Note: This page contains sample records for the topic voltage electric power from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Multiple voltage electrical power distribution system for automotive applications  

Microsoft Academic Search

Over the course of the 20th Century, the automobile electrical system has experienced one architectural change, one significant electrical power plant change and one notable change in the electrical storage component. There is now growing disparity in voltage level requirements between electronic and electrical loads to the point that a single voltage system may no longer be the most efficient

John M. Miller

1996-01-01

2

Software applications designed to optimize the voltage drops of the low voltage electric power supply installations  

Microsoft Academic Search

The developed software applications are dedicated to optimize the voltage drops of the low voltage electric power installations. Thru optimizing, it is understood the loading capacity estimation of the electrical potential of the transformer posts and the voltage droppings calculation for the formed elements of the electric power supply installations. The obtained values are later compared with the prescribed admitted

Cristina Gabriela Saracin; Marin Saracin

2011-01-01

3

A Particle Swarm Optimization for Reactive Power and Voltage Control in Electric Power Systems  

Microsoft Academic Search

This paper presents a particle swarm optimization (PSO) for reactive power and voltage control (Volt\\/Var Control: VVC) in electric power systems considering voltage security. VVC can be formulated as a mixed-integer nonlinear optimization problem (MINLP). The proposed method expands the original PSO to handle a MINLP and determines an on-line VVC strategy with continuous and discrete control variables such as

Yoshikazu Fukuyama; Shinichi Takayama; Yosuke Nakanishi; Hirotaka Yoshida

1999-01-01

4

A methodology for the assessment of short duration voltage variations in electric power distribution systems  

Microsoft Academic Search

This paper deals with a new methodology for the assessment of power quality indices in electric power distribution systems. Power quality indices concerning short duration voltage variations, i.e. voltage sags and swells, are particularly introduced taking into account the needs for establishing power quality standards. The paper also presents a new proposal for a measurement protocol, a testing procedure to

N. Kagan; E. L. Ferrari; N. M. Matsuo; S. X. Duarte; J. L. Cavaretti; A. Tenorio; L. R. Souza

2002-01-01

5

DC Voltage Control of the DC Micro-Grid for Super High Quality Electric Power Distribution  

Microsoft Academic Search

``DC Micro-grid'' is a novel power system using dc distribution in order to provide super high quality electric power. The power is distributed through dc distribution line and converted to required ac or dc voltages by converters placed near loads. The load side converters do not need transformers by choosing proper distributed dc voltage (±170V). The dc distribution line is

Hiroaki Kakigano; Yushi Miura; Toshifumi Ise; Ryohei Uchida

2007-01-01

6

Human exposure to power frequency electric and magnetic fields inside a very high voltage power station  

Microsoft Academic Search

The paper presents the electric and magnetic fields distribution at steady-state operation in a very recently rehabilitated 400\\/220 kV voltage power station, taking into account the on-site equipments arrangement. The experimental measurement values are compared with the public and professional electromagnetic field exposure limits imposed by the EU 2004\\/40\\/EC Directive and by the local legislation. Colour maps of the electric

Calin Munteanu; l. T. Pop; Ciprian Diaconu; M. Ilia

2007-01-01

7

Fundamental research into high voltages for further development of electric power distribution systems  

Microsoft Academic Search

In order to guarantee correct electric power distribution, the use of voltages between 765 and 1200 kV was investigated. This fundamental research was conducted in an 1800 kV outdoor test station. After describing the connection and protection devices of the three stage high voltage generating transformer, and the tested equipment which has to withstand humidity, rain, dirt accumulation, snow, ice,

E. Gockenbach; W. Buch; M. Crucius; A. Diessner; H. Luehrmann

1982-01-01

8

Common station system for voltage and reactive power regulation at the Mosenergo TETs-27 heating and electric power plant  

SciTech Connect

The system for common station regulation of the voltage and reactive power at the Mosenergo TETs-27 heating and electric power plant is described briefly. Features of the algorithms for this system, which uses programs and instrumentation from the automatic control system for the electrical equipment in the 450 MW power generation unit No. 3, are examined.

Krasnova, M. E. [JSC 'Institute Energoset'proekt' (Russian Federation)

2009-05-15

9

DC Voltage Control of the DC Micro-Grid for Super High Quality Electric Power Distribution  

NASA Astrophysics Data System (ADS)

“DC Micro-grid” is a novel power system using dc distribution in order to provide super high quality electric power. The power is distributed through dc distribution line and converted to required ac or dc voltages by converters placed near loads. The load side converters do not need transformers by choosing proper distributed dc voltage (±170V). The dc distribution line is composed of 3 power lines: +170V line, neutral line and -170V line. The voltages of ±170V have to be balanced to supply high quality power. In this paper, a voltage balancing control method for dc distribution is proposed and studied. Computer simulation results demonstrated that dc micro-grid was able to supply both ac and dc power to loads simultaneously and stably by 3-wire dc distribution and load side converters.

Kakigano, Hiroaki; Miura, Yushi; Ise, Toshifumi; Uchida, Ryohei

10

Investigating the Electric Power Distribution System (EPDS) Bus Voltage in the Presence of Distributed Generation (DG)  

Microsoft Academic Search

This paper investigates the Electric Power Distribution System (EPDS) bus voltage in the presence of Distributed Generation (DG). Distribution Company's (Discos) planner endeavor to develop new planning strategies for their network in order to serve the load growth and provide their customers with a reliable electric supply. In this research work, five different cases including preplanned islanding and grid-connected mode

Hasham Khan; Mohammad Ahmad Choudhry; Tahir Mahmood; Aamir Hanif

2006-01-01

11

A particle swarm optimization for reactive power and voltage control in electric power systems considering voltage security assessment  

Microsoft Academic Search

This paper presents a particle swarm optimization (PSO) for reactive power and voltage control (Volt\\/Var Control: VVC) considering voltage security assessment (VSA). VVC can be formulated as a mixed-integer nonlinear optimization problem (MINLP). The proposed method expands the original PSO to handle a MINLP and determines an on-line VVC strategy with continuous and discrete control variables such as automatic voltage

Hirotaka Yoshida; Yoshikazu Fukuyama; Shinichi Takayama; Yosuke Nakanishi

1999-01-01

12

A framework for the analysis of voltage collapse in electric power systems  

SciTech Connect

The phenomenon of voltage collapse in a power system is manifested as a progressive decline (i.e., sagging) in bus voltages, notably load bus voltages, over a relatively long time frame (i.e., seconds to minutes). At present, the voltage collapse problem is not fully understood; which makes its prevention, assessment and control difficult. Further complicating this problem is the confusion over whether voltage collapse is steady-state or dynamic in nature. The main contribution of this thesis is the formulation of a decision support framework to evaluate the accuracy of Performance Indices (PI's) used to assess voltage instability phenomena, such as voltage collapse, in electric power systems. It is shown that many of the criteria proposed in the literature to assess voltage stability can be rewritten in terms of scalar PI's and corresponding threshold values of the PI's. Based on this framework, criteria to assess voltage stability are reformulated as decision rules; so that, the misclassification errors incurred in using the criteria can be expressed in terms of (i) the probability of missing a voltage unstable event and (ii) the probability of false alarm. It is shown that the key to quantifying these misclassification errors are the definitions and characterizations of a Voltage Stability (VS) Region, which is based on the power system model and signifies the universal set of possible impacts on the system, and an Approximate Voltage Stability (AVS) Region, which is defined by the voltage stability criterion. Moreover, based on this framework, an optimization problem is formulated whose solution provides an accurate criterion to predict static mechanisms of voltage instability which satisfies a given trade-off in the number of misses and false alarms by the operator.

Mercede, F.J.

1989-01-01

13

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

Microsoft Academic Search

This report provides background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist on alternatives in environmental documents. EMF strengths at 0 {+-} 200 ft from centerline were calculated for ac overhead lines, and for 345 and 230-kV ac underground line and

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

1994-01-01

14

A posturing strategy against voltage instabilities in electric power systems  

Microsoft Academic Search

The problem of system collapse or blackout characterized by a local severe voltage depression is generally believed to be associated with inadequate VAR support at key busses. The authors discuss techniques for improving the system security with respect to this index. The effect of adding capacitors are examined. They also present a continuation technique that redistributes the system generation to

A. Tiranuchit; R. J. Thomas

1988-01-01

15

Fundamental Research into High Voltages for Further Development of Electric Power Distribution Systems.  

National Technical Information Service (NTIS)

In order to guarantee correct electric power distribution, the use of voltages between 765 and 1200 kV was investigated. This fundamental research was conducted in an 1800 kV outdoor test station. After describing the connection and protection devices of ...

E. Gockenbach W. Buch M. Crucius A. Diessner H. Luehrmann

1982-01-01

16

A Reduced-Part, Triple-Voltage DC-DC Converter for Electric Vehicle Power Management  

SciTech Connect

Electrical power systems in future hybrid and fuel cell vehicles may consist of three voltage nets; 14 V, 42 V and high voltage (>200 V) buses. A soft-switched, bi-directional dc-dc converter using only four switches was proposed for interconnecting the three nets. This paper presents a reduced- part dc-dc converter, which decreases the converter cost while retaining all the favorable features of the original topology. Simulation and experimental data are included to verify a simple power flow control scheme.

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

2007-01-01

17

Investigations of the Quality of Hospital Electric Power Supply and the Tolerance of Medical Electric Devices to Voltage Dips  

Microsoft Academic Search

Medical devices driven by electric power have come to be commonly used in hospitals, and rapid changes of voltage or current\\u000a can easily cause them to fail. A stable and high quality power supply is indispensable in order to maintain safety in the\\u000a modern clinical setting. Therefore, we investigated the quality of the power supply in a hospital and determined

Eisuke Hanada; Shuuya Itoga; Kyoko Takano; Takato Kudou

2007-01-01

18

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

SciTech Connect

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

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

1994-11-01

19

Technical evaluation of the adequacy of station electric distribution system voltages for the Haddam Neck Nuclear Power Plant  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Haddam Neck Nuclear Power Plant. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analysis shows that the electric distribution system has the capacity and capability to supply adequate voltage to the class 1E equipment, provided that the grid is maintained at or above the administrative minimum limits.

Selan, J.C.

1982-02-01

20

Technical evaluation of the adequacy of station electric distribution system voltages for the Yankee Rowe Nuclear Power Station  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Yankee Rowe Nuclear Power Station. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analysis shows that the station electric distribution system has the capacity and capability to supply voltage to the Class 1E equipment with their design ratings for the worst case loading condition.

Selan, J.C.

1981-05-29

21

Technical evaluation of the adequacy of station electric-distribution-system voltages for the Pilgrim Nuclear Power Station, Unit 1  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Pilgrim Nuclear Power Station, Unit 1. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses demonstrated that for the worst case conditions established, the Class 1E equipment will automatically start and continue to operate within the equiment design voltage rating.

Selan, J.C.

1981-12-28

22

Higher voltage aircraft power systems  

Microsoft Academic Search

Modern aircraft designs are focused on minimising the use of engine bleed air, eliminating gearboxes, and reducing the reliance on hydraulic systems. Instead, many of these mechanical systems will be replaced with electrical versions. The increasing amounts of electrical power that will be shipped through an aircraft means that it is increasingly difficult to rely on low voltage power systems

Ian Cotton; Andrew Nelms

2008-01-01

23

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

2009-04-08

24

A new electrically braked bicycle ergometer with low voltage power supply  

Microsoft Academic Search

The ergometer is braked by an induction clutch fed by a 24 Volt power supply. The current is varied in parallel with the voltage read from a ten-turn potentiometer, the resistance of which is controlled by an electromotor operated via two microswitches mounted close to a lever arm radiating horizontally from the clutch and carrying the calibration load. In this

Flemming Bonde-Petersen

1974-01-01

25

The investigation of an electric arc in the long cylindrical channel of the powerful high-voltage AC plasma torch  

NASA Astrophysics Data System (ADS)

The comparison of conductivity obtained in experiments with calculated values is made in this paper. Powerful stationary plasma torches with prolonged period of continuous work are popular for modern plasmachemical applications. The maximum electrode lifetime with the minimum erosion can be reached while working on rather low currents. Meanwhile it is required to provide voltage arc drop for the high power achievement. Electric field strength in the arc column of the high-voltage plasma torch, using air as a plasma-forming gas, does not exceed 15 V/cm. It is possible to obtain the high voltage drop in the long arc stabilized in the channel by the intensive gas flow under given conditions. Models of high voltage plasma torches with rod electrodes with power up to 50 kW have been developed and investigated. The plasma torch arcs are burning in cylindrical channels. Present investigations are directed at studying the possibility of developing long arc plasma torches with higher power. The advantage of AC power supplies usage is the possibility of the loss minimization due to the reactive power compensation. The theoretical maximum of voltage arc drop for power supplies with inductive current limitations is about 50 % of the no-load voltage for a single-phase circuit and about 30 % for the three-phase circuit. Burning of intensively blown arcs in the long cylindrical channel using the AC power supply with 10 kV no-load voltage is experimentally investigated in the work. Voltage drops close to the maximum possible had been reached in the examined arcs in single-phase and three-phase modes. Operating parameters for single-phase mode were: current -30 A, voltage drop -5 kV, air flow rate 35 g/s; for three-phase mode: current (40-85) A, voltage drop (2.5-3.2) kV, air flow rate (60-100) g/s. Arc length in the installations exceeded 2 m.

Rutberg, Ph G.; Popov, S. D.; Surov, A. V.; Serba, E. O.; Nakonechny, Gh V.; Spodobin, V. A.; Pavlov, A. V.; Surov, A. V.

2012-12-01

26

The reality of generation and distribution of electric power, Part 2: the other face of ultrahigh voltage power transmission  

Microsoft Academic Search

In this sequel, I examine power transmission and consider some of the equipment and instruments. Transmission equipment starts with towers, pylons, conductors, accessories, such as insulators, connectors, and splicers, and I discuss their importance. Special attention is given to the voltage limiting effects of corona discharges. The pros and contras of power transmission with alternating current (ac) and direct current

Alex Hebra

2012-01-01

27

Technical evaluation of the adequacy of station electric-distribution-system voltages for the St. Lucie Nuclear Power Plant, Unit 1  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the St. Lucie Nuclear Power Plant, Unit 1. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The voltage analysis submitted has adequately demonstrated the capacity and capability of the electrical distribution system to supply adequate voltage to the Class 1E equipment under worst case operating conditions.

Selan, J.C.

1981-10-05

28

Technical Evaluation Report on the Adequacy of Station Electric Distribution System Voltages for the Peach Bottom Atomic Power Station. Units 2 and 3.  

National Technical Information Service (NTIS)

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Peach Bottom Atomic Power Station, Units 2 and 3. The evaluation is to determine if the onsite distribution system, in conjunction ...

R. L. White

1982-01-01

29

A sensitivity approach to the sizing of insulated power cables in low and medium voltage electrical power distribution systems  

Microsoft Academic Search

The sizing of insulated power cables for use in electrical power distribution systems is based on definite engineering criteria. Cable or conductor size for a given current loading (ampacity) is the cross-sectional area or size of the current carrying portion of the cable, namely the conductor expressed in AWG (American Wire Gauge) or KCM (Kilocircular mils). The most commonly used

A. K. Hiranandani

1989-01-01

30

Technical-evaluation report on the adequacy of station electric-distribution-system voltages for the Vermont Yankee Nuclear Power Station. Document No. 50-271  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Vermont Yankee Nuclear Power Station. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The evaluation finds that the voltage analyses submitted demonstrate that adequate voltage will be supplied to the Class 1E equipment under worst case conditions.

Selan, J.C.

1982-09-03

31

The influence of nonlinear loads on the power quality of the New Zealand low voltage electrical power distribution network  

Microsoft Academic Search

Reducing electrical consumption by eliminating large inefficient loads and introducing smaller more efficient loads, results in large, conventional, linear loads being replaced by smaller modern nonlinear loads. Their electronic front ends make these nonlinear loads more efficient, but they inject harmonics into the power network, bringing total harmonic distortion in New Zealand to near our limit of 5%. To date

Michael S Witherden; Ramesh Rayudu; Rémy Rigo-Mariani

2010-01-01

32

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

33

An intelligent on line voltage regulation in power distribution system  

Microsoft Academic Search

In a reliable power system one of the most important requirements is to maintain the voltage at consumer premises within permissible ranges to ensure high quality of customer service. Since the voltage profile is consistently varied by load fluctuations hence it should be controlled by voltage regulators. Voltage stability and power quality of electrical systems depend on the proper voltage

Shrabani Pal; Sudipta Nath

2010-01-01

34

Optimal Daubechies' wavelet bases for detection of voltage sags in electric power distribution and transmission systems  

NASA Astrophysics Data System (ADS)

Wavelet analysis of voltage sag completely depends on the choice of the wavelet basis. For better detection performance via wavelet analysis, the choice of the optimal wavelet basis must be provided within the constraints of the uncertainty principle which restricts arbitrary assignment of time-frequency resolution. In this paper, we describe local properties of the wavelet basis and voltage sag signal in terms of time duration and frequency bandwidth parameters. After comparison of the local properties of the wavelet basis and voltage sag signal, we suggest a set of performance indexes to measure the time-frequency resolution relation between the wavelet basis and the voltage sag signal. This procedure of determining the optimal wavelet basis can be extended to other possible applications of wavelets.

Shin, YongJune; Powers, Edward J.; Grady, W. M.; Bhatt, S. C.

1999-10-01

35

A three-level DC-DC converter with wide-input voltage operations for ship-electric-power-distribution systems  

Microsoft Academic Search

This paper describes a newly developed 3-level DC-DC converter with wide-input voltage operations for ship-electric-power-distribution systems. The proposed converter is designed with zero-voltage-switching (ZVS) techniques. The operational principles, designs details and performance of the converter are discussed along with soft-switching characteristics and load transients through experimental waveforms. The converter achieved about 95% efficiency over wide 7kW load conditions.

Byeong-Mun Song; Robert McDowell; Andy Bushnell

2003-01-01

36

A three-level DC-DC converter with wide-input voltage operations for ship-electric-power-distribution systems  

Microsoft Academic Search

This paper describes a newly developed three-level dc-dc converter with wide-input voltage operations for ship-electric-power-distribution systems. The proposed converter is designed with zero-voltage-switching (ZVS) techniques. The operational principles, design details and performances of the converter are discussed along with soft-switching characteristics through experimental results. Furthermore, design criteria on the dc-dc converter are focused on the minimization of the circulation current

Byeong-Mun Song; Robert McDowell; Andrew Bushnell; Joel Ennis

2004-01-01

37

Study and modeling of noise on the low voltage part of the electrical power distribution network between 30 kHz and 1 MHz  

Microsoft Academic Search

In this paper, an extensive set of noise measurements on the low voltage part of the electrical power distribution network is presented. These measurements were taken in a laboratory environment for several months by means of a spectrum analyzer. Automatic remote measurement software was specifically designed and used for this purpose. The frequencies considered range from 30 kHz to 1

Francisco J. Simois; José I. Acha

2001-01-01

38

Defining safe operating voltages for aerospace electrical systems  

Microsoft Academic Search

Increased electrical power demands are being experienced on the new generation of aircraft due to an increased reliance on electrical technology such as air conditioning, de-icing systems and electrical flight control actuation. Sustaining the transmission of hundreds of kilowatts of electrical power at low voltages, typical around 115 V, is not feasible owing to the penalties incurred due to high

I. Cotton; A. Nelms; M. Husband

2007-01-01

39

Line voltage stability calculations in power systems  

Microsoft Academic Search

Voltage instability and voltage collapses are increasingly attracting worldwide interest. Operating power system closer to its stability limits, transferring large amounts of powers from long distance and an inadequate supply of reactive power contribute to system voltage instability and eventually to voltage collapse. Accurate calculations of voltage stability, precise prediction of voltage collapse points and low time consumption of procedures

F. A. Althowibi; M. W. Mustafa

2010-01-01

40

Electrical power generating system  

SciTech Connect

An electrical power generating system includes a prime mover having a throttle control for converting a source of input energy into a mechanical output. The system includes an electrical generator having a plurality of output windings and a field winding for exciting the output windings. The generator is mechanically coupled to the mechanical output of the prime mover. Means are provided for sensing a plurality of parameters related to the performance of the system and further means are provided for converting each of the sensed parameters into a digital signal indicative of the magnitude of the sensed parameter. Additional means are provided responsive to the digital signals for developing a plurality of electrical output signals. The electrical output signals are utilized to control either or both the generator and the prime mover to thereby control the output of the power generating system. The system is further provided with circuits for sensing the phase position of the generator output voltage and current and the voltage in a main electrical power conductor. Accordingly, when the generator output is added to the power in the main power conductors, it is done so in phase. Some of the parameters sensed are generator output voltage , current and frequency, generator field winding current and engine throttle position. A digital logic circuit controls the excitation of the generator field winding to thereby control the generator output voltage and current.

Dimitrios, J.T.; Mezera, J.R.; Phillips, G.R.

1982-03-30

41

Voltages induced by lightning on electric power distribution lines: Field data and analysis results for the period July 1984-1986  

SciTech Connect

Measurements have been made during 1984 and 1985 at the NASA Kennedy Space Center, Florida using a newly-developed spherical antenna of the time-domain horizontal and vertical electric fields from lightning return strokes. Statistics are presented for the fields of 42 return strokes. The peak horizontal field was about 0.03 of the peak critical field; the horizontal field had a mean risetime and a falltime to half value about 0.3 ..mu..s prior to the peak in the vertical field. Voltage has also been measured at one end of an unenergized power distribution line about 500 m in length and 10 m in height. Tables of measured peak voltages are given. By way of a newly-written computer program, the line voltage has been calculated using the measured fields as inputs. Agreement between the voltage measurement and theory is generally good. The lightning horizontal electric field can significantly contribute to the induced line voltage. The horizontal fields become larger as the earth conductivity decreases. 16 figs., 3 tabs.

Thomson, E.M.

1988-03-01

42

Electrical power supply for short term power interruptions  

Microsoft Academic Search

A direct current power supply for instantaneously providing tens of kilowatts of electrical energy for brief periods, such as 100 ms, during momentary power interruptions between a load and an electrical power source having a supply voltage includes a capacitor having an initial voltage charge preferably greater than the supply voltage. The cathode of a Zener diode is operably coupled

Russell E. Hammond; Robert L. Northup; Alan G. Shimp; Francis B. Fassnacht

1991-01-01

43

Phasor measurement application for power system voltage stability monitoring  

Microsoft Academic Search

Monitoring voltage stability is an important task for ensuring secure operation of electrical power networks. In this paper, a phasor measurement based voltage stability monitoring scheme is proposed. By using phasor measurement units and transformer tap position changes, voltage stability indices can be computed at load supply points in the operational time scale. Because this scheme is only based on

Le Fu; Bikash C. Pal; Brian J. Cory

2008-01-01

44

Electric power system with line drop compensation  

SciTech Connect

This patent describes an electric power system having line drop compensation. It comprises a controllable electric power source having an output for supplying voltage to a power bus; a local voltage regulator; a remote voltage regulator for sensing voltage on the power bus; a pulse width to trim bias converter for receiving the pulse width modulated signal and for producing a trim signal having a magnitude representative of the duty cycle of the pulse width modulated signal; and means for combining the control signal with the trim signal to produce a modified control signal for controlling the output voltage of the power source to produce a predetermined voltage at the point of regulation.

Kessler, L.L.

1992-05-26

45

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

46

Regenerative Power Control for Electric Bicycle  

Microsoft Academic Search

This paper presents the design regenerative power control for electric bicycle. PM brushless dc motor use on electric bicycle. In electrical bicycle system occurs due to the regenerative power regulating to prevent a DC-link over-voltage condition. Regenerative power control circuit is absorbing regenerative power in the battery. Details of the motor and the electronic converter are given. The regenerative power

N. Somchaiwong; W. Ponglangka

2006-01-01

47

A High-voltage Safety Protection Method for Electric Vehicle Based on FPGA  

Microsoft Academic Search

Currently, the voltages of power supply on electric vehicle are far higher than the level that people can endure. Aiming at the high voltage safety of electric vehicle, a solution based on FPGA is introduced, which gives a real time detection for creepage of power supply and person's getting an electric shock on electric vehicle, and which cuts off the

Lu Bi; Xuezhe Wei; Zechang Sun

2006-01-01

48

Estimating of loadability margin of a power system by comparing Voltage Stability Indices  

Microsoft Academic Search

Estimating the margin in the loadability of the power system is essential in the real time voltage stability assessment. Voltage stability is currently one of the most important research areas in the field of electrical power system. The condition of voltage stability in a power system can be known using voltage stability indices (VSI). The loading margin is one of

M. V. Suganyadevia; C. K. Babulal

2009-01-01

49

Optimal power flow incorporating voltage collapse constraints  

Microsoft Academic Search

The paper presents applications of optimization techniques to voltage collapse studies. First a “maximum distance to voltage collapse” algorithm that incorporates constraints on the current operating conditions is presented. Second, an optimal power flow formulation that incorporates voltage-stability criteria is proposed. The algorithms are tested on a 30-bus system using a standard power flow model, where the effect of limits

William Rosehart; C. Canizares; Victor Quintana

1999-01-01

50

Technical evaluation of the adequacy of station electric distribution systems voltages for the Calvert Cliffs Nuclear Power Plant, Units 1 and 2. Docket Nos. 50-317, 50-318  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Calvert Cliffs Nuclear Power Plant, Units 1 and 2. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses submitted demonstrate that adequate voltage will be supplied to the Class 1E equipment under worst case conditions.

Selan, J. C.

