, and station growth considerations are discussed. The Phase B Advanced Development hardware program is summarized and a status of Phase B preliminary tradeoff studies is presented.

Simon, William E.; Nored, Donald L.

1987-01-01

189

75 FR 23823 - Sixth Northwest Electric Power and Conservation Plan  

Federal Register 2010, 2011, 2012, 2013

...PACIFIC NORTHWEST ELECTRIC POWER AND CONSERVATION PLANNING COUNCIL Sixth Northwest Electric Power and Conservation Plan AGENCY: Pacific Northwest Electric Power and Conservation Planning Council (Northwest Power...

2010-05-04

190

70 FR 12757 - Fifth Northwest Electric Power and Conservation Plan  

Federal Register 2010, 2011, 2012, 2013

...PACIFIC NORTHWEST ELECTRIC POWER AND CONSERVATION PLANNING COUNCIL Fifth Northwest Electric Power and Conservation Plan AGENCY: Pacific Northwest Electric Power and Conservation Planning Council (Northwest Power...

2005-03-15

191

63 FR 42083 - Northwest Conservation and Electric Power Plan  

Federal Register 2010, 2011, 2012, 2013

...PACIFIC NORTHWEST ELECTRIC POWER AND CONSERVATION PLANNING COUNCIL Northwest Conservation and Electric Power Plan AGENCY: Pacific Northwest Electric Power and Conservation Planning Council (Northwest Power...

1998-08-06

192

78 FR 7774 - Alaska Electric Light and Power Company; Notice of Preliminary Permit Application Accepted for...  

Federal Register 2010, 2011, 2012, 2013

...Alaska Electric Light and Power Company filed an application...f) of the Federal Power Act (FPA), proposing...5-megavolt-ampere (MVA) transformer to adjust voltage to...Alaska Electric Light & Power, 5601 Tonsgard Ct...Commission strongly encourages electronic filing, documents...

2013-02-04

193

Bounds on Power Savings Using Runtime Dynamic Voltage Scaling: An Exact Algorithm and a Lineartime  

E-print Network

@princeton.edu ABSTRACT Dynamic voltage/frequency scaling (DVFS) has been shown to be an efficient power/energy reduction voltage/frequency voltage levels and different pro­ gram states. We then show a fast linear time heuristic dissipation varies linearly with frequency and quadratically with supply voltage as given by the equation

Martonosi, Margaret

194

Applicability of Recovery Voltage and On-Line Partial Discharge Measurements for Condition Assessment of High Voltage Power Transformers.  

National Technical Information Service (NTIS)

This thesis will focus on condition assessment methodologies of one of the most expensive electrical components: the power transformer. This power transformer fulfils an indispensable role in the AC power grid. Moreover, on the long term, this seems to be...

J. P. Van Bolhuis

2002-01-01

195

TEP Power Partners Project [Tucson Electric Power  

SciTech Connect

The Arizona Governor’s Office of Energy Policy, in partnership with Tucson Electric Power (TEP), Tendril, and Next Phase Energy (NPE), formed the TEP Power Partners pilot project to demonstrate how residential customers could access their energy usage data and third party applications using data obtained from an Automatic Meter Reading (AMR) network. The project applied for and was awarded a Smart Grid Data Access grant through the U.S. Department of Energy. The project participants’ goal for Phase I is to actively engage 1,700 residential customers to demonstrate sustained participation, reduction in energy usage (kWh) and cost ($), and measure related aspects of customer satisfaction. This Demonstration report presents a summary of the findings, effectiveness, and customer satisfaction with the 15-month TEP Power Partners pilot project. The objective of the program is to provide residential customers with energy consumption data from AMR metering and empower these participants to better manage their electricity use. The pilot recruitment goals included migrating 700 existing customers from the completed Power Partners Demand Response Load Control Project (DRLC), and enrolling 1,000 new participants. Upon conclusion of the project on November 19, 2013: ? 1,390 Home Area Networks (HANs) were registered. ? 797 new participants installed a HAN. ? Survey respondents’ are satisfied with the program and found value with a variety of specific program components. ? Survey respondents report feeling greater control over their energy usage and report taking energy savings actions in their homes after participating in the program. ? On average, 43 % of the participants returned to the web portal monthly and 15% returned weekly. ? An impact evaluation was completed by Opinion Dynamics and found average participant savings for the treatment period1 to be 2.3% of their household use during this period.2 In total, the program saved 163 MWh in the treatment period of 2013.

None

2013-11-19

196

Optimized silicon low-voltage power MOSFET's for high-frequency power conversion  

Microsoft Academic Search

The specific results obtained from a systematic optimization of low-voltage silicon power MOSFET technologies are discussed. The areas discussed include system impact, unit cell optimization, device and process modeling, fabrication technology development, and measured results. The device technologies optimized include 30 V, 50 V, and 100 V vertical power DMOSFETs with refractory silicide gate and contact metallizations. Devices with the

Krishna Shenai; Charles S. Korman; John P. Walden; Alexander J. Yerman; B. Jayant Baliga

1989-01-01

197

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

1989-01-01

198

Power system voltage stability and agent based distribution automation in smart grid  

NASA Astrophysics Data System (ADS)

Our interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The increased inter-area power transfers, aging infrastructure, and old technologies, have caused many problems including voltage instability, widespread blackouts, slow control response, among others. These problems have created an urgent need to transform the present electric power system to a highly stable, reliable, efficient, and self-healing electric power system of the future, which has been termed "smart grid". This dissertation begins with an investigation of voltage stability in bulk transmission networks. A new continuation power flow tool for studying the impacts of generator merit order based dispatch on inter-area transfer capability and static voltage stability is presented. The load demands are represented by lumped load models on the transmission system. While this representation is acceptable in traditional power system analysis, it may not be valid in the future smart grid where the distribution system will be integrated with intelligent and quick control capabilities to mitigate voltage problems before they propagate into the entire system. Therefore, before analyzing the operation of the whole smart grid, it is important to understand the distribution system first. The second part of this dissertation presents a new platform for studying and testing emerging technologies in advanced Distribution Automation (DA) within smart grids. Due to the key benefits over the traditional centralized approach, namely flexible deployment, scalability, and avoidance of single-point-of-failure, a new distributed approach is employed to design and develop all elements of the platform. A multi-agent system (MAS), which has the three key characteristics of autonomy, local view, and decentralization, is selected to implement the advanced DA functions. The intelligent agents utilize a communication network for cooperation and negotiation. Communication latency is modeled using a user-defined probability density function. Failure-tolerant communication strategies are developed for agent communications. Major elements of advanced DA are developed in a completely distributed way and successfully tested for several IEEE standard systems, including: Fault Detection, Location, Isolation, and Service Restoration (FLISR); Coordination of Distributed Energy Storage Systems (DES); Distributed Power Flow (DPF); Volt-VAR Control (VVC); and Loss Reduction (LR).

Nguyen, Cuong Phuc

199

Controllability and diagnosis in electric power systems  

Microsoft Academic Search

While modern electric power systems are often operated under stressed conditions, there is an increasing social demand for reliable electricity supplies. The reliable operation of a power system depends on the power system's ability to maintain a normal operating condition following a disturbance. This study focuses on two aspects of power systems: Controllability and diagnosis, both concerned with the power

Mingguo Hong

1998-01-01

200

Electric Power Reliability in Chemical Plants  

E-print Network

The quality and reliability of utility-generated electric power is presently receiving a great deal of attention from the chemical and refining industry. What changes have taken place to make electric power reliability a major topic of discussion...

Cross, M. B.

201

Electrical biasing and voltage contrast imaging in a focused ion beam system  

SciTech Connect

We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of advanced failure analysis applications including (1) real time evaluation of device electrical behavior during milling and deposition, (2) verification of IC functional modifications without removal from the FIB system, and (3) ultraprecision control for cross sectioning of deep submicron structures, such as programmed amorphous silicon antifuses. We have also developed FIB system voltage contrast imaging that can be used for a variety of failure analysis applications. The use of passive voltage contrast imaging for defect localization and for navigation on planarized devices will be illustrated. In addition, we describe new, biased voltage contrast imaging techniques and provide examples of their application to the failure analysis of complex ICs. We discuss the necessary changes in system operating parameters to perform biased voltage contrast imaging.

Campbell, A.N.; Soden, J.M.; Rife, J.L. [Sandia National Labs., Albuquerque, NM (United States); Lee, R.G. [Micrion Corp., Peabody, MA (United States)

1995-09-01

202

Application of Superconducting Power Cables to DC Electric Railway Systems  

NASA Astrophysics Data System (ADS)

For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.

Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru

203

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

E-print Network

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

Bellan, Paul M.

204

Voltage and frequency stabilisation of wind-diesel hybrid remote area power systems  

Microsoft Academic Search

This paper presents voltage and frequency stabilisation methods of a hybrid wind-diesel power system. A technique for power sharing between a wind energy conversion system and a diesel generator system is also addressed during the wind-diesel hybrid operation. The output voltage and frequency of the wind energy conversion system is controlled by a load side converter. The voltage and frequency

Abu Mohammad Osman Haruni; Ameen Gargoom; M. E. Haque; M. Negnevitsky

2009-01-01

205

Predicting Voltage Instability of Power System via Hybrid System Reachability Analysis  

Microsoft Academic Search

Estimating voltage instability of power systems is important for reduction of large blackouts. This paper proposes to use reachability analysis of hybrid systems for predicting voltage instability of a power system. The reachability analysis is performed by computing backward reachable sets for unsafe sets of hybrid automata. The automata represent continuous voltage dynamics and discrete operations by relay devices. The

Yoshihiko Susuki; Takashi Hikihara

2009-01-01

206

Hybrid fiber optic voltage sensor for remote monitoring of electrical submersible pump motors  

Microsoft Academic Search

We report on the design and experimental evaluation of the hybrid fiber Bragg grating (FBG) piezoelectric voltage sensor developed specifically for remote monitoring of electrical submersible pump (ESP) motors. Unlike a previously reported transducer based on a single piezoelectric element, the voltage rating of the presented device could be as low as 500 V due to the use of a

Lukasz Dziuda; Pawel Niewczas; Grzegorz Fusiek; James R. McDonald

2005-01-01

207

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices  

DOEpatents

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Chassin, David P. (Pasco, WA); Donnelly, Matthew K. (Kennewick, WA); Dagle, Jeffery E. (Richland, WA)

2011-12-06

208

Multi-Objective Differential Evolution for Voltage Security Constrained Optimal Power Flow in Deregulated Power Systems  

NASA Astrophysics Data System (ADS)

Voltage stability is an important issue in the planning and operation of deregulated power systems. The voltage stability problems is a most challenging one for the system operators in deregulated power systems because of the intense use of transmission line capabilities and poor regulation in market environment. This article addresses the congestion management problem avoiding offline transmission capacity limits related to voltage stability by considering Voltage Security Constrained Optimal Power Flow (VSCOPF) problem in deregulated environment. This article presents the application of Multi Objective Differential Evolution (MODE) algorithm to solve the VSCOPF problem in new competitive power systems. The maximum of L-index of the load buses is taken as the indicator of voltage stability and is incorporated in the Optimal Power Flow (OPF) problem. The proposed method in hybrid power market which also gives solutions to voltage stability problems by considering the generation rescheduling cost and load shedding cost which relieves the congestion problem in deregulated environment. The buses for load shedding are selected based on the minimum eigen value of Jacobian with respect to the load shed. In the proposed approach, real power settings of generators in base case and contingency cases, generator bus voltage magnitudes, real and reactive power demands of selected load buses using sensitivity analysis are taken as the control variables and are represented as the combination of floating point numbers and integers. DE/randSF/1/bin strategy scheme of differential evolution with self-tuned parameter which employs binomial crossover and difference vector based mutation is used for the VSCOPF problem. A fuzzy based mechanism is employed to get the best compromise solution from the pareto front to aid the decision maker. The proposed VSCOPF planning model is implemented on IEEE 30-bus system, IEEE 57 bus practical system and IEEE 118 bus system. The pareto optimal front obtained from MODE is compared with reference pareto front and the best compromise solution for all the cases are obtained from fuzzy decision making strategy. The performance measures of proposed MODE in two test systems are calculated using suitable performance metrices. The simulation results show that the proposed approach provides considerable improvement in the congestion management by generation rescheduling and load shedding while enhancing the voltage stability in deregulated power system.

Roselyn, J. Preetha; Devaraj, D.; Dash, Subhransu Sekhar

2013-11-01

209

A Multiharvested Self-Powered System in a Low-Voltage Low-Power Technology  

Microsoft Academic Search

A multiharvesting system conception focused on low- voltage (up to 2.5 V) and low-power applications is presented and validated as a point-of-view system. Using just this appli- cation-specified integrated circuit, with a total quiescent power consumption of 160 ?W, the harvesting system is able to collect and manage energy from different power sources, such as solar light (indoor environment), vibration

J. Colomer-Farrarons; P. Miribel-Catala; A. Saiz-Vela; J. Samitier

2011-01-01

210

Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power System  

E-print Network

Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power collapse will occurs in a wind power system is discussed next. The method of power flow calculation is the specific analysis of a given simplified wind power system. Keywords--voltage collapse; Newton

Lavaei, Javad

211

A Multi-agent Based Cooperative Voltage and Reactive Power Control  

NASA Astrophysics Data System (ADS)

In order to maintain system voltage within the optimal range and prevent voltage instability phenomena before they occur, a variety of phase modifying equipment is installed in optimal locations throughout the power system network and a variety of methods of voltage reactive control are employed. The proposed system divided the traditional method to control voltage and reactive power into two sub problems; “voltage control” to adjust the secondary bus voltage of substations, and “reactive power control” to adjust the primary bus voltage. In this system, two types of agents are installed in substations in order to cooperate “voltage control” and “reactive power control”. In order to verify the performance of the proposed method, it has been applied to the model network system. The results confirm that our proposed method is able to control violent fluctuations in load.

Ishida, Masato; Nagata, Takeshi; Saiki, Hiroshi; Shimada, Ikuhiko; Hatano, Ryousuke

212

Requirements on electrical power infrastructure by electric vehicles  

Microsoft Academic Search

With an increasing number of electric vehicles in operation new requirements on the electrical power networks will occur. Currently these networks are designed to supply on average a typical household load of around 2 kW. If electric vehicles will be connected then this household load might, depending on simultaneity of charging process and charging power, increase to more than 10

M. Hable; C. Schwaegerl; Liang Tao; A. Ettinger; R. Ko?berle; E.-P. Meyer

2010-01-01

213

Urban exposure to ELF magnetic field due to high-, medium- and low-voltage electricity supply networks.  

PubMed

The regional environment protection agency (ARPA) of the Aosta Valley region in north Italy performed a survey of magnetic field triggered by the power supply network in high, medium and low voltages on the entire area of Aosta town. The electrical distribution system for houses was not however taken into account. The aim of the survey was to evaluate the global population exposure and not simply the assessment of the legal exposure limit compliance. PMID:19843546

Bottura, V; Cappio Borlino, M; Carta, N; Cerise, L; Imperial, E

2009-12-01

214

Transformation of Trichoderma harzianum by high-voltage electric pulse  

Microsoft Academic Search

We have developed conditions for an efficient method of genetic transformation in Trichoderma harzianum, using high-voltage electroporation. Transformation was obtained with a plasmid carrying the Escherichia coli, hygromycin B phosphotransferase gene as a dominant selectable marker, and the gpd promoter and trpC terminator from Aspergillus nidulans. The transformation frequency is up to 400 transformants per µg of plasmid DNA. The

G. H. Goldman; M. Montagu; A. Herrera-Estrella

1990-01-01

215

Operational Problems of Primary ENEL (Italian Electricity Board) Power Distribution Station in Naples (Italy). Analysis for Reliability Improvement.  

National Technical Information Service (NTIS)

The paper reports the results of the first part of a research carried out on primary ENEL (Italian Electricity Board) power distribution stations in Naples, Italy. Reliabilty problems, due to electric aging, were investigated relevant to medium voltage su...

E. Elli, W. Mosca, G. De Seta, I. Vitto

1987-01-01

216

Limiting electric fields of HVDC overhead power lines.  

PubMed

As a consequence of the increased use of renewable energy and the now long distances between energy generation and consumption, in Europe, electric power transfer by high-voltage (HV) direct current (DC) overhead power lines gains increasing importance. Thousands of kilometers of them are going to be built within the next years. However, existing guidelines and regulations do not yet contain recommendations to limit static electric fields, which are one of the most important criteria for HVDC overhead power lines in terms of tower design, span width and ground clearance. Based on theoretical and experimental data, in this article, static electric fields associated with adverse health effects are analysed and various criteria are derived for limiting static electric field strengths. PMID:24573710

Leitgeb, N

2014-05-01

217

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

Bulk power system voltage phenomena - III: Voltage stability, security & control, Davos. If the loading margin is danger- ously small, then controls to steer the power system away from the fold to select controls to avoid voltage collapse. This paper justifies the use of static power models to com

Dobson, Ian

218

Design and Construction of Low Cost High Voltage dc Power Supply for Constant Power Operation  

NASA Astrophysics Data System (ADS)

Pulsed load applications like laser based systems need high voltage dc power supplies with better regulation characteristics. This paper presents the design, construction and testing of dc power supply with 1 kV output at 300 W power level. The designed converter has half bridge switched mode power supply (SMPS) configuration with 20 kHz switching. The paper covers the design of half bridge inverter, closed loop control, High frequency transformer and other related electronics. The designed power supply incorporates a low cost OPAMP based feedback controller which is designed using small signal modelling of the converter. The designed converter was constructed and found to work satisfactorily as per the specifications.

Kumar, N. S.; Jayasankar, V.

2013-06-01

219

Voltage saturation in electrical contacts via viscoplastic creep  

Microsoft Academic Search

Electrical contact resistance affects the performance of electrical switches and other current-carrying interfaces. This study investigates the behavior of electrical contact resistance for copper–copper and aluminum–aluminum sphere-on-flat contact as a function of current through the interface. It is observed that the contact resistance may either increase or decrease with increasing current, depending on the current level as well as the

Dinesh G. Bansal; Jeffrey L. Streator

2011-01-01

220

Design considerations for high-voltage high-power full-bridge zero-voltage-switched PWM converter  

Microsoft Academic Search

A steady-state analysis is presented with complete characterization of the converter operation. A small-signal model of the converter is established. The design procedures based on the analysis are presented and the various losses in the circuit assessed. Critical design considerations for a high-power, high-voltage application are analyzed. The results of the analysis are verified using a high-voltage. 2 kW prototype

J. A. Sabate; V. Vlatkovic; R. B. Ridley; F. C. Lee; B. H. Cho

1990-01-01

221

Ferroelectric Emission Cathodes for Low-Power Electric Propulsion  

NASA Technical Reports Server (NTRS)

Low- or no-flow electron emitters are required for low-power electric thrusters, spacecraft plasma contactors, and electrodynamic tether systems to reduce or eliminate the need for propellant/expellant. Expellant-less neutralizers can improve the viability of very low-power colloid thrusters, field emission electric propulsion devices, ion engines, Hall thrusters, and gridded vacuum arc thrusters. The NASA Glenn Research Center (GRC) is evaluating ferroelectric emission (FEE) cathodes as zero expellant flow rate cathode sources for the applications listed above. At GRC, low voltage (100s to approx. 1500 V) operation of FEE cathodes is examined. Initial experiments, with unipolar, bipolar, and RF burst applied voltage, have produced current pulses 250 to 1000 ns in duration with peak currents of up to 2 A at voltages at or below 1500 V. In particular, FEE cathodes driven by RF burst voltages from 1400 to 2000 V peak to peak, at burst frequencies from 70 to 400 kHz, emitted average current densities from 0.1 to 0.7 A/sq cm. Pulse repeatability as a function of input voltage has been initially established. Reliable emission has been achieved in air background at pressures as high as 10(exp -6) Torr.

Kovaleski, Scott D.; Burke, Tom (Technical Monitor)

2002-01-01

222

Analysis of electrical tree propagation in XLPE power cable insulation  

NASA Astrophysics Data System (ADS)

Electrical treeing is one of the major breakdown mechanisms for solid dielectrics subjected to high electrical stress. In this paper, the characteristics of electrical tree growth in XLPE samples have been investigated. XLPE samples are obtained from a commercial XLPE power cable, in which electrical trees have been grown from pin to plane in the frequency range of 4000-10,000 Hz, voltage range of 4-10 kV, and the distances between electrodes of 1 and 2 mm. Images of trees and their growing processes were taken by a CCD camera. The fractal dimensions of electric trees were obtained by using a simple box-counting technique. The results show that the tree growth rate and fractal dimension was bigger when the frequency or voltage was higher, or the distance between electrodes was smaller. Contrary to our expectation, it has been found that when the distance between electrodes changed from 1 to 2 mm, the required voltage of the similar electrical trees decreased only 1or 2 kV. In order to evaluate the difficulties of electrical tree propagation in different conditions, a simple energy threshold analysis method has been proposed. The threshold energy, which presents the minimum energy that a charge carrier in the well at the top of the tree should have to make the tree grow, has been computed considering the length of electrical tree, the fractal dimension, and the growth time. The computed results indicate that when one of the three parameters of voltage, frequency, and local electric field increase, the trends of energy threshold can be split into 3 regions.

Bao, Minghui; Yin, Xiaogen; He, Junjia

2011-04-01

223

Voltage transfer function as an optical method to characterize electrical properties of liquid crystal devices.  