1982-04-09

51

Induction voltage adder architectures and electrical characteristics  

Microsoft Academic Search

In this paper we use three different designs for induction voltage adders to be used in radiographic X-ray sources to illustrate the differences between possible IVA architectures, and between their electrical characteristics as these affect the radiographic diodes that the IVAs drive. The architectures are chosen considering the spaces in which the FVAs must fit, and the electrical characteristics are

I. Smith; P. Corcoran; V. Carboni; V. Bailey; H. Kishi; D. L. Johnson; J. Maenchenb; I. Molinab; R. Carlson; D. Fulton; K. Hahnc; J. Smith; D. Droemerd; K. Thomas; M. Phillips; S. Croxon; R. Forgan

2003-01-01

52

High voltage direct current modelling in optimal power flows  

Microsoft Academic Search

Two-terminal high voltage direct current (HVDC) transmission links are in operation throughout the world. They are key elements in electrical power networks; their representation is oversimplified or ignored in most power system studies. This is particularly the case in Optima Power Flow (OPF) studies. Hence, an OPF program has been extended to incorporate HVDC links, taking due account of overlapping

H. Ambriz-Pérez; E. Acha; C. R. Fuerte-Esquivel

2008-01-01

53

Electric Power Demand and Emerging Technology in Highly-sophisticated Electric Power Systems  

Microsoft Academic Search

In the last few years, the increase of the electric power demand has been remarkable, especially in Asia district. In such trend, the electric power system of Japan has been supplied with high quality, high reliability and highly-stabilized electric power. This is supported by highly-sophisticated electric power system which prides oneself on high voltage and large capacity. In this paper,

Satoshi Matsumoto; Masayuki Hikita

2004-01-01

54

Voltage stability indices for stressed power systems  

Microsoft Academic Search

The use of static voltage stability indices based on a singular value decomposition of the power flow Jacobian matrix and matrices derived from the Jacobian matrix is discussed. It is shown that such indices, together with the singular vectors, contain substantial and important information about the proximity to voltage instability and also about critical buses and disturbances from a voltage

P. A. Loef; G. Andersson; D. J. Hill

1993-01-01

55

Position detection method using induced voltage for battery charge on autonomous electric power supply system for vehicles  

Microsoft Academic Search

It is desirable that battery driven vehicles are charged in automatically with contactless and high-efficiency. The magnetic coupling that is one of the contactless charges is suitable. However, a precise positioning system of a power supply unit is required in this method. This paper proposes a relative position detection method between the power supply unit and the autonomous vehicle. Especially

Tomohiro Hata; Tutomu Ohmae

2004-01-01

56

CURRENT source with controlled power supply voltage  

NASA Astrophysics Data System (ADS)

This work presents examination of a novel current source circuit. The implementation of a linear combination of two reference voltages and a voltage drop across a load resistor to control a power supply voltage in a typical bipolar current source allows limitation of the correlation between the output stage collector-emitter voltage and the load current, resistance. The first reference voltage, Vref1, controls the load current, while the second reference voltage, Vref2, controls the output stage emitter-collector voltage. Consequently, this voltage is independent of the load current and resistance, which is particularly important for reducing the influence of Early effect. The presented circuit is characterized by a simple design and relatively low cost.

Sikora, Jaroslaw

2013-07-01

57

Soft Computing for Voltage Stability Analysis and Contingency Ranking in Power System  

Microsoft Academic Search

Voltage stability has recently become a challenging problem for many power systems. Voltage instability is one phenomenon that could happen in power system due to its stressed condition. The result would be the occurrence of voltage collapse which leads to total blackout to the whole system Investigation and online monitoring of power system stability have become vital factors to electric

C. Subramani; S. S. Dash; M. Arun Bhaskar; M. Jagadeeshkumar; K. Balaji

2009-01-01

58

TOPEX electrical power system  

NASA Astrophysics Data System (ADS)

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

59

Low power, scalable multichannel high voltage controller  

DOEpatents

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

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

2006-03-14

60

Low power, scalable multichannel high voltage controller  

DOEpatents

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

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

2008-03-25

61

Artificial neural network approach in determining voltage stability in power system networks  

Microsoft Academic Search

Voltage stability problems have been one of the major concerns for electric utilities as a result of system heavy loading. As electric power systems are operated under increasingly stressed conditions, the ability to maintain voltage stability becomes a growing concern. This paper reports on an investigation on the application of artificial neural networks (ANNs) in voltage stability assessment. A multilayer

A. Arunagiri; B. Venkatesh; Stella Morris

2002-01-01

62

Integration of the Premium Power Supply on Electric Power System  

Microsoft Academic Search

This paper describes an inverter-interfaced distributed generation (DG) system that is interconnected with the electric power system (EPS). This system has two main goals such as to serve the customer with reliable electric power and to improve power quality like harmonics and voltage event. This system is interfaced through the series and the shunt inverters because inverters are effective to

Jin-Woo Park; Il-Yop Chung; Kyoung-Nam Kim; Jong-Hun Lee; Seung-Il Moon; Byung-Moon Han

2005-01-01

63

Influence of a wind farm in the dynamic voltage stability of a power network  

Microsoft Academic Search

The electrical power production from dispersed energy sources or distributed generation is playing an increasing role in the supply of electricity in the liberalized electricity markets. Distributed generation can have a significant impact on the power flow, voltage profile, stability and the power quality for both customers and electricity suppliers. In this paper it is studied and analysed the influence

R. M. Monteiro Pereira; C. M. Machado Ferreira; F. P. Maciel Barbosa

2009-01-01

64

Low Voltage Bulk Power System Restoration Simulation  

Microsoft Academic Search

Time is the crucial element in restorative state control for electric power systems. One method for reenergizing large portions of a blacked out electric power system with a minimum of switching and thus time to restoration, is described. Results of a simulated system restart utilizing actual power system facilities are compared to power flow studies. The simulation tests were performed

Edward Simburger; Francis Hubert

1981-01-01

65

Interphase power controller with voltage injection  

SciTech Connect

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

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

1994-10-01

66

Magnetic power inverter: AC voltage generation from DC magnetic fields  

NASA Astrophysics Data System (ADS)

We propose a method that allows power conversion from DC magnetic fields to AC electric voltages using domain wall (DW) motion in ferromagnetic nanowires. The device concept relies on spinmotive force, voltage generation due to magnetization dynamics. Sinusoidal modulation of the nanowire width introduces a periodic potential for a DW, the gradient of which exerts variable pressure on the traveling DW. This results in time variation of the DW precession frequency and the associated voltage. Using a one-dimensional model, we show that the frequency and amplitude of the AC outputs can be tuned by the DC magnetic fields and wire-design.

Ieda, Jun'ichi; Maekawa, Sadamichi

2012-12-01

67

Voltage Stability Assessment of Multi-Machine Power Systems Using Energy Function and Neural Networks Techniques  

Microsoft Academic Search

Voltage stability problems have been one of the major concerns for electric utilities as a result of heavy loading of power system. Steady state voltage stability analysis is effectively used to determine a stability margin that shows how close the current operating point of a power system to the voltage collapse point. This article presents a generalized energy function for

A. Y. Abdelaziz; M. M. Abu-Elnaga; M. A. Elsharkawy; K. M. Elbahrawy

2006-01-01

68

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

69

Voltage Drop Calculations for Electrically Short Insulated Conductors  

Microsoft Academic Search

The equivalent circuit of an insulated conductor is described and a definition given for circuits that are electrically short in length. Two ``short-line'' methods for calculating voltage drop and regulation for alternating current power systems are outlined, and example calculations are included. Accuracy of the short-line treatment is compared with a long-line analysis. Data are provided to facilitate the calculations,

Thomas A. Kommers

1981-01-01

70

Characteristic of voltage dips (sags) in power systems  

Microsoft Academic Search

This paper analyzes the characteristic of voltage dips in power systems with special emphasis on unbalanced dips and electrical components analysis. A generalized dip model is built for all unbalanced dips, taking into account the fault types, transformer types and load connections. It shows the transformation for different types of unbalanced dips. The characterization results in a so-called remaining complex

Lidong Zhang; M. H. J. Bollen

2000-01-01

71

Calculation of geomagnetically induced currents (GIC) in a high-voltage electric power transmission system and estimation of effects of overhead shield wires on GIC modelling  

Microsoft Academic Search

Geomagnetically induced currents (GIC) flowing in ground-based technological networks, such as electric power transmission grids, are the ground end of the space weather chain originating from the Sun. GIC constitute a possible source of problems to the system. Matrix formulas enabling the calculation of GIC in a power grid have been presented before. In this paper, we summarise the formulas

Risto Pirjola

2007-01-01

72

Functional electrical stimulation by nanogenerator with 58 V output voltage.  

PubMed

We demonstrate a new type of integrated nanogenerator based on arrays of vertically aligned piezoelectric ZnO nanowires. The peak open-circuit voltage and short-circuit current reach a record high level of 58 V and 134 ?A, respectively, with a maximum power density of 0.78 W/cm(3). The electric output was directly applied to a sciatic nerve of a frog, inducing innervation of the nerve. Vibrant contraction of the frog's gastrocnemius muscle is observed as a result of the instantaneous electric input from the nanogenerator. PMID:22594588

Zhu, Guang; Wang, Aurelia C; Liu, Ying; Zhou, Yusheng; Wang, Zhong Lin

2012-05-18

73

Analyzing power MOSFET breakdown voltage using simulators  

Microsoft Academic Search

A comprehensive analysis of the performance of the power MOSFET using process and device simulators is described. The power MOSFET process is simulated using TSUPREM and the simulated profile is used as an input to MEDICI to simulate the device performance. The dependence of the breakdown voltage on the device parameters, epi-layer thickness and doping concentration, and the parameter variations

Malgorzata Chrzanowska-Jeske

1996-01-01

74

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

75

Magnetic fields dispersed by high-voltage power lines: an advanced evaluation method based on 3-D models of electrical lines and the territory.  

PubMed

An advanced numerical evaluation tool is proposed for calculating the magnetic flux density dispersed by high-voltage power lines. When compared to existing software packages based on the application of standardized methods, this tool turned out to be particularly suitable for making accurate evaluations on vast portions of the territory, especially when the contribution of numerous aerial and/or underground lines must be taken into account. The aspects of the tool of greatest interest are (1) the interaction with an electronic archive of power lines, from which all the information necessary for the calculation is obtained; (2) the use of three-dimensional models of both the power lines and the territory crossed by these; (3) the direct interfacing with electronic cartography; and finally (4) the use of a representation procedure for the results that is based on contour maps. The tool had proven to be very useful especially for Environmental Impact Assessment procedures relative to new power lines. PMID:15550699

Andreuccetti, D; Zoppetti, N

2004-01-01

76

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

77

OPTIMIZED PLACEMENT OF VOLTAGE MEASUREMENT DEVICES FOR DETERMINING LOCATION OF SINGLE LINE-TO-GROUND FAULTS ON OVERHEAD ELECTRIC POWER DISTRIBUTION FEEDERS  

Microsoft Academic Search

Solving the fault location problem on electric power distribution networks requires careful selection of the placement strategy for the data acquisition and signal processing instrumentation on the feeder, as well as the computational algorithms that use these data to pinpoint the actual location or an area that contains the location of the fault. This work presents a mathematical model for

RODRIGO A. F. PEREIRA; LUIS G. W. DA SILVA; MLADEN KEZUNOVIC; JOSÉ R. S. MANTOVANI

78

High Power Medium Voltage Electronic Load.  

National Technical Information Service (NTIS)

A Pulse Width Modulation (PWM) type, high power (2Kw) medium voltage (200V) electronic load suitable for operation as a stand alone instrument or as an integral part of a more complex test configuration is described. In stand alone operation, the load pow...

M. Martin H. J. N. Spruijt

1989-01-01

79

Development of voltage stability constrained optimal power flow (VSCOPF)  

Microsoft Academic Search

This paper presents an application of optimization techniques incorporating voltage stability constraints. L-index that indicates voltage collapse proximity is adapted into the OPF formulation. This paper shows the impact of incorporation of voltage security constraint into optimal power flow formulation in which the active power dispatch problem is associated with guaranteeing adequate voltage security levels in power systems. It provides

S. Kim; T.-Y. Song; M.-H. Jeong; B. Lee; Y.-H. Moon; J.-Y. Namkung; G. Jang

2001-01-01

80

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

81

Electric steering power electronics  

Microsoft Academic Search

Vehicular power steering systems incorporating electric motors to either drive the hydraulic pump or the steering gear must offer long term reliability and yet be cost competitive. The electronics used to manage the steering system's electric motor includes large power transistor devices and single chip MCUs (microcontrollers). These active electronic devices and the motor type affect the performance of the

R. J. Valentine

1996-01-01

82

High voltage high frequency power transformer for pulsed power application  

Microsoft Academic Search

This paper presents a new topology for a high voltage 50kV, high frequency (HF) 20kHz, multi-cored transformer. The transformer is suitable for use in pulsed power application systems. The main requirements are: high voltage capability, small size and weight. The HV, HF transformer is the main critical block of a high frequency power converter system. The transformer must have high

Todor Filchev; Fabio Carastro; Pat Wheeler; Jon Clare

2010-01-01

83

Bi-directional power control system for voltage converter  

DOEpatents

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.

Garrigan, N.R.; King, R.D.; Schwartz, J.E.

1999-05-11

84

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

85

Electromagnetic Effects of High-Voltage High Power Equipment  

Microsoft Academic Search

The induced magnetic flux density B from a high-voltage high-power electrical equipment such as an aircore reactor is calculated as a function of distance from, axial length, diameter, height above the ground and number of ampere-turns of the equipment. Rigorous and approximate formulas have been developed for calculating B. Guidelines for using the approximate formulas with regard to their applicability

M. M. A. Salama; R. Hackam

1984-01-01

86

Modular high voltage power supply for chemical analysis  

DOEpatents

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

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

2010-05-04

87

Modular high voltage power supply for chemical analysis  

DOEpatents

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

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

2007-01-09

88

Modular high voltage power supply for chemical analysis  

DOEpatents

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

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

2008-07-15

89

Canadian National Power Quality Survey: frequency of industrial and commercial voltage sags  

Microsoft Academic Search

In 1991, the Canadian Electrical Association (CEA) took a proactive approach to power quality problems and initiated a three-year “Canadian National Power Quality Survey” involving 22 utilities. This paper presents the survey results of the frequency of voltage sags at industrial and commercial sites, monitored at their utilization voltage levels (e.g., 120 V, 347 V) and on the utility primary

Don O. Koval; M. Brent Hughes

1997-01-01

90

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

91

Voltage and power flow control of grid connected wind generation system using DSTATCOM  

Microsoft Academic Search

Recently the usage of distribution generation has significantly increased in the electric power distribution system. Wind generation system has potential application for the grid support. The voltage of the direct driven permanent magnet wind generators (PMSG) is variable due to the intermittent nature of the wind energy. Fluctuating voltage and power is of major concern in the converter based grid

R. S. Bajpai; R. Gupta

2008-01-01

92

Effects of power frequency voltages on amputated human limb  

PubMed Central

Carter, A. O., and Morley, R. (1969).Brit. J. industr. Med.,26, 224-230. Effects of power frequency voltages on amputated human limb. Electric voltages of between 40 and 500 V at 50 Hz and 120 and 240 V direct were applied to freshly amputated mid-thigh legs connected to a heart-lung machine. Current and voltage were recorded against time. The direct currents showed a rise of current with time and caused little skin damage. The make and break of the current caused contractions of the muscles. The alternating currents produced by voltages between 30 and 80 V showed a steady rise with progressive skin damage. With alternating voltages of 250 and 500 V the current showed a rapid rise, with an equally rapid fall after a period of time. The current wave-form was nonsinusoidal and, after the fall, showed unidirectional impulses. Muscular contraction was tonic but later became clonic due to the impulses of current. This progression has been described in held-on electric shock accidents. Images

Carter, A. O.; Morley, R.

1969-01-01

93

Aggregation of voltage and frequency dependent electrical loads  

NASA Astrophysics Data System (ADS)

Electrical loads play a very important role in the behaviour of an electric power system. Since there is a tremendous number of different loads in the system, representing each load with its own model becomes impractical for system level studies. This thesis deals with the issue of aggregating loads to simplify system level studies. Six new and accurate aggregate static load models, a novel EMTP based load model, and four very accurate aggregate induction machine models have been developed. The proposed aggregate load models are voltage and frequency dependent and accommodate the different data formats of individual loads. By including the information of voltage and frequency dependence, the models can be used in larger ranges of studies than the conventional aggregate static load models, thus resulting in more accurate representations. The valid voltage range of the models is about 75% to 125% of rated voltage and, the valid range of frequency of the models is about 85% to 115% of rated frequency. The proposed EMTP load model represents a load with basic circuit elements. The model consists of two varied turns ratio transformers and two varied admittance RLC circuits. It represents the voltage dependence and the frequency dependence of a load separately, resulting in a much simpler load representation than a conventional load model. The model not only improves the accuracy of load representations, bus also broadens the EMTP application in studies other than the transient analyses, such as power flow studies. The proposed aggregate induction machine models have been developed based on the specifications and circuit parameters of individual machines. Since the specification of the machines are the most basic information of the devices, they provide a natural and accurate representation of the machines. The circuit parameters of the machines reflect the behaviour of the devices, they can be used to compose the machines under high and low frequencies, resulting in a simple and accurate machine representation. These two different aggregate models accommodate the data availability of individual machines. To verify the validity of the proposed load models, field tests from published literature are compared with computer simulations. The simulation results of some test systems obtained (i) by the proposed load models, (ii) by the conventional load models, and (iii) by solving the original systems without aggregating their circuit components are also compared. The results of these comparisons prove that the proposed load models can represent loads in power systems more accurately than the existing load models. The proposed load models have been developed into computer software packages with the high level computer programming language Ada 95.

Louie, Kwok-Wai

94

Index-based reactive power compensation scheme for voltage regulation  

NASA Astrophysics Data System (ADS)

Increasing demand for electrical power arising from deregulation and the restrictions posed to the construction of new transmission lines by environment, socioeconomic, and political issues had led to higher grid loading. Consequently, voltage instability has become a major concern, and reactive power support is vital to enhance transmission grid performance. Improved reactive power support to distressed grid is possible through the application of relatively unfamiliar emerging technologies of "Flexible AC Transmission Systems (FACTS)" devices and "Distributed Energy Resources (DERS)." In addition to these infrastructure issues, a lack of situational awareness by system operators can cause major power outages as evidenced by the August 14, 2003 widespread North American blackout. This and many other recent major outages have highlighted the inadequacies of existing power system indexes. In this work, a novel "Index-based reactive compensation scheme" appropriate for both on-line and off-line computation of grid status has been developed. A new voltage stability index (Ls-index) suitable for long transmission lines was developed, simulated, and compared to the existing two-machine modeled L-index. This showed the effect of long distance power wheeling amongst regional transmission organizations. The dissertation further provided models for index modulated voltage source converters (VSC) and index-based load flow analysis of both FACTS and microgrid interconnected power systems using the Newton-Raphson's load flow model incorporated with multi-FACTS devices. The developed package has been made user-friendly through the embodiment of interactive graphical user interface and implemented on the IEEE 14, 30, and 300 bus systems. The results showed reactive compensation has system wide-effect, provided readily accessible system status indicators, ensured seamless DERs interconnection through new islanding modes and enhanced VSC utilization. These outcomes may contribute to optimal utilization of compensation devices and available transfer capability as well as reduce system outages through better regulation of power operating voltages.

Dike, Damian Obioma

95

High voltage VLF testing of power cables  

SciTech Connect

This publication describes a laboratory test program conducted with the objective to develop a test that would replace the existing dc withstand test. The article describes the methodology used to establish the voltage duration and magnitude of VLF (0.1 Hz) high voltage field tests suitable for crosslinked polyethylene (XLPE) insulated power cable. The results show that the voltage breakdown of laboratory aged XLPE cable at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz cause very little damage to the cable, and that 0.1 Hz testing appears to be a satisfactory alternate to dc testing. Preliminary values are suggested for voltage magnitude and time duration of cable acceptance, maintenance and proof tests at 0.1 Hz for XLPE cable rated up to 35 kV. A program is underway to similarly evaluate samples of service-aged XLPE cable; as well as to demonstrate the use of the preliminary test values at typical utility installations.

Eager, G.S.; Katz, C.; Fryszczyn, B. [Cable Technology Labs., Inc., New Brunswick, NJ (United States); Densley, J. [Ontario Hydro, Toronto, Ontario (Canada); Bernstein, B.S. [EPRI, Washington, DC (United States)

1997-04-01

96

Role of high power semiconductor devices in hybrid electric vehicles  

Microsoft Academic Search

A couple of decade ago when auto engineers decided to increase the voltage level of electrical power system drive, it was the advancement of silicon technology supporting their dream. Today the power electronics circuits play an important role in the success of electric, hybrid and fuel cell vehicles. Typical power electronics circuits in hybrid vehicles include electric motor drive circuits

Madhwi Kumari; P. R. Thakura; D. N. Badodkar

2011-01-01

97

NSTX electrical power systems  

Microsoft Academic Search

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics 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

S. Ramakrishnan; C. Neumeyer; R. Hatcher; E. Baker; H. Schneider; W. Reiersen; A. von Halle

1999-01-01

98

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

SciTech Connect

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

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

1994-01-01

99

NewSART automatic voltage and reactive power regulator for secondary voltage regulation: Design and application  

Microsoft Academic Search

Secondary Voltage Regulation (SVR) is part of the hierarchical control system of EHV transmission network, currently operated by the Italian Independent System Operator. SVR is being actuated using automatic voltage and reactive power regulators, named SART, in power stations rated more than 100 MVA. Each SART receives from the Regional Voltage Regulator a reactive level signal and implements it by

G. Sulligoi; M. Chiandone; V. Arcidiacono

2011-01-01

100

Power quality investigations of VSCF aircraft electric power systems  

Microsoft Academic Search

A model of the advanced aircraft electric power system is developed and studied under variable-speed constant-frequency (VSCF) operation. The frequency of the generator's output voltage is varied from 400-Hz to 800-Hz for different loading case-studies. Non-linear DC loads in addition to the different passive and dynamic AC loads are included in the simulation of the VSCF aircraft electric power system.

A. Eid; H. El-Kishky; M. Abdel-Salam; T. El-Mohandes

2010-01-01

101

Battery powered electric motor vehicle  

SciTech Connect

The battery energized electric motor vehicle has a main driving motor connected to the battery via a footpedal operated control circuit; an auxiliary electric motor for a steering device is connected to the battery in series with the main driving motor and across the control circuit of the latter so that a difference voltage between the battery voltage and the instant driving voltage applied to the main driving motor controls the steering device.

Olbrich, G.; Pfeffer, P.

1982-09-21

102

Electric power monthly  

SciTech Connect

The Energy Information Administration (EIA) prepares the Electric Power Monthly (EPM) for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. This publication provides monthly statistics 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. The EIA publishes statistics in the EPM on net generation by energy source, consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant. 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.

NONE

1995-08-01

103

Voltage \\/ Reactive Power Control Optimization with Economy and Security using Tabu Search  

Microsoft Academic Search

Following the deregulation of electric power market, the several power transactions and the distributed generation are on the rise increase year by year in Japan. If this trend continues, there is a likelihood that the power flow will be more complex coupled with a greater degree of uncertainty. Therefore it may be difficult for voltage\\/reactive power control (VQC) to maintain

Yoshiki Nakachi; Atsushi Kato; Hiroyuki Ukai

2007-01-01

104

THE SURFACE ELECTRIC FIELD OF CATENARY HIGH VOLTAGE OVERHEAD TRANSMISSION LINES  

Microsoft Academic Search

Most of the interference created by high voltage lines arises from the corona effect due to high electric fields (also called surface gradients) on the surface of the conductors of the line. Com- mon methods for the calculation of electric fields created by power transmission lines assume straight horizontal lines parallel to a flat ground. The influence of the sag

J. C. FERNANDEZ; H. L. SOIBELZON

105

Voltage stability based weak area clustering technique in power system  

Microsoft Academic Search

This paper presents the voltage stability based weak area clustering technique in power system. The technique employed voltage stability and line outage contingency analyses. From the voltage stability analysis, the sensitive lines in a system during stressed condition are identified, while line outage contingency analysis identified the critical line outages. A pre-developed voltage stability index was utilised as an indicator

Ismail Musirin; Titik Khawa Abdul Rahman

2004-01-01

106

Voltage stability and controllability indices for multimachine power systems  

Microsoft Academic Search

This paper presents a voltage stability index (VSI) and a voltage controllability index (VCI), related to the eigenvalues of m x m matrices in a multimachine power system made up of m synchronous generators and a number of infinite buses. System loads can have an arbitrary voltage sensitivity described by generalized voltage exponents. These nonlinear loads are linearized around an

C. D. Vournas

1995-01-01

107

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

108

Statistical analysis of the dynamic voltage electrical breakdown in nitrogen  

Microsoft Academic Search

The statistical analysis of the electrical breakdown in nitrogen at p=20 mbar using dynamic method is presented in this paper. The analysis was performed for the working voltage increase rates 50, 150, and 300 Vs-1. For each working, voltage increase rate a 1000 measurements were done. It was shown that results are lined up accidentally without any systematic trend. New

M. K. Radovic; Cedomir A. Maluckov

2001-01-01

109

Electric power monthly  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels of net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-06-01

110

Electric power monthly  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in this EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-07-01

111

Electrically powered motor vehicle  

SciTech Connect

An electrically powered vehicle achieves maximum structural strength with minimum weight by utilizing a combined body and chassis formed entirely of plastic material, molded and bonded into an integral composite structure which includes a central, hollow longitudinal beam, top, bottom, and side panels of the vehicle body portion, and a power unit supporting chamber at the forward end closing the forward end of the beam and tying it to the side panels. The beam holds the batteries, and the chamber contains all of the components of the power unit including the controlling device. The structure is thus as rigid and light as possible, in addition to eliminating any possibility of any unwanted grounding or electrical paths. The only metal in the vehicle is that of the additional components such as road wheels, suspension members, steering, and power unit and the fasteners and brackets used to retain them in mounted position.