PubMed

The voltage transfer function is a rapid and visually effective method to determine the electrical response of liquid crystal (LC) systems using optical measurements. This method relies on crosspolarized intensity measurements as a function of the frequency and amplitude of the voltage applied to the device. Coupled with a mathematical model of the device it can be used to determine the device time constants and electrical properties. We validate the method using photorefractive LC cells and determine the main time constants and the voltage dropped across the layers using a simple nonlinear filter model. PMID:24978729

Bateman, J; Proctor, M; Buchnev, O; Podoliak, N; D'Alessandro, G; Kaczmarek, M

2014-07-01

224

Wildlife and electric power transmission  

USGS Publications Warehouse

Hundreds of thousands of miles of transmission lines have been introduced into our natural environment. These lines and their corridors can be damaging or beneficial to wildlife communities depending on how they are designed, where they are placed, and when they are constructed and maintained. With the current trend toward UHV systems, new problems (associated with additional increments in audible noise, electric and magnetic force fields, etc.) must be addressed. We recommend the following areas for careful study: (1) the response of wilderness species to transmission lines and line construction and maintenance activities (2) the magnitude of bird collision and electrocution mortality, (3) the response of power corridor and power tower in habiting wildlife to laboratory and field doses of electro-chemical oxidants, corona noise, electric and magnetic fields, etc., (4) the productivity of tower inhabiting birds compared with nearby non-tower nesters, and (5) the influence of powerline corridors on mammalian and avian migration patterns. It is our hope that the questions identified in this study will help stimulate further research so that we can maximize wildlife benefits and minimize wildlife detriments.

Ellis, D.H.; Goodwin, J.G., Jr.; Hunt, J.R.

1978-01-01

225

Electrical Conductivity Measurements via a Low-Voltage Conductivity Channel  

Microsoft Academic Search

The electrical conductivity in combustion gases with four different compositions (2% potassium with 0%, 10%, 15%, and 20% aluminum by mass added to a hydrocarbon fuel burned in gaseous oxygen) was determined experimentally using conductivity channels with two geometrical configurations, one with a constant bore and one with a tapered bore. Electrical conductivity for these conditions was calculated using the

Robert Rhodes; Trevor Moeller; Dennis Keefer

2012-01-01

226

High-voltage, high-power, solid-state remote power controllers for aerospace applications  

NASA Technical Reports Server (NTRS)

Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.

Sturman, J. C.

1985-01-01

227

Multilevel voltage source inverters with phase shift SPWM and their applications in STATCOM and power line conditioner  

NASA Astrophysics Data System (ADS)

Reactive power compensation and harmonic reduction are two relevant research problems that exist in modern electric power systems. With the advancement of modern power electronics technology in both circuits and devices, new and better solutions are being proposed and applied to solve these two problems. To compensate reactive power, a cascading voltage source inverter with a Phase-Shift, Unipolar SPWM switching scheme is proposed. The main circuit of this inverter is composed of several identical voltage source H-bridge inverters connected in cascade form. Advantages of this scheme include use of identically rated storage capacitors, similarly rated switches and diodes, quick system response to load changes, and easily achievable redundancy. To solve the harmonic reduction problem, the flying capacitor multilevel voltage source inverter is adopted to construct a novel power line conditioner. The Phase Shift SPWM switching scheme is also employed to operate the switches of this inverter. As a result, it is possible to extend the new power line conditioner to distribution systems or industrial applications where voltage usually ranges from 4.16kV to 13.8kV. It is shown that the proposed power line conditioner not only balances the unbalanced load, but simultaneously compensates the reactive power as well.

Liang, Yiqiao

228

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

SciTech Connect

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

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

2008-01-01

229

A Novel Electrical Insulating Material for 275 kV High-Voltage HTS Cable with Low Dielectric Loss  

NASA Astrophysics Data System (ADS)

In the case of high temperature superconducting (HTS) power transmission cables at high voltage operation, the electrical insulation technique in consideration of the dielectric loss reduction becomes crucial. In this paper, we focused on a Tyvek/polyethylene (PE) sheet, instead of the conventional polypropylene laminated paper (PPLP). We obtained the dielectric characteristics (epsilonr, tan?) and partial discharge inception strength (PDIE) of PPLP, Tyvek and Tyvek/PE. We pointed out that the dielectric loss of 275 kV HTS cable with Tyvek/PE insulation will be reduced to 21 % of that with PPLP, and the total electrical loss including the AC loss will be reduced to 41 %.

Hayakawa, N.; Nishimachi, S.; Maruyama, O.; Ohkuma, T.; Liu, J.; Yagi, M.

2014-05-01

230

Scaling Analysis of On-Chip Power Grid Voltage Variations in Nanometer Scale ULSI  

E-print Network

significant amount of skew which in turn degrades the signal integrity. Key words: technology scaling, powerScaling Analysis of On-Chip Power Grid Voltage Variations in Nanometer Scale ULSI AMIR H. AJAMI, 1 analysis of the power supply distribution network voltage drop in DSM technologies. The effects of chip

Pedram, Massoud

231

Performance Analysis of a Hybrid Asymmetric Multilevel Inverter for High Voltage Active Power Filter Applications  

E-print Network

Performance Analysis of a Hybrid Asymmetric Multilevel Inverter for High Voltage Active Power voltage-source inverters connected in series (known as cascaded hybrid asymmetric multilevel inverter. Index Terms­ Active power filter, Multilevel inverter, Linear control. I. INTRODUCTION A ctive power

Catholic University of Chile (Universidad Católica de Chile)

232

Performance analysis of a hybrid asymmetric multilevel inverter for high voltage active power filter applications  

Microsoft Academic Search

An active power filter implemented with multiples single-phase full bridge voltage-source inverters connected in series (known as cascaded hybrid asymmetric multilevel inverter or binary multilevel VSI) is presented and analyzed in this paper. The proposed active power filter is aimed to compensate current harmonic components in medium and high voltage power distribution systems. A control scheme is developed to allow

M. G. Lopez; Luis Moran; J. C. Espinoza; J. R. Dixon

2003-01-01

233

Finite element field analysis of nonuniform surface contaminations on high voltage windings of electric machines  

Microsoft Academic Search

The analysis of electric fields in insulation systems containing conductive materials such as surface contaminations or grading tapes requires the solution of the complex Laplace equation. This paper presents two techniques of modeling thin conductive layers on the insulation of high voltage electric machines with electrodynamic finite element simulations. Case studies are performed to illustrate the benefits of employing finite

K. Weeber; M. Stutt; J. Dymond; R. Rehder

1996-01-01

234

The Effect of High Voltage, High Frequency Pulsed Electric Field on Slain Ovine Cortical Bone  

PubMed Central

High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction. PMID:24761375

Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

2014-01-01

235

The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.  

PubMed

High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction. PMID:24761375

Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

2014-04-01

236

SRF theory for voltage and frequency control of IAG based wind power generation  

Microsoft Academic Search

This paper deals with the control of voltage and frequency of an autonomous wind power generation based on isolated asynchronous generator (IAG) feeding three-phase four-wire loads. The proposed control scheme is using the synchronous reference frame (SRF) theory based current detection. The proposed voltage and frequency controller (VFC) consists of a three leg voltage source converter (VSC) with a battery

Bhim Singh; Shailendra Sharma

2009-01-01

237

Digital power factor meter design based on voltage-to-frequency conversion  

Microsoft Academic Search

This paper describes the development of an electronic power factor meter to replace the conventional electrodynamic type. The design is based on voltage-to-frequency conversion and digital counting techniques. Two DC signals are generated : the first proportional to the peak voltage Vm and the second proportional to Vm cos ?. These two signals are applied to two voltage-to-frequency converters (VFC).

M. S. M. AL-ANI; M. A. H. ABDUL-KARIM

1982-01-01

238

Advanced coupled voltage-frequency control for power efficient DVFS management  

E-print Network

Advanced coupled voltage-frequency control for power efficient DVFS management C. Albea1,2 , Diego-topic in complex System-on-Chip (SoC) designs. In the context of advanced technologies, Dynamic Voltage-Frequency are composed of independent actuators con- trolling the applied voltage and clock frequency. A predefined

Boyer, Edmond

239

Solid State Voltage and Frequency Controller for a Stand Alone Wind Power Generating System  

Microsoft Academic Search

This paper deals with the voltage and frequency controller of a wind turbine driven isolated asynchronous generator. The proposed voltage and frequency controller consists of an insulated gate bipolar junction transistor based voltage source converter along-with battery energy storage system at its dc link. The proposed controller is having bidirectional active and reactive powers flow capability by which it controls

Bhim Singh; Gaurav Kumar Kasal

2008-01-01

240

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

E-print Network

of restructured power system. This dissertation presents a new decomposition procedure to estimate voltage security usage by transactions. The procedure follows physical law and uses an index that can be monitored knowing the state of the system. The expression...

Nair, Nirmal-Kumar

2006-04-12

241

Compact portable electric power sources  

SciTech Connect

This report provides an overview of recent advances in portable electric power source (PEPS) technology and an assessment of emerging PEPS technologies that may meet US Special Operations Command`s (SOCOM) needs in the next 1--2- and 3--5-year time frames. The assessment was performed through a literature search and interviews with experts in various laboratories and companies. Nineteen PEPS technologies were reviewed and characterized as (1) PEPSs that meet SOCOM requirements; (2) PEPSs that could fulfill requirements for special field conditions and locations; (3) potentially high-payoff sources that require additional R and D; and (4) sources unlikely to meet present SOCOM requirements. 6 figs., 10 tabs.

Fry, D.N.; Holcomb, D.E.; Munro, J.K.; Oakes, L.C.; Matson, M.J.

1997-02-01

242

Automatic voltage imbalance detector  

DOEpatents

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

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

1984-01-01

243

Review of electric power engineering education worldwide  

Microsoft Academic Search

The Power Engineering Education Committee sponsored panel session gives an outline of the status of electric power system education in different countries of the world. Graduate and undergraduate electrical power engineering programs typical to a particular country are described. The descriptions include the concepts of graduate and undergraduate education, typical courses and laboratory schedules, tutorials, credits or number of courses

G. G. Karady; G. T. Heydt; M. Michel; P. Crossley; H. Rudnick; S. Iwamoto

1999-01-01

244

Electrical power technology for robotic planetary rovers  

NASA Technical Reports Server (NTRS)

Power technologies which will enable a range of robotic rover vehicle missions by the end of the 1990s and beyond are discussed. The electrical power system is the most critical system for reliability and life, since all other on board functions (mobility, navigation, command and data, communications, and the scientific payload instruments) require electrical power. The following are discussed: power generation, energy storage, power management and distribution, and thermal management.

Bankston, C. P.; Shirbacheh, M.; Bents, D. J.; Bozek, J. M.

1993-01-01

245

Electrical power requirements analysis. Single failure tolerant entry  

NASA Technical Reports Server (NTRS)

The results of an analysis of the orbiter electrical power system for the case of a single failure tolerant (SFT) entry are presented. The analysis was performed using the shuttle electrical power system analysis computer program. It was performed to permit assessment of the capability of the orbiter systems to support the proposed entry configuration and to provide the data necessary to identify potential constraints and limitations. Three contingency modes have been identified which would require an SFT entry. This analysis addresses an SFT entry resulting from the loss of two fuel cell powerplants, while on orbit. The results of the analysis indicate that, even under near optimum conditions, the fuel cell power demand will exceed the tested operating capacity of 16 kw, and that various electrical components may experience voltages below 24 VDC.

Pipher, M. D.; Green, P. A.; Wolfgram, D. F.

1977-01-01

246

Electric power annual 1997. Volume 2  

SciTech Connect

The Electric Power Annual 1997, Volume 2 contains annual summary statistics at national, regional, and state levels for the electric power industry, including information on both electric utilities and nonutility power producers. Included are data for electric utility retail sales of electricity, associated revenue, and average revenue per kilowatthour of electricity sold; financial statistics; environmental statistics; power transactions; and demand-side management. Also included are data for US nonutility power producers on installed capacity; gross generation; emissions; and supply and disposition of energy. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts, and the general public with historical data that may be used in understanding US electricity markets. 15 figs., 62 tabs.

NONE

1998-10-01

247

Technological Aspects: High Voltage  

E-print Network

This paper covers the theory and technological aspects of high-voltage design for ion sources. Electric field strengths are critical to understanding high-voltage breakdown. The equations governing electric fields and the techniques to solve them are discussed. The fundamental physics of high-voltage breakdown and electrical discharges are outlined. Different types of electrical discharges are catalogued and their behaviour in environments ranging from air to vacuum are detailed. The importance of surfaces is discussed. The principles of designing electrodes and insulators are introduced. The use of high-voltage platforms and their relation to system design are discussed. The use of commercially available high-voltage technology such as connectors, feedthroughs and cables are considered. Different power supply technologies and their procurement are briefly outlined. High-voltage safety, electric shocks and system design rules are covered.

Faircloth, D C

2013-01-01

248

New High Voltage Gain Dual-boost DC-DC Converter for Photovoltaic Power Systems  

Microsoft Academic Search

This article presents a new circuit topology of a high-voltage step-up boost DC-DC converter for photovoltaic power systems. The converter boosts the low-output voltage of the solar cell to the required voltage for the load. The proposed circuit has various advantages compared to the conventional boost converters, namely a higher boost rate with low duty cycle, lower voltage stress on

Khairy Sayed; Mazen Abdel-Salam; Adel Ahmed; Mahmoud Ahmed

2012-01-01

249

Electric Power Controller for Steering Wheel Management in Electric Cars  

E-print Network

Electric Power Controller for Steering Wheel Management in Electric Cars Vicente Milanés, Joshué transportation systems. Among these topics, the automation of the actuators involved in the management of a car. An electric car has been equipped with the system designed and tests to prove the behavior of the system

Paris-Sud XI, Université de

250

Electrical power generation by mechanically modulating electrical double layers.  

PubMed

Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future. PMID:23403587

Moon, Jong Kyun; Jeong, Jaeki; Lee, Dongyun; Pak, Hyuk Kyu

2013-01-01

251

Electric power market agent design  

NASA Astrophysics Data System (ADS)

The electric power industry in many countries has been restructured in the hope of a more economically efficient system. In the restructured system, traditional operating and planning tools based on true marginal cost do not perform well since information required is strictly confidential. For developing a new tool, it is necessary to understand offer behavior. The main objective of this study is to create a new tool for power system planning. For the purpose, this dissertation develops models for a market and market participants. A new model is developed in this work for explaining a supply-side offer curve, and several variables are introduced to characterize the curve. Demand is estimated using a neural network, and a numerical optimization process is used to determine the values of the variables that maximize the profit of the agent. The amount of data required for the optimization is chosen with the aid of nonlinear dynamics. To suggest an optimal demand-side bidding function, two optimization problems are constructed and solved for maximizing consumer satisfaction based on the properties of two different types of demands: price-based demand and must-be-served demand. Several different simulations are performed to test how an agent reacts in various situations. The offer behavior depends on locational benefit as well as the offer strategies of competitors.

Oh, Hyungseon

252

Easily disassembled electrical connector for high voltage, high frequency connections  

DOEpatents

An easily accessible electrical connector capable of rapid assembly and disassembly is described wherein a wide metal conductor sheet may be evenly contacted over the entire width of the conductor sheet by opposing surfaces on the connector which provide an even clamping pressure against opposite surfaces of the metal conductor sheet using a single threaded actuating screw. 13 figures.

Milner, J.R.

1994-05-10

253

Real Time Voltage and Current Phase Shift Analyzer for Power Saving Applications  

PubMed Central

Nowadays, high importance is given to low energy devices (such as refrigerators, deep-freezers, washing machines, pumps, etc.) that are able to produce reactive power in power lines which can be optimized (reduced). Reactive power is the main component which overloads power lines and brings excessive thermal stress to conductors. If the reactive power is optimized, it can significantly lower the electricity consumption (from 10 to 30%—varies between countries). This paper will examine and discuss the development of a measuring device for analyzing reactive power. However, the main problem is the precise real time measurement of the input and output voltage and current. Such quality measurement is needed to allow adequate action intervention (feedback which reduces or fully compensates reactive power). Several other issues, such as the accuracy and measurement speed, must be examined while designing this device. The price and the size of the final product need to remain low as they are the two important parameters of this solution. PMID:23112662

Krejcar, Ondrej; Frischer, Robert

2012-01-01

254

An electrically tunable-focusing liquid crystal lens with a low voltage and simple electrodes.  

PubMed

An electrically tunable focusing LC lens with a low voltage and simple planar electrodes is demonstrated. The inhomogeneous electric field of the LC lens without any hole-patterned-electrode is generated by using an embedded polymeric layer with a gradient distribution of dielectric constants (or relative permittivity). LC directors in the LC layer experience spatially inhomogeneous voltages even though a single voltage is applied to the planar electrodes. Such a LC lens has a low voltage (~2.6 V(rms)) and simple design of electrodes. The gradient distribution of dielectric constants of polymeric layer is discussed and the performance of the LC lens is investigated. The applications of such a LC lens are cell phones, webcam, and pico projectors. PMID:22330445

Lin, Hung-Chun; Lin, Yi-Hsin

2012-01-30

255

Test facilities for high power electric propulsion  

NASA Technical Reports Server (NTRS)

Electric propulsion has applications for orbit raising, maneuvering of large space systems, and interplanetary missions. These missions involve propulsion power levels from tenths to tens of megawatts, depending upon the application. General facility requirements for testing high power electric propulsion at the component and thrust systems level are defined. The characteristics and pumping capabilities of many large vacuum chambers in the United States are reviewed and compared with the requirements for high power electric propulsion testing.

Sovey, James S.; Vetrone, Robert H.; Grisnik, Stanley P.; Myers, Roger M.; Parkes, James E.

1991-01-01

256

Electromagnetic pulse and the electric power network  

SciTech Connect

This paper defines the nuclear electromagnetic pulse (EMP) - electric power system interaction problem. A description of high altitude EMP (HEMP) characteristics, source region EMP (SREMP) characteristics, and magnetohydrodynamics EMP (MHD-EMP) characteristics are presented. The results of initial calculations of EMP induced surges on electric power transmission and distribution lines are presented and compared with lightning induced surges. Potential EMP impacts on electric power systems are discussed, and an overview of the Department of Energy (DOE) EMP research program is presented.

Klein, K.W.; Barnes, P.R.; Zaininger, H.W.

1984-01-01

257

Electric power plant capital costs  

SciTech Connect

Due to the increase of technology options, it is becoming day by day more important to have an overview of electric power plants capital costs so to take the right decisions in the preliminary stages of the project choices. From 1970 through the 1980's and 1990's, the capital costs of traditional steam power plants increased steadily, due in part to the addition of more advanced, and more costly, pollution control equipment. On the other hand the availability of ample natural gas, the scaling up of gas turbine machinery and the appearance on the market of new technologies (PFB, IGCC, fuel cells, etc.) are offering new opportunities to the traditional utilities and to the new players including the independent power producers, developers and private operators. The costs indicated will be referred to the two main world markets, that is, the Western countries and Asian area. These costs are obviously for preliminary studies and project assessment. To minimize the cost/benefit ratio, the design activities of the architect-engineer consultant have a very important role. Impact of manufacturing area on main component costs and on erection works: The three main factors, which influence machinery price are: local labor cost, license or research cost and raw material cost. An additional impact on plant cost on local basis are the raw material cost for erection, erection manpower, their skill and components available/manufactured in the erection area. Local taxation and custom duties must also be considered. Labor costs in Eastern Germany are still much lower than in the West Germany, but they are not indicated in the survey. Portuguese and Greek workers have the lowest labor costs.

Dodero, G.; Castellie, D.; Coffetti, M.

1998-07-01

258

Hybrid fiber optic voltage sensor for remote monitoring of electrical submersible pump motors  

NASA Astrophysics Data System (ADS)

We report on the design and experimental evaluation of the hybrid fiber Bragg grating (FBG) piezoelectric voltage sensor developed specifically for remote monitoring of electrical submersible pump (ESP) motors. Unlike a previously reported transducer based on a single piezoelectric element, the voltage rating of the presented device could be as low as 500 V due to the use of a multilayer piezoelectric stack as the primary voltage-to-strain transducer. This enables the use of such sensors across a wider range of ESP applications, which often have subkilovolt voltage ratings. In addition to the design details, we present details of the full characterization of the device, including the hysteresis and temperature-dependence characteristics and discuss ways of eliminating or reducing these effects. We also demonstrate that the sensor can be used to simultaneously measure voltage and temperature.

Dziuda, L.; Niewczas, Pawel; Fusiek, G.; McDonald, James R.

2005-06-01

259

Determination of the cathode and anode voltage drops in high power low-pressure amalgam lamps  

SciTech Connect

For the first time, cathode and anode drops of powerful low-pressure amalgam lamps were measured. The lamp discharge current is 3.2 A, discharge current frequency is 43 kHz, linear electric power is 2.4 W/cm. The method of determination of a cathode drop is based on the change of a lamp operating voltage at variation of the electrode filament current at constant discharge current. The total (cathode plus anode) drop of voltage was measured by other, independent ways. The maximum cathode fall is 10.8 V; the anode fall corresponding to the maximal cathode fall is 2.4 V. It is shown that in powerful low pressure amalgam lamps the anode fall makes a considerable contribution (in certain cases, the basic one) to heating of electrodes. Therefore, the anode fall cannot be neglected, at design an electrode and ballast of amalgam lamps with operating discharge current frequency of tens of kHz.

Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Vasiliev, A. I., E-mail: vasiliev@npo.lit.ru; Kostyuchenko, S. V.; Sokolov, D. V.; Startsev, A. Yu. [Joint Stock Company NPO LIT (Russian Federation); Kudryavtsev, N. N. [Moscow Institute of Physics and Technology (State University) (Russian Federation)

2011-12-15

260

Computer Power. Part 2: Electrical Power Problems and Their Amelioration.  

ERIC Educational Resources Information Center

Describes electrical power problems that affect computer users, including spikes, sags, outages, noise, frequency variations, and static electricity. Ways in which these problems may be diagnosed and cured are discussed. Sidebars consider transformers; power distribution units; surge currents/linear and non-linear loads; and sizing the power

Price, Bennett J.

1989-01-01

261

Modelling and control of a seven level NPC voltage source inverter. Application to high power induction machine drive  

NASA Astrophysics Data System (ADS)

In this paper, we study a new kind of continuous-alternating converters: a seven-level neutral point clamping (NPC) voltage source inverter (VSI). We propose this inverter for applications in high voltage and high power fields. In the first part, we develop the knowledge and the control models of this inverter using the connections functions of the semi-conductors. After that, we present two pulse width modulation (PWM) algorithms to control this converter using its control model. We propose these algorithms for digital implementation. This multilevel inverter is associated to the induction machine. The performances obtained are full of promise to use it in the high voltage and high power fields of electrical traction.

Gheraia, H.; Berkouk, E. M.; Manesse, G.

2001-08-01

262

Power quality load management for large spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

Lollar, Louis F.

1988-01-01

263

An optically coupled power stimulus isolation unit with high voltage and fast rise time output.  

PubMed

Recent technological developments have created new devices that could improve and simplify the construction of stimulus isolators. HEXFET transistors can switch large currents and hundreds of volts in nanoseconds. The newer opto-isolators can give a pulse rise time of a few nanoseconds, with output compatible with MOSFET devices, in which delays are reduced to nanoseconds. Integrated DC/DC converters are now available. Using these new resources we developed a new electrical stimulus isolator circuit with selectable constant-current and constant-voltage modes, which are precise and easy to construct. The circuit works like a regulated power supply in both modes with output switched to zero or to free mode through an opto-isolator device. The isolator analyses showed good practical performance. The output to ground resistance was 10(11) ohms and capacitance 35 picofarads. The rise time and fall time were identical (5 microseconds) and constant. The selectable voltage or current output mode made it very convenient to use. The current mode, with higher output resistance values in low current ranges, permits intracellular stimulation even with tip resistances close to 100 megaohms. The high compliance of 200 V guarantees the value of the current stimulus. The very low output resistance in the voltage mode made the device highly suitable for extracellular stimulation with low impedance electrodes. Most importantly, these characteristics were achieved with a circuit that was easy to build and modify and assembled with components available in Brazil. PMID:10412556

Brasil, R O; Leal-Cardoso, J H

1999-06-01

264

Supply and threshold voltage scaling for low power CMOS  

Microsoft Academic Search

This paper investigates the effect of lowering the supply and threshold voltages on the energy efficiency of CMOS circuits. Using a first-order model of the energy and delay of a CMOS circuit, we show that lowering the supply and threshold voltage is generally advantageous, especially when the transistors are velocity saturated and the nodes have a high activity factor, In

Ricardo Gonzalez; Benjamin M. Gordon; Mark A. Horowitz

1997-01-01

265

Contribution Allocation for Voltage Stability In Deregulated Power Systems  

E-print Network

--P- controller, PI-controller and PID controller of a voltage regulator, the load flow equation of this system, control system and transmission part, etc. This paper focused on how to allocate the responsibility the contribution, and the analysis will help us design the controller and optimize the system to avoid the voltage

266

Methods for Estimation of Market Power in Electric Power Industry  

NASA Astrophysics Data System (ADS)

The article is related to a topical issue of the newly-arisen market power phenomenon in the electric power industry. The authors point out to the importance of effective instruments and methods for credible estimation of the market power on liberalized electricity market as well as the forms and consequences of market power abuse. The fundamental principles and methods of the market power estimation are given along with the most common relevant indicators. Furthermore, in the work a proposal for determination of the relevant market place taking into account the specific features of power system and a theoretical example of estimating the residual supply index (RSI) in the electricity market are given.

Turcik, M.; Oleinikova, I.; Junghans, G.; Kolcun, M.

2012-01-01

267

Analysis and calculation of lightning-induced voltages in aircraft electrical circuits  

NASA Technical Reports Server (NTRS)

Techniques to calculate the transfer functions relating lightning-induced voltages in aircraft electrical circuits to aircraft physical characteristics and lightning current parameters are discussed. The analytical work was carried out concurrently with an experimental program of measurements of lightning-induced voltages in the electrical circuits of an F89-J aircraft. A computer program, ETCAL, developed earlier to calculate resistive and inductive transfer functions is refined to account for skin effect, providing results more valid over a wider range of lightning waveshapes than formerly possible. A computer program, WING, is derived to calculate the resistive and inductive transfer functions between a basic aircraft wing and a circuit conductor inside it. Good agreement is obtained between transfer inductances calculated by WING and those reduced from measured data by ETCAL. This computer program shows promise of expansion to permit eventual calculation of potential lightning-induced voltages in electrical circuits of complete aircraft in the design stage.

Plumer, J. A.

1974-01-01

268

Superconductivity for electric power systems: Program overview  

SciTech Connect

Largely due to government and private industry partnerships, electric power applications based upon high-temperature superconductivity are now being designed and tested only seven years after the discovery of the high-temperature superconductors. These applications offer many benefits to the national electric system including: increased energy efficiency, reduced equipment size, reduced emissions, increased stability/reliability, deferred expansion, and flexible electricity dispatch/load management. All of these benefits have a common outcome: lower electricity costs and improved environmental quality. The U.S. Department of Energy (DOE) sponsors research and development through its Superconductivity Program for Electric Power Systems. This program will help develop the technology needed for U.S. industries to commercialize high-temperature superconductive electric power applications. DOE envisions that by 2010 the U.S. electric power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition.

Not Available

1995-02-01

269

Single-Stage PFC Power Supply with Universal Input and Automatic Voltage Clamping  

Microsoft Academic Search

This paper presents a single-phase single-stage power supply with power factor correction and automatic voltage clamping . This topology combines a boost input current shaper with a double winding clamped dc\\/dc converter. With this configuration, when the main switch is turned off, the voltage of the switch is automatically clamped to the sum of the two bulk capacitor voltages. The

DORIN CISMASIU; VIOREL POPESCU; DAN LASCU

270

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

E-print Network

) 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...

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

271

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

E-print Network

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

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

2008-01-01

272

Power Supply Design for High Voltage Capacitor Discharge Railgun Supply Using Thyristors  

Microsoft Academic Search

The detailed design and analysis of a thyristor based capacitor discharge power supply is important in the development of pulsed power technology to accurately predict the voltage and current stress of each component. Simulation of the switching predicts how the voltage is shared by series thyristors and helps size the thyristor snubber circuits. The peak current in the thyristor is

Alexander L. Julian; Jesse H. Black; William B. Maier II

2008-01-01

273

An ultra-low power voltage regulator for wireless sensor nodes  

Microsoft Academic Search

This paper presents an ultra-low power voltage regulator used for low power wireless sensor nodes. As the input conditions for these types of regulators can be quite different in terms of voltage range and transient speed, the introduced architecture is designed to be almost insensitive to these variations. Even if the pass device is formed by an NMOS transistor, low-dropout

Stefan Gruber; Hannes Reinisch; Hartwig Unterassinger; Martin Wiessflecker; G. Hofer; W. Pribyl; G. Holweg

2010-01-01

274

Voltage sag mitigation for a high frequency multistage power conversion system  

Microsoft Academic Search

A multistage power conversion scheme, capable of providing a regulated power supply despite disturbances in the source voltage or changes in the output load, is proposed. The high frequency power conversion system also provides compensation for acute voltage sags\\/swells and a faster transient response by employing appropriately controlled power electronics converters. Through the utilization of a bidirectional buck-boost DC-DC converter

M. Peterson; B. N. Singh

2008-01-01

275

Design and electrical charaterization of a low current high voltage compact arc plasma torch  

Microsoft Academic Search

A new compact plasma torch associated with a resonance power supply allows the generation of low power discharges (typically 100 W-1 kW) under high voltage (>1 kV) low current (<1 A) conditions. The resonance power supply allows continuous control of the discharge current, which is a major improvement with respect to the traditional dc power source based on a high

L. Fulcheri; J.-D. Rollier; J. Gonzalez-Aguilar

2007-01-01

276

A Novel Line Stability Index (NLSI) for Voltage Stability Assessment of Power Systems  

Microsoft Academic Search

The management of power systems has become more difficult than earlier because power systems are operated closer to security limits, environmental constraints restrict the expansion of transmission network, the need for long distance power transfer has increased and fewer operators are engaged in the supervision and operation of power systems. Voltage stability has become a major concern in many power

A. YAZDANPANAH-GOHARRIZI; R. ASGHARI

2007-01-01

277

Energy efficient ECS powered by a variable voltage\\/variable frequency power system  

Microsoft Academic Search

The invention is an ECS system designed to utilize an induction motor and a cabin compressor for providing pressurized air that serves as a source of energy for heating, cooling, pressurizing and other air needs of modern aircraft. An aircraft engine driven generator, preferably a permanent-magnet generator (of the samarium-cobalt, SmCo, type), furnishes variable-voltage\\/variable frequency, VV\\/VF, power to the motor.

Cronin

1984-01-01

278

Energy efficient ECS powered by a variable voltage\\/variable frequency power system  

Microsoft Academic Search

The invention is an ECS system designed to utilize an induction motor and a cabin compressor for providing pressurized air that serves as a source of energy for heating, cooling, pressurizing and other air needs of modern aircraft. An aircraft engine driven generator, preferably a permanent-magnet generator (of the samarium-cobalt, SmCo, type), furnishes variable-voltage\\/variable frequency, VV\\/VF, power to the motor.

Cronin

1985-01-01

279

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

DOEpatents

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

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

2000-01-01

280

Energy and Transient Power MinimizationEnergy and Transient Power Minimization using Multiple Supply Voltages andusing Multiple Supply Voltages and  

E-print Network

Outline of the Talk · Introduction and Related Work · Multiple Supply Voltages and Dynamic Frequency · Target :Major Motivation : Extending battery life for portable applicationsExtending battery life for portable · To increase battery life time · To increase battery efficiency · To maintain supply voltage levels · To reduce

Mohanty, Saraju P.

281

Reliability, Electric Power, and Public Versus Private Goods  

E-print Network

is delivered. Some of these public goods include voltage, frequency, and reliability of lines. Similarly including power, voltage, frequency, and reliability. Of these, only power is a pure private good. In contrast for customers who are receiving power, its voltage, frequency, and reliability provided over

282

Topics in high voltage pulsed power plasma devices and applications  

NASA Astrophysics Data System (ADS)

Pulsed power technology is one of the tools that is used by scientists and engineers nowadays to produce gas plasmas. The transient ultra high power is able to provide a huge pulse of energy which is sometimes greater than the ionization energy of the gas, and therefore separates the ions and electrons to form the plasma. Sometimes, the pulsed power components themselves are plasma devices. For example, the gas type switches can "turn on" the circuit by creating the plasma channel between the switch electrodes. Mini Back Lighted Thyratron, or as we call it, mini-BLT, is one of these gas type plasma switches. The development of the reduced size and weight "mini-BLT" is presented in this dissertation. Based on the operation characteristics testing of the mini-BLT, suggestions of optimizing the design of the switch are proposed. All the factors such as the geometry of the hollow electrodes and switch housing, the gas condition, the optical triggering source, etc. are necessary to consider when we design and operate the mini-BLT. By reducing the diameter of the cylindrical gas path between the electrodes in the BLT, a novel high density plasma source is developed, producing the plasma in the "squeezed" capillary. The pulsed power generator, of course, is inevitably used to provide the ionization energy for hydrogen gas sealed in the capillary. Plasma diagnostics are necessarily analyzed and presented in detail to properly complete and understand the capillary plasma. This high density plasma source (1019 cm-3) has the potential applications in the plasma wakefield accelerator. The resonant oscillation behavior of the particles in plasmas allows for dynamically generated accelerating electric fields that have orders of magnitude larger than those available in the conventional RF accelerators. Finally, the solid state switches are introduced as a comparison to the gas type switch. Pulsed power circuit topologies such as the Marx Bank, magnetic pulse compression and diode opening are used to accomplish the pulse generator design. Their applications for the transient plasma car engine combustion and bio-medical skin cancer cell treatments are also introduced.

Chen, Hao

283

Voltage and Frequency Control of a Stand Alone Brushless Wind Electric Generation Using Generalized Impedance Controller  

Microsoft Academic Search

In this paper, a new strategy for the control of terminal voltage and frequency of a stand-alone self-excited induction generator-(SEIG) based wind generator, working with variable speed and load is proposed. With a generalized impedance controller (GIC) (voltage source pulsewidth-modulated inverter with a dc-link battery), a new strategy to maintain the active and reactive power balance at the SEIG terminals

B. Venkatesa Perumal; Jayanta K. Chatterjee

2008-01-01

284

Impact of voltage and capacity on the electrical and acoustic output of intracorporeal electrohydraulic lithotripsy.  

PubMed

The electrical and acoustic output created by the spark discharge for electrohydraulic lithotripsy at the tip of a 3.3-F probe was evaluated. Spark generation was achieved by variable combinations of voltage and capacity. The effective electrical output was determined by means of a high-voltage probe, a current coil and a digital oscilloscope. Peak pressures, rise times and pulse width of the shock waves were recorded using a polyvinylidene difluoride needle hydrophone in 0.9% NaCl solution at a distance of 10 mm. The effective electrical output is lower than the calculated output, due to inductivities, capacities and resistances of the cables and plugs. The life of the probes is markedly shorter when a combination of high voltage and low capacity is used than with low voltage and high capacity corresponding to the same energy. The peak pressure and the slope of the shock front depend solely on the voltage, while the pulse width is correlated with the capacity. The pulse intensity integral of the shock wave is likely to be the best equivalent to the applied energy. PMID:1455568

Vorreuther, R; Engelking, R

1992-01-01

285

National Maglev initiative: California line electric utility power system requirements  

NASA Astrophysics Data System (ADS)

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Save, Phil

1994-05-01

286

National Maglev initiative: California line electric utility power system requirements  

NASA Technical Reports Server (NTRS)

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Save, Phil

1994-01-01

287

Novel High-Voltage, High-Power Piezoelectric Transformer Developed and Demonstrated for Space Communications Applications  

NASA Technical Reports Server (NTRS)

Improvements in individual piezoelectric transformer (PT) performance and the combination of these PTs in a unique modular topology under a Phase I contract with the NASA Glenn Research Center have enabled for the first time the simultaneous achievement of both high voltage and high power at much higher levels than previously obtained with any PT. Feasibility was demonstrated by a prototype transformer (called a Tap-Soner), which is shown in the preceding photograph as part of a direct-current to direct-current (dc-dc) converter having two outputs rated at 1.5 kV/5 W and 4.5 kV/20 W. The power density of 3.5 W/cm3 is significantly lower than for magnetic transformers with the same voltage and power output. This development, which is being done under a Small Business Innovation Research (SBIR) contract by Face Electronics, LC (Norfolk, VA), is based on improvements in the materials and design of Face's basic patented Transoner-T3 PT, shown in the left in the following figure. The T3 PT is most simply described as a resonant multilayer transducer where electrical energy at the input section is efficiently mechanically coupled to the output section, which then vibrates in a fundamental longitudinal mode to generate a high gain in voltage. The piezoelectric material used is a modified lead-zirconium-titanate-based ceramic. One of the significant improvements in PT design was the incorporation of a symmetrical double input layer, shown on the right in the following figure, which eliminated the lossy bending vibration modes characteristic of a single input layer. The performance of the improved PT was optimized to 1.5 kV/5 W. The next step was devising a way to combine the individual PTs in a modular circuit topology needed to achieve the desired high voltage and power output. Since the optimum performance of the individual PT occurs at resonance, the most efficient operation of the modular transformer was achieved by using a separate drive circuit for each PT. The output section consists of a separate output rectifier for each PT connected in series.

Carazo, Alfredo V.; Wintucky, Edwin G.

2004-01-01

288

SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The Site Electrical Power System receives and distributes utility power to all North Portal site users. The major North Portal users are the Protected Area including the subsurface facility and Balance of Plant areas. The system is remotely monitored and controlled from the Surface Operations Monitoring and Control System. The system monitors power quality and provides the capability to transfer between Off-Site Utility and standby power (including dedicated safeguards and security power). Standby power is only distributed to selected loads for personnel safety and essential operations. Security power is only distributed to essential security operations. The standby safeguards and security power is independent from all other site power. The system also provides surface lighting, grounding grid, and lightning protection for the North Portal. The system distributes power during construction, operation, caretaker, and closure phases of the repository. The system consists of substation equipment (disconnect switches, breakers, transformers and grounding equipment) and power distribution cabling from substation to the north portal switch gear building. Additionally, the system includes subsurface facility substation (located on surface), switch-gear, standby diesel generators, underground duct banks, power cables and conduits, switch-gear building and associated distribution equipment for power distribution. Each area substation distributes power to the electrical loads and includes the site grounding, site lighting and lightning protection equipment. The site electrical power system distributes power of sufficient quantity and quality to meet users demands. The Site Electrical Power System interfaces with the North Portal surface systems requiring electrical power. The system interfaces with the Subsurface Electrical Distribution System which will supply power to the underground facilities from the North Portal. Power required for the South Portal and development side activities of the subsurface facility will be provided at the South Portal by the Subsurface Electrical Distribution System. The Site Electrical Power System interfaces with the Off-Site Utility System for the receipt of power. The System interfaces with the Surface Operations Monitoring and Control System for monitoring and control. The System interfaces with MGR Site Layout System for the physical location of equipment and power distribution.

E.P. McCann

1999-04-16

289

Northeast Corridor Improvement Project Task 204: Electric Multiple-Unit Car and Locomotive Conversion for Dual-Voltage, Dual-Frequency Operation.  

National Technical Information Service (NTIS)

The report covers engineering requirements of converting electric MU cars and locomotives operating on the Northeast Corridor for dual-voltage, dual-frequency operation during and after rehabilitation of the electrification system for 25 kV, 60 Hz power. ...

1977-01-01

290

35. SITE BUILDING 004 ELECTRIC POWER STATION CONTROL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. SITE BUILDING 004 - ELECTRIC POWER STATION - CONTROL ROOM OF ELECTRIC POWER STATION WITH DIESEL ENGINE POWERED ELECTRIC GENERATION EQUIPMENT IN BACKGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

291

Investigation in to growth of electrical trees in XLPE cables under transient voltages  

Microsoft Academic Search

The authors study about inception, propagation and termination of electrical trees in XLPE cable insulation. They address the problem relating to development of electrical trees under various transient voltage profiles and detail the method of generating the experimental database. Also the physico-chemical changes in the treed zone are analysed using Wide Angle X-ray Diffraction (WAXD) and through Fourier Transform Infra-red

R. Sarathi; K. Sridhar

1998-01-01

292

ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The purpose of this revision of the System Description Document (SDD) is to establish requirements that drive the design of the electrical power system and their bases to allow the design effort to proceed to License Application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience are design engineers. This type of SDD leads and follows the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential to performing the design process. This SDD follows the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. Functional and operational requirements applicable to this system are obtained from ''Project Functional and Operational Requirements'' (F&OR) (Siddoway, 2003). Other requirements to support the design process have been taken from higher level requirements documents such as ''Project Design Criteria Document'' (PDC) (Doraswamy 2004), the fire hazards analyses, and the preclosure safety analysis. The above mentioned low-level documents address ''Project Requirements Document'' (PRD) (Canori and Leitner 2003) requirements. This SDD includes several appendices with supporting information. Appendix B lists key system charts, diagrams, drawings, and lists; and Appendix C is a list of system procedures.

M. Maniyar

2004-06-22

293

Electric Power monthly, November 1996  

SciTech Connect

This publication presents monthly electricity statistics for a wide audience including Congress, Federal and state agencies, the electric utility industry, and the general public. Purpose is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

NONE

1996-11-01

294

Power supply technology for electric guns  

SciTech Connect

Power supply technology for electric guns continues to mature at a rapid pace. Batteries, flywheels, capacitors, pulsed alternators, homopolar generators, inductors and high power switches are all viable components for electric gun systems. In this paper an assessment of the state-of-the-art technology for these components and potential for near-term and long-term growth is presented. Pulse power requirements for coilguns, electrothermal guns, and railguns are addressed, as well as energy storage techniques for multishot performance.

Gully, J.H. (Texas Univ., Austin, TX (United States). Center for Electromechanics)

1991-01-01

295

Power transmission cable development for the Space Station Freedom electrical power system  

NASA Technical Reports Server (NTRS)

Power transmission cable is presently being evaluated under a NASA Lewis Research Center advanced development contract for application in the Space Station Freedom (SSF) electrical power system (EPS). Evaluation testing has been performed by TRW and NASA Lewis Research Center. The results of this development contract are presented. The primary cable design goals are to provide (1) a low characteristic inductance to minimize line voltage drop at 20 kHz, (2) electromagnetic compatibility control of the 20-kHz ac power current, (3) a physical configuration that minimizes ac resistance and (4) release of trapped air for corona-free operation.

Schmitz, Gregory V.; Biess, John J.