Eve, W. R.; Gould, J. S.; Mccutchen, J. V.; Pelcher, A. M.; Watson, R. E.; Winquist, R. D.

1980-08-12

112

Analysis of voltage stability enhancement via unified power flow controller  

Microsoft Academic Search

This paper discusses the control of the unified power flow controller (UPFC) to improve power system voltage stability. A dynamical UPFC model is presented. The impact of the UPC model on voltage stability is clarified through bifurcation analysis. Robust techniques are employed for the series and shunt branches control and the DC capacitor voltage control. Only local measurements are required

H. Chen; Y. Wang; R. Zhou

2000-01-01

113

Voltage stability calculations in power transmission lines: Indications and allocations  

Microsoft Academic Search

In recent years, voltage stability problems have been increasing since power systems operate close to stability limits and large amounts of power are being transferred from long distance. Accurate determination of voltage collapse points with rapid line voltage stability analysis, indications and allocations, allows operators to take necessary action to prevent such collapse incidents. Although several methods have been used

F. A. Althowibi; M. W. Mustafa

2010-01-01

114

A desensitized controller for voltage regulation of power systems  

Microsoft Academic Search

In this paper, a robust linear voltage controller is proposed to improve power system stability and performance under varying operating conditions. This controller includes an automatic voltage regulator and power system stabilizer. It limits the variations of the terminal voltage, damps electromechanical oscillations and increases the excitation during and after a short circuit in all operating points. The design method

A. Heiiiche; H. Bourles; M. P. Houry

1995-01-01

115

Orbital solar electric power stations  

NASA Astrophysics Data System (ADS)

Various aspects of the development of space based solar electric power stations are discussed. Topics discussed include solar energy for the national economy, solar energy in space, a typical space-based solar electric power station, reasons for the low economic efficiency of space based solar electric power stations, the impact of solar electric power stations on the environment, the structural design of a small-scale space based solar electric power station, and the militarization of space.

Narimanov, Ye. A.; Virko, I. G.

1992-01-01

116

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

117

Power acceptability and voltage sag indices in the three phase sense  

Microsoft Academic Search

The electric power acceptability curves are an empirical set of curves that represent the intensity and duration of bus voltage disturbances. These curves are discussed with regard to the energy delivered to the load, and alternatives for the assessment and measurement of bus voltage sags. Special attention is given to the three phase case

R. S. Thallam; G. T. Heydt

2000-01-01

118

Induced voltages on fence wires and pipe lines by AC power transmission lines  

Microsoft Academic Search

A method is developed for calculating the induced voltages on fence wires and pipelines underneath AC power transmission lines. The method is based on the charge simulation techniques and takes into account disturbances of the electric field and potential due to the presence of the fence wire or pipeline underneath the line. The calculated and previously measured induced voltages on

M. M. Abdel-Salam; A. M. Al-Shehri

1992-01-01

119

Induced voltages on fence wires and pipelines by AC power transmission lines  

Microsoft Academic Search

A method is developed for calculating the induced voltages on fence wires\\/pipelines underneath AC power transmission lines. The method is based on the charge simulation technique and takes into account the disturbances of the electric field and potential due to the presence of the fence wire\\/pipeline underneath the line. The calculated values of the induced voltage on fence wires are

M. Abdel-Salam; A. Al-Shehri

2009-01-01

120

Reactive power dispatching for power system voltage security  

SciTech Connect

An optimization-based method is presented for determining the scheduling of reactive equipment (capacitors for example) on an hourly basis for maximum steady-state power system security during normal and post-contingency conditions. The method simultaneously deals with the effects of a number of contingencies, and includes all bus voltages as constraints. The intended application is to schedule existing capacitors during periods of light load to prevent abnormally high voltages from occurring during normal and post-contingency conditions. Results from tests using a Pennsylvania-New Jersey-Maryland Interconnection (PJM) model are presented.

Palmer, R.E.; Burchett, R.C.; Happ, H.H.; Vierath, D.R.

1983-12-01

121

Novel fast voltage stability index (FVSI) for voltage stability analysis in power transmission system  

Microsoft Academic Search

Since a couple of decades ago, voltage stability assessment has received increasing attention due to the complexity of power systems. With the increase in power demand and limited power sources has caused the system to operate at its maximum capacity. Therefore, a study that is able to determine the maximum capacity limit before voltage collapse must be carried out so

Ismail Musirin; Titik Khawa Abdul Rahman

2002-01-01

122

Controlling electric power demand  

SciTech Connect

Traditionally, demand control has not been viewed as an energy conservation measure, its intent being to reduce the demand peak to lower the electric bill demand charge by deferring the use of a block of power to another demand interval. Any energy savings were essentially incidental and unintentional, resulting from curtailment of loads that could not be assumed at another time. This article considers a microprocessor-based multiplexed system linked to a minicomputer to control electric power demand in a winery. In addition to delivering an annual return on investment of 55 percent in electric bill savings, the system provides a bonus in the form of alarm and monitoring capability for critical processes.

Eikenberry, J.

1984-11-15

123

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

124

Aircraft Electric Power-Supply System  

Microsoft Academic Search

An ever increasing demand for electric power in aircraft has been felt for some time. The necessity of using an electric storage battery started the practice of accompanying it with a d-c generator, first of low current and voltage capacity, later of 50-ampere 12-volt rating, and for the past few years of 200-ampere 24-volt output. In the largest four-engine aircraft,

J. E. Yarmack

1943-01-01

125

High voltage generator circuit with low power and high efficiency applied in EEPROM  

NASA Astrophysics Data System (ADS)

This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (Vth) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 ?m EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 ?W and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation.

Yan, Liu; Shilin, Zhang; Yiqiang, Zhao

2012-06-01

126

Impacts of electric vehicle loads on power distribution systems  

Microsoft Academic Search

Electric vehicles (EVs) are the most promising alternative to replace a significant amount of gasoline vehicles to provide cleaner, CO2 free and climate friendly transportation. On integrating more electric vehicles, the electric utilities must analyse the related impacts on the electricity system operation. This paper investigates the effects on the key power distribution system parameters like voltages, line drops, system

Jayakrishnan R. Pillai; Birgitte Bak-Jensen

2010-01-01

127

US electric power system reliability  

NASA Astrophysics Data System (ADS)

Electric energy supply, transmission and distribution systems are investigated in order to determine priorities for legislation. The status and the outlook for electric power reliability are discussed.

128

Innovative concepts for power station design in all electric ships  

Microsoft Academic Search

The paper points out innovative design issues of the shipboard power stations for all electric ships (AESs). Alternators and voltage control system operations are reviewed under an approach which emphasizes the impact of design choices on power generation and availability. The work moves from an in-deep analysis of modern cruise ship integrated electric power systems (IEPSs), in order to assess

A. Da Rin; S. Quaia; G. Sulligoi

2008-01-01

129

Modeling of the automotive 14 V power net for voltage stability analysis  

Microsoft Academic Search

The number of electrical components in cars has steadily increased in recent years. Furthermore, systems with high peak loads like engine-start-stop systems and x-by-wire systems will be employed in the near future. These peak loads lead to voltage fluctuations within the power net. To guarantee the proper functioning of all electrical components, a stable voltage supply is necessary. This paper

Rainer Gehring; J. Froschl; T. P. Kohler; H.-G. Herzog

2009-01-01

130

Global transient stability and voltage regulation for multimachine power systems  

Microsoft Academic Search

This paper addresses simultaneously the major fundamental and difficult issues of nonlinearity, uncertainty, dimensionality and globality to derive performance enhancing power system stability control. The main focus is on simultaneous enhancement of transient stability and voltage regulation of power systems. This problem arises from the practical concern that both frequency and voltage control are important indices of power system control

Mark Gordon; David J. Hill

2008-01-01

131

HIGH VOLTAGE POWER SUPPLIES FOR ION BEAMS ELECTRON COOLERS  

Microsoft Academic Search

High voltage power supplies, developed for feeding the electron coolers EC-35 and EC-300, are described in this report. Stabilized voltage power supplies with output voltages 35 kV and 300 kV with the current up to 5mA and stability up to 10 -5 are used for electron cooling of heavy ion beam. Under high potential of these power supplies there are

V. M. Veremeenko; R. V. Voskoboynikov; A. D. Goncharov; A. Evtushenko; V. V. Kolmogorov; M. N. Kondaurov; G. S. Kraynov; A. M. Kryuchkov; A. S. Medvedko; V. V. Parkhomchuk; S. P. Petrov; V. B. Reva; M. A. Tiunov; B. R. Karymov

132

Voltage Regulator for Battery Power Source.  

National Technical Information Service (NTIS)

A bipolar transistor in series with the battery as the control element also in series with a zener diode and a resistor is used to maintain a predetermined voltage until the battery voltage decays to very nearly the predetermined voltage. A field effect t...

J. M. Black

1979-01-01

133

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

Microsoft Academic Search

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

B. Szabodos; Uwe Schaible

1998-01-01

134

Power Transmission Path Analysis of Voltage Stability in Shandong Power System  

Microsoft Academic Search

Voltage stability of Shandong power system is analyzed by power transmission path analysis. Weak buses are decided by local voltage stability index. Voltage stability indices of both active power transmission paths from the west to the east and local reactive power transmission paths are computed with load increasing. The reactive power reserve indicator is also calculated and key factors that

Liang Wang; Yutian Liu

2006-01-01

135

Voltage versus VAr\\/power-factor regulation on synchronous generators  

Microsoft Academic Search

When paralleled to the utility bus, synchronous generators can be controlled using either terminal voltage or VAr\\/power factor (PF) control. Selection is dependent upon the size of the generator and the stiffness of the connecting utility bus. For large generators where the kVA is significant, these machines are usually terminal voltage regulated and dictate the system's bus voltage. When smaller

Thomas W. Eberly; Richard C. Schaefer

2002-01-01

136

Voltage stability considerations in composite power system reliability evaluation  

Microsoft Academic Search

This paper presents an approach which includes voltage stability considerations in the adequacy assessment of a composite power system. A fast technique for the probabilistic assessment of voltage stability is presented which can be used in conjunction with detailed contingency evaluation in a composite system adequacy assessment. Voltage stability is quantified using an indicator that can be easily included in

Roy Billinton; Saleh Aboreshaid

1998-01-01

137

Probabilistic load flow solution considering reactive power and voltage control  

Microsoft Academic Search

Voltage and Var control (VVC) schemes (i.e., centralized and decentralized controls) are discussed. Probabilistic load flow (PLF) method is applied on a real distribution system; the results from Monte Carlo simulations of both control schemes are compared. Models of WC element (on load tap changer, shunt capacitor and automatic voltage regulator of generator) are discussed. Voltage and reactive power in

N. Nimpitiwan; N. Chaiyabut

2007-01-01

138

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

139

Solar Thermal Electric Power Systems.  

National Technical Information Service (NTIS)

The objective of this research program is to develop design parameters for solar thermal electric power systems that can provide lowest cost electric power. Parametric performance and cost models are being developed for subsystems such as the concentrator...

1974-01-01

140

Power-supply voltage impact on circuit performance for half and lower submicrometer CMOS LSI  

Microsoft Academic Search

Based on theoretical understanding, the concept that the lower power supply voltage limit can be simply expressed by 1.1EcLeff, where Ec is the critical electric field necessary to cause carrier velocity saturation and Leff is the effective channel length, is introduced. Experimental results confirmed that 1.1EcLeff predicts a good guideline for power-supply voltage for CMOS devices over a wide range

MASAKAZU KAKUMU; M. Kinugawa

1990-01-01

141

Measuring Helical FCG Voltage with an Electric Field Antenna  

SciTech Connect

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

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

2011-08-01

142

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

143

Level-shifter free design of low power dual supply voltage CMOS circuits using dual threshold voltages  

Microsoft Academic Search

Usage of dual supply voltages in a digital circuit is an effective way of reducing power consumption due to the quadratic relation of supply voltage to power consumption. But the need for level shifters when a low voltage gate drives a high voltage gate has been a limiting factor preventing widespread usage of dual supply voltages in digital circuit design.

Abdulkadir U. Diril; Yuvraj S. Dhillon; Abhijit Chatterjee; Adit D. Singh

2005-01-01

144

Level-Shifter Free Design of Low Power Dual Supply Voltage CMOS Circuits Using Dual Threshold Voltages  

Microsoft Academic Search

Usage of dual supply voltages in a digital circuit is an effective way of reducing power consumption due to the quadratic relation of supply voltage to power consumption. But the need for level shifters when a low voltage gate drives a high voltage gate has been a limiting factor preventing widespread usage of dual supply voltages in digital circuit design.

Abdulkadir Utku Diril; Yuvraj Singh Dhillon; Abhijit Chatterjee; Adit D. Singh

2005-01-01

145

A High Voltage System with 60 High Voltage Power Supply Channels in 2U Height EURO Crate  

Microsoft Academic Search

A high voltage system contains 60 channels of high voltage power supplies in the Euro crate which is 2U in height, 19 inches in width and 50 cm in depth. The high voltage system is composed of 20 high voltage (HV) boards and one control board. Three channels of the high voltage power supplies are installed on the HV board.

Masatosi Imori; Nagataka Matsui; Masaya Ishino; Toshiyuki Kimura; Tomoharu Mieno; Satoru Imada; Masafumi Katsuno

146

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.

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

147

High Voltage Direct Current (HVDC) technology: An alternative means of power transmission  

Microsoft Academic Search

Energy consumption in the world is increasing, as well as the demand for efficient and quality electric power supply that ensures a greener environment. Consequently, the deployment of renewable energy sources has become imperative. The use of renewable resources like hydropower, solar and wind cannot be possible without electric transmission lines. High Voltage Alternating Current (HVAC), though an established technology

Chijioke Joe-Uzuegbu; Gloria Chukwudebe

2011-01-01

148

Manned spacecraft electrical power systems  

Microsoft Academic Search

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward 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

W. E. Simon; D. L. Nored

1987-01-01

149

Feedback control of electrode offset voltage during functional electrical stimulation.  

PubMed

Control of the electrode offset voltage is an important issue related to the processes of functional electrical stimulation because excess charge accumulation over time damages both the tissue and the electrodes. This paper proposes a new feedback control scheme to regulate the electrode offset voltage to a predetermined reference value. The electrode offset voltage was continuously monitored using a sample-and-hold (S/H) circuit during stimulation and non-stimulation periods. The stimulation current was subsequently adjusted using a proportional-integral (PI) controller to minimise the error between the reference value and the electrode offset voltage. During the stimulation period, the electrode offset voltage was maintained through the S/H circuit, and the PI controller did not affect the amplitude of the stimulation current. In contrast, during the non-stimulation period, the electrode offset voltage was sampled through the S/H circuit and rapidly regulated through the PI controller. The experimental results obtained using a nerve cuff electrode showed that the electrode offset voltage was successfully controlled in terms of the performance specifications, such as the steady- and transient-state responses and the constraint of the controller output. Therefore, the proposed control scheme can potentially be used in various nerve stimulation devices and applications requiring control of the electrode offset voltage. PMID:23685268

Chu, Jun-Uk; Song, Kang-Il; Shon, Ahnsei; Han, Sungmin; Lee, Soo Hyun; Kang, Ji Yoon; Hwang, Dosik; Suh, Jun-Kyo Francis; Choi, Kuiwon; Youn, Inchan

2013-05-16

150

Comparison of voltage security constrained optimal power flow techniques  

Microsoft Academic Search

This paper compares two different optimal power flow (OPF) formulations that consider voltage security in power systems. The techniques are both based on multi-objective optimization methodologies, so that operating costs and losses can be minimized while maximizing the \\

Claudio Caiiizares; William Rosehart; Alberto Berizzi; Cristian Bovo

2001-01-01

151

Determination of static voltage stability-margin of the power system prior to voltage collapse  

Microsoft Academic Search

adequate increase in the reactive power. Frequently, both power industry engineers and academic researchers study Voltage instability problems in power system are an system stability and planning by utilizing static load important issue that should be taken into consideration models (i.e. constant impedance, constant current, during the planning and operation stages of modem constant power, and combinations of these models)

M. K. Jalboub; A. M. Ihbal; H. S. Rajamtani; R. A. Abd-Alhameed

2011-01-01

152

Method of assessment of the state of charge and voltage level in the electric power distribution network. Implementation in the improvement of supply quality  

Microsoft Academic Search

Nowadays in order to know in real time the level of charge existing in a distribution network, the installation of a remote infrastructure of operation and supervision is necessary, allowing an immediate view of its electrical state, both normal operation as well as in case of incident. The analysis of the state of the network provides useful data for the

J. I. García-Román; E. Gonzalez-Romera; F. Barrero-González; D. Carmona-Fernández; J. A. Álvarez-Moreno

2006-01-01

153

Optimal reactive power and voltage control for radial distribution system  

Microsoft Academic Search

A new approach to optimal reactive power and voltage control problem in a radial distribution system is proposed in this paper. The optimal control problem is to find a proper dispatch schedule for shunt capacitor banks and on-load tap changer at substation and shunt capacitor banks on feeders such that the power loss is minimized and the voltage profile is

Yutian Liu; Peng Zhang; Xizhao Qiu

2000-01-01

154

AC power standard using a programmable Josephson voltage standard  

Microsoft Academic Search

This paper describes the implementation of a new quantum-based system for the generation of 120 V, 5 A, sinusoidal active and reactive power over the 50 Hz to 400 Hz frequency range. The system accurately relates the spectral amplitudes and phases of the voltage and current waveforms of the generated power to a programmable Josephson voltage standard (PJVS) using a

B. C. Waltrip; B. Gong; T. L. Nelson; Y. Wang; C. J. Burroughs; A. Rufenacht; S. P. Benz; P. D. Dresselhaus

2008-01-01

155

AC Power Standard Using a Programmable Josephson Voltage Standard  

Microsoft Academic Search

This paper describes the implementation of a new quantum-based system for the generation of 120 V RMS, 5 A RMS, sinusoidal, active, and reactive power over the 50 to 400 Hz frequency range. The system accurately relates the spectral amplitudes and phases of the voltage and current waveforms of the generated power to a programmable Josephson voltage standard (PJVS) by

Bryan C. Waltrip; Bo Gong; Thomas L. Nelson; Yicheng Wang; Alain Rüfenacht; Samuel P. Benz; Paul D. Dresselhaus

2009-01-01

156

Adaptive link capacitor voltage control for server power system  

Microsoft Academic Search

An adaptive link capacitor voltage variation control method for server power supply is proposed. In this paper, to increase the efficiency under light load condition, the proposed scheme adjusts nominal link capacitor voltage with the consideration of the hold-up time requirement. Thereby, the effective duty ratio of DC\\/DC stage can be expanded and we can save the power loss. Therefore,

Duk-You Kim; Young-Do Kim; Kyu-Min Cho; Gun-Woo Moon

2009-01-01

157

Analysis and design of Power R Gyrators for Voltage Regulation  

Microsoft Academic Search

This paper presents a new type of voltage regulators based on the power R-gyrators concept. Also, the semigyrator notion is introduced. Power R-semigyrators based in boost and boost-shunt converter are presented. Finally, voltage regulation is achieved with both types of semigyrators

A. Cid-Pastor; L. Martinez-Salamero; C. Alonso; B. Estibals; L. Seguier; G. Schweitz

2006-01-01

158

Electric-bicycle propulsion power  

Microsoft Academic Search

In a human-powered hybrid electric vehicle (HPHEV) the travel distance available from a single battery charge can be lengthened with power from another source, the cyclist's leg muscles. In a battery-powered electric bicycle the propulsion power goes mostly into overcoming aerodynamic drag. For example, at 18 km per hour (11 miles per hour) this drag represents 200 watts at the

Henry Oman; William C. Morchin; Frank E. Jamerson

1995-01-01

159

Modeling the motion of a toy train powered with a time-dependent applied voltage: Educational implementation and analysis  

Microsoft Academic Search

We describe the motion of an electric toy train engine that is powered by a time-dependent voltage and travels on a horizontal track. Effects such as friction, the electrically induced torque and electromotive force of the motor, resistance, inductance, and applied voltage are investigated to identify the impact of each on the train's performance. The parameters that describe these effects

D. P. Wick; M. W. Ramsdell

2004-01-01

160

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

161

DC bus voltage control for a distributed power system  

Microsoft Academic Search

This paper addresses voltage control of distributed DC power systems. DC power systems have been discussed as a result of the introduction of renewable, small-scale power generation units. Also, telecommunication power systems featuring UPS properties might benefit from a broader introduction of DC power systems. Droop control is utilized to distribute the load between the source converters. In order to

P. Karlsson; J. Svensson

2003-01-01

162

Milligram-scale high-voltage power electronics for piezoelectric microrobots  

Microsoft Academic Search

Piezoelectric actuators can achieve high efficiency and power density in very small geometries, which shows promise for microrobotic applications, such as flapping-wing robotic insects. From the perspective of power electronics, such actuators present two challenges: high operating voltages, ranging from tens to thousands of volts, and a low electromechanical coupling factor, which necessitates the recovery of unused electrical energy. This

Michael Karpelson; Gu-yeon Wei; Robert J. Wood

2009-01-01

163

Measurement of magnetic fields in an outdoor high voltage power substation  

Microsoft Academic Search

Human exposure to magnetic fields generated by distribution substations and power lines is one of the growing health concerns that has drawn much attention from Qatar General Electricity & Water Corporation (also called Kahramaa) and Qatar ministry of environment. This paper presents the results of magnetic field measurements in an outdoor high voltage 132\\/66kV power substation, located in the residential

Khaled Ellithy; Abdulaziz Al Shafai; Fahad Al Assiry

2009-01-01

164

Switch mode power supply with output voltage equalizer  

US Patent & Trademark Office Database

A switch mode power supply for feeding a single ended class D amplifier, having. two voltage sources (1, 2) is disclosed. The power supply comprises a voltage equalizer circuit including a coil (10) having a first terminal connected to said common point (3), a first switch (11) connected between a second terminal of the coil (10) and the positive side of the first source (1), a second switch (12) connected between said second terminal of the coil (1) and the negative side of the second source (2), and control circuitry (13, 14) for determining when the voltage (v 1, v2) of one of the voltage sources (1 or 2) exceeds a predetermined threshold value (vthresh,ON), and, in response to such a determination, periodically operate the switch (11 or 12) associated with said one voltage source ON and OFF, thereby redistributing energy from said one voltage source (1 or 2) to the other voltage source (2 or 1). The inventive voltage equalizer thus acts as a switch mode converter, redistributing energy from one voltage source to the other, thereby ensuring that the output voltages of both sources are essentially equal. Further, the voltage equalizer requires very few components, and is thus simple to implement. As the two switches only need to handle the excess of power they can be relatively small and cost efficient.

2008-04-22

165

High voltage, magnetically switched pulsed power systems  

SciTech Connect

The principles of magnetic switching are briefly described. Then the results of experiments on the following substantive topics for magnetic switching are presented: material properties and how they relate to switch performance, risetime limitations, and core insulation. Magnetic switching is then evaluated from a system perspective. An idealized pulse power system with 200 kJ or stored energy and a 40 ns output pulse is examined. The multi-megavolt electrical insulation requirements impose limitations on the switches. The cost of the magnetically switched system exceeds the cost of the conventional superpower generator system by up to 75%. The potential for reliability, reproducibility, and repetitive pulse capability must be evaluated for each application to offset the increased cost.

VanDevender, J.P.; Reber, R.A.

1981-01-01

166

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.

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

1995-01-01

167

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

168

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

DOEpatents

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

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

1994-01-01

169

Introduction of perturbing power filter to vehicle generation system for stabilizing electric power supply  

Microsoft Academic Search

In order to stabilize the electric power delivery from the alternator of a vehicle system, a conception of introducing the perturbing power filter (PPF) to vehicle generation system is proposed in this paper. Make use of PPF, the driven velocity of alternator transmitted from engine can be smoothened in constant. Consequently, the supply voltage of electric power can be maintained

Chung-Neng Huang

2005-01-01

170

59. View of high voltage (4160 volts alternating current) electric ...  

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

59. View of high voltage (4160 volts alternating current) electric load center and motor control center at mezzanine level in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

171

Teaching Electrical Energy, Voltage and Current: An Alternative Approach.  

ERIC Educational Resources Information Center

A program for teaching the concepts of electric energy, voltage, and current is proposed. The ideas and concepts are introduced in a sequence that places more emphasis on some aspects that are normally treated very briefly. A phenomenological orientation, qualitative and quantitative micro- and macroscopic treatments, and the inclusion of the…

Licht, Pieter

1991-01-01

172

Low Voltage Initiation of Damaging Arcs Between Electrical Contacts.  

National Technical Information Service (NTIS)

Metallic arcs were found to precede the firm contacting of electrical contacts which were closed without bounce. When the open-circuit voltages were below the ionization potential, the initiation of these arcs was found to depend on the presence of asperi...

R. E. Cuthrell

1975-01-01

173

Application of data mining to customer profile analysis in the power electric industry  

Microsoft Academic Search

In Japan, the Revised Electric Utility Industry Law went into effect on March 21, 2000. The partial deregulation into the retail electric power supply sector means that electric power for extra-high voltage customers can now be supplied from companies other than the 10 major electric power companies (EPCos) and electricity rates charged to customers can be determined freely according to

Masashi Kitayama; R. Matsubara; Y. Izui

2002-01-01

174

A particle swarm optimization for reactive power and voltage control considering voltage security assessment  

Microsoft Academic Search

Summary form only given, as follows. This paper presents a particle swarm optimization (PSO) for reactive power and voltage control (volt\\/VAr control: VVC) considering voltage security assessment (VSA). VVC can be formulated as a mixed-integer nonlinear optimization problem (MINLP). The proposed method expands the original PSO to handle a MINLP and determines an online VVC strategy with continuous and discrete

H. Yoshida; K. Kawata; Y. Fukuyama; S. Takayama; Y. Nakanishi

2001-01-01

175

Battery-powered electric bicycles  

Microsoft Academic Search

Electric bicycles powered with today's nickel-metal hydride batteries offer a 100 km range between recharges and have a potential of 300 km when polymer batteries become available. The author discusses the development of the electric bicycle, presents a mathematical model, and considers general requirements. The available battery powered electric bicycles are listed and some test comparisons are given

W. C. Morchin

1994-01-01

176

Power processing units for high power solar electric propulsion  

NASA Astrophysics Data System (ADS)

An evaluation of high-power processing units (PPUs) for multimegawatt solar electric propulsion (SEP) vehicles using advanced ion thrusters is presented. Significant savings of scale are possible for PPUs used to supply power to ion thrusters operating at 0.1 to 1.5 MWe per thruster. The PPU specific mass is found to be strongly sensitive to variations in the ion thruster's power per thruster and moderately sensitive to variations in the thruster's screen voltage due to varying the I(sp) of the thruster. Each PPU consists of a dc-to-dc converter to increase the voltage from the 500 V dc of the photovoltaic power system to the 5 to 13 kV dc required by the ion thrusters.

Frisbee, Robert H.; Das, Radhe S.; Krauthamer, Stanley

177

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

178

POWER SYSTEM RESTORATION WITH CONSTANT VOLTAGE PROFILE USING PID CONTROL  

Microsoft Academic Search

Power system security and reliability have become challenging issues in the present restructured scenario. The problem of monitoring the power flows and bus voltages in a power system is very important in maintaining system security and fast prediction is essential for controlling these quantities. As power systems have become more stressed due to increased loading and large interconnections, there will

K Sathish Kumar; S. Naveen R Rajaram V; Tamilselvan V Shanmugasundaram; I. G. Mohamed Nowfal; Hariharan T Jayabarathi

2009-01-01

179

Voltage control availability of distributed generators in power distribution system  

Microsoft Academic Search

In spite of many profitable or advantageous natures of distributed generators (DGs), for power systems, such badly behaved natures of DGs as (1) unstable power output, (2) voltage problem, (3)harmonics, (4)reverse power flow, etc. also exist. Therefore, it has been always emphasized that the unfavorable effects should not exist when distributed generators are connected to the power system. However, in

K. Nara; S. Ishizu; Y. Mishima

2005-01-01

180

Low-power scheduling with resources operating at multiple voltages  

Microsoft Academic Search

ABSTRACT This paper presents (i) a resource constrained,sche duling scheme,and (ii) a latency-constrained scheduling sc heme,that minimize power consumption for the case when,the resources operate,at multiple,voltages. ,The resource-constra ined scheduling,reduces,the power consumption by maximally utilizing resources operating at reduced,voltages a nd at the same time reducing the latency. The latency-constr ained scheduling scheme reduces the power consumption by assigning as

Wen-tsong Shine; C. Chakrabarti

2000-01-01

181

Electric power monthly, October 1994  

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.

Not Available

1994-10-21

182

Scrambling on electrical power grids  

Microsoft Academic Search

Deregulated, the U.S. electrical power grid system has shown the emergence of behaviors that include scrambling by buyers to purchase electricity and unexpected increasing costs of electricity to consumers. To infer those behaviors, in this paper, we adapt a theoretical framework, developed by Newman in his work on spread of epidemic disease on networks, to the propagation of electricity buying

Thomas V. Huynh; John S. Osmundson

2008-01-01

183

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

184

Apparatus for generating electrical power  

SciTech Connect

A continuous water flow from selected ones of a plurality of reservoirs passes through turbines or the like within an hydroelectric power station to produce electrical power. The reservoirs are cyclically filled and evacuated through the power station by operation of a plurality of gates interconnecting reservoirs having different water height levels and an adjacent source of tidal waters. By programmed operation of the gates a continuous water pressure head can be maintained at the power station to assure continuous electrical power generation.

Casebow, W.J.

1980-03-11

185

Effects of neutral point reactors and series capacitors on geomagnetically induced currents in a high-voltage electric power transmission system  

NASA Astrophysics Data System (ADS)

Geomagnetically induced currents (GIC) are DC-like currents compared to power transmission frequencies. Consequently, it may be possible to reduce the magnitudes of GIC by installing resistive components or series capacitors into a power grid. We simulate the effects of neutral point reactors and series capacitors on GIC in the Finnish 400 kV network. Reactors add an additional resistance to earthing leads of transformers, and series capacitors block the flow of GIC in transmission lines. The geoelectric field impacting the system is considered to be uniform. The use of reactors does not necessarily reduce the GIC risk. Although the installation of reactors tends to decrease GIC on the average, maximum GIC may even increase. Assuming a reactor at all stations results in a 50% reduction of the maximum GIC compared to the situation with no reactors. With up to four series capacitors, the maximum GIC is reduced by 40% when they are optimally located. However, even small changes in the topology of the grid can cause large changes in GIC. A combination of reactors and series capacitors could in principle provide a way to diminish the GIC risk. This study also emphasizes the difficulty of preventing GIC problems by these means.

ArajäRvi, Esko; Pirjola, Risto; Viljanen, Ari

2011-11-01

186

Electric power monthly, February 1993.  

National Technical Information Service (NTIS)

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the natio...

1993-01-01

187

Robust distribution and use of electric power  

NASA Astrophysics Data System (ADS)

One of the major problems related to the simultaneous operation of electrical converters in a wide open power system is the concordance between the characteristics of the feeder itself and the load. Nowadays we usually call Electric Power Quality or Electromagnetic Compatibility to this Concordance Degree. Currently, the most important non concordance are voltage sag (voltage dip) and short time interruptions, that is: decreasings in voltage RMS value lasting from some tenths of a second to several seconds. Current analysis usually study this problem from the feeder side, by means of morphological or stadistical approaches, or from the load side in order to evaluate immunity, emission or specific solutions. This line of research, undoubtly needed provided we need to know the current state of the power system and to increase the concordance degree, is not enough because of the huge variability between power lines and from one instant to another. Moreover, the legal boundaries that can support business decisions are not developed yet. The proposed new theory is widely contrasted by field and laboratory measurement. Detailed analysis include instant voltage, instant current, power system and load effects from many places inside the power system of Spain. This theory is a novel approach to the determination of Concordance Degree (CG) of a whole system (be it a distribution line or a single machine) and to the corrective steps needed to increase it. In addition, the proposed model allow a quantitative evaluation of corrective actions like the increase of energy system storage (in a mechanical to electrical convertible form) or/and the increase of the supplied reactive power. Profitability of corrective actions is mainly a function of the number of voltage dips (sags) and short time interruptions that happen in a given period of time. To reduce this number we have studied and developed new fault characterization and location algorithms designed specifically for medium voltage networks. These algorithms, applied to the recorded faults obtained in the widespread measure campaign we have performed, have allowed the analysis of the Fault Repeatness. Last, new lines of research are suggested, mainly focused on more detailed analytical models together with laboratory and field experiences, in order to provide a solid ground for the development of a realistic standard environment able to provide the highest Concordance Degree at the lowest system-as-a-whole cost.

Catalan Izquierdo, Saturnino

2001-07-01

188

High voltage power condition systems powered by flux compression generators  

SciTech Connect

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. 9 figs.

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

1989-01-01

189

Electrical Power Generating System.  

National Technical Information Service (NTIS)

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...

F. J. Nola

1981-01-01

190

Experimental investigation on voltage stability in vehicle power nets for power distribution management  

Microsoft Academic Search

The power demand and the complexity of vehicle power nets has increased continuously during the last years. Especially the high demands of chassis control systems can cause voltage drops that endanger the power net's stability. A power net test bench that enables experimental research on voltage stability in vehicular power nets is presented in this paper. Thereby the relevance of

Tom P. Kohler; Thomas Wagner; Andreas Thanheiser; Christiane Bertram; Dominik Buecherl; Hans-Georg Herzog; Joachim Froeschl; Rainer Gehring

2010-01-01

191

Power system voltage stability analysis using Modified Differential Evolution  

Microsoft Academic Search

The problem of voltage stability is one of the main concerns in the operation of power systems. Many approaches have been used to estimate the voltage stability limit. One of the approaches is determining the maximum loading point of the system. In this approach, the margin from the current operating point to the maximum loading point of the system is

C. Muthamil Selvi; K. Gnanambal

2011-01-01

192

Power system voltage stability assessment employing phasor measurement units  

Microsoft Academic Search

Employing Phasor Measurement Units in wide area monitoring and control of power systems and the availability of phase angles, a new look at the voltage stability indices is performed in this paper. A systematic approach for comparing these indices is presented, where the behavior of different indices to a step load change, for studying long term voltage stability, is compared.

H. Mesgarnejad; S. M. Shahrtash

2010-01-01

193

Inspection of Insulators on High-Voltage Power Transmission Lines  

Microsoft Academic Search

Porcelain insulators are widely used in overhead high-voltage power transmission lines in order to provide adequate insulation to withstand switching and lightning over voltages. Since the useful serviceable life of the individual insulator element and insulator strings is hard to predict, they must be verified periodically to insure that adequate reliability is maintained at all times. Over the years, many

Sunsin Han; Ru Hao; Jangmyung Lee

2009-01-01

194

Power pollution due to grid connected wind electric converter  

Microsoft Academic Search

Analyses the harmonic behaviour of a wind electric converter in a grid connected mode under varying wind speed condition. The power quality of interconnected grid-windmill system performance is specified in terms of harmonic orders and total harmonic distortion. The fluctuations in wind reflect in the output power. The voltage and current wave forms are observed in reference to power quality

W. Z. Gandhare; G. R. Bhagwatikar

2000-01-01

195

Power quality monitoring for electric substation ancillary services supplying  

Microsoft Academic Search

Power quality is the study of the sources, effects and control of disturbances which propagate via the electric power supply. The disturbances change the supply RMS voltage or its waveform (or very occasionally the frequency) and may originate from various sources. Within the paper, the authors are focusing on power quality monitoring. The presented approach refers to substation ancillary services

N. Chiosa; S. Kilyeni; C. Barbulescu; D. Jigoria-Oprea

2010-01-01

196

Measurement of Direct Current Voltage Causing Electrical Pitting  

NASA Astrophysics Data System (ADS)

It is widely known that electrical pitting occurs when an electrical current is passed through a ball or roller bearing. The authors have investigated critical electrical current density causing electrical pitting and have shown that it occurs in a ball bearing even at an extremely low current. In this paper we present the results of an experiment in which a small ball bearing was supplied with a direct current (DC) voltage to determine the voltage required to induce a current. A film of grease acts as the insulator on an antifriction bearing used, and the thickness of this film is an important consideration and the current must pass through this film. Four types of grease were used on the bearing, which was rotated at various speed during 500 hours. A potential of 1.3V to 1.5V was necessary to induce the flow of current. The results indicate that the voltage supplied by typical dry cell batteries is sufficient to drive a currents through a small bearing, and that the experimental conditions had little effect on the magnitude of the flowing current.

Noguchi, Shoji; Kakinuma, Shin-Nosuke; Kanada, Tohru

197

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

198

Detection and classification of electrical supply voltage quality to electrical motors using the Fuzzy-Min-Max neural network  

Microsoft Academic Search

Generally electrical motors have a designed lifespan of more than 20 years when supplied with the proper rated voltage and acceptable voltage waveforms. However when motors are subjected to lowered levels of supply voltage quality conditions appearing simultaneously due to disturbances of overvoltage or undervoltage, voltage unbalance and voltage waveform distortions, it causes motor windings to be seriously overheated and

Harapajan Singh; Mohd Zaki Abdullah; Anas Qutieshat

2011-01-01

199

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

200

A Fixed-Voltage Power Supply for Transistor Circuits.  

National Technical Information Service (NTIS)

Fixed-voltage regulated power supplies are described for use with transistor circuits. Specific circuits are described for regulators supplying 13 to 31 volts at currents up to one ampere. Circuit modifications are given which make the basic regulators us...

D. W. Howell

1964-01-01

201

Transient stability and voltage regulation in power systems with renewable distributed energy resources  

Microsoft Academic Search

In this paper, energy storage used to enhance the transient stability of an electrical power system with renewable power generation is investigated. The passivity-based control design method (IDA-PBC) is used to achieve power angle stability and frequency and voltage regulation after the occurrence of a large disturbance (a symmetrical three-phase short circuit transmission line fault). The performance of the control

Adirak Kanchanaharuthai; Vira Chankong; Kenneth Loparo

2011-01-01

202

A practical voltage-stability-constrained optimal power flow  

Microsoft Academic Search

This paper proposes a novel and practical method to enforce a voltage stability constraint (VSC) in an optimal power flow (OPF) auction model, based on the minimum singular value and minimum singular vectors of the power flow Jacobian. The proposed technique is based on a singular value decomposition of the power flow Jacobian at a given solution point, plus an

Rafael J. Avalos; Claudio A. Canizares; Miguel F. Anjos

2008-01-01

203

Student's understanding of voltage in simple parallel electric circuits  

NSDL National Science Digital Library

This paper reports an investigation of the performance of school students at age 15 on written diagnostic questions involving the prediction of meter readings in simple electric circuits with parallel branches. Results show that these students tend to perceive such questions in resistance-current terms, with a primary focus on resistor addition, rather than in voltage terms, with two loads being driven from the same source. Common errors in predicting voltages across parallel branches suggest that few students use a mental model of solving parallel circuit problems but instead attempt to solve problems by mechanical use of the V=IR equation. Implications for the teaching of electric circuits at this level are identified.

Millar, Robin; Beh, K. L.

2006-06-19

204

Electric power applications of superconductivity  

Microsoft Academic Search

The development of superconducting systems for electric power is driven by the promise of improved efficiency, smaller size, and reduced weight as compared to existing technologies and by the possibility of new applications. Superconducting power components can also contribute to improved power quality and increased system reliability. This paper addresses historical developments and technology status of four superconducting power applications:

WILLIAM V. HASSENZAHL; DREW W. HAZELTON; BRIAN K. JOHNSON; PETER KOMAREK; MATHIAS NOE; CHANDRA T. REIS

2004-01-01

205

Data Transmission over the Medium Voltage Power Line Communication Channel  

Microsoft Academic Search

This paper investigates the suitability of utilizing a medium voltage power line as a data communication channel. The channel can be modeled as having a time-varying, frequency-dependent, signal-to-noise ratio over the communication bandwidth. Other key factors presented in the channel model are attenuation and propagation delay. Simulation studies are used to test the suitability of the medium voltage power line

Poobalan Govender; Sunil Bipraj

2006-01-01

206

Power voltage current convertor using quasi complementary MOSFET current mirrors.  

PubMed

A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. G? output impedance and distortion below 1% can be obtained with no trimming or transistor matching. PMID:22312182

Maclachlan, R A; Riviere, C N

2011-10-13

207

Power voltage current convertor using quasi complementary MOSFET current mirrors  

PubMed Central

A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. G? output impedance and distortion below 1% can be obtained with no trimming or transistor matching.

MacLachlan, R. A.; Riviere, C. N.

2011-01-01

208

Secondary and Tertiary Voltage Regulation based on optimal power flows  

Microsoft Academic Search

This paper proposes a combined Secondary and Tertiary Voltage Regulation (SVR+TVR) methodology based on real-time optimal power flows (OPFs) to periodically update the generators' voltage regulator set points. Minimum active power losses (MAPL) and maximum loadability (ML) OPF approaches are used for the proposed SVR+TVR control. The presented technique is compared against a “classical” SVR control, where the pilot-bus set

Bo Hu; Claudio A. Cañizares; Mingbo Liu

2010-01-01

209

High-frequency characteristics of high-voltage power line  

Microsoft Academic Search

This paper presents a major high-frequency characteristic of high-voltage overhead power line: amplitude characteristics, group delay and noise characteristics. Since measurements of high-frequency power-line characteristics are rare due to permission of power utilities for access to power lines, computer simulations have a crucial role in design of communication systems via power lines. Simulated high-frequency and noise characteristics of 400 kV

N. Suljanovic; A. Mujcic; M. Zajc; J. F. Tasic

2003-01-01

210

Integration of D-Statcom based photovoltaic cell power in low voltage power distribution grid  

Microsoft Academic Search

The main aim of this paper is the voltage regulation which is one of the most important operational requirement in power network at both transmission and distribution levels. Whenever there is a penetration of photovoltaic cell power to the low voltage distributed grid, there occur the problem of mismatch in voltage and frequency in the network, perhaps caused by non

R. Indumathi; M. Venkateshkumar; R. Raghavan

2012-01-01

211

Control of electric power systems  

Microsoft Academic Search

The increase in size and complexity of interconnected electric power systems, coupled with the industrial commitment to maximize security at a minimum cost, has led to the development of many special control devices. These control devices ensure that the electric power system is able to operate, without instability, under a wide range of system conditions. This article presents a tutorial

Magdi S. Mahmoud; ABdulla Ismail

2003-01-01

212

Ignitor Electrical Power Supply System  

Microsoft Academic Search

An iterative optimization process to reduce the total installed electrical power required for Ignitor has been performed, bringing its value down to about 70% of that estimated originally. Ignitor is planned to be installed within the 400 kV Station of Rondissone (near Turin). The required electrical power (1000 MVA \\/ 320 MVAr, including 480 MVAr locally compensated through static system,

Alberto Coletti; Roberto Coletti; Pietro Costa; Giuseppe Maffia; Giuseppe Ramogida; Massimo Roccella; Maurizio Santinelli; Fabio Starace

2004-01-01

213

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

214

Design of high voltage pulsed power supply using storage battery as prime power source  

Microsoft Academic Search

This paper introduces a design of high voltage pulse power supply that uses storage battery as prime power resource. This high voltage pulse power supply system can work without alternating current power supply and can be controlled by the remote control centre. Besides, some important information can be gained and displayed on the computer, such as the position, status, measured

Yu-wei Wang; Da Li; Sheng-guang Cao; Jian-hua Yang; Shi Yang

2008-01-01

215

Digital multirate algorithms for measurement of voltage, current, power and flicker  

Microsoft Academic Search

Digital multirate processing, i.e, signal processing that involves more than one sample rate, permits computationally efficient estimation of several electrical quantities. The new multirate algorithms for active power, voltage and current do not require periodicity of the input signals or synchronous sampling and give excellent accuracy. They replace the integration or summation of conventional methods with digital low pass filtering,

L. Toivonen; J. Morsky

1994-01-01

216

Digital multirate algorithms for measurement of voltage, current, power and flicker  

Microsoft Academic Search

Digital multirate processing, i.e., signal processing that involves more than one sample rate, permits computationally efficient estimation of several electrical quantities. The new multirate algorithms for active power, voltage and current do not require periodicity of the input signals or synchronous sampling and give excellent accuracy. They replace the integration or summation of conventional methods with digital low pass filtering,

L. Toivonen; J. Moersky

1995-01-01

217

Physical and materials limitations on burnout voltage of GaAs power MESFET's  

Microsoft Academic Search

This paper presents a study of factors limiting the burnout voltage of GaAs power MESFET's. A new device geometry had been investigated. Novel techniques using electron-beam induced current (EBIC) in the drain loop in a scanning electron microscope (SEM) and the shift in carbon Auger line in a scanning Auger microscope (SAM) have been applied to study the bulk electric

S. Tiwari; L. F. Eastman; L. Rathbun

1980-01-01

218

Programmable timed electrical power management device  

SciTech Connect

A programmable timed electrical power management device protects and controls electrical equipment and peripherals which are plugged into it. The front of the housing containing the electrical circuitry is provided with a LCD display, a series of pressure sensitive switches for inputting function and control commands to control the operation of the device. A series of LED's mounted on the front of the housing indicate the operational status of the device. The back of the housing is provided with an AC power input receptacle, an on/off reset switch, a series of AC outlets which are divided into pairs of filtered banks, and two or more modular jacks for receiving the modular plug of a telephone, fax, and/or modem. The device circuitry includes a CPU, timer/calendar, a sound generator, voltage sensors, and a back-up battery power supply. The outlets and modular plugs are protected from electrical surges. Each bank of outlets can be selectively programmed to turn on and off at a different time of the day and different days of the week. When more than one bank is set to start at the same time, power is sequentially supplied to each electrical outlet bank allowing the voltage to stabilize before turning on the next bank. A warning tone will sound fifteen, ten, and five minutes prior to shutting off any of the banks, to alert the user that the system is approaching the preset time for the power to the outlets to be turned off, to prevent accidental loss of information. 9 figs.

Nyenya, S.S.

1994-01-11

219

Electric power monthly, June 1993  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. 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 kilowatt hour 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.

Not Available

1993-06-16

220

Error analysis in electric power system available transfer capability computation  

Microsoft Academic Search

A key concept in the restructuring of the electric power industry is the ability to accurately and rapidly quantify the capabilities of the transmission system. Transmission transfer capability is limited by a number of different mechanisms, including thermal, voltage, and stability constraints. This paper discusses the available transfer capability (ATC) definitions and determination guidelines approved by the North American Electric

Peter W Sauer; Santiago Grijalva

1999-01-01

221

Electrical injury  

MedlinePLUS

... wiring Flashing of electric arcs from high-voltage power lines Lightning Machinery or occupational-related exposures Young ... electrocuted by high-voltage electrical current (such as power lines) until the power is turned off. Do ...

222

Static var compensators stabilize power voltages  

SciTech Connect

This article discusses the operation of a static var compensator as installed by Alabama Power near a steel mill with a large arc furnace load. This is expected to result in a number of benefits, including flicker reduction, dynamic power factor correction, harmonics filtering and a reduction in system losses.

Burch, R.

1996-06-01

223

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

224

1986 rural electric power conference  

SciTech Connect

This book presents the papers given at a conference on power distribution systems for rural areas. Topics considered at the conference included distribution automation, the Athens automation and control experiment distribution automation project, critical issues in distribution system surge protection, the benefits of performing unbalanced voltage calculations, and an expert system for overcurrent protective device coordination.

Not Available

1986-01-01

225

Novel controllers for the 48-pulse VSC STATCOM and SSSC for voltage regulation and reactive power compensation  

Microsoft Academic Search

The paper investigates the dynamic operation of novel control scheme for both Static Synchronous Compensator (STATCOM) and Static Synchronous Series Compensator (SSSC) based on a new full model comprising a 48-pulse Gate Turn-Off thyristor voltage source converter for combined reactive power compensation and voltage stabilization of the electric grid network. The complete digital simulation of the STATCOM and SSSC within

M. S. El-Moursi; A. M. Sharaf

2005-01-01

226

Electric power monthly, September 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and State level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. 10 refs., 37 tabs.

Not Available

1989-12-14

227

Electric power monthly, June 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and state level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1989-09-13

228

Electric Power Monthly, November 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and state level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1990-02-12

229

Electric power monthly, July 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and State level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and retail prices data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison.

Not Available

1989-10-13

230

Electric power monthly, March 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and State level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1989-06-15

231

Electric power monthly, August 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and State level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption fuel stocks, quantity and quality fuel, and cost of fuel. 10 refs., 1 fig., 40 tabs.

Not Available

1989-11-14

232

Technical evaluation of the adequacy of station electric-distribution-system voltages for the Arkansas Nuclear One, Unit 2  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Arkansas Nuclear One, Unit 2. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses submitted demonstrate that the station's electric distribution system supplies adequate voltage to the Class 1E equipment under the worst case conditions analyzed.

Selan, J.C.

1982-03-10

233

Technical evaluation of the adequacy of station electric distribution system voltages for the Arkansas Nuclear One, Unit 1  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Arkansas Nuclear One, Unit 1. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses submitted demonstrate that the station's electric distribution system supplies adequate voltage to the Class 1E equipment under the worst case conditions analyzed.

Selan, J.C.

1981-12-16

234

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

235

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

236

High-voltage DC power conditioner  

Microsoft Academic Search

Modern radar systems, particularly mobile systems, require high-quality, compact, lightweight, dc power sources. High frequency (e.g., 10-kHz) power conditioners have been used to obtain the desired qualities. By adapting a variation of the series inverter circuit, liberally infused with artificial line-type pulse modulator technology, an effective, simple, and high-performance technique has been devised. Low-frequency (50- to 400-Hz) transformers are eliminated

D. L. Pruitt

1979-01-01

237

Process effects on high voltage electrical assembly performance. Final report  

SciTech Connect

Manufacturing processes and package configurations that affect the operation of some high voltage electrical assemblies have been evaluated. High voltage breakdown, adhesion problems, and encapsulated component and solder joint breakage have been relieved by improvements in residue analysis, cleaning and coating techniques, and stress relief coatings. A quantitative comparison of encapsulated lead stress relief systems has been completed to determine their effect on both component and solder joints during thermal cycling of encapsulated electronic assemblies. Evaluations have been conducted involving printed circuit board substrates with thermal expansion equal in all directions. A qualitative solder joint thermal cycle study was conducted to compare the effects of encapsulant, lead loops, and sleeving on solder joint failure.

Cummings, D.A.