1989-01-01

296

Electrical Model of Balanced AC HTS Power Cable  

NASA Astrophysics Data System (ADS)

The future electricity grid will be more sustainable and it will have more power transmission and distribution capability with more electrical power added from decentralized sources on distribution level and from wind parks and other large sources on transmission level. More interconnections and more underground transmission and distribution will be put up. Use of high temperature superconducting (HTS) power cables provides solutions to many of the future grid problems caused by these trends. In this paper we present an electrical model of a balanced 6 km-long three phase triaxial HTS power cable for the Dutch project being developed by a consortium of Alliander, Ultera™ and TUD. The cable currents in all three phases are balanced by selecting proper twist pitches and insulation thickness. The paper focuses on determining inductances, capacitances and AC losses of the balanced cable. Using the developed model, we also determine the voltage drop as function of the cable length, the neutral current and the effect of the imbalanced capacitances on the current distribution of the Dutch distribution cable. The model is validated and it can be used for accurate simulation of the electrical behaviour of triaxial HTS cables in electrical grids.

Zuijderduin, R.; Chevtchenko, O.; Smit, J. J.; Willén, D.; Melnik, I.; Geschiere, A.

297

Dynamic voltage and frequency management for a low-power embedded microprocessor  

Microsoft Academic Search

A dynamic voltage and frequency management scheme that autonomously controls the clock frequency (8 to 123 MHz at 0.5 MHz step) and adaptively controls the voltage (0.9 to 1.6 V at 5 mV step) with a leakage power compensation effect is developed for a low-power embedded microprocessor. It achieves 82% power reduction in personal information manager (PIM) application.

Satoshi Akui; Katsunori Seno; Masakatsu Nakai; Tetsumasa Meguro; Takahiro Seki; Tetsuo Kondo; Akihiko Hashiguchi; Hirokazu Kawahara; Kazuo Kumano; Masayuki Shimura

2004-01-01

298

A Low-power Low-voltage Direct Digital Frequency Synthesizer  

Microsoft Academic Search

A low-power low-voltage direct digital frequency synthesizer is presented in this paper. With the proposed efficient ROM compression method and other ROM reduction techniques, a compression ratio of 236 is achieved. Through low-power techniques at various design levels: low-voltage (2-V) operation, ROM reduction, the proposed parallel architecture, static conventional CMOS gates, and true single phase clocking scheme, an unparalleled power

Shyuan Liao; Liang-Gee Chen

1997-01-01

299

Measurements of induced voltages and currents in a distribution power line and associated atmospheric parameters  

NASA Technical Reports Server (NTRS)

The frequency and intensity of thunderstorms around the Kennedy Space Center (KSC) has affected scheduled launch, landing, and other ground operations for many years. In order to protect against and provide safe working facilities, KSC has performed and hosted several studies on lightning phenomena. For the reasons mentioned above, KSC has established the Atmospheric Science Field Laboratory (ASFL). At these facilities KSC launches wire-towing rockets into thunderstorms to trigger natural lightning to the launch site. A program named Rocket Triggered Lightning Program (RTLP) is being conducted at the ASFL. This report calls for two of the experiments conducted in the summer 1988 Rocket Triggered Lightning Program. One experiment suspended an electric field mill over the launching areas from a balloon about 500 meters high to measure the space charges over the launching area. The other was to connect a waveform recorder to a nearby distribution power line to record currents and voltages wave forms induced by natural and triggered lightning.

Santiago-Perez, Julio

1988-01-01

300

Hallam Nuclear Power Facility Electric Auxiliary-Power Systems  

Microsoft Academic Search

This paper describes the electric auxiliary-power systems in a sodium-cooled graphite-moderated nuclear reactor (SGR). Reliability requirements and methods of achieving them are discussed, and sodium-system preheating, a requirement unique to sodium-cooled reactors, is outlined. Nuclear instrumentation electric noise problems and methods of avoiding them are included. Auxiliary power requirements of a 360-mwe (electrical megawatt) SGR plant are compared with those

V. R. Pool

1963-01-01

301

Boosting the voltage of a salinity-gradient-power electrochemical cell by means of complex-forming solutions  

NASA Astrophysics Data System (ADS)

We report experiments on a concentration cell with zinc electrodes and ZnCl2 solutions at different concentrations, separated by a porous diaphragm. The cell is aimed at the conversion of the free energy associated to the concentration difference into electrical energy, for renewable and clean energy applications. Usually, the diffusion of the solute across the diaphragm constitutes a waste of free energy, which impairs the voltage generation of the concentration cell with respect to other well-known techniques that work quasi-reversibly, such as reverse electrodialysis or the "mixing entropy battery." Quite surprisingly, we find that the voltage produced by our concentration cell is significantly higher than the voltage obtained with the other quasi-reversible techniques. We show that the surplus voltage comes from the active transformation of the mixing free energy into electrical energy performed by the liquid junction, and we show the connection with the negative apparent transference number of the zinc ion. This fortunate consequence of using ZnCl2 solution is ultimately related to the formation of complexes. We present the results of a cell for power production, which has excellent performances with respect to known salinity-difference-power methods.

Marino, M.; Misuri, L.; Carati, A.; Brogioli, D.

2014-07-01

302

Calibration of an Infrared Camera for Thermal Characterization of High Voltage Power Electronic Components  

Microsoft Academic Search

Thermal performance of power electronic components is a limiting factor on the power density and design of high voltage high power systems. Therefore, accurate assessment and characterization on the thermal capabilities of these components is critical for the development and design of high density power applications. This paper presents a methodology for calibrating an infrared camera system for use in

T. E. Salem; D. Ibitayo; B. R. Geil

2005-01-01

303

Operational Experience of the World's First Transmission Level Voltage Hts Power Cable  

Microsoft Academic Search

Underground High Temperature Superconductor (HTS) power cables have attracted extensive interest in recent years due to their potential for high power density. With funding support from the United States Department of Energy (DOE), the world's first transmission voltage level HTS power cable has been designed, fabricated and permanently installed in Long Island Power Authority (LIPA) grid. The HTS cable was

J. F. Maguire; J. Yuan; F. Schmidt; R. Soika; S. Bratt; C. King; J. McNamara; T. E. Welsh

2010-01-01

304

Analysis and evaluation of near field noise voltage on power electronics circuits  

Microsoft Academic Search

Design procedure for power electronics circuit structures has recently been discussed for high power density circuits or thin structure converters. Then the control circuit may be connected close to the power circuit. When a pulse current flows into the power circuit, it radiates a magnetic field and it may produce a near field noise voltage in the control circuit and

Zen-nosuke Ariga; Keiji Wada

2009-01-01

305

Characteristic Analysis of DC Electric Railway Systems with Superconducting Power Cables Connecting Power Substations  

NASA Astrophysics Data System (ADS)

The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

Ohsaki, H.; Matsushita, N.; Koseki, T.; Tomita, M.

2014-05-01

306

Manager's guide to electrical power quality  

SciTech Connect

Electronic equipment has become exceedingly sensitive to the electrical environment. Industry standards to cope with this sensitivity have not been available when needed. Therefore, the term power quality has emerged as a catch-all to explain almost any malfunction of electronic equipment. When a malfunction occurs, for whatever reason, power quality can be invoked to make the power system the scapegoat and the equipment, or its installation, blameless. The power quality syndrome includes such issues as grounding, radio interference, transients, outages, harmonics, etc. Power compatibility or electrical environment compatibility (EEC) would be a more objective term to substitute for power quality. The sensitivity of today's electronic equipment arises from the equipment designers' lack of understanding and concern for the realities of the electrical environment and, to some extent, the utilities' lack of concern of the users' application problems. Consequently, to avoid process interruptions, the user's manager must mediate between the equipment and the power system. The manager must insure that specifications exist for both the equipment and all facets of the plant electrical environment, along with test procedures to insure that these specifications are met. The objective of this article is to show how a manager can handle EEC and, thus, avoid costly redesigns and down time of electrical equipment. Common fallacies, tools for defining the electrical equipment. Common fallacies, tools for defining the electrical environment and some applicable standards (existing and emerging) will also be discussed.

Ludbrook, A. (Ludbrook and Associates, Dundas, Ontario (Canada))

1993-05-01

307

High power density, high frequency, and high voltage pulse transformer  

Microsoft Academic Search

Summary form only given, as follows. In designing a compact and high efficiency TWT microwave amplifier, the role of a high power density DC power supply is very important. In order to reduce volume of the power supply, it is necessary to increase switching frequency of the power supply. The high operation frequency mainly reduces transformer volume in the power

S. C. Kim; S. H. Nam; D. T. Kim

2001-01-01

308

High power density, high frequency, and high voltage pulse transformer  

Microsoft Academic Search

In designing a compact and high efficiency TWT microwave amplifier, the role of a high power density DC power supply is very important. In order to reduce volume of the power supply, it is necessary to increase switching frequency of the power supply. The high operation frequency mainly reduces transformer volume in the power supply. However, a step-up ratio of

S. C. Kim; S. H. Nam; S. H. Kim; D. T. Kim; S. H. Jeong

2001-01-01

309

Educational Electrical Appliance Power Meter and Logger  

ERIC Educational Resources Information Center

The principles behind two different designs of inductive power meter are presented. They both make use of the microphone input of a computer which, together with a custom-written program, can record the instantaneous power of a domestic electrical appliance. The device can be built quickly and can be calibrated with reference to a known power

Nunn, John

2013-01-01

310

Tidal energy in electric power systems  

Microsoft Academic Search

This paper discusses the uses and advantages of tidal energy in restructured power systems. The paper defines the resources as well as the ways in which tidal energy is converted into electricity. The paper also reviews a few tidal power projects around the world. It also shows the working of hydro tidal power plant. A comparative review of renewable energy

S. Sheth; M. Shahidehpour

2005-01-01

311

Verification of voltage/frequency requirement for emergency diesel generator in nuclear power plant using dynamic modeling  

NASA Astrophysics Data System (ADS)

One major cause of the plant shutdown is the loss of electrical power. The study is to comprehend the coping action against station blackout including emergency diesel generator, sequential loading of safety system and to ensure that the emergency diesel generator should meet requirements, especially voltage and frequency criteria using modeling tool. This paper also considered the change of the sequencing time and load capacity only for finding electrical design margin. However, the revision of load list must be verified with safety analysis. From this study, it is discovered that new load calculation is a key factor in EDG localization and in-house capability increase.

Hur, Jin-Suk; Roh, Myung-Sub

2014-02-01

312

A high-voltage modulator for high-power RF source research  

Microsoft Academic Search

The authors present the design, construction, and operating results of a high-voltage modulator system capable of generating 700 kV, 2.5 ?s pulses at 5 pps into a load of 900 ?. The modulator is used to energize a variety of high-power microwave devices requiring voltage stability and reproducibility. Voltage ripple is less than 0.2% during the 1.0 ?s flat top,

W. Mulligan; G. Bekefi; S. C. Chen; B. G. Danly; R. J. Temkin

1990-01-01

313

A high-voltage modulator for high-power RF source research  

Microsoft Academic Search

The design, construction, and operating results of a high-voltage modulator system capable of generating 700-kV, 2.5-?s pulses at 5 p.p.s. into a load of 900 ? are presented. The modular is used to energize a variety of high power microwave devices requiring voltage stability and reproducibility. Voltage ripple is less than 0.2% during the 1.0-?s flat top, with a shot-to-shot

William J. Mulligan; S. C. Chen; G. Bekefi; B. G. Danly; Richard J. Temkin

1991-01-01

314

A new VME-based high voltage power supply for large photomultiplier systems  

Microsoft Academic Search

We describe a new high voltage power supply, developed for the leadglass calorimeter of the WA98 experiment at CERN. The high voltage is produced for each of the 10 080 photomultiplier tubes of the detector individually, by the same number of active bases with on-board Greinacher voltage multipliers. The full VME-based HV controller system, which addresses each base via bus

S. Neumaier; H. H. Gutbrod; T. Hubbeling; B. W Kolb; M. L Purschke; M S Ippolitov; V. Manko; G. Mgebrishvili; A. Nijanin; Yu Sibiryak; A A Tsvetkov; A. Vinogradov; C. Barlag; C. Blume; E.-M Bohne; D. Bucher; A. Claussen; Thomas Peitzmann; G. Schepers; H. Schlagheck

1995-01-01

315

High-voltage, high-power, ZVS, full-bridge PWM converter employing an active snubber  

Microsoft Academic Search

The authors present the analysis, design, and applications of a high-voltage, high-power, zero-voltage switched (ZVS), full-bridge (FB) pulse-width-modulated (PWM) converter with an active snubber in the secondary circuit. The nondissipative snubber completely eliminates the voltage overshoot and ringing across the rectifiers. The ringing of the parasitic capacitance of the rectifiers and the leakage inductance of the transformer are eliminated in

J. A. Sabate; V. Vlatkovic; R. B. Ridley; F. C. Lee

1991-01-01

316

30 CFR 77.500 - Electric power circuits and electric equipment; deenergization.  

Code of Federal Regulations, 2012 CFR

... 1 2012-07-01 2012-07-01 false Electric power circuits and electric equipment; deenergization. 77.500 Section... Electrical Equipment-General § 77.500 Electric power circuits and electric equipment;...

2012-07-01

317

30 CFR 75.509 - Electric power circuit and electric equipment; deenergization.  

Code of Federal Regulations, 2012 CFR

... 1 2012-07-01 2012-07-01 false Electric power circuit and electric equipment; deenergization. 75.509 Section... Electrical Equipment-General § 75.509 Electric power circuit and electric equipment;...

2012-07-01

318

30 CFR 75.509 - Electric power circuit and electric equipment; deenergization.  

Code of Federal Regulations, 2010 CFR

... 1 2010-07-01 2010-07-01 false Electric power circuit and electric equipment; deenergization. 75.509 Section... Electrical Equipment-General § 75.509 Electric power circuit and electric equipment;...

2010-07-01

319

30 CFR 77.500 - Electric power circuits and electric equipment; deenergization.  

Code of Federal Regulations, 2011 CFR

... 1 2011-07-01 2011-07-01 false Electric power circuits and electric equipment; deenergization. 77.500 Section... Electrical Equipment-General § 77.500 Electric power circuits and electric equipment;...

2011-07-01

320

Universal input single-phase single-stage power supply with power factor correction and automatic voltage clamping  

Microsoft Academic Search

A single-phase single-stage power supply with power factor correction and automatic voltage clamping is proposed in this paper. This topology combines a boost input current shaper with a new double winding clamped DC\\/DC power converter. With this configuration, when the main switch is turned off, the voltage of the switch is automatically clamped to the sum of the two bulk

Chongming Qiao; Keyue M. Smedley

2001-01-01

321

Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles  

Microsoft Academic Search

With the requirements for reducing emissions and improving fuel economy, automotive companies are developing electric, hybrid electric, and plug-in hybrid electric vehicles. Power electronics is an enabling technology for the development of these environmentally friendlier vehicles and implementing the advanced electrical architectures to meet the demands for increased electric loads. In this paper, a brief review of the current trends

Ali Emadi; Young Joo Lee; Kaushik Rajashekara

2008-01-01

322

Design and electrical charaterization of a low current high voltage compact arc plasma torch  

NASA Astrophysics Data System (ADS)

A new compact plasma torch associated with a resonance power supply allows the generation of low power discharges (typically 100 W-1 kW) under high voltage (>1 kV) low current (<1 A) conditions. The resonance power supply allows continuous control of the discharge current, which is a major improvement with respect to the traditional dc power source based on a high voltage transformer. In addition, this system is characterized by a high conversion efficiency that is crucial when it comes to industrial applications. It has been shown that different regimes ranging from streamer over gliding arc to continuous discharges were obtained depending on the operating conditions. The objective of this paper is a better understanding of the different observed behaviour through the determination of the main torch and power supply parameters.

Fulcheri, L.; Rollier, J.-D.; Gonzalez-Aguilar, J.

2007-02-01

323

30 CFR 77.906 - Trailing cables supplying power to low-voltage mobile equipment; ground wires and ground check...  

...cables supplying power to low-voltage mobile equipment; ground wires and ground...Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...cables supplying power to low-voltage mobile equipment; ground wires and...

2014-07-01

324

Electric power monthly, December 1993.  

National Technical Information Service (NTIS)

This publication provides monthly statistics at the US Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue pe...

1993-01-01

325

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

E-print Network

of the most promising directions. The method of plasma pyrolysis and gasification, where at waste processing-6]. High-current electric arcs or electric arc plasma torches are used practically in all plasma at sufficiently high power [7-11]. In the discharge chamber of a plasma torch the electrical energy input

Boyer, Edmond

326

Electrical properties of skin at moderate voltages: contribution of appendageal macropores.  

PubMed Central

The electrical properties of human skin in the range of the applied voltages between 0.2 and 60 V are modeled theoretically and measured experimentally. Two parallel electric current pathways are considered: one crossing lipid-corneocyte matrix and the other going through skin appendages. The appendageal ducts are modeled as long tubes with distributed electrical parameters. For both transport systems, equations taking into account the electroporation of lipid lamella in the case the lipid-corneocyte matrix or the walls of the appendageal ducts in the case of the skin appendages are derived. Numerical solutions of these nonlinear equations are compared with published data and the results of our own experiments. The current-time response of the skin during the application of rectangular pulses of different voltage amplitudes show a profound similarity with the same characteristics in model and plasma membrane electroporation. A comparison of the theory and the experiment shows that a significant (up to three orders of magnitude) drop of skin resistance due to electrotreatment can be explained by electroporation of different substructures of stratum corneum. At relatively low voltages (U < 30 V) this drop of skin resistance can be attributed to electroporation of the appendageal ducts. At higher voltages (U > 30 V), electroporation of the lipid-corneocyte matrix leads to an additional drop of skin resistance. These theoretical findings are in a good agreement with the experimental results and literature data. PMID:9533696

Chizmadzhev, Y A; Indenbom, A V; Kuzmin, P I; Galichenko, S V; Weaver, J C; Potts, R O

1998-01-01

327

Mechanical and electrical properties of GeSb2Te4 film with external voltage applied  

NASA Astrophysics Data System (ADS)

A GeSb2Te4 (GST) film was deposited by RF magnetron sputtering with microwave electron cyclotron resonance plasma chemical vapor deposition equipment. Mechanical and electrical properties together with the morphologies of the film were studied by a nanoindenter which was equipped with nano-electrical contact resistance (nano-ECR) tool and atomic force microscope (AFM). Results show that when no voltage applied between sample and indent tip during indenting, the pile-up phenomenon was observed, the hardness and elastic modulus increases with the load mainly due to the underestimate of the contact area; when external voltages of -7 V, -8 V, -9 V, -10 V were applied, the resistance of the film decreased with applied voltages in about four orders of magnitude, while the elastic modulus increased from 159 GPa to 233 GPa, this changing in mechanical and electrical properties demonstrated that phase change happen during intending, a shrinking region with radius of about 2.5 ?m was observed around the indentation when -8 V applied. Furthermore, indent load can also promote the phase change at given negative voltage.

Cheng, Guang-Gui; Zhang, Zhong-Qiang; Ding, Jian-Ning; Ling, Zhiyong; Chen, Yu-Bing

2013-11-01

328

Low Power Discrete Voltage Assignment Under Clock Skew , Jian Sun2  

E-print Network

Voltage (MTV) [2] assignment have drawn much attention of the EDA community. In MSV design, high supply is assigned to other cells to save power consumption. In MTV design, low threshold voltage is assigned to timing critical cells in a similar way. Since MSV assignment and MTV assignment problem share very

Zhou, Hai

329

Effects of applied voltages and dissolved oxygen on sustained power generation by microbial fuel cells  

E-print Network

Effects of applied voltages and dissolved oxygen on sustained power generation by microbial fuel chamber MFCs at the end of a cycle when the substrate is depleted. A slight increase in dissolved oxygen chamber for sustained performance of MFCs. Key words | anode, applied voltage, dissolved oxygen, microbial

330

Implementation of a Hybrid AC–AC Direct Power Converter With Unity Voltage Transfer  

Microsoft Academic Search

This paper presents a novel hybrid direct power converter (HDPC) which overcomes the two main disadvantages of matrix converters: limited voltage transfer ratio and low immunity to grid disturbance. The proposed converter is formed by integrating a reversible auxiliary boost converter in the dc link of the two-stage matrix converter. Therefore, the HDPC can provide unity voltage transfer ratio even

Thiwanka Wijekoon; Christian Klumpner; Pericle Zanchetta; Patrick W. Wheeler

2008-01-01

331

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

E-print Network

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

Kimball, Jonathan W.

332

TRANSIENT CURRENTSAM) VOLTAGES IN A POWER DISTRIBUTION SYSTEM DUE TO NATURAL LIGHTNING  

E-print Network

TRANSIENT CURRENTSAM) VOLTAGES IN A POWER DISTRIBUTION SYSTEM DUE TO NATURAL LIGHTNING M at Camp Blanding, Florida, during the 1995 and 19% experiments. Transient currents and voltages the test site duringthe 1995and 1996experiments, and its effects on the test system were recorded. On 10

Florida, University of

333

Analysis and design of electronic transformers for electric power distribution system  

Microsoft Academic Search

A transformer performs many functions such as voltage transformation, isolation and noise decoupling, and it is an indispensable component in electric power distribution systems. However, at low frequencies (60\\/50 Hz), it is a bulky and expensive component. In this paper, the concept of electronic transformers is further extended and explored for its suitability in power distribution systems. It should be

Moonshik Kang; Prasad N. Enjeti; Ira J. Pitel

1999-01-01

334

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

SciTech Connect

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.

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

2012-01-01

335

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

E-print Network

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 ...

Yang, Qing

336

Electromagnetic Pulse and the Electric Power Network.  

National Technical Information Service (NTIS)

This paper defines the nuclear electromagnetic pulse (EMP) - electric power system interaction problem. A description of high altitude EMP (HEMP) characteristics, source region EMP (SREMP) characteristics, and magnetohydrodynamics EMP (MHD-EMP) characteri...

K. W. Klein, P. R. Barnes, H. W. Zaininger

1984-01-01

337

Electric Power Transfer Capability: Concepts, Applications,  

E-print Network

Engineering Research Center A National Science Foundation Industry/University Cooperative Research Center University of Wisconsin-Madison Ray Zimmerman Cornell University Power Systems Engineering Research Center: Ian Dobson Rajesh Rajaraman Professor Senior Engineer Electrical & Computer Engineering Laurits R

338

A Novel Line Stability Index (NLSI) for Voltage Stability Assessment of Power Systems  

E-print Network

Abstract:- The management of power systems has become more difficult than earlier because power systems are operated closer to security limits, environmental constraints restrict the expansion of transmission network, the need for long distance power transfer has increased and fewer operators are engaged in the supervision and operation of power systems. Voltage stability has become a major concern in many power systems and many blackouts have been reported, where the reason has been voltage instability. This paper presents a novel line stability index (NLSI) referred to a line initiated from the voltage quadratic equation at the sending and resaving end of a representation of a 2-bus system. The line index in the interconnected system in which the value that is closed to one indicates that the line has reached its instability limit which could cause sudden voltage drop to the corresponding bus caused by the active and reactive load variation. The proposed index consider both active and reactive power to investigate the voltage stability because this index provides more precise results than those which consider only reactive power. To indicate the ability of proposed index, NEW ENGLAND 30 bus is utilized and simulation results show good conformity with the other stability index that proposed in literature. Key-Words:- Voltage stability index, Maximum permissible load, NLSI factor. 1

A. Yazdanpanah-goharrizi; R. Asghari

339

Realizing Low Power FPGAs: A Design Partitioning Algorithm for Voltage Scaling and A Comparative Evaluation of Voltage Scaling Techniques for FPGAs  

E-print Network

voltage island topologies and a detailed evaluation of each fabric in terms of overheads due reliability due to excessive heat generation (due to high power) is a concern, power improvement in FPGAs in turn may affect throughput) by changing the supply and threshold voltages. In ASICs it has been shown

Kuzmanovic, Aleksandar

340

Electric power needs in space  

NASA Technical Reports Server (NTRS)

The power requirements for specific float zone experiments in space are presented. Power figures for the Space Shuttle and projected available power for advanced vehicles are given. The following power related trends are derived: (1) float zone processing of up to 5 cm diameter silicon and 16.0 cm diameter cadmium telluride can be conducted on a Shuttle pallet mission; (2) float zone processing of up to 8.5 cm diameter silicon for 70% total heating efficiency can be conducted on the initial MEC/space platform; (3) projected available host vehicle power for float zone sample heating; (4) induction heating is found to be the most promising heating method; (5) process control and ease of equipment integration into the host vehicle influence heating method selection.

Waltz, D. M.

1981-01-01

341

Concepts for central solar electric power generation  

NASA Technical Reports Server (NTRS)

The investigation reported was conducted to select the best conceptual design of a power plant for the dynamic conversion of solar heat to electricity. Conversion of thermal energy to electricity was to be an accomplished with conventional turbomachinery. Questions of site selection are discussed along with solar energy collection systems, aspects of candidate system definition, and reference systems.

Kintigh, J. K.

1974-01-01

342

Electric power, economic growth in third world  

Microsoft Academic Search

Increasing demand for electricity remains a prerequisite for economic growth, says Mohan Munasinghe of the World Bank in Washington. This truism presents decision makers in the Third World with a major dilemma: if they spend their scarce resources on capital-intensive electric power projects, they won't have anything left to solve the problems of acute poverty and malnutrition, but if they

Munasinghe

2009-01-01

343

Electrical safety for an offshore power system  

Microsoft Academic Search

This paper describes the electrical safety for a power system analysis. For an efficient and reliable electrical system, routine and detailed maintenance must be performed. One method of preventive maintenance uses infrared thermography. This technology visually depicts heat differentials in a circuit breakers and transformers that are housed in metal-glad switchgear. Predictive maintenance involves testing equipment for proper operation. This

L. M. Lavie

2004-01-01

344

Global Climate Change Electric Power Industry  

E-print Network

description of the global warming which been attributed to the unprecedented accumulation CO2 and other GHG atmospheric CO2 and reduce the risks of global warming. Reducing CO2 emissions will be a centuryGlobal Climate Change and the Electric Power Industry to appear in Competitive Electricity Markets

Ford, Andrew

345

Design of a pulsewidth-modulated resonant converter for a high-output-voltage power supply  

NASA Astrophysics Data System (ADS)

The design and fabrication of a parallel resonant converter circuit and a high-frequency step-up transformer used to supply an adjustable dc voltage to a load is described. The 500-W system is operated from 115/230 V single-phase 60Hz power, which is rectified and filtered to form a 310-V dc link. A two-transistor half-bridge circuit operating at a fixed frequency above the ciruits resonant frequency converts the dc voltage to an ac voltage at approximately 20 kHx. This high-frequency voltage is transformed with a low-capacitance oil-impregnated ferrite transformer. The output voltage is rectified to form a dc voltage with a maximum value of 90-kV peak. The output voltage is adjustable using pulsewidth modulation of the conduction time of the two transistors in the power circuit. The energy stored in the resonant circuit provides a sinusoidal transformer voltage at fixed frequency over a wide range of control. The system is provided with a closed-loop peak-voltage regulator and an on-off capability from the control electronics. The transformer is designed for a specific value of inductance and capacitance to operate at the desired resonant frequency and characteristic impedance.

Turnbull, Fred G.; Tompkins, Russell E.

1987-12-01

346

A low-voltage low-power wideband CMOS variable gain amplifier using active negative feedback  

Microsoft Academic Search

This paper describes the design and realization of a low-voltage low-power RF variable gain amplifier in a 0.18 um CMOS technology. The proposed amplifier employs an active negative feedback technique to achieve wide bandwidth operation. Simulation results showed that the proposed circuit could achieve 1.78-GHz bandwidth with 13.04-dB gain under a single 1-V power supply voltage, while draining current less

S. Sakphrom; A. Thanachayanont; P. Khumsat

2009-01-01

347

Overview of power converter designs feasible for high voltage transformer-less wind turbine  

Microsoft Academic Search

Many leading wind turbine manufacturers are pushing forward in variable-speed wind turbines, often exceeding 5 MW. Therefore, novel designs and concepts for optimal high power wind turbines appeared. One of the most promising concepts is the high voltage (10-35 kV) transformer-less topology. High voltage design enables low power losses and elimination of bulky step-up transformer from the wind turbine system.

Michal Sztykiel

2011-01-01

348

Minimization of dynamic and static power through joint assignment of threshold voltages and sizing optimization  

Microsoft Academic Search

We describe an optimization strategy for minimizing total power consumption using dual threshold voltage (Vth) technology. Significant power savings are possible by simultaneous assignment of Vth with gate sizing. We propose an efficient algorithm based on linear programming that jointly performs Vth assignment and gate sizing to minimize total power under delay constraints. First, linear programming assigns the optimal amounts

David Nguyen; Abhijit Davare; Michael Orshansky; David G. Chinnery; Brandon Thompson; Kurt Keutzer

2003-01-01

349

A technique for power supply harmonic impedance estimation using a controlled voltage disturbance  

Microsoft Academic Search

A method for power system impedance estimation is presented. The method employs a power converter to inject a voltage transient onto the supply system. As the technique employs controlled power electronic devices it may be used as a stand alone piece of a portable measurement equipment, or it may be embedded into the functions of an active shunt filter for

Mark Sumner; Ben Palethorpe; David W. P. Thomas; Pericle Zanchetta; Maria Carmela Di Piazza

2002-01-01

350

Instantaneous input electrical power measurements of HITU transducer  

NASA Astrophysics Data System (ADS)

HITU (High Intensity Theraupetic Ultrasound) transducers are widely used in therapeutic ultrasound in medicine. The output ultrasonic power of HITU transducer can be measured in number of methods described in IEC 61161 standard [1]. New IEC standards specifically for measurement of HITU equipment are under development. The ultrasound power radiated from a transducer is dependent on applied input electrical voltage and current and consequently power. But, up to now, no standardised method has been developed and adopted for the input electrical power measurements. Hence, a workpackage was carried out for the establishment of such method in the frequency range of 1 to 3 MHz as a part of EURAMET EMRP Era-net plus "External Beam Cancer Therapy" project. Several current shunts were developed and evaluated. Current measurements were also realized with Philips current probe and preamplifier at NPL and Agilent current probe at UME. In this paper, a method for the measurement of instantaneous electrical power delivered to a reactive ultrasound transducer in the required frequency range is explored.

Karaböce, B.; Gülmez, Y.; Rajagapol, S.; Shaw, A.

2011-02-01

351

Automating a spacecraft electrical power system using expert systems  

NASA Technical Reports Server (NTRS)

Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

Lollar, L. F.

1991-01-01

352

Power coupling and electrical characterization of a radio-frequency micro atmospheric pressure plasma jet  

NASA Astrophysics Data System (ADS)

We propose an efficient RF power coupling scheme for a micro atmospheric pressure plasma jet operating in helium. The discharge gap is used as a resonant element in a series LC circuit. In resonance, the voltage across the discharge gap is amplified and the ignition of the plasma is enabled with the input RF power as low as 0.5 W. High power coupling efficiency and simplicity of the circuit allow accurate electrical characterization of the discharge. Systematic measurements of the dissipated power as a function of the applied voltage are reported for the discharge operating in helium with molecular admixtures of N2 and O2.

Marinov, D.; Braithwaite, N. St. J.

2014-12-01

353

Power Processing for a Conceptual Project Prometheus Electric Propulsion System  

NASA Technical Reports Server (NTRS)

NASA has proposed a bold mission to orbit and explore the moons of Jupiter. This mission, known as the Jupiter Icy Moons Orbiter (JIMO), would significantly increase NASA s capability to explore deep space by making use of high power electric propulsion. One electric propulsion option under study for JIMO is an ion propulsion system. An early version of an ion propulsion system was successfully used on NASA's Deep Space 1 mission. One concept for an ion thruster system capable of meeting the current JIMO mission requirement would have individual thrusters that are 16 to 25 kW each and require voltages as high as 8.0 kV. The purpose of this work is to develop power processing schemes for delivering the high voltage power to the spacecraft ion thrusters based upon a three-phase AC distribution system. In addition, a proposed DC-DC converter topology is presented for an ion thruster ancillary supply based upon a DC distribution system. All specifications discussed in this paper are for design convenience and are speculative in nature.

Scina, Joseph E., Jr.; Aulisio, Michael; Gerber, Scott S.; Hewitt, Frank; Miller, Leonard; Elbuluk, Malik; Pinero, Luis R. (Technical Monitor)

2005-01-01

354

Hysteresis, Phase Transitions and Dangerous Transients in Electrical Power Distribution Systems  

E-print Network

The majority of dynamical studies in power systems focus on the high voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially-extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatio-temporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially-extended phases defined by individual motor states--a "normal" state where the ...

Duclut, Charlie; Chertkov, Michael

2012-01-01

355

Power system modeling and analysis of electric ship propulsion system  

Microsoft Academic Search

This paper deals with modeling and characteristic analysis of a large powered electric ship propulsion system. Particularly, electric power system modeling has been accomplished in accordance with the electric power network mainly composed of generators, switchboards, variable frequency devices, electric motors, and etc. In addition, electric power system analysis has been performed via load flow analysis. In particular, abnormal operating

Sanggon Lee; Sanghoon Kim; Yu-seok Jeong; Sang-Yong Jung

2009-01-01

356

Power Conditioning System Modelling for Nuclear Electric Propulsion  

NASA Technical Reports Server (NTRS)

NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.

Metcalf, Kenneth J.

1993-01-01

357

Management of the geomagnetically induced current risks on the national grid company's electric power transmission system  

Microsoft Academic Search

The National Grid Company plc (NGC) is the owner and operator of one of the world's largest privatised high-voltage electric power transmission systems in England and Wales at 400 and 275kV. As owner operator it is responsible for the secure and reliable delivery of electrical energy to all the 25 million electricity supply customers in England and Wales. The transmission

I. Arslan Erinmez; John G Kappenman; William A Radasky

2002-01-01

358

PWM Inverter with Voltage Boosters with Regenerating Capability Augmented by Electric Double-Layer Capacitor  

NASA Astrophysics Data System (ADS)

An interior permanent magnet (IPM) motor drive system which has regenerating capability augmented by electric double-layer capacitors (EDLCs) is proposed. In the proposed system, EDLCs are arranged in series with batteries so that a lesser number of the EDLCs and batteries will be required. The proposed system has two bi-directional voltage boosters: one is for both the batteries and EDLCs to control the dc-link voltage of a PWM inverter and the other is for only the EDLCs and is used to control the energy flow from and to the EDLCs. In this paper, a strategy to control the energy flow to and from the EDLCs is explained and its effectiveness is confirmed by simulation and experimental results. Furthermore, the efficiencies of the voltage booster, inverter, PM motor, and whole system are measured for the system with the basic configuration, i.e., which consists of only one bi-directional voltage booster and PWM inverter. Then, the steady-state characteristics are determined. Finally, the efficiency of the voltage boosters in the proposed system is determined, and the advantage of the proposed PM motor drive system is discussed.

Yamamoto, Kichiro; Imakiire, Akihiro; Iimori, Kenichi

359

75 FR 2564 - Virginia Electric and Power Company D/B/A Dominion Virginia Power and Old Dominion Electric...  

Federal Register 2010, 2011, 2012, 2013

...Electric and Power Company D/B/A Dominion Virginia Power and Old Dominion Electric Cooperative; Combined License Application...Power (Dominion), acting on its own behalf and as agent for Old Dominion Electric Cooperative (ODEC), submitted to the...

2010-01-15

360

Power Processing, Part 1. Electric Machinery Analysis.  

ERIC Educational Resources Information Center

This publication was developed as a portion of a two-semester sequence commencing at either the sixth or seventh term of the undergraduate program in electrical engineering at the University of Pittsburgh. The materials of the two courses, produced by a National Science Foundation grant, are concerned with power conversion systems comprising power

Hamilton, Howard B.

361

Bounds on Power Savings Using Runtime Dynamic Voltage Scaling: An Exact Algorithm and a Linear-time  

E-print Network

@princeton.edu ABSTRACT Dynamic voltage/frequency scaling (DVFS) has been shown to be an efficient power/energy reduction voltage/frequency voltage levels and different pro- gram states. We then show a fast linear time heuristic dissipation varies linearly with frequency and quadratically with supply voltage as given by the equation

Martonosi, Margaret

362

Wireless Power Transfer for Electric Vehicles  

SciTech Connect

As Electric and Hybrid Electric Vehicles (EVs and HEVs) become more prevalent, there is a need to change the power source from gasoline on the vehicle to electricity from the grid in order to mitigate requirements for onboard energy storage (battery weight) as well as to reduce dependency on oil by increasing dependency on the grid (our coal, gas, and renewable energy instead of their oil). Traditional systems for trains and buses rely on physical contact to transfer electrical energy to vehicles in motion. Until recently, conventional magnetically coupled systems required a gap of less than a centimeter. This is not practical for vehicles of the future.

Scudiere, Matthew B [ORNL; McKeever, John W [ORNL

2011-01-01

363

New live line tester for porcelain suspension insulators on high-voltage power lines  

SciTech Connect

Suspension insulator assemblies known as insulator strings are used in overhead power transmission lines to mechanically support high-voltage conductors while providing adequate insulation to withstand switching and lightning overvoltages. Since the useful life in service of the individual insulator elements making up these strings is hard to predict, they must be verified periodically to insure that adequate line reliability is maintained at all times. Over the years many testing methods have been used for this purpose, each one with its own advantages and disadvantages. Until now at Hydro-Quebec, porcelain insulators had been tested by the buzz method which simply consists of applying a short-circuit to each insulator in a string and listening for a buzz-like sound indicating a good insulator. However, safety considerations that preclude short-circuiting insulators and other disadvantages of that method have led Hydro-Quebec to undertake and complete the development of a new insulator tester. The working principle of this new device is based on the automatic measurement and recording of the electric field along the insulator string which decreases considerably in front of an internally-shorted insulator. The tester is slid along the string while the insulators are counted automatically. The information from tests on up to 200 strings can be stored in the device to be later transferred in a host computer for interpretation and/or permanent storage. The new tester also gives information on voltage distribution along the insulator strings which can be useful for the design of future power transmission lines.

Vaillancourt, G.H.; St-Jean, M. (Hydro-Quebec, Varennes, Quebec (Canada)); Bellerive, J.P. (Hydro-Quebec, Montreal, Quebec (Canada)); Jean, C. (Positron Inc., Montreal, Quebec (Canada))

1994-01-01

364

Precise synchronization of phasor measurements in electric power systems  

NASA Technical Reports Server (NTRS)

Phasors representing positive sequence voltages and currents in a power network are in the most important parameters in several monitoring, control, and protection functions in interconnected electric power networks. Recent advances in computer relaying have led to very efficient and accurate phasor measurement systems. When the phasors to be measured are separated by hundreds of miles, it becomes necessary to synchronize the measurement processes, so that a consistent description of the state of the power system can be established. Global Positioning System (GPS) transmissions offer an ideal source for synchronization of phasor measurements. The concept and implementation of this technique are described. Several uses of synchronized phasor measurements are also described. Among these are improved state estimation algorithms, state estimator enhancements, dynamic state estimates, improved control techniques, and improved protection concepts.

Phadke, Arun G.

1990-01-01

365

Contribution of dielectric dispersions to voltage waveforms arising from electrical stimulation.  

PubMed

This study presents an analysis of the effect of incorporating a subset of the complete set of dielectric dispersions in electric field models of implanted electrical stimulation. An analytic volume conductor model was used to determine the voltage waveform at a distance of 5mm from a point current stimulus for 17 different biological tissues. The RMS error of the voltage waveform resulting from the incorporation of a subset of all poles with respect to the voltage waveform resulting from the incorporation of the complete set of dispersive poles was calculated. The stimulus amplitude necessary to elicit action potential propagation in a myelinated mammalian nerve fibre in each of the dispersive models was also determined using a multi-compartment cable axon model. It was found that, for all tissues, removal of dispersions with pole frequencies greater than 1 MHz had a negligible effect on the threshold stimulation amplitude, suggesting that they may be neglected when constructing volume conductor models of electrical stimulation. However, removal of low-frequency dispersions below 1 MHz resulted in greater reductions in the threshold stimulus amplitudes necessary for activation of axons, with errors of up to 86% observed. PMID:23366841

Grant, Peadar F; Lowery, Madeleine M

2012-01-01

366

High Voltage Breakdown and SQUID Performance for the Neutron Electric Dipole Moment Experiment  

NASA Astrophysics Data System (ADS)

A new search for a permanent electric dipole moment (EDM) of the neutron is underway at the Oak Ridge Spallation Neutron Source. A non-zero EDM would be a signal of time reversal symmetry violation and improve our understanding of the matter-antimatter asymmetry of the universe. The experiment will use a Superconducting Quantum Interference Device (SQUID) to infer the precession of ultracold neutrons held in a superfluid helium bath, in the presence of applied electric and magnetic fields. The experiment's sensitivity is proportional to the applied electric field. Neither the maximum practical size of the electric field nor the behavior of SQUIDs in proximity to this field are presently understood. Therefore we have constructed a small prototype (to decrease the cool-down time) to verify that SQUIDs can function in a high voltage environment and when exposed to RF interference. Another goal is to determine what characteristics allow us to maximize the electric field without breakdown. To do this we measure the breakdown voltage in both normal and superfluid helium at a variety of temperatures and (more uniquely) at different pressures, as well as test a variety of electrode materials.

Huffer, Craig; Liu, Chen-Yu; Long, Josh; Karcz, Maciej

2007-10-01

367

Miniature whirlwinds produced in the laboratory by high-voltage electrical discharges.  

PubMed

Laboratory experiments showed that under certain conditions of vorticity the electrical heatinig produced by a high-voltage discharge at atmospheric pressure can cause the formation of a miniature tornado-like vortex. Once it forms, this vortex stabilizes the electrical discharge along its axis and changes its character from that of a spark to high-pressure variety of a glow discharge. Electrical and dynamic parameters were measured. By relating observations and measurements made in these experiments to previous work and to analogous situations in nature, it is concluded that the heating produced by electrical discharges in a large storm may play a significant role in forming and maintaining natural tornadoes. PMID:17731044

Ryan, R T; Vonnegut, B

1970-06-12

368

Electrical oscillation in SmS induced by a constant external voltage  

NASA Astrophysics Data System (ADS)

We have observed a persistent voltage oscillation induced by constant external electric fields in the nonmagnetic narrow-gap semiconductor SmS. This oscillation appears with a large nonlinear conduction in a relatively low electric field of a few kV/cm. We find that the oscillation frequency clearly changes on addition of an external capacitor parallel to the sample, indicating that the oscillation does not arise from the Joule heating effect. This oscillation is analyzed in terms of a carrier charging-discharging model, which is associated with an electric-field-induced insulator-to-metal transition as proposed in the oxide insulator VO2. This model reasonably explains the observed oscillation phenomenon, implying the existence of a possible instability toward a conductive state driven by the electric field.

Takahashi, H.; Okazaki, R.; Taniguchi, H.; Terasaki, I.; Saito, M.; Imura, K.; Deguchi, K.; Sato, N. K.; Suzuki, H. S.