1978-08-01

238

Interpreting recent power quality surveys to define the electrical environment  

Microsoft Academic Search

Recent AC power line monitoring projects have enabled a better understanding of the typical electrical environment within which sensitive electronic equipment must be able to operate. Voltage variations caused by utility protective and regulation devices, as well as variations caused by load equipment, contribute to the total power quality picture. Regardless of the origin of these variations, the load equipment

Douglas S. Dorr; M. Brent Hughes; Thomas M. Gruzs; Robert E. Jurewicz; John L. McClaine

1997-01-01

239

Interpreting recent power quality surveys to define the electrical environment  

Microsoft Academic Search

Recent AC power line monitoring projects have enabled a better understanding of the typical electrical environment within which sensitive electronic equipment must be able to operate. Voltage variations caused by utility protective and regulation devices as well as variations caused by load equipment contribute to the total power quality picture. Regardless of the origin of these variations, the load equipment

Douglas S. Dorr; Thomas M. Gruzs; M. B. Hughes; Robert E. Jurewicz; Gurcharn Dang; John L. McClaine

1996-01-01

240

A new zero voltage and zero current power switching technique  

NASA Astrophysics Data System (ADS)

An outline is presented of work done by the authors on a novel converter topology where the power switching occurs at both zero current and zero voltage, giving it some major advantage over the present state of the art. A description is given of the application of this topology to both high- and low-output-voltage converters. Design details and test results are given, together with a full analysis of the operation of the converters.

Weinberg, A. H.; Ghislanzoni, L.

241

On Power Quality of Variable-Speed Constant-Frequency Aircraft Electric Power Systems  

Microsoft Academic Search

In this paper, a comprehensive model of the variable-speed constant-frequency aircraft electric power system is developed to study the performance characteristics of the system and, in particular, the system power quality over a frequency range of operation of 400 Hz to 800 Hz. A fully controlled active power filter is designed to regulate the load terminal voltage, eliminate harmonics, correct

Ahmad Eid; Hassan El-Kishky; Mazen Abdel-Salam; Mohamed T. El-Mohandes

2010-01-01

242

Emission Characteristics and Interference Constraint of Overhead Medium-Voltage Broadband Power Line (BPL) Systems  

Microsoft Academic Search

We investigate the measurement, interference and capacity issues of the overhead medium-voltage (MV) broadband over power line (BPL) systems operating between 1.7 and 80 MHz. The MV power lines are modeled as a 3-phase set of parallel wires with infinite length and above a lossy earth. Electric field strength is calculated. Two important parameter settings are addressed for the measurement

Song Liu; Larry J. Greenstein

2008-01-01

243

Electric power monthly, April 1993  

SciTech Connect

The Electric Power Monthly is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. 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.

Not Available

1993-05-07

244

Electric power monthly, May 1993  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. 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.

Not Available

1993-05-25

245

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

Code of Federal Regulations, 2013 CFR

...or operation of equipment near high-voltage power lines. 56.12071 Section...or operation of equipment near high-voltage power lines. When equipment...moved or operated near energized high-voltage powerlines (other than...

2013-07-01

246

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Movement of high-voltage power centers and portable transformers...STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.812 Movement of high-voltage power centers and portable...

2013-07-01

247

30 CFR 75.812-2 - High-voltage power centers and transformers; record of examination.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false High-voltage power centers and transformers; record...STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.812-2 High-voltage power centers and transformers;...

2013-07-01

248

The apparent power of electric circuits with switching elements in single-phase systems  

Microsoft Academic Search

This paper presents calculation of the apparent power of electric circuits with switching elements and various loads in single-phase systems. Attention is paid to the difference between such fundamental concepts as ldquothe electromotive force (EMF) of a voltage sourcerdquo and ldquothe input voltage of an electric circuitrdquo causing the electric current to flow. On that ground, an analysis of apparent

Oleksandr Osnach

2009-01-01

249

Technical evaluation of the adequacy of station electric-distribution-system voltages for the Duane Arnold Energy Center  

SciTech Connect

The technical evaluation of the adequacy of the station electric distribution system voltages for the Duane Arnold Energy Center is documented. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analyses submitted demonstrate that the offsite power sources in conjunction with the onsite distribution system has sufficient capacity and capability to supply adequate voltages to the Class 1E equipment under worst case conditions.

Selan, J.C.

1981-10-12

250

Fast high-power\\/high-voltage switch using series-connected IGBTs with active gate-controlled voltage-balancing  

Microsoft Academic Search

There exists an acute need for fast high-voltage solid-state switches in a broad area of applications. With the proposed method of active gate-controlled voltage balancing, fast high power\\/high voltage semiconductor switches with working voltages of several kilovolts using series-connected insulated gate bipolar transistors (IGBT) can be realized. Transient and static voltage balancing is tested on an experimental 3.5 kV\\/300 A

Christian Gerster

1994-01-01

251

Design and control of Series DC Active Filter (SDAF) for shipboard Medium-Voltage DC power system  

Microsoft Academic Search

Shipboard power system (SPS) can have either ac or dc distribution systems, or a c ombination of both ac and dc distribution systems. However, the Navy has identified Medium- Voltage DC (MVDC) as a long-term solution for electric power distribution to meet the high pow er density requirements in future shipboard power systems. Thyristor bridges are a v iable front-end

Hesam Mirzaee; Babak Parkhideh; Subhashish Bhattacharya

2011-01-01

252

Nuclear electromagnetic pulse (EMP) and electric power systems  

SciTech Connect

A nuclear detonation at high altitudes produces a transient electromagnetic pulse (EMP) of high-intensity electromagnetic fields. A single high-altitude burst can subject most of the continental United States to a strong EMP. These intense fields induce voltage and current transients in electrical conductors. Surges would be induced by EMP in transmission and distribution circuits and in control and communication elements in electric power systems throughout the national grid. Such widespread disturbances could upset the stability of electrical energy systems and result in massive power failures. The extent and nature of EMP-caused damages are not well known for utility electric power systems. Failures are likely to be associated with insulation damage and failures of low-voltage and solid-state components. It is concluded from a review of past studies that EMP may pose a serious threat to the nation's electrical energy supply.

Barnes, P.R.; Vance, E.F.; Askins, H.W. Jr.

1984-04-01

253

Applying power quality characteristics of wind turbines for assessing impact on voltage quality  

NASA Astrophysics Data System (ADS)

Injection of wind power into an electric grid affects the voltage quality. As the voltage quality must be within certain limits to comply with utility requirements, the effect should be assessed prior to installation. To assess the effect, knowledge about the electrical characteristics of the wind turbines is needed or else the result could easily be an inappropriate design of the grid connection. The electrical characteristics of wind turbines are manufacturer-specific but not site-specific. This means that, having the actual parameter values for a specific wind turbine, the expected impact of the wind turbine type on voltage quality when deployed at a specific site, possibly as a group of wind turbines, can be calculated. The methodology for this is explained and illustrated by case studies considering a 5 × 750 kW wind farm on a 22 kV distribution feeder. The detailed analysis suggests that the wind farm capacity can be operated at the grid without causing unacceptable voltage quality. For comparison, a simplified design criterion is considered assuming that the wind farm is only allowed to cause a voltage increment of 1%. According to this criterion, only a very limited wind power capacity would be allowed. Measurements confirm, however, the suggestion of the detailed analysis, and it is concluded that a simplified design criterion such as the 1% rule should not be used for dimensioning the grid connection of wind farms. Rather, this article suggests a systematic approach including assessment of slow voltage variations, flicker, voltage dips and harmonics, possibly supported by more detailed analyses, e.g. system stability if the wind farm is large or the grid is very weak, and impact on grid frequency in systems where wind power covers a high fraction of the load, i.e. most relevant for isolated systems.

Giæver Tande, John Olav

2002-01-01

254

The commoditization of electric power  

SciTech Connect

Electric power is fast becoming a commodity-a unique commodity that is currently traded actively in the wholesale power market among electric companies and large industrial consumers, and inevitably will be offered competitively to retail customers. U.S. electric utilities are learning to face a world in which competition overshadows cooperation, open markets are replacing a regulated customer base, and the rate of return is increasingly driven by market forces, not the rulings of regulatory commissions. In this environment, some companies are positioned for success with strong financial portfolios, low-cost generation, and transmission resources. Others are burdened with high-cost investments, high-priced fuel and power contracts, and inadequate transmission options. Given the diversity of today's electric industry, the transition to open markets will not be smooth. But as the process unfolds, buyers and sellers alike will need information on the dynamics of the market. To this end, the FORTNIGHTLY and Resource Data International Inc. (RDI) of Boulder, CO, will provide statistical tables and narrative that track electric power markets on a monthly basis. The Market Indicators table provides three key statistics electric output, average production cost, and retail rates-for each North American Electric Reliability Council region. The Wholesale Market Watch table provides five key statistics-electric generation, retail sales, surplus/deficit energy (calculated), production cost, and retail rates-for 30 selected companies.

Not Available

1994-04-15

255

The physics of electric power systems  

NASA Astrophysics Data System (ADS)

The article describes electric power systems from a physicist's point of view. In contrast to common introductory textbooks on power systems, the emphasis is on the physical design, that is the material selection and the choice of the geometrical shape, of the fundamental components as it follows from the function and serves the main purpose. Why do power system components look the way they look? This is the question addressed in an accessible way. Four fundamental components are needed to make the most elementary power system: overhead transmission lines, transformers, synchronous generators, and circuit breakers. High-voltage overhead lines make efficient long-distance transmission of electric power possible. Transformers step up the power from the generating plant and cascade it down to the final consumption. For their ability to control, independently, real and reactive power, synchronous generators are the most common type of generators. And it is only through the immediate extinction of plasma arcs in circuit breakers that shortcircuit currents can be interrupted and faulty segments of the grid disconnected.

Ohler, C.

2013-06-01

256

Electric power monthly, August 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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. 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.

Not Available

1993-08-13

257

Experimental Investigation of Breakdown Voltage and Electrical Breakdown Time Delay of Commercial Gas Discharge Tubes  

Microsoft Academic Search

This article presents the experimental results of DC dynamic breakdown voltage Ub for small voltage increase rates and electrical breakdown time delay td of commercial gas discharge tubes. It was shown that Ub is a stochastic value with Gauss distribution for voltage increase rates >=2 V\\/s. In order to determine the static breakdown voltage Us as a deterministic quantity, the

Milic Momcilo Pejovic; Momcilo Milic Pejovic; Koviljka Stankovic

2011-01-01

258

Electric field and voltage sensing at 50 Hz using a thermally poled silica optical fibre  

NASA Astrophysics Data System (ADS)

Lab trials of two simple voltage sensor configurations demonstrate the basis of a field deployable voltage sensor capable of measuring the line voltage of a high voltage electricity transmission line. Sensor operation at 50 Hz is demonstrated with sampling rates up to 1000 Hz in the two separate experiments.

Michie, A.; Bassett, I. M.; Haywood, J. H.; Ingram, J.

2007-10-01

259

Voltage control in electric distribution grids by aggregation of distributed energy units  

Microsoft Academic Search

Keeping voltage limits in electric networks is obligatory. Voltage constraints often cause additional costs for network reinforcement or more distance connection points when distributed generators are to be connected in medium- and low-voltage grids. In this paper, we present three different approaches for voltage control by aggregation of controllable distributed energy units. We also present the results of a physical

M. Braun; J. Ringelstein

2009-01-01

260

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

2012-02-24

261

Electrical Analysis of Wind Power  

NSDL National Science Digital Library

For this experiment, students use a DC motor as a generator and various shaped turbine designs to test which design produces the most electrical power. Using a fan to generate the "wind", students attach different blades made of folded paper or card stock to the motor to see how much power is generated.

Peterson, Lina J.

262

[A novel voltage multiplier for X-ray power supply].  

PubMed

In this paper, a seriesly connected three phase bipolar symmetrical voltage multiplier (VM) is proposed, which is a novel VM for X-ray power supply. It consists of three single phase bipolar symmetrical VM, which are connected in series at their smoothing columns. The charging and discharging process occurs six times in a cycle and the frequency of the output voltage ripple is six times as large as the drive signal frequency. The proposed VM has three times larger output voltage and three times smaller ripple factor as compared to single phase bipolar symmetrical VM, and smaller voltage drop and faster dynamic response than those of the series connected three phase symmetrical VM. The simulation is provided to show the feasibility of proposed VM. PMID:22097261

Tang, Zhide; Yang, Hong; Wang, Guantao; Zhang, Zhengmao

2011-10-01

263

Electric power monthly, June 1994  

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.

Not Available

1994-06-01

264

Electric power monthly, August 1992  

SciTech Connect

The Electric Power Monthly. (EPM) is prepared by the Survey Management Division; Office of coal, Nuclear, Electric and alternate Fuels, Energy information Administration (EIA), Department of energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sold. data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-08-21

265

Electric power monthly, November 1994  

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.

Not Available

1994-11-01

266

Electrical power trade-offs  

SciTech Connect

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.

1983-12-01

267

Manned spacecraft electrical power systems  

SciTech Connect

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward 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.

Simon, W.E.; Nored, D.L.

1987-03-01

268

Scattering Parameters-Based Channel Characterization and Modeling for Underground Medium-Voltage Power-Line Communications  

Microsoft Academic Search

Power-line communications (PLC) technologies rely on the power grid for data transmission. Since the communications channel is already deployed, this communication alternative is specially interesting for the power grid owner (i.e., the electrical utility). The medium-voltage (MV) distribution network, located after the last step-down electrical substation with typical levels from 6 to 25 kV, directly feeds large consumers and small

Ricard Aquilue; Miquel Ribo; Joan Ramon Regue; Joan LluÍs Pijoan; GermÁn Sanchez

2009-01-01

269

Uninterruptible power supplies of small power with the improved shape of output voltage  

Microsoft Academic Search

The modern requirements for quality characteristics of voltage, shaped by uninterruptible power supplies, are not created in devices of small power (tens and hundreds watt), produced by domestic and foreign manufacturers. The necessity of a decrease of weight-dimension characteristics for the results in formation of output voltage in the form of the rectangular pulse differ considerably from harmonics. The inverter

V. F. Dmitrikov; N. B. Dogadin

2002-01-01

270

Centralized wind power plant voltage control with optimal power flow algorithm  

Microsoft Academic Search

This thesis presents a method of controlling the reactive power injected into a medium-voltage collection system by multiple wind turbine generators such that the voltage at one bus is maintained at a specified level. The proposed control accounts for the system impedance between the wind turbine generator terminals and the point of interconnect, and utilizes an optimal power flow algorithm

Jared Andrew Kline

2011-01-01

271

Electric power monthly, April 1994  

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. This publication provides monthly statistics at the U.S., 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. This April 1994 issue contains 1993 year-end data and data through January 1994.

Not Available

1994-04-01

272

Electric power monthly, May 1994  

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. This publication provides monthly statistics 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. Statistics by company and plant are published 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

1994-05-01

273

Decoupling capacitors for power distribution systems with multiple power supply voltages  

Microsoft Academic Search

To decrease power consumption without affecting circuit speed, several power supply voltages are used in modern high performance ICs such as microprocessors. To maintain the impedance of a power distribution system below a specified level, multiple decoupling capacitors are placed at different levels of the power grid hierarchy. The system of decoupling capacitors used in power distribution systems with multiple

Mikhail Popovich; Eby G. Friedman

2004-01-01

274

Impact of wind turbine systems on power system voltage stability  

Microsoft Academic Search

This paper investigates the effect of fixed speed and variable speed grid-connected wind generators on the voltage stability of a power system network. The wind generators considered are the squirrel cage induction generator (SCIG), which is a fixed speed, the doubly-fed induction generator (DFIG) and the direct driven synchronous generator (DDSG) which are variable speed. Studies were conducted on a

D. Devaraj; R. Jeevajyothi

2011-01-01

275

Power optimization of variable-voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. The energy efficiency of systems-on-a-chip (SOC) could be much improved if one were to vary the supply voltage dynamically at run time. We develop the design

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1999-01-01

276

Solving customer power quality problems due to voltage magnification  

Microsoft Academic Search

Reports by a Duke Power customer concerning equipment malfunctioning coincident with the switching of a 100 kV shunt capacitor bank led to field measurements and EMTP simulations to identify the possible sources of the problems and to find an economical solution. Measurements and simulation revealed the occurrence of voltage magnification at the customer's site due to the effects of three

R. A. Adams; S. W. Middlekauff; E. H. Camm; J. A. McGee

1998-01-01

277

A Family of Computerized UHF Power and Voltage Meters  

Microsoft Academic Search

Some designs are described for thermal UHF power and voltage detectors in which an indirectly heated thermistor is used as load and sensing element. A personal computer provides the indicator and has a sound adaptor in the form of an extension card.

A. I. Mekhannikov

2003-01-01

278

Power Losses and Thermal Modeling of A Voltage Source Inverter.  

National Technical Information Service (NTIS)

This thesis presents thermal and power loss models of a three phase IGBT voltage source inverter used in the design of the 625KW fuel cell and reformer demonstration which is a top priority for the Office of Naval Research. The ability to generate thermal...

M. C. Oberdorf

2006-01-01

279

STATCOM control for power system voltage control applications  

Microsoft Academic Search

A static compensator (STATCOM) is a device that can provide reactive support to a bus. It consists of voltage sourced converters connected to an energy storage device on one side and to the power system on the other. In this paper the conventional method of PI control is compared and contrasted with various feedback control strategies. A linear optimal control

Pranesh Rao; M. L. Crow; Zhiping Yang

2000-01-01

280

Test results of high-voltage, high-power, solid-state remote power controllers  

NASA Astrophysics Data System (ADS)

This report discusses the results of testing high-voltage, high-power, solid-state remote power controllers (RPC) using RPCs designed and built by John C. Sturman at the Lewis Research Center, Cleveland, Ohio, and utilizing the Autonomously Managed Power Systems (AMPS) breadboard/test facility. These test results are used to determine usefulness of the RPCs for future applications in high-voltage direct-current space power.

Johnson, Yvette Binford; Kapustka, Robert E.

1988-03-01

281

Reliability consideration for a high power zero-voltage-switching flyback power supply  

Microsoft Academic Search

In this study, a high power zero-voltages-witching flyback power supply is presented. An appropriate efficiency is achieved by designing an auxiliary circuit for reduction of dynamic losses in the power switch. Due to the importance of reliability in the switch mode power supplies, reliability assessment is discussed for this zero-voltage-switching flyback converter in details. This paper illustrates that flyback topology

Arash Rahnamaee; Jafar Milimonfared; Kaveh Malekian; Mohammad Abroushan

2008-01-01

282

Power optimization of variable voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. We develop the design methodology for the low power core-based real-time system-on-chip based on dynamically variable voltage hardware. The key challenge is to develop effective scheduling

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1998-01-01

283

A modular optically powered floating high voltage generator.  

PubMed

The feasibility of fully floating high voltage (HV) generation was demonstrated producing a prototype of a modular HV system. The primary power source is provided by a high efficiency semiconductor power cell illuminated by a laser system ensuring the floating nature of each module. The HV is then generated by dc-dc conversion and a HV multiplier. The possibility of series connection among modules was verified. PMID:23464232

Antonini, P; Borsato, E; Carugno, G; Pegoraro, M; Zotto, P

2013-02-01

284

Electric power monthly, May 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and State level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and retail prices data by one month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 10 refs., 1 fig., 3 tabs.

Not Available

1989-08-14

285

A VME Board Prototype of High Voltage Power Supply Incorporating Piezoelectric Ceramic Transformer  

Microsoft Academic Search

A high voltage power supply channel produces a stabilized direct current high voltage, utilizing a piezoelectric ceramic transformer to generate high voltage. With the intention of developing a 16-channel VME board, a single channel VME board was prototyped, where a high voltage power supply was implemented on a VME board so that a computer could control the power supply. The

Masatosi Imori; Takashi Taniguchi; Toshiyuki Kimura; Satoru Imada

286

A DSTATCOM controller tuned by Particle Swarm Optimization for an Electric Ship Power System  

Microsoft Academic Search

In an all-electric ship power system, the power quality problems mainly arise due to the pulsed loads, which cause the degradation of the overall system performance. The paper proposes the application of DSTATCOM to improve these power quality problems of an electric ship. DSTATCOM is a shunt compensation device, which regulates the bus voltage by injecting reactive power during the

Pinaki Mitra; Ganesh K. Venayagamoorthy

2008-01-01

287

Asynchronized Turbogenerators as a Means of Improving the Stability and Voltage Control in Electric Networks  

Microsoft Academic Search

Voltage level normalization in networks of voltage class 220 – 500 kV is a long-standing problem for power pool systems in Russia. In recent years, this was due mainly to reduced power consumption and, as a consequence, the generation of reactive power by underloaded power transmission lines. At present, because of the limited means for reactive power compensation, synchronous turbo

I. A. Labunets; P. V. Sokur; N. D. Pinchuk; I. A. Kadi-Ogly; A. G. Loginov; A. V. Fadeev; V. T. Zinakov; E. V. Chernyshev; P. A. Sheiko

2004-01-01

288

Maximum Output Power Control Using Short-Circuit Current and Open-Circuit Voltage of a Solar Panel  

NASA Astrophysics Data System (ADS)

A control method to optimize the output power of a solar cell is necessary because the output of a solar cell strongly depends on solar radiation. We here proposed two output power control methods using the short-circuit current and open-circuit voltage of a solar panel. One of them used a current ratio and a voltage ratio (?? control), and the other used a current ratio and a short-circuit current--electric power characteristic coefficient (?? control). The usefulness of the ?? and the ?? control methods was evaluated. The results showed that the output power controlled by our proposed methods was close to the maximum output power of a solar panel.

Kato, Takahiro; Miyake, Takuma; Tashima, Daisuke; Sakoda, Tatsuya; Otsubo, Masahisa; Hombu, Mitsuyuki

2012-10-01

289

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

290

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

291

Application of high voltage electric field (HVEF) drying technology in potato chips  

NASA Astrophysics Data System (ADS)

In order to improve the drying efficiency and qualities of vegetable by high voltage electric field (HVEF), potato chips as a representative of vegetable was dried using a high voltage electric drying systems at 20°C. The shrinkage rate, water absorption and rehydration ratio of dried potato chips were measured. The results indicated that the drying rate of potato chips was significantly improved in the high voltage electric drying systems. The shrinkage rate of potato chips dried by high voltage electric field was 1.1% lower than that by oven drying method. And the rehydration rate of high voltage electric field was 24.6% higher than that by oven drying method. High voltage electric field drying is very advantageous and can be used as a substitute for traditional drying method.

Bai, Yaxiang; Shi, Hua; Yang, Yaxin

2013-03-01

292

Super junction LDMOS with enhanced dielectric layer electric field for high breakdown voltage  

NASA Astrophysics Data System (ADS)

The lateral super junction (SJ) power devices suffer the substrate-assisted depletion (SAD) effect, which breaks the charge balance of SJ resulting in the low breakdown voltage (BV). A solution based on enhancing the electric field of the dielectric buried layer is investigated for improving the BV of super junction LDMOSFET (SJ-LDMOS). High density interface charges enhance the electric field in the buried oxide (BOX) layer to increase the block voltage of BOX, which suppresses the SAD effect to achieve the charge balance of SJ. In order to obtain the linear enhancement of electric field, SOI SJ-LDMOS with trenched BOX is presented. Because the trenched BOX self-adaptively collects holes according to the variable electric field strength, the approximate linear charge distribution is formed on the surface of the BOX to enhance the electric field according to the need. As a result, the charge balance between N and P pillars of SJ is achieved, which improves the BV of SJ-LDMOS to close that of the idea SJ structure.

Wenlian, Wang; Bo, Zhang; Zhaoji, Li

2011-02-01

293

Electric power monthly. [Contains glossary  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in this EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-07-01

294

Electric Power Monthly, March 1994  

SciTech Connect

The Electric Power Monthly (EPM) 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. Data on quantity, quality, and cost of fossil fuels lag data on net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour by 1 month. This difference in reporting appears in the US, Census division, and State level tables. However, for purposes of comparison, plant-level data are presented for the earlier month.

NONE

1994-03-01

295

Electric power monthly, February 1993  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1993-02-22

296

Electric power monthly, December 1991  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1991-12-16

297

Electric power monthly, March 1993  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1993-03-17

298

Electric Power Monthly, April 1992  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-04-24

299

Electric power monthly. [Contains glossary  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels of net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-06-01

300

Technical evaluation of the adequacy of station electric distribution system voltages for the San Onofre Nuclear Generating Station, Unit 1  

SciTech Connect

This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the San Onofre Nuclear Generating Station, Unit. The evaluation is to determine if the onsite distribution system in conjunction with the offsite power sources has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The analysis submitted demonstrates that acceptable voltages will be supplied to the Class 1E equipment under worst-case conditions.

Selan, J.C.