2014-05-01

369

Multiloop Rapid-Rise/Rapid Fall High-Voltage Power Supply  

NASA Technical Reports Server (NTRS)

A proposed multiloop power supply would generate a potential as high as 1.25 kV with rise and fall times <100 s. This power supply would, moreover, be programmable to generate output potentials from 20 to 1,250 V and would be capable of supplying a current of at least 300 A at 1,250 V. This power supply is intended to be a means of electronic shuttering of a microchannel plate that would be used to intensify the output of a charge-coupled-device imager to obtain exposure times as short as 1 ms. The basic design of this power supply could also be adapted to other applications in which high voltages and high slew rates are needed. At the time of reporting the information for this article, there was no commercially available power supply capable of satisfying the stated combination of voltage, rise-time, and fall-time requirements. The power supply would include a preregulator that would be used to program a voltage 1/30 of the desired output voltage. By means of a circuit that would include a pulse-width modulator (PWM), two voltage doublers, and a transformer having two primary and two secondary windings, the preregulator output voltage would be amplified by a factor of 30. A resistor would limit the current by controlling a drive voltage applied to field-effect transistors (FETs) during turn-on of the PWM. Two feedback loops would be used to regulate the high output voltage. A pulse transformer would be used to turn on four FETs to short-circuit output capacitors when the outputs of the PWM were disabled. Application of a 0-to-5-V square to a PWM shut-down pin would cause a 20-to-1,250-V square wave to appear at the output.

Bearden, Douglas

2007-01-01

370

Voltage Sag Mitigation Strategies for an Indian Power Systems: A Case Study  

NASA Astrophysics Data System (ADS)

Under modern deregulated environment, both utilities and customers are concerned with the power quality improvement but with different objectives/interests. The utility reconfigure its power network and install mitigation devices, if needed, to improve power quality. The paper presents a strategy for selecting cost-effective solutions to mitigate voltage sags, the most frequent power quality disturbance. In this paper, mitigation device(s) is/are inducted in the optimal network topology at suitable places for their better effectiveness for further improvement in power quality. The optimal placement is looked from utility perspectives for overall benefit. Finally, their performance is evaluated on the basis of reduction in total number of voltage sags, reduction in total number of process trips and reduction in total financial losses due to voltage sags.

Goswami, A. K.; Gupta, C. P.; Singh, G. K.

2014-08-01

371

Small nuclear power generation units, and electric power system interconnection  

Microsoft Academic Search

In this paper, we introduced a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power generation units (SNPGU). Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use

Sang-Seung Lee; Jong-Keun Park; Seung-Il Moon; Yong-Tae Yoon; Jong-Won Kim; Goon-Cherl Park

2006-01-01

372

Electrical power integration for lunar operations  

NASA Technical Reports Server (NTRS)

Electrical power for future lunar operations is expected to range from a few kilowatts for an early human outpost to many megawatts for industrial operations in the 21st century. All electrical power must be imported as chemical, solar, nuclear, or directed energy. The slow rotation of the Moon and consequent long lunar night impose severe mass penalties on solar systems needing night delivery from storage. The cost of power depends on the cost of the power systems the cost of its transportation to the Moon, operating cost, and, of course, the life of the power system. The economic feasibility of some proposed lunar ventures depends in part on the cost of power. This paper explores power integration issues, costs, and affordability in the context of the following representative lunar ventures: (1) early human outpost (10 kWe); (2) early permanent lunar base, including experimental ISMU activities (100 kWe); (3) lunar oxygen production serving an evolved lunar base (500 kWe); (4) lunar base production of specialized high-value products for use on Earth (5 kWe); and (5) lunar mining and production of helium-3 (500 kWe). The schema of the paper is to project likely costs of power alternatives (including integration factors) in these power ranges, to select the most economic, to determine power cost contribution to the product or activities, to estimate whether the power cost is economically acceptable, and, finally, to offer suggestions for reaching acceptability where cost problems exist.

Woodcock, Gordon

1992-01-01

373

Power Management Unit A digitalized Embedded Linear Voltage Regulator for  

E-print Network

, DVD player, car, electric motors, display devices, trains, ... #12;Page 4Copyright © Infineon & Convenience Xenon Light, Seat Position, Climate Control, Dashboard Safety Airbag, ABS Brakes, Adaptive Cruise Hybrid Battery Management Mirror IntroductionIntroduction Modern high-end cars contain up to one hundred

Wichmann, Felix

374

Power processing methodology. [computerized design of spacecraft electric power systems  

NASA Technical Reports Server (NTRS)

Discussion of the interim results of a program to investigate the feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems. The object of the total program is to develop a flexible engineering tool which will allow the power processor designer to effectively and rapidly assess and analyze the tradeoffs available by providing, in one comprehensive program, a mathematical model, an analysis of expected performance, simulation, and a comparative evaluation with alternative designs. This requires an understanding of electrical power source characteristics and the effects of load control, protection, and total system interaction.

Fegley, K. A.; Hansen, I. G.; Hayden, J. H.

1974-01-01

375

Control of voltage resonance type power supplies by an auxiliary switch  

Microsoft Academic Search

In variable-period output control of a voltage resonance-type converter, the minimum output power is obtained in the subclass-E mode and the maximum output power is obtained at such a duty ratio that the off-time is half the resonance period. In an example, the ration of the maximum output power to the minimum output power was 16:1. When the period was

Toshihiro Onodera; Toshiba Corp

1991-01-01

376

United States Space Nuclear Electric Power Program.  

NASA Technical Reports Server (NTRS)

The principal characteristics and design features of major systems and technological developments in U.S. space nuclear power activities are reviewed, covering radioisotope thermoelectric generators, reactor space electric power technology, and the advanced liquid metal cooled power reactor program. The topics also include heat source design and development, thermoelectric efficiency, high performance thermoelectric materials, and alloy developments. The U.S. Space Electric Power Program is described as one aimed at the development of a minimum number of standard components and power modules for both radioisotopes and reactor systems that will meet the widest possible range of future requirements. The need to reduce the high cost of the isotopic generators already used in space missions is stressed.

Newby, G. A.

1972-01-01

377

Miniaturized, low-voltage power converters with fast dynamic response  

E-print Network

This thesis introduces a two-stage architecture that combines the strengths of switched capacitor (SC) techniques (small size, light-load performance) with the high efficiency and regulation capability of switch-mode power ...

Giuliano, David (David Michael)

2013-01-01

378

78 FR 1252 - Schneider Electric, U.S.A., Subsidiary of Schneider Electric, Power Business Unit, Power...  

Federal Register 2010, 2011, 2012, 2013

...Electric, Power Business Unit, Power Solutions Division, Including On-Site Leased Workers From Volt Workforces Solutions and Resource Tek, Lavergne, TN...Electric, Power Business Unit, Power Solutions Division, including on-site...

2013-01-08

379

Pulse-power characteristic of VIVA-1 (Versatile Inductive Voltage Adder)  

NASA Astrophysics Data System (ADS)

Versatile Inductive Voltage Adder, (VIVA-1), with high potential gradient was successfully developed to be in operation. It was designed to produce output pulse of 4 MV, 60 ns by adding 2 MV pulses in 2 stages of induction cells, where amorphous cores are installed. Within approx. 40 percent of full charge voltage, pulse power characteristics of Marx generator, pulse forming line (PFL), transmission line (TL), and induction cells were tested for three types of loads: open circuit; dummy load of CuSO4 resistor; and electron diode. In open circuit test, approx. 2.0 MV of output voltage was obtained with good reproducibility. Dependence of output voltage on diode impedance was evaluated by using a dummy load, and good agreement was obtained with that expected. An E-beam diode was operated successfully, and approx. 18 kA of beam current was obtained at diode voltage of approx. 1 MV.

Shimiya, K.; Hozumi, Y.; Aoyama, T.; Shigeta, M.; Shibata, Kiyoshi; Sekimoto, Y.; Masugata, Katsumi; Yatsui, Kiyoshi

1990-10-01

380

Galena Electric Power A Situational Analysis  

SciTech Connect

The purpose of the investigation is to compare the economics of various electrical power generation options for the City of Galena. Options were assessed over a 30-year project period, beginning in 2010, and the final results were compared on the basis of residential customer electric rates ($/kWh). Galena's electric utility currently generates power using internal combustion diesel engines and generator sets. Nearby, there is an exposed coal seam, which might provide fuel for a power plant. Contributions to the energy mix might come from solar, municipal solid waste, or wood. The City has also been approached by Toshiba, Inc., as a demonstration site for a small (Model 4S) nuclear reactor power plant. The Yukon River is possibly a site for in-river turbines for hydroelectric power. This report summarizes the comparative economics of various energy supply options. This report covers: (1) thermal and electric load profiles for Galena; (2) technologies and resources available to meet or exceed those loads; (3) uses for any extra power produced by these options; (4) environmental and permitting issues and then; and (5) the overall economics of each of the primary energy options.

Robert E. Chaney; Stephen G. Colt; Ronald A. Johnson; Richard W. Wiles; Gregory J. White

2008-12-31

381

Department of Electrical Engineering and Computer Science Electrical-Power & Energy Systems Concentration Catalog 2014  

E-print Network

Department of Electrical Engineering and Computer Science Electrical- Power & Energy Systems The department requires at least a C in every computer engineering, computer science, electrical engineering

Grissino-Mayer, Henri D.

382

Method of assembling an electric power  

DOEpatents

A method of assembling and providing an electric power apparatus. The method uses a heat resistant housing having a structure adapted to accommodate and retain a power circuit card and also including a bracket adapted to accommodate and constrain a rigid conductive member. A power circuit card having an electrical terminal is placed into the housing and a rigid conductive member into the bracket. The rigid conductive member is flow soldered to the electrical terminal, thereby exposing the heat resistant housing to heat and creating a solder bond. Finally, the rigid conductive member is affirmatively connected to the housing. The bracket constrains the rigid conductive member so that the act of affirmatively connecting does not weaken the solder bond.

Rinehart, Lawrence E. (Lake Oswego, OR); Romero, Guillermo L. (Phoenix, AZ)

2007-05-03

383

Electrical Power Production Facilities from Green Energy Sources  

Microsoft Academic Search

Green power refers to electricity supplied from more readily renewable energy sources than traditional electrical power sources. Green power products have become widespread in many electricity markets worldwide and can be derived from renewable energy sources. The environmental advantages of the production and use of green electricity by using green electricity seem to be clear. Using green energy sources like

Ayhan Demirbas

2006-01-01

384

Design of wide power supply, high performance voltage regulator with BCD process  

Microsoft Academic Search

This paper analyzes a voltage regulator with widely range of power supply which is essential module in switching mode power supply. It is composed of Pre-charging Circuit, Bandgap Reference Circuit, Current Reference Circuit, Thermal Protect Circuit and Low-dropout (LDO) regulator. A frequency compensation method with buffer stage isolation is utilized, that conduces to the improvements of transient response and PSR

Zhidong Liu; Xigen Jin; Ning Jin; Yuan He; Yuhua Cheng

2010-01-01

385

Control methods for three-phase active power filters under non-ideal mains voltages  

Microsoft Academic Search

In this paper, the control algorithms for a three-phase three-wired shunt active power filter under distorted or unbalanced mains voltages conditions are analysed. According to the compensation objectives, a direct method, based on the power balance concept is used and compared to the standard pq algorithm. It allows to impose systematically sinusoidal mains currents in phase with the balanced symmetrical

M. Machmoum; N. Bruyant

2000-01-01

386

Voltage and current sensing in power electronic converters using sigma-delta A\\/D conversion  

Microsoft Academic Search

This paper presents a novel approach to voltage and current measurement in power electronics using a sigma-delta A\\/D converter. The system converts the analog input signal into a digital stream of data. By averaging the digital data stream over a switching period of the power converter, the required measurement is obtained. Harmonic distortion of the input waveform and noise caused

A. Mertens; D. Eckardt

1996-01-01

387

Comparison of switching devices in scalable switch concept for medium voltage medium frequency power conversion  

Microsoft Academic Search

This paper provides a comparison of switch concepts for medium frequency (MF) medium voltage (MV) applications in the lower power range (> 1 kHz). The comparison is based on measurements of actual discrete switches for hard-switched and ZVS forward topologies. It is shown that standard low power IGBTs in a scalable switch can be used to obtain the lowest losses

Jochen Mast; Guntram Scheible; Henry Gueldner

2001-01-01

388

A novel electrode power profiler for dimmable ballasts using DC link voltage and switching frequency controls  

Microsoft Academic Search

A novel electrode power profiler for dimmable ballasts using series-resonant parallel-loaded inverter is presented. Dimming of the fluorescent lamp is primarily based on reducing the dc link voltage. Variations of the electrode power (due to the decrease in the lamp current) during dimming is compensated by changing the switching frequency of the inverter, so that the resonant tank circuit current

Stephen T. S. Lee; Henry Shu-Hung Chung; S. Y. R. Hui

2004-01-01

389

Assessment of the Impact of SFCL on Voltage Sags in Power Distribution System  

Microsoft Academic Search

This paper assesses and analyses the effects of super- conducting fault current limiter (SFCL) installed in power dis- tribution system on voltage sags. First of all, resistor-type SFCL is modeled using PSCAD\\/EMTDC to represent the quench and recovery characteristics based on the experimental results. Next, typical power distribution system of Korea is modeled. When the SFCLisinstalledinvariouslocationsfromthestartingpointtoend point of feeders, improvement

Jong-Fil Moon; Sung-Hun Lim; Jae-Chul Kim; Sang-Yun Yun

2011-01-01

390

Risks of leukaemia among residents close to high voltage transmission electric lines.  

PubMed Central

OBJECTIVES: To reassess the risk of leukaemia associated with residential exposure near high voltage transmission electric lines of 49 kV and above in view of the recent publications. METHODS: Through a review of papers considering the risk of leukaemia among people living near high voltage transmission lines, the combined risks of leukaemia were calculated for distances < or = 50 m and < or = 25 m and for exposures at 2 mG, 3 mG, 4 mG, and 10 mG. RESULTS: The combined analysis of the contributive studies indicated an estimate of risk (odds ratio (OR)) for exposure > or = 2 mG of 1.3, 95% confidence interval (95%CI) 1.0 to 1.7. The ORs increased with exposures at 3 mG, 4 mG, and 10 mG. The risks were also increased for distances of 50 and 25 m from the lines. CONCLUSIONS: This meta-analysis tends to confirm the presence of an association between exposure to magnetic fields and leukaemia among people who reside in the vicinity of high voltage transmission electric lines of > or = 49 kV. There is consistency across studies. Measures of exposure used in the studies were either distance from the lines or calculated fields estimated from pertinent line features. The results apply to adults as well as to children. PMID:9423573

Theriault, G; Li, C Y

1997-01-01

391

Protection against lightning surge voltages on communication lines and power lines  

SciTech Connect

Sensitive electronic systems are shielded against electromagnetic interferences (lightning, EMP). The shielding efficiency is reduced by field coupling through apertures and particularly by feeding of interfering currents through cable entries. In case these cables are connected to the inputs of electronic devices, the surge voltages may disturb or even destroy these devices or single electronic components, particularly semiconductors. Special passive protection circuits for communication and power lines against lightning- and EMP-induced surge voltages are developed. The edge steepnesses of the applying surge voltages show values of 2kV/us (lightning) up to 2kV/ns (EMP).

Haseborg, J.L.t.; Trinks, H.

1983-01-01

392

Repetitive avalanche cycling of low-voltage power trench n-MOSFETs  

Microsoft Academic Search

Low voltage discrete power trench n-MOSFETs in TO-220 packages have been subjected to over 200 million cycles of repetitive unclamped inductive switching (UIS) at a mounting base temperature of 150° C and at different avalanche currents. Hot-hole injection into the gate dielectric during avalanche conduction causes a reduction in the threshold voltage as the number of avalanche cycles increase. The

Olayiwola Alatise; Ian Kennedy; George Petkos; K. Heppenstall; K. Khan; J. Parkin; A. Koh; P. Rutter

2010-01-01

393

New approaches to provide ride-through for critical loads in electric power distribution systems  

NASA Astrophysics Data System (ADS)

The extensive use of electronic circuits has enabled modernization, automation, miniaturization, high quality, low cost, and other achievements regarding electric loads in the last decades. However, modern electronic circuits and systems are extremely sensitive to disturbances from the electric power supply. In fact, the rate at which these disturbances happen is considerable as has been documented in recent years. In response to the power quality concerns presented previously, this dissertation is proposing new approaches to provide ride-through for critical loads during voltage disturbances with emphasis on voltage sags. In this dissertation, a new approach based on an AC-DC-AC system is proposed to provide ride-through for critical loads connected in buildings and/or an industrial system. In this approach, a three-phase IGBT inverter with a built in Dc-link voltage regulator is suitably controlled along with static by-pass switches to provide continuous power to critical loads. During a disturbance, the input utility source is disconnected and the power from the inverter is connected to the load. The remaining voltage in the AC supply is converted to DC and compensated before being applied to the inverter and the load. After detecting normal utility conditions, power from the utility is restored to the critical load. In order to achieve an extended ride-through capability a second approach is introduced. In this case, the Dc-link voltage regulator is performed by a DC-DC Buck-Boost converter. This new approach has the capability to mitigate voltage variations below and above the nominal value. In the third approach presented in this dissertation, a three-phase AC to AC boost converter is investigated. This converter provides a boosting action for the utility input voltages, right before they are applied to the load. The proposed Pulse Width Modulation (PWM) control strategy ensures independent control of each phase and compensates for both single-phase or poly-phase voltage sags. Algorithms capable of detecting voltage disturbances such as voltage sags, voltage swells, flicker, frequency change, and harmonics in a fast and reliable way are investigated and developed in this dissertation as an essential part of the approaches previously described. Simulation and experimental work has been done to validate the feasibility of all approaches under the most common voltage disturbances such as single-phase voltage sags and three-phase voltage sags.

Montero-Hernandez, Oscar C.

2001-07-01

394

A combined compensation method for the output voltage of an insulated core transformer power supply.  

PubMed

An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA. PMID:24985809

Yang, L; Yang, J; Liu, K F; Qin, B; Chen, D Z

2014-06-01

395

Kysat-2 electrical power system design and analysis  

NASA Astrophysics Data System (ADS)

In 2012, Kentucky Space, LLC was offered the opportunity to design KYSat-2, a CubeSat mission which utilizes an experimental stellar-tracking camera system to test its effectiveness of determining the spacecraft's attitude while on orbit. Kentucky Space contracted Morehead State University to design the electrical power system (EPS) which will handle all power generation and power management and distribution to each of the KYSat-2 subsystems, including the flight computer, communications systems, and the experimental payload itself. This decision came as a result of the success of Morehead State's previous CubeSat mission, CXBN, which utilized a custom built power system and successfully launched in 2011. For the KYSat-2 EPS to be successful, it was important to design a system which was efficient enough to handle the power limitations of the space environment and robust enough to handle the challenges of powering a spacecraft on orbit. The system must be developed with a positive power budget, generating and storing more power than will be stored by KYSat-2 over mission lifetime. To accomplish this goal, the use of deployable solar panels has been utilized to double the usable surface area of the satellite for power generation, effectively doubling the usable power of the satellite system on orbit. The KYSat-2 EPS includes of set of gold plated deployable solar panels utilizing solar cells with a 26% efficiency. Power generated by this system is fed into a shunt regulator circuit which regulates the voltage generated to be stored in a 3-cell series battery pack. Stored powered is maintained using a balancing circuit which increases the efficiency and lifetime of the cells on-orbit. Power distribution includes raw battery voltage, four high-power outputs (two 5V and two 3.3 V) and a low-noise, low power 3.3V output for use with noise sensitive devices, such as microcontrollers. The solar panel deployment system utilizes the nichrome wire which draws current directly from the battery pack which a solid state relay receives logic-high signal. This nichrome wire, while under current, cuts a nylon wire which holds the solar panels in a stowed state prior to deployment on orbit. All logic control, current/voltage measurement, and commanding/communications is handled through the use of a Texas Instruments MSP430 microcontroller over UART serial communications. Results of the completed EPS demonstrated high-power output efficiencies approaching 90% under the highest anticipated loads while on orbit. They showed maximum noise levels of approximately +/- 41.30 mV at 83.10 MHz under maximum load. The low-noise 3.3V outputs displayed very little noise, however, this came at the cost of efficiency showing only 26% efficiency at the outputs when under maximum load. The EPS has been successfully integrated with other KYSat-2 subsystems including the spacecraft flight computer, in which the flight computer was able to communicate with the EPS and carry out its functions while functioning solely off the power distributed by the power system. Finally, testing on the solar panels show that a positive voltage margin was achieved when under light and the deployment system was able to cut the nylon wire completely under control by the EPS.

Molton, Brandon L.

396

Time evolution of electrical degradation under high-voltage stress in GaN high electron mobility transistors  

E-print Network

In this work, we investigate the time evolution of electrical degradation of GaN high electron mobility transistors under high voltage stress in the OFF state. We found that the gate current starts to degrade first, followed ...

Joh, Jungwoo

397

Energy conserving electrical power control circuit  

SciTech Connect

An energy conserving circuit for controlling supply of electrical power to various loads such as a street lamp or a hot water heater comprises a photoelectric device for starting a timer when a change from daylight to dark is sensed at sundown, and a load power control responsive to the timer to switch between power-off and power-on states. With a street lamp the timer and power control means are connected to switch the power control means to power-on state at the beginning of the delay period at sundown and later, well before sunrise, to switch to power-off state. In the case of a household hot water heater the switching of the power control to power-on state is delayed until the peak demand hours have ended after sundown. The photoelectric device will normally cause the power control to switch to poweroff state at sunrise. But a second timer may be added which is responsive to the photoelectric device to start a second timing period ending after normal sunrise so that switching to power-off will occur if the photoelectric device does not or cannot respond to sunrise.

Grady, J.K.

1982-12-07

398

Resonating models for the electric power market  

NASA Astrophysics Data System (ADS)

This paper describes the economic phenomenon of price spiking in electric power markets and introduces an alternative way to model it. A stochastic FitzHugh-Nagumo dynamics in a special regime is proposed as a basic model for the power market, and an extension of the FitzHugh-Nagumo system is introduced to improve the statistical features of the basic model. Ideas from stochastic and coherence resonance are used to discuss the models.

Lucheroni, Carlo

2007-11-01

399

Power control for battery-electric bicycles  

Microsoft Academic Search

Electric bicycles powered with nickel-metal hydride batteries offer a 100-km range between recharges, and have a potential of 300 km when polymer batteries become available. These vehicles, when implemented by installing power kits on existing bicycles, can offer low-coat, pollution-free transportation for bringing education, health services, and communication to remote areas in developing nations. Solar-photovoltaic battery charging can avoid fuel

Binod Kumar; Henry Oman

1993-01-01

400

Design considerations for large space electric power systems  

NASA Technical Reports Server (NTRS)

As power levels of spacecraft rise to the 50 to 100 kW range, it becomes apparent that low voltage (28 V) dc power distribution and management systems will not operate efficiently at these higher power levels. The concept of transforming a solar array voltage at 150 V dc into a 1000 V ac distribution system operating at 20 kHz is examined. The transformation is accomplished with series-resonant inverter by using a rotary transformer to isolate the solar array from the spacecraft. The power can then be distributed in any desired method such as three phase delta to delta. The distribution voltage can be easily transformed to any desired load voltage and operating frequency. The reasons for the voltage limitations on the solar array due to plasma interactions and the many advantages of a high voltage, high frequency at distribution system are discussed.

Renz, D. D.; Finke, R. C.; Stevens, N. J.; Triner, J. E.; Hansen, I. G.

1983-01-01

401

Generalized Bohm’s criterion and negative anode voltage fall in electric discharges  

SciTech Connect

The value of the voltage fall across the anode sheath is found as a function of the current density. Analytic solutions are obtained in a wide range of the ratio of the directed velocity of plasma electrons v{sub 0} to their thermal velocity v{sub T}. It is shown that the voltage fall in a one-dimensional collisionless anode sheath is always negative. At the small values of v{sub 0}/v{sub T}, the obtained expression asymptotically transforms into the Langmuir formula. Generalized Bohm’s criterion for an electric discharge with allowance for the space charge density ?(0), electric field E(0), ion velocity v{sub i}(0), and ratio v{sub 0}/v{sub T} at the plasma-sheath interface is formulated. It is shown that the minimum value of the ion velocity v{sub i}{sup *}(0) corresponds to the vanishing of the electric field at one point inside the sheath. The dependence of v{sub i}{sup *} (0) on ?(0), E(0), and v{sub 0}/v{sub T} determines the boundary of the existence domain of stationary solutions in the sheath. Using this criterion, the maximum possible degree of contraction of the electron current at the anode is determined for a short high-current vacuum arc discharge.

Londer, Ya. I.; Ul’yanov, K. N., E-mail: kulyanov@vei.ru [Lenin All-Russian Electrotechnical Institute (Russian Federation)

2013-10-15

402

Miniaturized Power Processing Unit Study: A Cubesat Electric Propulsion Technology Enabler Project  

NASA Technical Reports Server (NTRS)

This study evaluates High Voltage Power Processing Unit (PPU) technology and driving requirements necessary to enable the Microfluidic Electric Propulsion technology research and development by NASA and university partners. This study provides an overview of the state of the art PPU technology with recommendations for technology demonstration projects and missions for NASA to pursue.

Ghassemieh, Shakib M.

2014-01-01

403

ACEEE Int. J. on Electrical and Power Engineering, Vol. 01, No. 03, Dec 2010 2010 ACEEE  

E-print Network

@tce.edu Abstract In today s high-power electrical drives using vector controlled induction machines, voltage source (Indirect Vector Control) is also presented. To verify the design of controllers and system performance by the vector control scheme is equivalent to a separately excited dc machine. Nowadays, the flux-feed forward

Paris-Sud XI, Université de

404

Electrical safety problems in MV-power networks of a surface mining  

Microsoft Academic Search

Problems of an electric shock hazard in middle voltage (6 kV-30 kV) power networks of brown coal surface minings in Poland are discussed. They are found based on two years of investigations carried out for real ground fault conditions

B. Miedzitiski; Z. Okraszewski; S. Szkolka; A. Szymanski

1999-01-01

405

Electric Power Market Simulations Using Individuals  

E-print Network

in Most Open Markets for Non- Contracted Energy Accepted Supply Bids Loads Served All Accepted BidsElectric Power Market Simulations Using Individuals as Agents Guenter Conzelmann Argonne National Laboratory Argonne, IL 60439, USA guenter@anl.gov #12;2 Market Simulations Allow Us to Explore Market

Kemner, Ken

406

Emerging Electric Power Systems and Future Grid  

NSDL National Science Digital Library

This page provides a 2011 presentation on electric power systems and future grid by P.K. Sen, Colorado School of Mines, for ATEEC/CSM's Sustainable Energy Education and Training (SEET) Technology Workshop. This resource is free to download. Users must first create a login with ATEEC's website to access the file.

Sen, P. K.

2013-08-14

407

Electrical Extension Cords Relocatable Power Taps  

E-print Network

Electrical Extension Cords & Relocatable Power Taps: (RPT's) #12; If either device is not use; In summary it's a - "flexible multi- conductor cord having an attachment plug at one end for plugging unto of mostly plastic rather than copper; So a 16 gauge cord may only have the copper content of a 24 gauge

Jia, Songtao

408

Voltage multi-stability in distribution grids with power flow reversal  

E-print Network

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.

Hung D. Nguyen; Konstantin Turitsyn

2014-04-25

409

The Tucson Electric Power Solar Test Yard  

NASA Astrophysics Data System (ADS)

In collaboration with Tucson Electric Power we studied the performance of twenty different grid-tied photovoltaic systems, consisting of over 600 PV modules in all. We added data acquisition hardware to monitor DC power from the modules, AC power from the inverters, PV module temperatures, and meteorological data such as the irradiance incident on the PV systems. We report measurements of PV system yields and efficiencies over periods of minutes, days, and years. We also report temperature and irradiance coefficients of efficiency and measurements of long-term degradation. We also use our data to validate models that predict the output from PV systems.

Lonij, Vincent; Orsburn, Sean; Salhab, Anas; Kopp, Emily; Brooks, Adria; Jayadevan, Vijai; Greenberg, James; St. Germaine, Michael; Allen, Nate; Jones, Sarah; Hardesty, Garrett; Cronin, Alex

2011-10-01

410

Electric Power Research Institute: Journal Online  

NSDL National Science Digital Library

The Electric Power Research Institute (EPRI) produces an online journal that covers many important developments in power generation and distribution. Most of the articles deal with technological breakthroughs in this field; this can include, for example, environmental issues, energy efficiency, energy storage, and power plant operation. The EPRI journal is divided into six departments on the Web site. In the Field is a section that describes the latest applications and innovations at EPRI. The Discovery section looks more closely at the research conducted at the institute. Some of the articles may note a particular product available for purchase; however, all of them can be viewed without cost.

Dietrich, David

2007-07-08

411

A low-power area efficient voltage reference and data generation unit for inductively powered implant system  

Microsoft Academic Search

This paper reports a low-power sensor signal processing and load shift keying (LSK) telemetry scheme for an inductively powered implant system. The entire system manifests a voltage reference (VR), a potentiostat, and a current controlled oscillator (CCO). All of the functional blocks are designed using subthreshold MOSFETs to achieve ultra-low-power consumption. Relatively simpler architecture of the VGR saves area and

M. Roknsharifi; M. R. Haider; S. K. Islam

2011-01-01

412

Air ion mobility spectra and concentrations upwind and downwind of overhead AC high voltage power lines  

NASA Astrophysics Data System (ADS)

Corona ions produced by high-voltage power lines (HVPLs) can alter the nearby electrical environment, potentially increasing aerosol charge levels downwind. However, there is a lack of knowledge concerning the concentration and mobility of ions from AC HVPLs and their dispersion away from the line. We present ion concentration and mobility measurements made near AC HVPLs in South-West England. Examples of typical mobility spectra are shown highlighting features commonly observed. Corona was observed during 33 of 46 measurements, at 9 of 11 sites, with positive or ‘bipolar' (both polarities) ion production commonly seen. Ion production usually increases atmospheric concentrations by only a modest amount, but extreme cases can enhance concentration by an order of magnitude or more. A polarity imbalance is required to increase aerosol charge via ion attachment; this was observed on 15 of 24 days when positive corona was observed, but was not seen for negative ions. Ion mobility was higher downwind compared with upwind for both ion polarities, but the increase was not statistically significant. Future work should focus on identifying and characterising ‘heavy-producing' HVPLs, and obtaining results in conditions which may favour negative ion production e.g. high humidity, inclement weather or during nighttime.

Wright, Matthew D.; Buckley, Alison J.; Matthews, James C.; Shallcross, Dudley E.; Henshaw, Denis L.

2014-10-01

413

Versatile 3-channel high-voltage power supply for microchip capillary electrophoresis.  

PubMed

The fabrication of a battery operated 3-channel high voltage power supply for microchip capillary electrophoresis is described. The power supply consists of two positive and one negative DC-DC converters, a microprocessor controlled timer, a battery and a transformer to recharge the battery and feed the high voltage relays. This arrangement allows the possibility to control the potentials applied in the 0 to +/-4000 V range to a variety of microchip setups. It can also be easily adapted to perform either gated or pinched injection. The inclusion of a rechargeable battery was adopted to feed the DC-DC converters to reduce noise levels and achieve portability. PMID:15007467

García, Carlos D; Liu, Yan; Anderson, Paul; Henry, Charles S

2003-11-01

414

Development of a linear piston-type pulse power electric generator for powering electric guns  

NASA Astrophysics Data System (ADS)

The development of a linear piston-type electric pulse-power generator capable of powering electric guns and EM (rail and coil) guns and ET guns, presently under development, is discussed. The pulse-power generator consists of a cylindrical armature pushed by gases from the combustion of fuel or propellant through an externally produced magnetic field. An arrangement of electrodes and connecting straps serves to extract current from the moving armature and to send it to an external load (the electric gun).

Summerfield, Martin

1993-01-01

415

PASP, a high voltage array/plasma interaction experiment. [Photovoltaic Array Space Power  

NASA Technical Reports Server (NTRS)

The author discusses the photovoltaic array space power (PASP) experiment, which is designed to obtain data on the interaction between high-voltage photovoltaic arrays and the polar, low-earth plasma environment. Up to six small test arrays (three each of planar and concentrator designs) can be voltage biased over a range of +/- 500 V. During the bias voltage sequence, the array current leakage is measured and array arc events are monitored. If any arcing occurs the arc characteristics will be measured by a transient pulse monitor. An emitter is included to allow voltage bias to be applied to a plasma-charged or uncharged spacecraft. Similarly, the frames of the concentrator arrays can be left floating or can be tied to the negative array terminal. An environmental data scan is made before each bias voltage sequence. This scan collects information on the plasma, array-current-versus-voltage curves, and neutral particle partial pressure. The requirement for high voltages created problems which were met by circuit isolation and logical fault protection.

Burger, Dale R.

1991-01-01

416

Flex-gear electrical power transmission  

NASA Technical Reports Server (NTRS)

This study was conducted to develop an alternative way of transferring electricity across a continuously rotating joint, with little wear and the potential for low electrical noise. The problems with wires, slip rings, electromagnetic couplings, and recently invented roll-rings are discussed. Flex-gears, an improvement of roll-rings, are described. An entire class of flexgear devices is developed. Finally, the preferred flex-gear device is optimized for maximum electrical contact and analyzed for average mechanical power loss and maximum stress. For a device diameter of six inches, the preferred device is predicted to have a total electrical contact area of 0.066 square inches. In the preferred device, a small amount of internal sliding produces a 0.003 inch-pound torque that resists the motion of the device.

Vranish, John; Peritt, Jonathan

1993-01-01

417

High Voltage Electrostatic Pendulum  

E-print Network

A pendulum powered by high voltage electricity is described. The pendulum consists of two conducting plates(thin foil) separated by copper rods and are insulated from each other. High voltage is applied to these plates through the connecting copper rods. Another stationary aluminum plate(thin foil) is placed in front of the pendulum such that it serves to attract the pendulum plates and makes electrical contact with them enabling charge transfer between the stationary plate and the pendulum plates. The pendulum is powered by the energy stored in the capacitance between the stationary aluminum plate and the pendulum plate. Attempt has been made to obtain the time period of oscillations as a function of applied voltage and other parameters. The derived formula for the time period has been verified experimentally. This apparatus can be used to demonstrate electrical phenomena in general and in particular electrical energy stored in conductors of small dimensions.

Baddi, Raju

2012-01-01

418

Fast voltage stability assessment and reinforcement in an interconnected power system  

NASA Astrophysics Data System (ADS)

It is believed that voltage stability analysis will be more difficult due to the full utilization of transmission systems and the growth of inter-utility power transfer. An online voltage stability analyzing system which can be incorporated into the EMS to deal with the threats of suddenly arising voltage collapses is presented. Operating margin prediction, voltage stability assessment and reinforcement are three major functions. Two predicting methods are proposed to calculate the operating margin according to current operating condition and the anticipative system state. A fast risk indicator based on the saddle-node bifurcation theory is designed to predict the proximity of a system to voltage collapse. A novel CPF method which can trace the power flow solution path through the nose point without notorious numerical difficulties is presented. Speed is the advantage of former method, while accuracy is the important feature of latter one. Voltage stability assessment is required to predict steady-state conditions of a system following a large number of anticipated transmission branch or generator outages. An efficient and simple method based on voltage sensitivity changing rates is proposed for quickly identify the weak buses in a large-scale system. An effective contingency selection function relying on search algorithms built into power flow solutions is designed to filter out most of harmless contingencies for system operators who are working with rapidly changing load/generation patterns and a wide variety of operating conditions. A contingency evaluation function having the ability to deal with real-time numerous contingencies in a very short period of time is utilized to find high-severity contingencies. Var compensation and load shedding are two remedial measures of reinforcement function. Suitable var compensation scheme has three contributions: extending operating margin to avoid voltage collapses, fully utilizing the transmission infrastructure to earn economic benefits, and reducing the number of must-run units to eliminate monopoly profits. A load shedding method is designed to provide protection from fatal voltage collapses occurring outside of prior planning and operating studies. Two practical large-scale power systems and their interconnections are used to study voltage stability throughout this dissertation.

Hsiao, Wen-Ta

419

Important parameters affecting the cell voltage of aqueous electrical double-layer capacitors  

NASA Astrophysics Data System (ADS)

This study discusses and demonstrates how the open-circuit potential and charges stored in the working potential window on positive and negative electrodes affect the cell voltage of carbon-based electrical double-layer capacitors (EDLCs) in aqueous electrolytes. An EDLC consisting of two activated carbon electrodes is employed as the model system for identifying these key parameters although the potential window of water decomposition can be simply determined by voltammetric methods. First, the capacitive performances of an EDLC with the same charge on positive and negative electrodes are evaluated by cyclic voltammetric, charge-discharge, electrochemical impedance spectroscopic (EIS) analyses, and inductance-capacitance-resistance meter (LCR meter). The principles for obtaining the highest acceptable cell voltage of such symmetric ECs with excellent reversibility and capacitor-like behaviour are proposed. Aqueous charge-balanced EDLCs can be operated as high as 2.0 V with high energy efficiency (about 90%) and only 4% capacitance loss after the 600-cycle stability checking. The necessity of charge balance (but not capacitance balance) for positive and negative electrodes is substantiated from the lower acceptable cell voltage of charge-unbalanced EDLCs.

Wu, Tzu-Ho; Hsu, Chun-Tsung; Hu, Chi-Chang; Hardwick, Laurence J.

2013-11-01

420

Multifunctional Voltage Source Inverter for Renewable Energy Integration and Power Quality Conditioning  

PubMed Central

In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity. PMID:25177725

Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

2014-01-01

421

High-voltage electrical apparatus utilizing an insulating gas of sulfur hexafluoride and helium  

DOEpatents

High-voltage electrical apparatus includes an outer housing at low potential, an inner electrode disposed within the outer housing at high potential with respect thereto, and support means for insulatably supporting the inner electrode within the outer housing. Conducting particles contaminate the interior of the outer housing, and an insulating gas electrically insulates the inner electrode from the outer housing even in the presence of the conducting particles. The insulating gas is comprised of sulfur hexafluoride at a partial pressure of from about 2.9 to about 3.4 atmospheres absolute, and helium at a partial pressure from about 1.1 to about 11.4 atmospheres absolute. The sulfur hexafluoride comprises between 20 and 65 volume percent of the insulating gas.

Wootton, Roy E. (Murrysville, PA)

1980-01-01

422

Optimal Endogenous Carbon Taxes Electric Power Supply Chains with Power Plants  

E-print Network

Optimal Endogenous Carbon Taxes for Electric Power Supply Chains with Power Plants Anna Nagurney for the determination of optimal carbon taxes applied to electric power plants in the con- text of electric power supply portion of such policy inter- ventions directed at the electric power industry. The general framework

Nagurney, Anna

423

Voltage dip immunity aspects of power-electronics equipment — Recommendations from CIGRE\\/CIRED\\/UIE JWG C4.110  

Microsoft Academic Search

This paper presents some of the results from an international working group on voltage-dip immunity. The working group has made a number of recommendations to reduce the adverse impact of voltage dips. Specific recommendations to researchers and manufacturers of power-electronic equipment are: considering all voltage dip characteristics early in the design of equipment; characterize performance of equipment by means of

M. H. J. Bollen; S. Cundeva; J.-M. R. Gordon; S. Z. Djokic; K. Stockman; J. V. Milanovic; R. Neumann; G. Ethier

2010-01-01

424

Fuel cell power plants for electric utilities  

SciTech Connect

Increase in power densities, and lifetime, has made phosphoric acid fuel cells (PAFC) a possible, viable electric generator. A 4.5MW demonstrator produced by United Technologies has been installed at Con Edison in New York City. Modifications to simplify the process, use commercial parts, improve performance, and create fuel flexibility have been successful. A Fuel Cell Users Group serves as surrogate users, and provides information on applications and benefits of PAFC to utilities. The electric utility market for fuel cells was assessed using the novel ''utility generation expansion model'' and methodology.

Gillis, E.A.; Fickett, A.P.

1983-06-01

425

Carbon pricing, nuclear power and electricity markets  

SciTech Connect

In 2010, the NEA in conjunction with the International Energy Agency produced an analysis of the Projected Costs of Electricity for almost 200 power plants, covering nuclear, fossil fuel and renewable electricity generation. That analysis used lifetime costs to consider the merits of each technology. However, the lifetime cost analysis is less applicable in liberalised markets and does not look specifically at the viewpoint of the private investor. A follow-up NEA assessment of the competitiveness of nuclear energy against coal- and gas-fired generation under carbon pricing has considered just this question. The economic competition in electricity markets is today between nuclear energy and gas-fired power generation, with coal-fired power generation not being competitive as soon as even modest carbon pricing is introduced. Whether nuclear energy or natural gas comes out ahead in their competition depends on a number of assumptions, which, while all entirely reasonable, yield very different outcomes. The analysis in this study has been developed on the basis of daily data from European power markets over the last five-year period. Three different methodologies, a Profit Analysis looking at historic returns over the past five years, an Investment Analysis projecting the conditions of the past five years over the lifetime of plants and a Carbon Tax Analysis (differentiating the Investment Analysis for different carbon prices) look at the issue of competitiveness from different angles. They show that the competitiveness of nuclear energy depends on a number of variables which in different configurations determine whether electricity produced from nuclear power or from CCGTs generates higher profits for its investors. These are overnight costs, financing costs, gas prices, carbon prices, profit margins (or mark-ups), the amount of coal with carbon capture and electricity prices. This paper will present the outcomes of the analysis in the context of a liberalised electricity market, looking at the impact of the seven key variables and provide conclusions on the portfolio that a utility would be advised to maintain, given the need to limit risks but also to move to low carbon power generation. Such portfolio diversification would not only limit financial investor risk, but also a number of non-financial risks (climate change, security of supply, accidents). (authors)

Cameron, R.; Keppler, J. H. [OECD Nuclear Energy Agency, 12, boulevard des Iles, 92130 Issy-les-Moulineaux (France)

2012-07-01

426

Wind power trading options in competitive electricity market  

Microsoft Academic Search

Integration of wind power into the competitive electricity market presents challenges to power system planners and operators. It is not possible for wind generators to bid into the competitive electricity market due to high cost and intermittent nature of available power. This paper analyses and proposes the pricing mechanism for wind power in the competitive electricity market. The both demand

S. N. Singh; I. Erlich

2006-01-01

427

A new technique for voltage stability analysis in a power system and improved loadflow algorithm for distribution network  

SciTech Connect

Voltage collapse may occur in a power system due to lost in voltage stability in the system. Therefore voltage stability analysis is important in order to identify critical buses in a power system i.e., buses which are closed to their voltage stability limits and thus enable certain measures to be taken by the control engineer in order to avoid any incidence of voltage collapse. This paper presents a new technique to determine the static voltage stability of load buses in a power system for a certain operating condition and hence identifies load buses which are close to voltage collapse. A voltage stability index with respect to a load bus is formulated from the voltage equation derived from a two bus network and it is computed using Thevenin equivalent circuit of the power system referred to a load bus. This index indicates how far the load buses from their voltage stability limits and hence identifies the critical buses. The performance of this index is tested using 9 bus radial network and the 24 bus IEEE Reliability Test System for its validity. A comparison is also made between this index and the impedance ratio used by Sterling et al. as the voltage collapse indicator. This paper also presents a new loadflow technique to compute power flow solution for radial network which found to be more superior than the Second Order Newton Raphson and Distflow since it takes less iterations to give a loadflow solution.