1982-01-14

301

Development of a commercially applicable prototypes for on-line monitoring of partial discharges and pollution effects on safety of high voltage power equipment  

Microsoft Academic Search

Electric utilities have been facing major concerns related to the ageing and deterioration of high voltage power equipment in service. With advancing technologies in the field of sensors and data acquisition systems it is feasible to develop and implement on-line condition monitoring systems for high voltage equipment. In the Department of Electrical Engineering, RMIT University, major research projects are in

S. Shihab; T. Taskin; J. Grzan

1998-01-01

302

Power Usage and Electrical Circuit Analysis for Electric Arc Furnaces  

Microsoft Academic Search

Power usage in ultrahigh-powered electric arc furnaces requires considerably more investigation into system parameters, furnace secondary circuit analysis, and operating characteristics than previously given to normal powered electric arc furnaces. The power input must be analyzed from the infinite electric utility bus to the arc at the electrode. All interested parties must participate in the analysis to assure a mutual

J. J. Trageser

1980-01-01

303

Observation of voltage fluctuations in a Superconducting Magnet during MHD power generation  

Microsoft Academic Search

Fluctuating voltage signals on the potential taps of the ANL 5.0 T MHD Superconducting Dipole Magnet have been observed during MHD power generation at the U-25B Facility at the High Temperature Institute (IVTAN) Moscow, USSR. Various other thermodynamic and electrical parameters of the U-25B flow train have been recorded, and statistical analysis concerning correlations between the phenomena with a view

R. P. Smith; R. C. Niemann; M. R. Kraimer; T. E. Zinneman

1979-01-01

304

Observation of voltage fluctuations in a superconducting magnet during MHD power generation  

Microsoft Academic Search

Fluctuating voltage signals on the potential taps of the ANL 5.0 T MHD Superconducting Dipole Magnet have been observed during MHD power generation at the U-25B Facility at the High Temperature Institute (IVTAN) Moscow, USSR. Various other thermodynamic and electrical parameters of the U-25B flow train have been recorded, and statistical analysis concerning correlations between the phenomena with a view

R. P. Smith; R. C. Niemann; M. R. Kraimer; T. E. Zinneman

1978-01-01

305

Observation of voltage fluctuations in a superconducting magnet during MHD power generation  

Microsoft Academic Search

Fluctuating voltage signals on the potential taps of the ANL 5.0 T MHD Superconducting Dipole Magnet have been observed during MHD power generation at the U-25B Facility at the High Temperature Institute (IVTAN) Moscow, USSR. Various other thermodynamic and electrical parameters of the U-25B flow train have been recorded, and statistical analysis concerning correlations between the phenomena with a view

R. P. Smith; R. C. Niemam; M. R. Kraimer; T. E. Zinneman

1979-01-01

306

Efficient power conversion for ultra low voltage micro scale energy transducers  

Microsoft Academic Search

Energy harvesting has emerged as a feasible and attractive option to improve battery lifetime in micro-scale electronic systems such as biomedical implants and wireless sensor nodes. A key challenge in designing micro-scale energy harvesting systems is that miniature energy transducers (e.g., photovoltaic cells, thermo-electric generators, and fuel cells) output very low voltages (0--0.4V). Therefore, a fully on-chip power converter (usually

Chao Lu; Sang Phill Park; Vijay Raghunathan; Kaushik Roy

2010-01-01

307

A method for encapsulating high voltage power transformers  

NASA Astrophysics Data System (ADS)

Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a carboxyl terminated butadiene nitril (CTBN) modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a diallyl phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.

Sanchez, Robert O.

308

A method for encapsulating high voltage power transformers  

SciTech Connect

Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a CTBN modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a Diallyl Phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.

Sanchez, R.O.

1990-01-01

309

Electric Power Monthly, June 1988  

SciTech Connect

The 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 Energy Information Administration (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. The Electric Power Monthly contains information from three data sources: the Form EIA-759, 'Monthly Power Plant Report'; the Federal Energy Regulatory Commission (FERC) Form 423, 'Monthly Report of Cost and Quality of Fuels for Electric Plants{sup ;} and the Form EIA-826, {sup M}onthly Electric Sales and Revenue Report with State Distributions'. The Form EIA-759 collects data from all operators of electric utility generating plants (except those having plants solely on standby), approximately 800 of the more than 3,200 electric utilities in the United States. To reduce the reporting burden for utilities, the FERC Form 423 and Form EIA-826 data are based on samples, which cover less than 100 percent of all central station generating utilities. The FERC Form 423 collects data from steam-electric power generating plants with a combined installed nameplate capacity of 50 megawatts or larger (approximately 230 electric utilities). The 50-megawatt threshold was established by FERC. The Form EIA-826 collects sales and revenue data in the residential, commercial, industrial, and other sectors of the economy. Other sales data collected include public street and highway lighting, other sales to public authorities, sales to railroads and railways, and interdepartmental sales. Respondents to the Form EIA-826 were statistically chosen and include approximately 225 privately and publicly owned electric utilities from a universe of more than 3,200 utilities. The sample selection for the Form EIA-826 is evaluated annually. Currently, the Form EIA-826 data account for approximately 83 percent of the electricity sales in the United States. Sources of data are described in more detail in the Technical Notes of the Electric Power Annual (DOE/EIA-0348).

NONE

1988-06-15

310

Multi Power Port Converter for Hybrid Electric Vehicles Using Multi Phase Bidirectional FlyBack Topology  

Microsoft Academic Search

For hybrid electric vehicles the batteries and the drive DC-link may be at different voltages. The batteries are at low voltage to obtain higher volumetric efficiencies and the DC-link is at higher voltage to have higher efficiency on the motor side. Therefore a power interface between the batteries and the drive's DC-link is essential. This power interface should handle power

T. Bhattacharya; S. Giri V; K. Mathew; L. Umanand

2006-01-01

311

Electric power monthly, September 1994  

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 EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. 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 net generation by energy source; consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units.

Not Available

1994-09-01

312

High-power-factor electronic ballast with constant DC-link voltage  

Microsoft Academic Search

This paper presents a high-power-factor (HPF) electronic ballast based on a single power processing stage with constant DC-link voltage. The switching frequency is controlled to maintain the DC-link voltage and the voltage across the switches constant, independently of changes in the AC-input voltage. This control method assures zero-voltage switching (ZVS) for the specified AC-input-voltage range. Besides, with an appropriate design

Ricardo de Oliveira Brioschi; J. L. F. Vieira

1998-01-01

313

1-V power supply high-speed digital circuit technology with multithreshold-voltage CMOS  

Microsoft Academic Search

1-V power supply high-speed low-power digital circuit technology with 0.5-?m multithreshold-voltage CMOS (MTCMOS) is proposed. This technology features both low-threshold voltage and high-threshold voltage MOSFET's in a single LSI. The low-threshold voltage MOSFET's enhance speed performance at a low supply voltage of 1 V or less, while the high-threshold voltage MOSFET's suppress the stand-by leakage current during the sleep period.

S. Mutoh; T. Douseki; Y. Matsuya; T. Aoki; S. Shigematsu; J. Yamada

1995-01-01

314

Influence of electric power distribution system design on harmonic propagation  

Microsoft Academic Search

The impact of the design parameters of electric power distribution systems on the propagation of harmonic distortion is investigated. This conceptual study is based on simulations on a generalized distribution system model, and leads to an increased insight in the mechanisms of the generation and propagation of voltage distortion. Moreover, analytical expressions are presented that predict the impact of changing

J. A. Ghijselen; W. A. Ryckaert; J. A. Melkebeek

2004-01-01

315

Stability analysis of large electric power systems  

SciTech Connect

Modern electric power systems are large and complicated, and, in many regions of the world, the generation and transmission systems are operating near their limits. Ensuring the reliable operation of the power system requires engineers to study the response of the system to various disturbances. The responses to large disturbances are examined by numerically solving the nonlinear differential-algebraic equations describing the power system. The response to small disturbances is typically studied via eigenanalysis. The Electric Power Research Institute (EPRI) recently developed the Extended Transient/Mid-term Stability Program (ETMSP) to study large disturbance stability and the Small Signal Stability Program Package (SSSP) to study small signal stability. The primary objectives of the work described in this report were to (1) explore ways of speeding up ETMSP, especially on mid-term voltage stability problems, (2) explore ways of speeding up the Multi-Area Small-Signal Stability program (MASS), one of the codes in SSSP, and (3) explore ways of increasing the size of problem that can be solved by the Cray version of MASS.

Elwood, D.M.

1993-01-01

316

Electric power monthly, December 1989  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decision makers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and state level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and average retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and retail prices data by 1 month. This difference in reporting appears in the national, Census division, and state level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. More information can be obtained by writing or calling the National Energy Information Center, EI-231, Forrestal Building, Washington, DC 20585, (202)586-8800. The 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. 10 refs., 1 fig., 40 tabs.

Not Available

1990-03-13

317

Pulsed power for electric guns  

Microsoft Academic Search

Pulsed power requirements for electric guns are described and preferred technologies for energy storage and pulse compression are discussed. Primary approaches are rotating machines and capacitor based, pulse-forming networks, but alternative technologies that may offer some operational benefits are also discussed. These include linear magnetic flux compressors, cryogenically cooled, high-temperature superconducting inductors, novel dielectrics for energy storage, and pulsed magnetohydrodynamic

Ian R. McNab

1997-01-01

318

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.

319

Electric power monthly, August 1988  

SciTech Connect

The /ital Electric Power Monthly (EPM)/ focuses on the electric utility industry in the United States. Detailed, plant-level data are contained in the /ital Electric Power Quarterly/. More information can be obtained by writing or calling the National Energy Information Center, EI-231, Forrestal Building, Washington, DC 20585, (202) 586-8800. The 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 Energy Information Administration (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. Year-to-date 1987 data for sales and prices in previously published issues of the /ital EPM/ were preliminary. The 1987 values in this issue are revised Form EIA-826, ''Monthly Electric Sales and Revenue Report with State Distributions,'' data. Final 1987 sales data will be available from the Form EIA-861,'' Annual Electric Utility Report.'' 10 refs., 1 fig., 27 tabs.

Not Available

1988-11-10

320

Continuous electricity generation at high voltages and currents using stacked microbial fuel cells.  

PubMed

Connecting several microbial fuel cell (MFC) units in series or parallel can increase voltage and current; the effect on the microbial electricity generation was as yet unknown. Six individual continuous MFC units in a stacked configuration produced a maximum hourly averaged power output of 258 W m(-3) using a hexacyanoferrate cathode. The connection of the 6 MFC units in series and parallel enabled an increase of the voltages (2.02 V at 228 W m(-3)) and the currents (255 mA at 248 W m(-3)), while retaining high power outputs. During the connection in series, the individual MFC voltages diverged due to microbial limitations at increasing currents. With time, the initial microbial community decreased in diversity and Gram-positive species became dominant. The shift of the microbial community accompanied a tripling of the short time power output of the individual MFCs from 73 W m(-3) to 275 W m(-3), a decrease of the mass transfer limitations and a lowering of the MFC internal resistance from 6.5 +/- 1.0 to 3.9 +/- 0.5 omega. This study demonstrates a clear relation between the electrochemical performance and the microbial composition of MFCs and further substantiates the potential to generate useful energy by means of MFCs. PMID:16749711

Aelterman, Peter; Rabaey, Korneel; Pham, Hai The; Boon, Nico; Verstraete, Willy

2006-05-15

321

Electrical power generation and distribution system  

Microsoft Academic Search

Problems associated with moving fuel from remote sources to large centralized power generation plants are avoided with an economical system for collecting power from small stations located near the scattered, remote fuel sites. To avoid a need for many massive, costly transformers, a plurality of relatively low voltage generating stations are connected in series to cumulatively produce the high voltage

Jeppson

1977-01-01

322

Test wire for high voltage power supply crowbar system  

SciTech Connect

The klystron microwave amplifier tubes used in the Low Energy Demonstration Accelerator (LEDA) and to be used in the Accelerator Production of Tritium (APT) plant have a strict upper limit on the amount of energy which can be safely dissipated within the klystron`s vacuum envelope during a high voltage arc. One way to prevent damage from occurring to the klystron microwave amplifier tube is through the use of a crowbar circuit which diverts the energy stored in the power supply filter capacitors from the tube arc. The crowbar circuit must be extremely reliable. To test the crowbar circuit, a wire that is designed to fuse when it absorbs a predetermined amount of energy is switched between the high voltage output terminals. The energy required to fuse the wire was investigated for a variety of circuits that simulated the power supply circuit. Techniques for calculating wire length and energy are presented along with verifying experimental data.

Bradley, J.T. III; Collins, M.

1997-09-01

323

Electrical ageing of polyethylene power cables insulation subjected to an electric field in the presence of water  

Microsoft Academic Search

Under the action of an electric field and in the presence of water, water trees develop inside power cables insulations. Regardless of their type, shape or dimension, water trees contribute to the worsening of electrical properties, especially lowering the inception voltages of partial discharges and electrical trees leading to breakdown (1). In this paper an experimental study regarding the variation

Mihai Plopeanu; Petru V. Notingher; Cristina Stancu; Sorin Grigorescu

2011-01-01

324

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

325

Probabilistic Vulnerability Assessment Based on Power Flow and Voltage Distribution  

SciTech Connect

Risk assessment of large scale power systems has been an important problem in power system reliability study. Probabilistic technique provides a powerful tool to solve the task. In this paper, we present the results of a study on probabilistic vulnerability assessment on WECC system. Cumulant based expansion method is applied to obtain the probabilistic distribution function (PDF) and cumulative distribution function (CDF) of power flows on transmission lines and voltage. Overall risk index based on the system vulnerability analysis is calculated using the WECC system. The simulation results based on WECC system is used to demonstrate the effectiveness of the method. The methodology can be applied to the risk analysis on large scale power systems.

Ma, Jian; Huang, Zhenyu; Wong, Pak C.; Ferryman, Thomas A.

2010-04-30

326

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

327

Electric power monthly, February 1994  

SciTech Connect

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 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 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

1994-02-16

328

Electric power monthly, October 1992  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. 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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-10-16

329

Electric power monthly, February 1992  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. 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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publications provides monthly statistics at the national. Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, new generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Not Available

1992-02-25

330

Electric power monthly, April 1989  

SciTech Connect

This report is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); Department of Energy. The purpose of this publication is to provide energy decisionmakers with accurate and timely information. The EPM presents monthly summaries of electric utility statistics at the national, Census division, and state level for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and retail prices of electricity. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generating, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag the most net generation, fuel consumption, fuel stocks, electricity sales, and retail prices data by 1 month. This difference in reporting appears in the national, Census division, and state level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 1 fig., 37 tabs.

Not Available

1989-07-18

331

Intelligent Voltage and Reactive Power Control of Mini-Hydro Power Stations for Maximisation of Real Power Export  

Microsoft Academic Search

Operating the automatic voltage regulator (AVR) of a water turbine-driven synchronous generator in constant power factor mode may lead to excessive voltage variations. Depending on the capacity of the hydro-generator and the inherent voltage variation in the network, operating in constant voltage mode may lead the machine and AVR into excess excitation and shut-down or failure. Furthermore, network operators need

Aristides E. Kiprakis; A. Robin Wallace

332

Multi-model based fault detection for the power system of more electric aircraft  

Microsoft Academic Search

This paper presents a suitable scheme for the fault detection and isolation of a high voltage DC electrical network in more electric aircraft. Concerning a more electric aircraft architecture comprising one variable frequency generator, one 18-pulse autotransformer, power electronic converters, high voltage DC transmission lines, electromagnetic actuators and numerous constant electrical loads e.g. lighting and PCs, the multi-model detection approach

Y. Ji; J. Bals

2009-01-01

333

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

334

Capacity of Overhead Medium Voltage Power Line Communication Channels  

Microsoft Academic Search

This paper considers broadband transmission via the overhead medium voltage (MV) grid. The MV broadband over power lines (MV\\/BPL) channels considered are three-phase overhead MV lines above lossy plane ground. To determine the end-to-end transfer function of any MV\\/BPL configuration the scattering matrix method is adopted. Various topologies of MV\\/BPL transmission channels have been studied with regard to their end-to-end

Athanasios G. Lazaropoulos; Panayiotis G. Cottis

2010-01-01

335

COOLMOSTM-a new milestone in high voltage power MOS  

Microsoft Academic Search

Recently, a new technology for high voltage power MOSFETs has been introduced: the CoolMOSTM. Based on the new device concept of charge compensation, the RDS(on) area product for e.g. 600 V transistors has been reduced by a factor of 5. The devices show no bipolar current contribution like the well known tail current observed during the turn-off phase of IGBTs.

L. Lorenz; G. Deboy; A. Knapp; M. Marz

1999-01-01

336

Design of Simple Structure Neural Voltage Regulator for Power Systems  

Microsoft Academic Search

\\u000a This paper presents a simple neural Automatic Voltage Regulator (AVR) for power systems. By representing the proposed neuro-controller\\u000a in s-domain, its parameters can be obtained analytically to ensure system stability. Results of simulation studies on a nonlinear\\u000a third order generator model with the proposed neuro-controller using calculated parameters are given. Results of simulation\\u000a studies demonstrate the effectiveness of this simple

Mahdi Jalili-kharaajoo

2005-01-01

337

The Design of Low-voltage Welding Power Distribution  

Microsoft Academic Search

This paper is an effort to state clearly and to present a solution for the problems encountered in the design of one of the vital constituents of a-c restance-welder power supply¿the low-voltage feeder. The scope of the paper is much wider, however, since the determination of design loads from the probability standpoint for the purpose of determining maximum allowable impedance

Comfort A. Adams; John R. Fetcher; Arthur C. Johnson

1944-01-01

338

New technological trends in high-voltage power circuit breakers  

Microsoft Academic Search

This article introduces a comprehensive survey on new trends in high-voltage (HV) power circuit breakers (CBs) technology. Applying the new puffer and the self-blast technologies, the ratings of SF6 CBs have reached upto 1,100 kV, 80 kA, and 50 GVA, which is the world's largest gas insulated switchgear (GIS), with independent pole operation and utilizing the advantages of external composite

IBRAHIM A. METWALLY

2006-01-01

339

System for Stabilizing the Magnitude and Frequency of Voltages in a Micro Hydroelectric Power Plant with Asymmetric Ballast Regulation  

Microsoft Academic Search

Regulation of the electric power generated by an autonomous electric-supply system fed from a micro hydroelectric plant (microHEP) using an additional ballast load is an effective means of stabilizing the magnitude and frequency of its voltages.Power that can be diffused in ballast can be regulated using thyristor phase-regulating devices or thyristor keys that commutate a set of ballast resistances in

B. V. Lukutin; E. B. Shandarova

2001-01-01

340

MOSFET-Automotive Power MOSFETs-Low-Gate-Voltage-Controlled Power MOSFETs,  

National Technical Information Service (NTIS)

Power MOSFETs which have low on-resistance and operate at lower gate voltage have been in strong demand according to the recent trend of increasing application of electronics to the automotive industry. In response to this demand, low-gate-voltage-control...

H. Tanita K. Kitamura I. Kawashima A. Kayahara

1988-01-01

341

Power storage system for electric railway  

SciTech Connect

This invention relates to a power storage system for electric railway which comprises a motor-generator connected to a power system for feeding an electric vehicle with electric power, and a flywheel coupled to the motor-generator, and in which the motor-generator is allowed to store the electric power and thereafter discharge it in correspondence with approach of the electric vehicle to a predetermined running section and running thereof in the section.

Kawamura, T.

1985-06-11

342

Novel high-voltage power lateral MOSFET with adaptive buried electrodes  

NASA Astrophysics Data System (ADS)

A new high-voltage and low-specific on-resistance (Ron,sp) adaptive buried electrode (ABE) silicon-on-insulator (SOI) power lateral MOSFET and its analytical model of the electric fields are proposed. The MOSFET features are that the electrodes are in the buried oxide (BOX) layer, the negative drain voltage Vd is divided into many partial voltages and the output to the electrodes is in the buried oxide layer and the potentials on the electrodes change linearly from the drain to the source. Because the interface silicon layer potentials are lower than the neighboring electrode potentials, the electronic potential wells are formed above the electrode regions, and the hole potential wells are formed in the spacing of two neighbouring electrode regions. The interface hole concentration is much higher than the electron concentration through designing the buried layer electrode potentials. Based on the interface charge enhanced dielectric layer field theory, the electric field strength in the buried layer is enhanced. The vertical electric field EI and the breakdown voltage (BV) of ABE SOI are 545 V/?m and -587 V in the 50 ?m long drift region and the 1 ?m thick dielectric layer, and a low Ron,sp is obtained. Furthermore, the structure also alleviates the self-heating effect (SHE). The analytical model matches the simulation results.

Zhang, Wen-Tong; Wu, Li-Juan; Qiao, Ming; Luo, Xiao-Rong; Zhang, Bo; Li, Zhao-Ji

2012-07-01

343

Study on Terminal Voltage and Power Factor Control of Induction Generators for Wind Power Generation System  

NASA Astrophysics Data System (ADS)

This paper deals with two types of control method concerning induction generator used in wind power generating station. One is aiming at keeping the voltage magnitude of the node of the station and the other is aiming at keeping the constant power factor through the branch connecting to the station. Both of them are able to be in controllable area by adjusting generator reactive power using compensating capacitor. At first, the theoretical equations expressing terminal voltage and power factor for induction generator are derived, and then the compensating capacitor corresponding to the wind velocity variation is determined quantitatively. By using the proposed control method, it is confirmed to be able to keep the terminal voltage and operating power factor of wind power generation system to a target value even in the case when the abrupt deviation is caused by wind power disturbance.

Senjyu, Tomonobu; Sueyoshi, Norihide; Kuninaka, Ryo; Uezato, Katsumi; Fujita, Hideki; Funabashi, Toshihisa

344

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.

345

Electric power monthly, July 1994  

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. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. 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. Data on quantity, quality, and cost of fossil fuels lag data on net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour by 1 month. This difference in reporting appears in the US, Census division, and State level tables. However, for purposes of comparison, plant-level data are presented for the earlier month.

Not Available

1994-07-01

346

The relative evimunity of the skin and cardiovascular system to the direct effects of high voltage - high frequency component electrical pulses  

Microsoft Academic Search

This paper summarizes our testing to date of commercdy available battery powered hand held electric pulse generators, sometimes called TASER's, stun guns, or Less Than Lethal Weapons (LTLW). We present the generalized electronic properties of these devices along with physiologic effects on human and animal subjects. providing a differential voltage divider factor of 1ooO. Further voltage division was accomplished using

Robert A. Stratbucker; Matthew G. Marsh

1993-01-01

347

EMTP based stability analysis of Space Station Electric Power System in a test bed environment  

Microsoft Academic Search

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)

Narayan V. Dravid; Thomas J. Kacpura; Andrew M. O'Connor

1992-01-01

348

Electric power monthly, January 1990  

SciTech Connect

The EPM is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag and net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison.

Not Available

1990-04-24

349

Application of Newton's optimal power flow in voltage\\/reactive power control  

Microsoft Academic Search

An application of Newton's optimal power flow methods to secondary voltage\\/reactive power control in transmission networks is considered. An efficient computer program based on sparse matrix\\/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power

M. Bjelogrlic; M. S. Calovic; P. Ristanovic; B. S. Babic

1990-01-01

350

Multiobjective optimal power flows to evaluate voltage security costs in power networks  

Microsoft Academic Search

In this paper, new optimal power flow (OPF) techniques are proposed based on multiobjective methodologies to optimize active and reactive power dispatch while maximizing voltage security in power systems. The use of interior point methods together with goal programming and linearly combined objective functions as the basic optimization techniques are explained in detail. The effects of minimizing operating costs, minimizing

William D. Rosehart; Claudio A. Cañizares; Victor H. Quintana

2003-01-01

351

Electric field and voltage distribution on ZnO surge arrester  

Microsoft Academic Search

In the present paper with the aid of PC-Opera-8.7 a 21 kV surge arrester with and without broken shed is simulated for electrical field and voltage distribution. The effects of broken shed on electric field and voltage distribution, also position of broken shed are investigated and results are shown.

B. Vahidi; R. S. Nassab; J. Sh. Moghani; S. H. Hosseinian

2004-01-01

352

Effect of electrical-utility-system voltage harmonics on induction motors  

SciTech Connect

Distortion of the electrical utility system voltage waveform can result in damage to or malfunction of user electrical equipment. An experiment was carried out to determine the effect of utility voltage harmonics on the temperature rise of single-phase induction motors. The results suggest that utility voltage harmonics do not significantly affect the operating temperature of a single-phase induction motor until the amplitudes of the harmonics are much larger than the amplitudes currently present in the US utility system.

Rasmussen, N.E.

1981-03-01

353

Energy Conservation in the Electric Power System.  

National Technical Information Service (NTIS)

The possibilities for energy conservation in the Norwegian electric power supply system are analysed. This power system is based exclusively on hydroelectric power and consists of water storage reservoirs, pipes and tunnels for water transport, power plan...

A. Killingtveit K. Tvinnereim

1983-01-01

354

Power Sales to Electric Utilities  

SciTech Connect

The Public Utilities Regulatory Policies Act (PURPA) of 1979 requires that electrical utilities interconnect with qualifying facilities and purchase electricity at a rate based upon their full avoided costs (i.e., costs of providing both capacity and energy). Qualifying facilities (QF) include solar or geothermal electric units, hydropower, municipal solid waste or biomass-fired power plants, and cogeneration projects that satisfy maximum size, fuel use, ownership, location, and/or efficiency criteria. In Washington State, neither standard power purchase prices based upon a proxy ''avoided plant'', standard contracts, or a standard offer process have been used. Instead, a variety of power purchase contracts have been negotiated by developers of qualifying facilities with investor-owned utilities, public utility districts, and municipally-owned and operated utilities. With a hydro-based system, benefits associated with resource acquisition are determined in large part by how compatible the resource is with a utility's existing generation mix. Power purchase rates are negotiated and vary according to firm energy production, guarantees, ability to schedule maintenance or downtime, rights of refusal, power plant purchase options, project start date and length of contract; front-loading or levelization provisions; and the ability of the project to provide ''demonstrated'' capacity. Legislation was also enacted which allows PURPA to work effectively. Initial laws established ownership rights and provided irrigation districts, PUDs, and municipalities with expanded enabling powers. Financial processes were streamlined and, in some cases, simplified. Finally, laws were passed which are designed to ensure that development proceeds in an environmentally acceptable manner. In retrospect, PURPA has worked well within Washington. In the state of Washington, 20 small-scale hydroelectric projects with a combined generating capacity of 77 MW, 3 solid waste-to-energy facilities with 55 MW of electrical output, 4 cogeneration projects with 34.5 MW of generating capability, and 4 wastewater treatment facility digester gas-to-energy projects with 5 MW of electrical production have come on-line (or are in the final stages of construction) since the passage of PURPA. These numbers represent only a small portion of Washington's untapped and underutilized cogeneration and renewable resource generating potentials. [DJE-2005

None

1989-02-01

355

Investigation of various generator reactive power reserve (GRPR) definitions for online voltage stability\\/security assessment  

Microsoft Academic Search

Voltage stability in power system is influenced by reactive support at various locations. It is desirable to monitor the reactive power reserves as system conditions change. There is a need to find a relationship between the reactive power reserves and system security with respect to voltage stability margin and voltage violations. In this paper we have investigated how different approaches

B. Leonardi; V. Ajjarapu

2008-01-01

356

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

Code of Federal Regulations, 2010 CFR

...111.79-13 Different voltages and power types. If receptacle...vessel are supplied by different voltages (e.g., 110 volts and...types of power (e.g., AC and DC), each receptacle...receptacle outlet of an incompatible voltage or type of power....