Abdul Rahman, T.K.; Jasmon, G.B.

1995-12-31

428

EMTP based stability analysis of space station electric power system in a test bed environment  

NASA Technical Reports Server (NTRS)

The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability) under certain conditions. Criteria for instability are examined and verified for a single device. Suggested extension of the criteria to a system operation is examined by using the EMTP model of the PMAD DC test bed. Wherever possible, data from the test bed is compared with the modeling results.

Dravid, Narayan V.; Kacpura, Thomas J.; Oconnor, Andrew M.

1992-01-01

429

EMTP based stability analysis of Space Station Electric Power System in a test bed environment  

NASA Technical Reports Server (NTRS)

The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability) under certain conditions. Criteria for instability are examined and verified for a single device. Suggested extension of the criteria to a system operation is examined by using the EMTP model of the PMAD dc test bed. Wherever possible, data from the test bed is compared with the modeling results.

Dravid, Narayan V.; Kacpura, Thomas J.; O'Connor, Andrew M.

1992-01-01

430

Recent advances in the mitigation of AC voltages occurring in pipelines located close to electric transmission lines  

Microsoft Academic Search

In joint-use corridors where both pipelines and AC electric transmission lines are present, a portion of the energy contained in the electromagnetic field surrounding the electric transmission lines is captured by each pipeline, resulting in induced AC voltages which vary in magnitude throughout the length of each pipeline. During a fault on any of the transmission lines, energization of the

R. D. Southey; F. P. Dawalibi; W. Vukonich

1994-01-01

431

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

E-print Network

takes into account the induction motor dynamic characteristics which influence the transient voltage were generally not designed to connect power generation facilities. DG integration in these passive, furnaces, etc. The exact composition of a load is difficult to estimate as the load magnitude

Pota, Himanshu Roy

432

Method for reducing fuel cell output voltage to permit low power operation  

DOEpatents

Fuel cell performance is degraded by recycling a portion of the cathode exhaust through the cells and, if necessary, also reducing the total air flow to the cells for the purpose of permitting operation below a power level which would otherwise result in excessive voltage.

Reiser, Carl A. (Glastonbury, CT); Landau, Michael B. (West Hartford, CT)

1980-01-01

433

A bilevel programming approach for power system operation planning considering voltage stability and economic dispatch  

Microsoft Academic Search

This paper presents a model for power systems operation planning that aims to maximizing the voltage stability margin and also the economic dispatch, formulated as a bilevel programming problem (BPP). The objective is to obtain a solution for the network operation planning that takes into account both technical and economical aspects. The bilevel model allows system operators to define different

D. A. Arias; A. A. Mota; L. T. M. Mota; C. A. Castro

2008-01-01

434

New, zero voltage switching, high frequency boost converter topology for power factor correction  

Microsoft Academic Search

This paper introduces a technique for combining zero-voltage-switching with boost converter technology to enable high frequency, high efficiency operation of the converter. The combination creates a new topology which is effective to meet the power factor correction and harmonic reduction requirements of new EMC standards. The unique topology provides limitation of the recovery current of the boost diode and uses

John A Bassett

1995-01-01

435

High-power, high-voltage generator with a multi-pulse twin output  

Microsoft Academic Search

Summary form only given, as follows. The Pulsed Power Group at Loughborough University is presently investigating the possibility of producing twin series of high-voltage pulses from the single discharge of a capacitor into an array of exploding metallic fuses. A low-energy prototype generator based on exploding foils has been designed and constructed, and shown to function close to the performance

B. M. Novac; I. R. Smith; K. Gregory

2001-01-01

436

Power losses evaluation of three multilevel converter topologies for direct interface with medium voltage grids  

Microsoft Academic Search

Acknowledgementsproject this report is based on was funded by E.ON as part of the E.ON International Research Initiative. Responsibility for the content of this publication lies with the author. Abstract paper presents the power losses evaluation and comparison of three different Mega Watt MW scale multilevel converter topologies proposed for interfacing energy storage systems to medium voltage grids using Medium

Mohamed Rashed; Christian Klumpner; Greg Asher

2011-01-01

437

Design and Fabrication of Ultralight High-Voltage Power Circuits for Flapping-Wing Robotic Insects  

E-print Network

Design and Fabrication of Ultralight High-Voltage Power Circuits for Flapping-Wing Robotic Insects@seas.harvard.edu Abstract-- Flapping-wing robotic insects are small, highly ma- neuverable flying robots inspired by biological insects and useful for a wide range of tasks, including exploration, environmen- tal monitoring

Wood, Robert

438

Low-voltage low-power novel CCII topologies and applications  

Microsoft Academic Search

Novel topologies of second generation current conveyors (CCIIs) working at low supply voltage (lower than 1.5 V) with reduced power consumption (in the ?W range) are presented. The proposed CCII has been applied to the design of different functions such as capacitance multiplication, integrated filtering, sinusoidal waveform generation, grounded and floating inductance simulation, etc.. To extend the dynamic range of

Giuseppe Ferri; Nicola Carlo Guerrini

2001-01-01

439

Power Quality Solutions for Light Rail Public Transportation Systems Fed by Medium-Voltage Underground Cables  

Microsoft Academic Search

In this paper, the combination of a thyristor-switched shunt reactor and a current source converter-based active power filter has been proposed for mitigation of power quality (PQ) problems of Light Rail public Transportation Systems (LRTSs) fed by long medium-voltage underground cables. A case study has been carried out on a typical LRTS to assess the performance of the proposed solution

Alper Terciyanli; Adnan Acik; Alper Cetin; Muammer Ermis; I??k Cadirci; Cezmi Ermis; Turan Demirci; Haz?m Faruk Bilgin

2012-01-01

440

Low Voltage CMOS Power Amplifier with Rail-to-Rail Input and Output  

Microsoft Academic Search

This paper describes a CMOS power amplifier with rail-to-rail input and output, also suitable for low voltage applications.\\u000a The amplifier uses Simple Miller Compensation with high bandwidth stage to robustly and power efficiently compensate the amplifier.\\u000a Circuit also includes a common mode adapter block, based on resistive level shift network, to implement rail-to-rail input\\u000a and optional adaptive biasing block, which

Mikko Loikkanen; Juha Kostamovaara

2006-01-01

441

A medium voltage power supply with enhanced ignition characteristics for plasma torch in waste disposal system  

Microsoft Academic Search

This paper investigates a power supply of medium voltage with enhanced ignition characteristics for plasma torch in waste disposal system. Series resonant half-bridge topology is presented to be a suitable ignition circuitry. The ignition circuitry is integrated into the main power conversion system of a multi-phase staggered three-level dc-dc converter with a diode front-end rectifier. The plasma torch rated for

Yongsug Suh; Kyungsub Jung

2010-01-01

442

High-voltage (270 V) dc power-generating system for fighter aircraft  

NASA Astrophysics Data System (ADS)

The advantages of using high voltage, direct current advanced power generating systems in fighter aircraft are discussed. Weight reduction is achieved. Efficiency is increased 85 to 90 percent by eliminating the constant speed drive. Power interruptions are eliminated. There are no speed restrictions and no powerline constraints. Personal safety is increased by eliminating the hold on frequency, present in ac systems, which causes muscle contractions.

McGinley, K. M.

1983-06-01

443

High-voltage (270 V) dc power-generating system for fighter aircraft  

NASA Technical Reports Server (NTRS)

The advantages of using high voltage, direct current advanced power generating systems in fighter aircraft are discussed. Weight reduction is achieved. Efficiency is increased 85 to 90 percent by eliminating the constant speed drive. Power interruptions are eliminated. There are no speed restrictions and no powerline constraints. Personal safety is increased by eliminating the hold on frequency, present in ac systems, which causes muscle contractions.

Mcginley, K. M.

1983-01-01

444

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

Microsoft Academic Search

This paper surveys recent research on CMOS low voltage and low power IC designs for wireless applications. Advancements and\\u000a challenges in using nanometer IC processes are addressed, and the impacts of device scaling on wireless systems are discussed.\\u000a Recent advances in device technologies and system architectures are presented. State-of-the-art low power wireless systems,\\u000a both from academia and from industry, are

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

2007-01-01

445

A low power low phase noise CMOS voltage-controlled oscillator  

Microsoft Academic Search

A novel low power consumption and low phase noise CMOS cross-coupled LC-tank voltage-controlled oscillator (VCO) is presented. Added negative transconductance technique is used in the proposed VCO in order to improve the phase noise of the circuit by increasing the quality factor of the tank. Furthermore, common mode double-pseudo-resistance utilized in the proposed circuit helps to achieve low power consumption

Mohammad Niaboli-Guilani; Alireza Saberkari; Reza Meshkin

2010-01-01

446

Wind power fluctuations mitigation by DC-Link voltage control of variable speed wind turbines  

Microsoft Academic Search

This paper presents a simulation model of a MW-level variable speed wind turbine with a permanent magnet synchronous generator (PMSG) and a full-scale converter developed in the simulation tool of PSCAD\\/EMTDC. Grid connected wind turbines are fluctuating power sources during continuous operation. A novel wind power fluctuations mitigation method by DC-link voltage control of variable speed wind turbines is proposed

Weihao Hu; Zhe Chen; Yue Wang; Zhaoan Wang

2008-01-01

447

Test Results From a Simulated High-Voltage Lunar Power Transmission Line  

NASA Technical Reports Server (NTRS)

The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, Ohio was modified to simulate high-voltage transmission capability. The testbed simulated a 1 km transmission cable length from the ATU to the LPSF using resistors and inductors installed between the distribution transformers. Power factor correction circuitry was used to compensate for the reactance of the distribution system to improve the overall power factor. This test demonstrated that a permanent magnet alternator can successfully provide high-frequency ac power to a lunar facility located at a distance.

Birchenough, Arthur; Hervol, David

2008-01-01

448

Test Results from a Simulated High Voltage Lunar Power Transmission Line  

NASA Technical Reports Server (NTRS)

The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was modified to simulate high voltage transmission capability. The testbed simulated a 1 km transmission cable length from the ATU to the LPSF using resistors and inductors installed between the distribution transformers. Power factor correction circuitry was used to compensate for the reactance of the distribution system to improve the overall power factor. This test demonstrated that a permanent magnet alternator can successfully provide high frequency AC power to a lunar facility located at a distance.

Birchenough, Arthur; Hervol, David

2008-01-01

449

Electrical machines technology for aerospace power generators  

NASA Astrophysics Data System (ADS)

Electric power generators for aerospace and aircraft applications are now required to be more reliable. It is noted that the wound field synchronous generator has been the workhorse for producing 400-Hz AC electric power for many years. Substantial evolution has occurred over the years by replacing low-speed generators with the 24,000-rpm design. The quality of the AC waveform produced by the wound field generators is excellent, the excitation power requirement is low, and control of output power is easily accomplished under abnormal operating conditions. Other changing requirements include variety of power types, increased reliability, and higher speeds and temperatures. It is pointed out that wound field synchronous generators have limitations due to rotating windings and rotating rectifiers. Other options such as self-regulating permanent magnet generators, switched reluctance generators, reluctance generators, flux switches overcome these limitations. It is suggested that the selection from these options must be based on the specific requirements for a given application, evaluating overall system constraints such as weight, performance, and cost.

Vaidya, Jayant G.

450

Space nuclear power applied to electric propulsion  

NASA Technical Reports Server (NTRS)

Space reactor power systems with characteristics ideal for advanced spacecraft systems applications are discussed. These characteristics are: high power-to-weight ratio (15 to 33 W/kg); high volume density (high ballistic coefficient); no preferential orientation in orbit; long operational life; high reliability; and total launch and operational safety. These characteristics allow the use of electric propulsion to raise spacecraft from low earth parking orbits to operational orbits, greatly increasing the useful orbit payload for a given launch vehicle by eliminating the need for a separation injection stage. A proposed demonstration mission is described.

Vicente, F. A.; Karras, T.; Darooka, D.; Isenberg, L.

1989-01-01

451

Electric power industry competition: Growing, or shrinking?  

SciTech Connect

A recent analysis submitted to the Federal Energy Regulatory Commission by the Environmental Action Foundation, in response to FERC`s MEGA-NOPR, challenges the accepted view that competition in the electric power industry is growing. Some of the rebuttals are: (1) the trend is toward fewer competitors in the generation market; (2) utilities with a stake in generation remain the monopoly seller, having the exclusive power to determine who sells into their territory; (3) vertically integrated utilities control information that provides a crucial advantage when competing in the market for generation. Each of these is briefly explained.

NONE

1996-03-01

452

Nuclear power source for electric propulsion  

NASA Technical Reports Server (NTRS)

A low specific weight (20 to 40 Kg/Kwe), long life (6 to 10 year), 100 to 400 KWe nuclear electric propulsion (NEP) system can deliver 2,000 to 10,000 Kg payloads for intensive study of our solar system. The nuclear power source is about 80% of the NEP system mass, thus the NASA program is focused on developing the power source technology. Because of the long life requirements, direct thermal to electric energy conversion technology (thermionic and thermoelectric) is being pursued. In order to meet the low specific weight it is necessary to develop a 10 to 15% conversion module with a 875 K minimum heat rejection temperature and a 1675 K maximum input temperature. The thermoionic converter is about 9% efficient at these temperatures. The thermoelectric converter is limited to a 1300 K input temperature. So, the thermionic program is focused on improving the efficiency while the thermoelectric program is focused on increasing the temperature.

Mondt, J. F.; Stapfer, G.; Hsieh, T.

1979-01-01

453

Hubble Space Telescope electrical power system  

NASA Technical Reports Server (NTRS)

The Hubble Space Telescope (HST) electrical power system (EPS) is supplying between 2000 and 2400 W of continuous power to the electrical loads. The major components of the EPS are the 5000-W back surface field reflector solar array, the six nickel-hydrogen (NiH2) 22-cell 88-Ah batteries, and the charge current controllers, which, in conjunction with the flight computer, control battery charging. The operation of the HST EPS and the results of the HST NiH2 six-battery test are discussed, and preliminary flight data are reviewed. The HST NiH2 six-battery test is a breadboard of the HST EPS on test at Marshall Space Flight Center.

Whitt, Thomas H.; Bush, John R., Jr.

1990-01-01

454

Use of negative capacitance to provide voltage amplification for low power nanoscale devices.  

PubMed

It is well-known that conventional field effect transistors (FETs) require a change in the channel potential of at least 60 mV at 300 K to effect a change in the current by a factor of 10, and this minimum subthreshold slope S puts a fundamental lower limit on the operating voltage and hence the power dissipation in standard FET-based switches. Here, we suggest that by replacing the standard insulator with a ferroelectric insulator of the right thickness it should be possible to implement a step-up voltage transformer that will amplify the gate voltage thus leading to values of S lower than 60 mV/decade and enabling low voltage/low power operation. The voltage transformer action can be understood intuitively as the result of an effective negative capacitance provided by the ferroelectric capacitor that arises from an internal positive feedback that in principle could be obtained from other microscopic mechanisms as well. Unlike other proposals to reduce S, this involves no change in the basic physics of the FET and thus does not affect its current drive or impose other restrictions. PMID:18052402

Salahuddin, Sayeef; Datta, Supriyo

2008-02-01

455

Electric Power From Ambient Energy Sources  

SciTech Connect

This report summarizes research on opportunities to produce electric power from ambient sources as an alternative to using portable battery packs or hydrocarbon-fueled systems in remote areas. The work was an activity in the Advanced Concepts Project conducted by Pacific Northwest National Laboratory (PNNL) for the Office of Research and Development in the U.S. Department of Energy Office of Nonproliferation and National Security.

DeSteese, John G.; Hammerstrom, Donald J.; Schienbein, Lawrence A.

2000-10-03

456

Electric power plant emissions and public health  

SciTech Connect

The generation of electric power is one important source of pollutants such as mercury, sulfur dioxide, nitrogen oxides, and fine particulate matter that can affect the respiratory, cardiovascular, and central nervous systems and cause pregnancy complications. But protecting people from environmental health hazards has become increasingly complex. Air pollutants are often invisible and travel many miles virtually undetected. Nurses can play a critical role in preventive strategies, as well as in the national debate on energy production and dependence on fossil fuels.

O'Connor, A.B.; Roy, C. [Faculty of Maine Dartmouth Family Medical Residency, Fairfield, ME (United States)

2008-02-15

457

Electric generating prospects for nuclear power  

Microsoft Academic Search

Most of the nuclear power plants in the U.S. today are of the light-water variety. In many parts of the U.S. these plants are competitive with plants burning coal, but the electricity that they generate will be more costly in the future as uranium supplies deplete. A promising possible answer to the cost problem is the fast-neutron reactor, which produces

Manson Benedict

1970-01-01

458

High-Voltage Power Supply With Fast Rise and Fall Times  

NASA Technical Reports Server (NTRS)

A special-purpose high-voltage power supply can be electronically switched on and off with fast rise and fall times, respectively. The output potential is programmable from 20 to 1,250 V. An output current of 50 A can be sustained at 1,250 V. The power supply was designed specifically for electronically shuttering a microchannel plate in an x-ray detector that must operate with exposure times as short as 1 ms. The basic design of the power supply is also adaptable to other applications in which there are requirements for rapid slewing of high voltages. The power-supply circuitry (see figure) includes a preregulator, which is used to program the output at 1/30 of the desired output potential. After the desired voltage has been set, the outputs of a pulse width modulator (PWM) are enabled and used to amplify the preregulator output potential by 30. The amplification is achieved by use of two voltage doublers with a transformer that has two primary and two secondary windings. A resistor is used to limit the current by controlling the drive voltage of two field-effect transistors (FETs) during turn-on of the PWM. A pulse transformer is used to turn on four FETs to short-circuit four output capacitors when the outputs of the PWM have been disabled. The most notable aspects of the performance of the power supply are a rise time of only 80 s and a fall time of only 60 s at a load current of 50 A or less. Another notable aspect is that the application of a 0-to-5-V square wave to a shutdown pin of the PWM causes the production of a 0-to-1,250-V square wave at the output terminals.

Bearden, Douglas B.; Acker, Richard M.; Kapuslka, Robert E.

2007-01-01

459

Solar thermal electric power information user study  

SciTech Connect

The results of a series of telephone interviews with groups of users of information on solar thermal electric power are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from five solar thermal electric power groups of respondents are analyzed: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Utilities, Electric Power Engineers, and Educators. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

1981-02-01

460

An implementation of particle swarm optimization to evaluate optimal under-voltage load shedding in competitive electricity markets  

NASA Astrophysics Data System (ADS)

Load shedding is a crucial issue in power systems especially under restructured electricity environment. Market-driven load shedding in reregulated power systems associated with security as well as reliability is investigated in this paper. A technoeconomic multi-objective function is introduced to reveal an optimal load shedding scheme considering maximum social welfare. The proposed optimization problem includes maximum GENCOs and loads' profits as well as maximum loadability limit under normal and contingency conditions. Particle swarm optimization (PSO) as a heuristic optimization technique, is utilized to find an optimal load shedding scheme. In a market-driven structure, generators offer their bidding blocks while the dispatchable loads will bid their price-responsive demands. An independent system operator (ISO) derives a market clearing price (MCP) while rescheduling the amount of generating power in both pre-contingency and post-contingency conditions. The proposed methodology is developed on a 3-bus system and then is applied to a modified IEEE 30-bus test system. The obtained results show the effectiveness of the proposed methodology in implementing the optimal load shedding satisfying social welfare by maintaining voltage stability margin (VSM) through technoeconomic analyses.

Hosseini-Bioki, M. M.; Rashidinejad, M.; Abdollahi, A.

2013-11-01

461

Space station electrical power system availability study  

NASA Technical Reports Server (NTRS)

ARINC Research Corporation performed a preliminary reliability, and maintainability (RAM) anlaysis of the NASA space station Electric Power Station (EPS). The analysis was performed using the ARINC Research developed UNIRAM RAM assessment methodology and software program. The analysis was performed in two phases: EPS modeling and EPS RAM assessment. The EPS was modeled in four parts: the insolar power generation system, the eclipse power generation system, the power management and distribution system (both ring and radial power distribution control unit (PDCU) architectures), and the power distribution to the inner keel PDCUs. The EPS RAM assessment was conducted in five steps: the use of UNIRAM to perform baseline EPS model analyses and to determine the orbital replacement unit (ORU) criticalities; the determination of EPS sensitivity to on-orbit spared of ORUs and the provision of an indication of which ORUs may need to be spared on-orbit; the determination of EPS sensitivity to changes in ORU reliability; the determination of the expected annual number of ORU failures; and the integration of the power generator system model results with the distribution system model results to assess the full EPS. Conclusions were drawn and recommendations were made.

Turnquist, Scott R.; Twombly, Mark A.

1988-01-01

462

46 CFR 129.326 - Dual-voltage generators.  

Code of Federal Regulations, 2013 CFR

...326 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage...

2013-10-01

463

46 CFR 129.326 - Dual-voltage generators.  

Code of Federal Regulations, 2011 CFR

...326 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.326 Dual-voltage generators. If a dual-voltage...

2011-10-01