2009-10-01

357

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

Code of Federal Regulations, 2010 CFR

...111.79-13 Different voltages and power types. If receptacle...vessel are supplied by different voltages (e.g., 110 volts and...types of power (e.g., AC and DC), each receptacle...receptacle outlet of an incompatible voltage or type of power....

2010-10-01

358

Voltage and Frequency Control of Isolated Asynchronous Generator with Reduced Switch Integrated Voltage Source Converter in Isolated Wind Power Generation  

Microsoft Academic Search

This paper deals with the I.cos¿ algorithm for the voltage and frequency control (VFC) of an autonomous wind power generation using an isolated asynchronous generator (IAG) feeding three-phase four-wire loads. The reference source currents are estimated using the I.cos¿ algorithm to control the voltage and frequency of IAG system. Two-leg voltage source converter (VSC) with split capacitor and an isolated

Shailendra Sharma; Bhim Singh

2009-01-01

359

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

Microsoft Academic Search

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

Murty

2000-01-01

360

Control system for electric power plant  

SciTech Connect

This patent describes a control system for a power plant. The power plant consists of a generator including means for producing a generator filed, a turbine for converting the flow of a fluid into mechanical power to drive the generator, a control means for regulating the flow of the fluid, a voltage regulator for controlling the generator field to thereby control the voltage produced by the generator, a bus, and a main circuit breaker for selectively connecting the generator to the bus, the control system comprising: nonvolatile memory means for storing configuration data comprising a plurality of configuration parameters for the power plants; input means for producing input data including data indicating a speed of the turbine, a position of the control means, a current and a voltage produced by the generator, a current and a voltage produced by the generator, a current and a voltage on the bus, and a position of the main circuit breaker; multitasking processing means for processing the input data in accordance with the configuration data, to thereby produce control signals including breaker signals for tripping and closing the main circuit breaker, voltage level signals for establishing a voltage setpoint for the voltage regulator, and a control signal for controlling the position of the control means and, edit means for enabling an operator to edit the configuration data, to thereby configure the control system for a particular power plant.

McManus, K.L.; McManus, P.J.

1988-11-29

361

Dynamic voltage regulation and power export in a distribution system using distributed generation  

Microsoft Academic Search

The major aim of power quality (PQ) enhancing techniques is to maintain a specified voltage magnitude at a desired frequency\\u000a for sensitive loads irrespective of faults on the power distribution network. The dynamic voltage restorer (DVR) is a device\\u000a used to mitigate voltage sags to regulate load voltage. This paper presents a mathematical model for leading series voltage\\u000a injection to

Aamir Hanif; Muhammad Ahmed Choudhry

2009-01-01

362

Electric vehicles as a new power source for electric utilities  

Microsoft Academic Search

Electric-drive vehicles, whether fueled by batteries or by liquid or gaseous fuels generating electricity on-board, will have value to electric utilities as power resources. The power capacity of the current internal combustion passenger vehicle fleet is enormous and under-utilized. In the United States, for example, the vehicle fleet has over 10 times the mechanical power of all current U.S. electrical

Steven E. Letendre

1997-01-01

363

Optimization Design of MultiLevel Combination Electrostatic Precipitator Electric Field Voltage Control  

Microsoft Academic Search

For realizing automatic voltage control and automatic protection, the traditional mechanical potentiometer was replaced by an automatic unit with hardcore device: microcomputer-single chip and digital programmable potentiometer (DPP), and the power voltage of the electrostatic precipitator (ESP) were adjusted exactly by the auto unit. The automatic control process of the ESP's work voltage was described in detail by a three

Li Qing; Liu Lihua; Liu Zhiqiang; Zhang Bo; Xiao Zhenlei

2010-01-01

364

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

SciTech Connect

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

None

2012-01-25

365

Programmable voltage regulating method for high voltage DC power supply based on digital potentiometer and linear photoelectric coupling  

Microsoft Academic Search

In order to solve the disadvantages caused by mechanical slide rheostat that they were big errors and low precision, a novel voltage regulation method for high voltage DC power supply was introduced. The key of this method were digital potentiometer Maxim 5455 and linear photoelectric coupling LOC110, and application programs were compiled using Visual Basic which was graphical compiling language,

Chen Xin; Mi Yan; Li Cheng-xiang; Yao Chen-guo; Du Lin; Wang Shi-shou

2008-01-01

366

30 CFR 75.704 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems.  

Code of Federal Regulations, 2013 CFR

...Grounding frames of stationary high-voltage equipment receiving power from...Grounding frames of stationary high-voltage equipment receiving power from... The frames of all stationary high-voltage equipment receiving power...

2013-07-01

367

30 CFR 77.703 - Grounding frames of stationary high-voltage equipment receiving power from ungrounded delta systems.  

Code of Federal Regulations, 2013 CFR

...Grounding frames of stationary high-voltage equipment receiving power from...Grounding frames of stationary high-voltage equipment receiving power from... The frames of all stationary high-voltage equipment receiving power...

2013-07-01

368

VSCF aircraft electric power system performance with active power filters  

Microsoft Academic Search

A three-phase three-wire shunt active power filter (APF) is presented to regulate the load terminal voltage, eliminate harmonics, correct supply power-factor and balance the nonlinear unbalanced loads. A three-phase based current controlled voltage source inverter is used as an active power filter. The control algorithm for the APF is based on the perfect harmonic cancellation method which provides a three-phase

A. Eid; H. El-Kishky; M. Abdel-Salam; T. El-Mohandes

2010-01-01

369

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

SciTech Connect

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. The electric motor itself in the preferred embodiment is a highly reliable squirrel-cage induction motor powered directly from the VV/VF supply, with the result that its speed is proportional to the generator frequency, which in turn is dependent on the aircraft engine speed. The main cabin compressor and a secondary (auxiliary) supercharging compressor are both mounted on the motor shaft. The motor-compressor configuration is further characterized in that the ac motor has pole-changing winding (typically two), which permits two speed operation, while the cabin compressor is provided with inlet guide vanes. The interactive combination of these two features makes it possible to furnish the requisite air mass flow and pressurization levels over the conditions of variable air density and variable atmospheric pressure, as the airplane operates throughout its flight envelope.

Cronin, M.J.

1984-07-31

370

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

SciTech Connect

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. The electric motor itself in the preferred embodiment is a highly reliable squirrel-cage induction motor powered directly from the VV/VF supply, with the result that its speed is proportional to the generator frequency, which in turn is dependent on the aircraft engine speed. The main cabin compressor and a secondary (auxiliary) supercharging compressor are both mounted on the motor shaft. The motor-compressor configuration is further characterized in that the ac motor has pole-changing winding (typically two), which permits two speed operation, while the cabin compressor is provided with inlet guide vanes. The interactive combination of these two features makes it possible to furnish the requisite air mass flow and pressurization levels over the conditions of variable air density and variable atmospheric pressure, as the airplane operates throughout its flight envelope.

Cronin, M. J.

1985-10-15

371

Large-scale wind power integration and voltage stability limits in regional networks  

Microsoft Academic Search

When planning and developing large-scale wind power plants in areas distant from the main power transmission system, voltage control assessments and reactive power compensation are increasingly important. Voltage stability of the regional network may be a main limitation with respect to maximum rating and operation of the wind power plant Technical constraints in relation to wind power integration in weak

M. P. Palsson; T. Toftevaag; K. Uhlen; J. O. G. Tande

2002-01-01

372

Reactive power control of wind farms for voltage control applications  

Microsoft Academic Search

In the last few years, there is a strong trend towards decentralised production and supply, leading to a situation where a growing number of small and medium size producers will be connected to energy networks. But at the same time, the power quality of the generation must be ensured and this means that the electrical parameters of the distribution network

A. Tapia; G. Tapia; J. X. Ostolaza

2004-01-01

373

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

374

Dual signal frequencies and voltage levels for low power and temperature-gradient tolerant clock distribution  

Microsoft Academic Search

A methodology based on supply voltage and frequency scaling for lowering the power consumption and temperature fluctuations induced skew of clock distribution networks is proposed in this paper. The clock signal is distributed globally at a scaled supply voltage and frequency. The optimum supply voltage that minimizes clock skew is 44% less than the nominal supply voltage in a 0.18?m

Sherif A. Tawfik; Volkan Kursun

2007-01-01

375

Fast voltage stability assessment and reinforcement in an interconnected power system  

Microsoft Academic Search

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

Wen-Ta Hsiao

1998-01-01

376

Boost Rectifier Power Factor Correction Circuits with Improved Harmonic and Load Voltage Regulation Responses  

Microsoft Academic Search

The time domain step response for rapid load changes can be improved in boost type power factor correction circuits by using a capacitor voltage model. In single phase PFC circuits, the dc bus voltage must have a significant voltage ripple at twice the mains frequency due to energy balance requirements. In traditional implementations, the presence of this ripple voltage causes

Peter Wolfs; Peter Thomas

2007-01-01

377

Development of a 60 Hz Power Standard Using SNS Programmable Josephson Voltage Standards  

Microsoft Academic Search

We are implementing a new standard for 60 Hz power measurements based on precision sinusoidal reference voltages from two independent programmable Josephson voltage standards (PJVS): one for voltage and one for current. The National Institute of Standards and Technology PJVS systems use series arrays of Josephson junctions to produce accurate quantum-based DC voltages. Using stepwise-approximation synthesis, the PJVS systems produce

Samuel P. Benz; Paul D. Dresselhaus; Bryan C. Waltrip; Thomas L. Nelson; Yonuk Chong; Jonathan M. Williams; Dale Henderson; Pravin Patel; Luis Palafox; Ralf Behr

2007-01-01

378

A Nonlinear Voltage Regulator With One Tunable Parameter for Multimachine Power Systems  

Microsoft Academic Search

This paper proposes a nonlinear voltage regulator with one tunable parameter for multimachine power systems. Based on output feedback linearization, this regulator can achieve simultaneous voltage regulation and small-signal performance objectives. Conventionally output feedback linearization has been used for voltage regulator design by taking infinite bus voltage as reference. Unfortunately, this controller has poor small-signal performance and cannot be applied

Gurunath Gurrala; Indraneel Sen

2011-01-01

379

Design of new diesel-electric power supply unit for military vehicles  

Microsoft Academic Search

This paper introduces a new designed diesel-electric power-supply unit developed for military purposes. The power-supply unit is divided to two main electric parts, (i) input part which is composed of a sensorless controlled active voltage source rectifier supplied by a permanent magnet synchronous generator, and (ii) output part which is composed of a four-leg three-phase voltage source inverter with a

Z. Peroutka; T. Glasberger; J. Molna?r

2010-01-01

380

Power Control of New Wind Power Generation System with Induction Generator Excited by Voltage Source Converter  

NASA Astrophysics Data System (ADS)

This paper investigates advantages of new combination of the induction generator for wind power and the power electronic equipment. Induction generator is popularly used for the wind power generation. The disadvantage of it is impossible to generate power at the lower rotor speed than the synchronous speed. To compensate this disadvantage, expensive synchronous generator with the permanent magnets is sometimes used. In proposed scheme, the diode rectifier is used to convert the real power from the induction generator to the intermediate dc voltage, while only the reactive power necessary to excite the induction generator is supplied from the voltage source converter (VSC). This means that the rating of the expensive VSC is minimized and total cost of the wind power generation system is decreased compared to the system with synchronous generator. Simulation study to investigate the control strategy of proposed system is performed. The results show the reduction of the VSC rating is prospective.

Morizane, Toshimitsu; Kimura, Noriyuki; Taniguchi, Katsunori

381

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

382

Use a less power low voltage IGBT converter to adjust speed of a full power medium voltage induction motor of fan or pump  

Microsoft Academic Search

To solve the difficulty of medium voltage variable frequency drive of fan or pump, a technique, rotor-side variable frequency drive (RVFD), is introduced that a less power (0.2-0.3P\\/sub N\\/) low voltage (<400 V) IGBT converter is used to adjust speed of a full power medium voltage (6-10 kV) motor. The features of the technique are: simple circuit, less large devices,

Chunjie Wang; Xiaoliang Ma

2004-01-01

383

More-electric aircraft electrical power system accelerated functional modeling  

Microsoft Academic Search

The development of future more-electric aircraft (MEA) is a major trend in modern aircraft electric power system (EPS) engineering that results in a significantly increased number of onboard loads driven by power-electronics. Development of appropriate EPS architectures, ensuring the power system integrity, stability and assessment of overall system quality and performance under possible normal and abnormal scenarios requires extensive simulation

S. V. Bozhko; T. Wu; Y. Tao; G. M. Asher

2010-01-01

384

Experimental Investigation of Breakdown Voltage and Electrical Breakdown Time Delay of Commercial Gas Discharge Tubes  

NASA Astrophysics Data System (ADS)

This article presents the experimental results of DC dynamic breakdown voltage Ub for small voltage increase rates and electrical breakdown time delay td of commercial gas discharge tubes. It was shown that Ub is a stochastic value with Gauss distribution for voltage increase rates ?2 V/s. In order to determine the static breakdown voltage Us as a deterministic quantity, the mean values of the dynamic breakdown voltage \\bar{U}b as a function of voltage increase rate k were extrapolated until the intersection with \\bar{U}b axis using linear fit. The intersection point (for k = 0) correspond to Us value. Additional experiments were performed in order to verify the temperature stability of these components over the wide temperature range from 25 to 250 °C. The experimental results of electrical breakdown time delay are also presented in the paper. Electrical breakdown time delay if often refereed as delay response and it is also very important parameter of gas filled devices. It was shown when the voltage higher then 310 V is applied to those components, the mean value of electrical breakdown time delay \\bar{t}d insignificantly varies to the value of relaxation time ?? 1 s, while the breakdown probability is close to one for the voltages higher then 380 V. These facts show that the commercial gas discharge tubes are very reliable for the protection for voltages higher then 380 V.

Pejovi?, Mili? Mom?ilo; Pejovi?, Mom?ilo Mili?; Stankovi?, Koviljka

2011-08-01

385

Electric Power Monthly, February 1987  

SciTech Connect

In February 1987, net generation from nuclear-powered units represented a record share, 18.9%, of the total electricity produced during the month. The previous record share, 18.5%, occurred in December 1986. Net generation from nuclear energy was 36,598 gigawatthours in February 1987, 12% higher than in February 1986. Net generation from hydroelectric units was 21,216 gigawatthours in February 1987, 9% lower than the February 1986 level. In comparison with previous February generation levels, the hydroelectric net generation level has not been this low since February 1981 when electric utilities reported 21,099 gigawatthours. The reservoir levels in the Northwest, an area which is a major producer of hydroelectricity, were low in February 1987. As a result, electric utilities in the Pacific Contiguous Census Division reported 23% less generation from hydroelectric units in February 198 as compared to the same month a year ago. In January 1987, (the latest month of available cost data) the average cost of the fossil fuels delivered to electric utility steam plants (of 50-megawatt installed nameplate capacity or larger) was lower than in January 1986. Specifically, on a cents-per-million-Btu basis, the average cost of coal was 150.4, 6% lower, the average cost of petroleum was 370.0, 24% lower, and the average cost of gas was 233.6, 26% lower. When the average cost of fuels in January 1987 was compared with the average cost of fuels for December 1986, electric utilities paid a 2% increase for deliveries of gas and a 20% increase for deliveries of petroleum. However, the cost to utilities for deliveries of coal decreased 1% for this time period. 27 tabs.

Not Available

1987-02-01

386

Neural network based overcurrent voltage controlled protection system in large electrical networks  

Microsoft Academic Search

Generation stations are considered extremely vital part of power system. Overcurrent voltage controlled relays are extensively used as backup protection of generators. Coordination between generator overcurrent voltage controlled relays and transmission line directional overcurrent relays represents a tedious task in power system protection as it depends heavily on network topology and system parameters. Mis-coordination is normally practiced in this situation.

Yasser G. Mostafa; M. Shafik Aly

2009-01-01

387

COMPOSITE LOAD SENSITIVITY IN VOLTAGE STABILITY PROBLEM SOLVED BY UNIFIED POWER FLOW CONTROLLER  

Microsoft Academic Search

Alleviation of voltage stability problem by using Unified Power Flow Controller (UPFC) represents main concern of this paper. The UPFC is analysed as the device capable of giving voltage support and\\/or co- ordinating power flow control action. Voltage stability problem is viewed from longer-term time domain response of a composite load model. Sensitivity analysis is applied with respect to parameters

Nijaz Dizdarevi? S; Göran Andersson

2002-01-01

388

Voltage stability constrained load curtailment procedure to evaluate power system reliability measures  

Microsoft Academic Search

This paper reports a method to evaluate composite power system reliability indices incorporating the voltage stability margin criteria. To compute the load curtailment evaluation, an optimal power flow (OPF) computation algorithm, considering the steady state voltage stability margin constraint is developed. A steady state voltage stability indicator is first discussed for its applicability as a suitable indicator for representing stability

G. M. Huang; Nirmal-Kumar C Nair

2002-01-01

389

Accuracy Analysis of Static Voltage Stability Indices Based On Power Flow Model  

Microsoft Academic Search

There are some voltage stability indices for voltage security assessment and calculating stable margin from operating point to voltage instability at each load bus. Most of those indices are based on static analyses using power flow model. This paper aims to verifying the accuracy of representative power flow model based indices by small signal stability analysis and dynamic time domain

Huadong Sun; Xiaoxin Zhou; Ruomei Li

2005-01-01

390

A comparative study of voltage stability indices in a power system  

Microsoft Academic Search

The paper compares the effectiveness of voltage stability indices in providing information about the proximity of voltage instability of a power system. Three simple voltage stability indices are proposed and their effectiveness is compared with some of the recently proposed indices. The comparison is carried out over a wide range of system operating conditions by changing the load power factor

A. K. Sinha; D. Hazarika

2000-01-01

391

A DC voltage control method of cascaded H-bridge inverter for power quality conditioner  

Microsoft Academic Search

In recent years, multilevel technology has become an effective and practical solution for moderate and high voltage application field. In all multilevel technology, cascade multilevel inverters have become the major circuits used in power quality conditioners. Evidently,the voltage balancing problem of DC capacitors of cascade inverters is a key problem to the power quality conditioners. This paper explores voltage balancing

Yanhui Qiu; Yingjie He; Jinjun Liu; Fang Zhuo

2010-01-01

392

Incorporation of dynamic voltage stability constraints in the ATC determination of power system  

Microsoft Academic Search

The evaluation of available transfer capability (ATC) in deregulated power system should take into account thermal limits, transient, steady-state and dynamic angle stability as well as the voltage stability limits. The consideration of voltage stability in the determination of ATC, however, was usually neglected. On the other hand, under the power market environment, voltage instability becomes a more important consideration

Y. Cheng; T. S. Chung; C. Y. Chung; C. W. Yu

2004-01-01

393

Profile-based optimization of power performance by using dynamic voltage scaling on a PC cluster  

Microsoft Academic Search

Currently, several of the high performance processors used in a PC cluster have a DVS (dynamic voltage scaling) architecture that can dynamically scale processor voltage and frequency. Adaptive scheduling of the voltage and frequency enables us to reduce power dissipation without a performance slowdown during communication and memory access. In this paper, we propose a method of profiled-based power-performance optimization

Yoshihiko Hotta; Mitsuhisa Sato; Hideaki Kimura; Satoshi Matsuoka; Taisuke Boku; Daisuke Takahashi

2006-01-01

394

Transformerless power line voltage conditioner and regulator based on CA PWM Chopper  

Microsoft Academic Search

Utility power quality problems like input voltage unbalance and sag conditions severely stress electronic equipment. Voltage sag forecasting is a complex issue, since it involves a large variety of random factors, such as: type of shortcircuits in the power system, location of faults, protective system performance and atmospheric discharges. Recently, the AC-AC converters have been proposed as voltage compensator. In

Jose-Maria Flores-Arias; A. Moreno-Munoz; R. Real-Calvo; J. R. Sanchez

2010-01-01

395

Optical sensors for electrical elements of a medium voltage distribution network  

NASA Astrophysics Data System (ADS)

The aging of most of the components of the National transmission and distribution system can potentially influence the reliability of power supply in a Medium Voltage (MV) network. In order to prevent possible dangerous situations, selected diagnostic indicators on electrical parts exploiting reliable and potentially low-cost sensors are required. This paper presents results concerning two main research activities regarding the development and application of innovative optical sensors for the diagnostic of MV electrical components. The first concerns a multi-sensor prototype for the detection of pre-discharges in MV switchboards: it is the combination of three different types of sensors operating simultaneously to detect incipient failure and to reduce the occurrence of false alarms. The system is real-time controlled by an embedded computer through a LabView interface. The second activity refers to a diagnostic tool to provide significant real-time information about early aging of MV/Low Voltage (LV) transformers by means of its vibration fingerprint. A miniaturized Optical Micro-Electro-Mechanical System (MEMS) based unit has been assembled for vibration measurements, wireless connected to a remote computer and controlled via LabView interface. Preliminary comparative tests were carried out with standard piezoelectric accelerometers on a conventional MV/LV test transformer under open circuit and in short-circuited configuration.

De Maria, Letizia; Bartalesi, Daniele; Serragli, Paolo; Paladino, Domenico

2012-03-01

396

PMUs optimized allocation using a tabu search algorithm for fault location in electric power distribution system  

Microsoft Academic Search

Phasor measurement units (PMUs) optimized allocation allows control, monitoring and accurate operation of electric power distribution systems, improving reliability and service quality. Good quality and considerable results are obtained for transmission systems using fault location techniques based on voltage measurements. Based on these techniques and performing PMUs optimized allocation it is possible to develop an electric power distribution system fault

R. A. F. Pereira; L. G. W. da Silva; J. R. S. Mantovani

2004-01-01

397

Alterations in arterial function after high-voltage electrical injury  

PubMed Central

Introduction The aim of this study was to evaluate the functional changes of the arterial endothelium and smooth muscle after a high-voltage electrical injury (HVEI), using flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD). Methods Twenty-five male patients injured in the upper extremities by current due to contact with more than 20,000 volts were enrolled in the study. FMD and NMD were measured on the brachial artery within 48 hours after HVEI, and follow-up FMD and NMD were evaluated six weeks later. In addition, we enrolled an age, sex and body mass index matched healthy control group consisting of 25 individuals. Including FMD and NMD, all the variables of the control group were investigated one time and compared with the initial and six week follow-up data of the HVEI group. Results A significantly lower initial FMD was seen in the HVEI group compared with the control group (2.1 ± 1.2% versus 13.6 ± 3.4%, P < 0.01). At the six week follow-up, the FMD of the HVEI group had significantly improved compared to the initial FMD (2.1 ± 1.2% versus 5.1 ± 2.1%, P < 0.01), but it was still lower than the FMD of the control group (5.1 ± 2.1% versus 13.6 ± 3.4%, P < 0.01). A significantly lower NMD was seen both initially and at the six week follow-up compared with the NMD of the control group (7.3 ± 4.7% versus 20.4 ± 4.1%, P < 0.01 and 11.4 ± 6.7% versus 20.4 ± 4.1%, P < 0.01, respectively). The FMD study of the contralateral arm which was uninjured by HVEI was available in six patients. In those patients, the six week follow-up FMD was significantly improved in the HVEI arm compared with the initial FMD (1.8 ± 0.6% versus 4.4 ± 1.6%, P < 0.01). However, in the contralateral uninjured arm, there was no difference between the initial and the six week follow-up FMDs (5.5 ± 1.4% versus 6.9 ± 2.2%, P = 0.26). Conclusions After HVEI, the endothelial and smooth muscle functions of the brachial artery were significantly decreased for at least six weeks. Long term cautious care might be needed for all victims of HVEI, because there is a chance of increased risk of thrombosis or stenosis in the injured arm.

2012-01-01

398

Threshold voltage of luminescence and electrical tree inception in low-density polyethylene  

SciTech Connect

The characteristics of luminescence observed during the initiation of an electrical tree have been studied for polyethylene subjected to high electrical stresses. Use of a light detection system which is at least three orders-of-magnitude more sensitive than conventional partial discharge detectors shows that luminescence occurs during tree initiation and this luminescence is not due to partial discharges. Applying a constant high voltage to the polymer or interrupting the voltage several times does not change the behavior of luminescence. The light starts at about the same voltage and its intensity returns to the same value as before the interruption. This behavior is contrary to that observed for partial discharges. The luminescence inception voltage is the threshold voltage at which the polymer starts to degrade. Thus, it is important that the insulation of electrical equipment be protected from transient overvoltages which exceed the threshold level.

Bamji, S.S.; Bulinski, A.T.; Densley, R.J.

1988-06-15

399

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

400

DC link voltage control strategy of grid-connected wind power generation system  

Microsoft Academic Search

In wind power generation systems, the turbulence of the wind will result in power variations and thus affect the DC link voltage ripples and the power quality in the grid. A fuzzy logic controller is designed in this paper for reducing the DC link voltage ripples of the permanent magnet wind power generation system. The simulation model is built under

Jianzhong Zhang; Ming Cheng

2010-01-01

401

Voltage stability margin improvement using shunt capacitors and active and reactive power management  

Microsoft Academic Search

Improvement of the power system economical dispatch from voltage stability margin viewpoint is studied in this paper and for that a methodology is proposed. The considered time interval is short term operation. Active and reactive power (generation) re-dispatch injection is the basis of proposed method and voltage stability will be achieved using generated reactive power by shunt capacitors in power

H. Omidi; B. Mozafari; A. Parastar; M. A. Khaburi

2009-01-01

402

Design and installation of extra high voltage cryogenic dielectric test facilities for the superconducting electric equipment  

NASA Astrophysics Data System (ADS)

Superconducting electric equipments have a lot of advantages over the conventional devices such as improvements in overall efficiency, size reduction, high current carrying capability, and also environment-friendly products. Owing to these advantages, many research institutes have been tried to develop commercial superconducting devices, which could be applicable to the high voltage and high current electric networks. But up to now, most of the research works to develop commercial products were delayed because it was not easy to acquire reliable high voltage insulation properties and optimum insulation design skills considering extremely low temperature environments. Furthermore, it was difficult to determine optimum high voltage insulation level due to the lack of high voltage cryogenic dielectric test facilities. Thus, in order to establish the cryogenic dielectric technology regarding insulating design, cryogenic dielectric test skills, and to implement more reliable high voltage superconducting devices, high voltage cryogenic dielectric test facilities should be prepared for extra high voltage superconducting electric equipments. Recently, cryogenic dielectric test facilities were installed including 3 m long 2 m wide cryostat system with bushing, and 1.6 MVA lightening impulse generators, 400 kVA AC overvoltage test system in Korea. In this paper, design and installation of high voltage cryogenic dielectric test system including very big size FRP cryostat and high voltage bushing were minutely introduced. And some test results to develop high voltage bushings for liquid nitrogen cryostat in order to implement extra high voltage level bushings were illustrated. These test facilities will be fully utilized for the optimization of insulation design for extra high voltage superconducting electric equipments.

Lee, S. H.; Shin, W. J.; Khan, Umer A.; Oh, S. H.; Seong, J. K.; Lee, B. W.

2011-11-01

403

A Reduced-Part, Triple-Voltage DC-DC Converter for EV/HEV Power Management  

SciTech Connect

Electrical power systems in future hybrid and fuel cell vehicles may consist of three voltage nets: 14 V, 42 V, and high voltage (>200 V) buses. A soft-switched, bidirectional dc-dc converter that uses only four switches was proposed for interconnecting the three nets. This paper presents a reduced-part dc-dc converter, which decreases the converter cost while retaining all the favorable features of the original topology. Experimental data are included to verify a simple power flow control scheme.

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

2009-01-01

404

HEMP interaction with an electric power distribution circuit. Final report  

SciTech Connect

A high altitude nuclear burst, detonated at a height of 50 km or more, causes two types of electromagnetic pulses, high altitude EMP (HEMP) and magnetohydrodynamic EMP, which will interact with electric power systems. Previous work indicated that millions of miles of electric distribution systems in the United States may be especially vulnerable to HEMP incident simultaneously throughout large portions of the United States. Purpose of this work was to perform an initial assessment of HEMP induced surges on a simplified electric distribution system. This report presents the assumptions, methodology, and resulting induced transient voltages and currents at various points in the distribution circuit in the microsecond timeframe, considering the impacts of HEMP incident simultaneously throughout the distribution system for a range of parametric conditions. Results of this work suggest that EMP could induce voltage transients that far exceed the basic insulation level (BIL) of distribution systems and that a more detailed analysis is warranted.

Zaininger, H.W.; Jaszewski, G.M.

1985-08-01

405

A novel single-phase power-factor-corrected voltage regulator  

Microsoft Academic Search

This paper presents a new single-phase power-factor-corrected (PFC) AC\\/DC voltage regulator using a parallel power processing scheme. By combining a PFC cell and a DC\\/DC cell into a new power converter structure, higher conversion efficiency than those of the conventional cascaded configurations can be achieved while maintaining good power factor and fast output voltage regulation. Moreover, the storage capacitor voltage

D. D. C. Lu; D. K. W. Cheng; Y. S. Lee

2001-01-01

406

Imaging and estimation of human abdominal fat by electrical impedance tomography using multiple voltage measurement patterns.  

PubMed

A measuring device for human abdominal fat from the conductivity image derived by electrical impedance tomography (EIT) is rarely found. This study was aimed to reconstruct precise conductivity images from multiple voltage measurements in different patterns of the combination of current and voltage electrodes. We examined two voltage measuring patterns using electrodes located at upper and lower levels around the abdomen of a subject. In the experiment, after 1024 voltage data were taken from one specified voltage measurement pattern, another 1024 data were also taken continuously using another pattern. The reconstruction of conductivity image was made using entire data. As a result, the tomography image was improved compared with the image obtained from single voltage measurement pattern. We then obtained the histogram of the conductivities and estimated the area of abdominal fat. The present method using multiple voltage measurement patterns would be effective, if the measuring time can be much reduced through future modification of the tomography device. PMID:24110433

Yamaguchi, Tohru F; Katashima, Mitsuhiro; Wang, Li-Qun; Kuriki, Shinya

2013-07-01

407

Mine electrical power systems. Transients protection, reliability investigation, and safety testing of mine electrical power systems. Volume V--periodic inspection of mine electrical power systems. Open file report (final) 24 Jun 74-15 aug 78  

Microsoft Academic Search

This report presents the results of an investigation into the feasibility of periodically measuring parameters of the insulation for a mine electrical power system to detect incipient faults. The variety of insulation parameters evaluated included insulation resistance, dissipation factor, power factor (versus applied voltage), current harmonics, leakage current, infrared radiation, as well as certain circuit breaker parameters and tests. To

E. K. Stanek; M. M. Hassan; Y. C. Chou; H. Shamash

1979-01-01

408

Ultra low-voltage\\/low-power digital floating-gate circuits  

Microsoft Academic Search

This paper describes a novel technique for implementing ultra low-voltage\\/low-power digital circuits. The effective threshold voltage seen from a control gate is adjusted during a UV-light-activated tuning procedure. The optimal effective threshold voltage matching the supply voltage and speed may be programmed by UV light through an activated conductance between the power rails and the floating gates. Measured results are

Yngvar Berg; Dag T. Wisland; Tor S. Lande

1999-01-01

409

Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks  

SciTech Connect

This report describes the development of a cascading outage analyzer that, given an initial disturbance on an electric power system, checks for thermal overloads, under-frequency and over-frequency conditions, and under-voltage conditions that would result in removal of elements from the system. The analyzer simulates the successive tripping of elements due to protective actions until a post-event steady state or a system blackout is reached.

Ross Baldick; Thekla Boutsika; Jin Hur; Manho Joung; Yin Wu; Minqi Zhong

2009-01-31

410

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

411

Hybrid Method to Assess Sensitive Process Interruption Costs Due to Faults in Electric Power Distribution Networks  

Microsoft Academic Search

This paper shows a new hybrid method for risk assessment regarding interruptions in sensitive processes due to faults in electric power distribution systems. This method determines indices related to long duration interruptions and short duration voltage variations (SDVV), such as voltage sags and swells in each customer supplied by the distribution network. Frequency of such occurrences and their impact on

Juan C. Cebrian; Nelson Kagan

2010-01-01

412

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

413

Relation Between Electric Power and Temperature Difference for Thermoelectric Generator  

NASA Astrophysics Data System (ADS)

The thermoelectric generation is the direct energy conversion method from heat to electric power. The conversion method is a very useful utilization of waste energy because of its possibility using a thermal energy below 423K. This research objective is to establish the thermoelectric technology on an optimum system design method and efficiency, and cost effective thermoelectric element in order to extract the maximum electric power from a wasted hot water. This paper is considered in manufacturing a thermoelectric generator and manufacturing of thermoelectric generator with 32 thermoelectric modules. It was also found that the electric voltage of thermoelectric generator with 32 modules slowly changed along temperature differences and the maximum power of thermoelectric generator using thermoelectric generating modules can be defined as temperature function.

Woo, Byung Chul; Lee, Hee Woong

414

The thin SOI TGLDMOS transistor: a suitable power structure for low voltage applications  

NASA Astrophysics Data System (ADS)

This paper is addressed to the analysis of the trench gate LDMOS transistor (TGLDMOS) in a thin SOI technology and to investigate its suitability for low voltage power applications. The static and dynamic performances have been extensively analyzed by means of numerical simulations and compared with a conventional thin SOI power LDMOS transistor. The specific on-state resistance of the analyzed TGLDMOS structure is lower than that of the LDMOS counterpart, but the structure design has to be optimized to minimize the added contributions to the parasitic capacitances. In this sense, a modified TGLDMOS is also proposed to reduce the gate-drain capacitance and to increase the frequency capability. The expected electrical performance improvements of both TGLDMOS and modified TGLDMOS power transistors corroborate their suitability for 80 V switching and amplifying applications.

Cortés, I.; Fernández-Martínez, P.; Flores, D.; Hidalgo, S.; Rebollo, J.

2007-10-01

415

Advanced medium-voltage bidirectional dc-dc conversion systems for future electric energy delivery and management systems  

NASA Astrophysics Data System (ADS)

The distributed renewable energy generation and utilization are constantly growing, and are expected to be integrated with the conventional grid. The growing pressure for innovative solutions will demand power electronics to take an even larger role in future electric energy delivery and management systems, since power electronics are required for the conversion and control of electric energy by most dispersed generation systems Furthermore, power electronics systems can provide additional intelligent energy management, grid stability and power quality capabilities. Medium-voltage isolated dc-dc converter will become one of the key interfaces for grid components with moderate power ratings. To address the demand of medium voltage (MV) and high power capability for future electric energy delivery and management systems, the power electronics community and industry have been reacting in two different ways: developing semiconductor technology or directly connecting devices in series/parallel to reach higher nominal voltages and currents while maintaining conventional converter topologies; and by developing new converter topologies with traditional semiconductor technology, known as multilevel converters or modular converters. The modular approach uses the well-known, mature, and cheaper power semiconductor devices by adopting new converter topologies. The main advantages of the modular approach include: significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and time; power systems can be easily reconfigured to support varying input-output specifications; and possibly higher efficiency and power density of the overall system. Input-series output-parallel (ISOP) modular configuration is a good choice to realize MV to low voltage (LV) conversion for utility application. However, challenges still remain. First of all, for the high-frequency MV utility application, the low switching loss and conduction loss are must-haves for high efficiency, while bidirectional power flow capability is a must for power management requirement. To address the demand, the phase-shift dual-halfbridge (DHB) is proposed as the constituent module of ISOP configuration for MV application. The proposed ISOP DHB converter employs zero-voltage-switching (ZVS) technique combined with LV MOSFETs to achieve low switching and conduction losses under high frequency operation, and therefore high efficiency and high power density, and bidirectional power flow as well. Secondly, a large load range of high efficiency is desired rather than only a specific load point due to the continuous operation and large load variation range of utility application, which is of high importance because of the rising energy cost. This work proposes a novel DHB converter with an adaptive commutation inductor. By utilizing an adaptive inductor as the main energy transfer element, the output power can be controlled by not only the phase shift but also the commutation inductance, which allows the circulating energy to be optimized for different load conditions to maintain ZVS under light load conditions and minimize additional conduction losses under heavy load conditions as well. As a result, the efficiency at both light and heavy load can be significantly improved compared with the conventional DHB converter, and therefore extended high-efficiency range can be achieved. In addition, current stress of switch devices can be reduced. The theoretical analysis is presented and validated by the experimental results on a 50 kHz, 1 kW dc-dc converter module. Thirdly, input-voltage sharing and output-current sharing are critical to assure the advantages of the ISOP modular configuration. To solve this issue, an identically distributed control scheme is proposed in this work. The proposed control scheme, using only one distributed voltage loop to realize both input-voltage and output-current sharing, provides plug-and-play capability, possible high-level fault tolerance, and easy implementatio

Fan, Haifeng

416

Electric Power: Decisions for the Future.  

ERIC Educational Resources Information Center

Reviews the past 25 years of electricity consumption in the United States and considers the implications for the near future. Discusses strategies for energy conservation and provides a student activity for measuring and conserving electric power. (Author/JOW)

Cardon, Phillip L.; Preston, John

2003-01-01

417

Electric Power: Decisions for the Future.  

ERIC Educational Resources Information Center

|Reviews the past 25 years of electricity consumption in the United States and considers the implications for the near future. Discusses strategies for energy conservation and provides a student activity for measuring and conserving electric power. (Author/JOW)|

Cardon, Phillip L.; Preston, John

2003-01-01

418

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

419

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

420

Power Ratings of an Electric Motor for Electric Vehicles.  

National Technical Information Service (NTIS)

This report presents the methodology used to calculate the peak and continuous power ratings of a Switched Reluctance Motor (SRM) used for electric propulsion of an Electric Vehicle (EV). A procedure is given to calculate the peak and continuous power rat...

S. S. Ramamurthy J. C. Balda

1999-01-01

421

Electric Power Plants and Electricity Generation in Turkey  

Microsoft Academic Search

Electricity demand in Turkey grows rapidly as a result of the rate of population growth, a rapid industrialization, and economic development. When the Republic of Turkey was founded in 1923, its installed capacity of electricity production and the total electricity production were only 33 MW and 45 GWh, respectively. But, Turkey's installed power capacity reached 38,843.5 MW with an annual

M. Bilgili; B. ?ahin

2009-01-01

422

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

423

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

424

Solar thermal electric power information user study  

NASA Astrophysics Data System (ADS)

The results of a series of telephone interviews with groups of users of information on solar thermal electric power are described. These results identified types of information each group needed and the best ways to get 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.

Belew, W. W.; Wood, B. L.; Marle, T. L.; Reinhardt, C. L.

1981-02-01

425

Study on electrical strength of suspension insulators in steep impulse voltage range  

SciTech Connect

High and steep lightning surge voltages sometimes cause electrical punctures of suspension insulators. Microscopic analysis clarifies electrical breakdown mechanism of ceramic material. V-t characteristics of the insulators are closely examined. Chance of the puncture depends on the dimensions of the insulators, steepness of the impulse voltages and the number of impulse occurrences. Empirical equations relating to these parameters has been established based on laboratory test results. Calculation shows no risk of puncture on the quality insulators for the impulse voltages of 2,500 kV/{micro}s steepness which is required by the standards.

Morita, K.; Suzuki, Y.; Nozaki, H. [NGK Insulators, Ltd., Mizuho, Nagoya (Japan)

1997-04-01

426

Electric power annual 1995. Volume I  

SciTech Connect

The Electric Power Annual presents a summary of electric power industry 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 data that may be used in understanding U.S. electricity markets. The Electric Power Annual is prepared by the Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); U.S. Department of Energy. In the private sector, the majority of the users of the Electric Power Annual are researchers and analysts and, ultimately, individuals with policy- and decisionmaking responsibilities in electric utility companies. Financial and investment institutions, economic development organizations interested in new power plant construction, special interest groups, lobbyists, electric power associations, and the news media will find data in the Electric Power Annual useful. In the public sector, users include analysts, researchers, statisticians, and other professionals with regulatory, policy, and program responsibilities for Federal, State, and local governments. The Congress and other legislative bodies may also be interested in general trends related to electricity at State and national levels. Much of the data in these reports can be used in analytic studies to evaluate new legislation. Public service commissions and other special government groups share an interest in State-level statistics. These groups can also compare the statistics for their States with those of other jurisdictions.

NONE

1996-07-01

427

Electric power quality and efficiency of power supply  

Microsoft Academic Search

The quality of power supply depends on the quality of electrical energy, and also on the frequency and duration of probable interruptions in power supply, which increase with decrease of electric power quality (EPQ). The problem of EPQ has an important economic and technical significance for all countries, including Israel. Based on well-known experiences of solving the main aspects of

A. Lipsky; A. Braunstein; N. Miteva; M. Slonim

2000-01-01

428

Optical dc current and voltage measurement by superposing ac magnetic or electric field  

NASA Astrophysics Data System (ADS)

Optical DC current and voltage measurement using Faraday or Pockels effect necessitates the compensation of light intensity variation with some methods, because it is possible the intensity variation may give rise to a measuring error. We have proposed a method which suggests superposing AC magnetic field on linearly polarized light or AC electric field on elliptically polarized light and compensating light intensity variation by detecting AC components caused by constant AC magnetic or electric field. Experiments of long term stability for DC current and voltage measurement were carried out by using flint glass for DC current measurement and B12SiO20 (BSO) crystals for DC voltage measurement. An experimental result of DC current measurement where DC current of 1.0 A was passed under AC current of 1 kHz 1.5 Arms showed that the modulation depth without compensation through AC magnetic field varied largely with time because of the temperature rise of the flint glass, but that with compensation through AC magnetic field hardly varied with time and the effectiveness of AC magnetic field superposition was confirmed. The same compensation method was applied to optical DC voltage measurement using Pockels effect. An experimental result of DC voltage measurement where DC voltage of 500 V was applied under AC voltage of 5 kHz 50 Vrms clarified that the time variation of the modulation depth with compensation through AC electric field was small compared with that without compensation through AC electric field.

Higaki, Masaru; Fujii, Kunio; Yamaguchi, Shizuo

1999-05-01

429

Power quality load management for large spacecraft electrical power systems  

NASA Astrophysics Data System (ADS)

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.

1988-09-01

430

GENERALIZED SENSITIVITY EVALUATION OF ELECTRICAL POWER SYSTEMS  

Microsoft Academic Search

The material presented in this thesis is a logical extension of and addition to previous work on network sensitivities as applied to power system analysis and planning. The continuing tendency of supplementing the existing extra-high voltage a.c. transmission systems with high-voltage d.c.(HVDC) lines has been taken into consideration, and various relevant component models have been investigated using a new hybrid

HARKIRAT KAUR GREWAL

1987-01-01

431

Generalized Sensitivity Evaluation of Electrical Power Systems  

Microsoft Academic Search

The material presented in this thesis is a logical extension of and addition to previous work on network sensitivities as applied to power system analysis and planning. The continuing tendency of supplementing the existing extra-high voltage a.c. transmission systems with high-voltage d.c.(HVDC) lines has been taken into consideration, and various relevant component models have been investigated using a new hybrid

Harkirat Kaur Grewal

1986-01-01

432

Electromagnetic Noise Superimposed on the Electric Power Supply to Electronic Medical Equipment  

Microsoft Academic Search

The use of mobile medical electronic equipment driven at low electric power outputs has progressed rapidly in recent years. Voltage change and noise superimposed on the power supply could create obstacles to the operation of medical electronic equipment. We observed the quality of the power supply of medical electronic equipment in a university hospital, and found approximately 5% distortion on

Eisuke Hanada; Kyoko Takano; Kenji Kodama

2003-01-01

433

Energy Management Fuzzy Logic Supervisory for Electric Vehicle Power Supplies System  

Microsoft Academic Search

This paper introduces an energy management strategy based on fuzzy logic supervisory for road electric vehicle, combining a fuel cell power source and two energy storage devices, i.e., batteries and ultracapacitors. The control strategy is designed to achieve the high-efficiency operation region of the individual power source and to regulate current and voltage at peak and average power demand, without

AndrÉ Augusto Ferreira; JosÉ Antenor Pomilio; Giorgio Spiazzi; Leonardo de Araujo Silva

2008-01-01

434

Power flow management strategies for a local DC Distribution System of More Electric Aircraft  

Microsoft Academic Search

The local DC Power Distribution System of More Electric Aircraft has to be able to sustain bidirectional power flow to and from electromechanical devices. Because the mechanical source (Turbine Engine) is unidirectional, some storage and dissipation systems are necessary to store or\\/and dissipate the returned energy to maintain the DC bus voltage to the reference value. Different power management strategies

He Zhang; Fabien MOLLET; Stefan BREBAN; Christophe SAUDEMONT; Benoît ROBYNS

2010-01-01

435

29 CFR 1910.269 - Electric power generation, transmission, and distribution.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Electric power generation, transmission...IEEE Guide for Field Testing Power Apparatus Insulation. IEEE...for Protective Grounding of Power Lines. IEEE Std. 1067-1990...and Testing of Conductive Clothing for Use on Voltages up to...

2009-07-01

436

29 CFR 1910.269 - Electric power generation, transmission, and distribution.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Electric power generation, transmission...IEEE Guide for Field Testing Power Apparatus Insulation. IEEE...for Protective Grounding of Power Lines. IEEE Std. 1067-1990...and Testing of Conductive Clothing for Use on Voltages up to...

2010-07-01

437

A methodology for monitoring harmonic distortions in electric power distribution systems  

Microsoft Academic Search

This paper deals with a methodology for the assessment of power quality indices in electric power distribution system, particularly related to voltage harmonic distortions. The paper also presents a proposal for a measurement protocol, a testing procedure to evaluate existing power quality meters and recommendations for the introduction of consistent harmonic assessment indices and parameters to support the implementation of

N. Kagan; E. L. Ferrari; N. M. Matsuo; S. X. Duarte; J. L. Cavaretti; A. Tenorio; L. R. Souza

2002-01-01

438

Intelligent management of distributed generators reactive power for loss minimization and voltage control  

Microsoft Academic Search

This paper presents an intelligent approach for managing reactive power from a group of distributed generators (DG) connected to low voltage (LV) bus. The objective is to minimize active power losses and keep the voltage profiles in the network within specified limit. This approach finds optimal DG reactive power and optimal tap changer position for main substation transformer every fifteen

Mohd Zamri Che Wanik; Istvan Erlich; Azah Mohamed

2010-01-01

439

A family of PFC voltage regulator configurations with reduced redundant power processing  

Microsoft Academic Search

This paper discusses a systematic method for deriving basic converter configurations that achieve power factor correction (PFC) and voltage regulation. The discussion begins with a general three-port representation of power supplies that provide PFC and voltage regulation. Based on this representation and a power flow consideration, a systematic procedure is derived to generate all possible minimal configurations. Among these configurations,

Chi K. Tse; Martin H. L. Chow; Martin K. H. Cheung

2001-01-01

440

Load rates of low voltage transformers and medium voltage profile assessments on a real distribution electric grid based on average Daily Load Profile (DLP) of a housing for a high penetration of plug-in hybrid electric vehicles (PHEVs)  

Microsoft Academic Search

This paper assesses the impact of PHEVs on a real medium voltage distribution electric grid based on average Daily Loads Profiles (DLPs) of a PHEV and of a housing. For three penetration rates, we show the important effects on load rates of low voltage transformers which compose the studied urban substation. Nevertheless, we demonstrate the robustness of medium voltage electric

H. Turker; A. Florescu; S. Bacha; D. Chatroux

2011-01-01

441

Dual-threshold voltage assignment with transistor sizing for low power CMOS circuits  

Microsoft Academic Search

We demonstrate a novel algorithm for assigning the threshold voltage to the gates in a digital random logic complementary metal-oxide-semiconductor (CMOS) circuit for a dual-threshold voltage process. The tradeoff between static and dynamic power consumption has been explored. When used along with device sizing and supply voltage reduction techniques for low power, the proposed algorithm can reduce the total power

P. Pant; R. K. Roy; A. Chattejee

2001-01-01

442

Optimum voltage regulator placement in a radial power distribution network  

Microsoft Academic Search

A computer algorithm for optimal voltage control with voltage regulators, suitable for large radial distribution networks is given in this paper. An objective function concerning the total cost of the voltage regulators (investment and maintenance cost) as well as the cost of losses of the examined networks is developed and constitutes the base of the algorithm. This algorithm makes the

Anastasia S. Safigianni; George J. Salis

2000-01-01

443

Growing the Space Station's Electrical Power Plant.  

National Technical Information Service (NTIS)

For over a decade NASA LeRC has been defining, demonstrating, and evaluating power electronic components and multi-kilowatt, multiply redundant, electrical power systems as part of OAST charter. Whether one considers aircraft (commercial transport/militar...

G. R. Sundberg

1990-01-01

444

Electricity Production at Fuel Cell Power Plants.  

National Technical Information Service (NTIS)

The essentially higher efficiency of electricity production is the most significant advantage of the fuel cell power plant compared to the conventional power plants. The maximum efficiency obtained in techno-economic estimates has been about 55%. The oper...

J. Leppaelahti

1989-01-01

445

Does voltage predict return to work and neuropsychiatric sequelae following electrical burn injury?  

PubMed

Voltage has historically guided the acute management and long-term prognosis of physical morbidity in electrical injury patients; however, few large studies exist that include neuropsychiatric morbidity in final outcome analysis. This review compares high (>1000 V) to low (<1000 V) voltage injuries, focusing on return to work and neuropsychiatric sequelae following electrical burn injury. Patients with electrical injuries admitted to the University of North Carolina Jaycee Burn Center between 2000 and 2005 were prospectively entered into a trauma database, then retrospectively reviewed. Patients were divided into 4 cohorts: high voltage (>1000 V), low voltage (<1000 V), flash arc, and lightning. Demographics, hospital course, and follow-up were recorded to determine physical and neuropsychiatric morbidity. Differences among cohorts were tested for statistical significance. Over 5 years, 2548 patients were admitted to the burn center, including 115 patients with electrical injuries. There were 110 males and 5 females, with a mean age of 35 years (range, 0.75-65 years). The cause of the electrical injury was high voltage in 60 cases, low voltage in 25 cases, flash arc in 29 cases and lightning in 1 case. The mean total body surface area burn was 8% (range, 0%-52%). The etiology was work-related electrical injury in 85 patients. Mean follow-up period was 352 days with 13 (11%) patients lost to follow-up. Patients with high voltage injuries had significantly larger total body surface area burn, longer ICU stays, longer hospitalizations, and significantly higher rates of fasciotomy, amputation, nerve decompression and outpatient reconstruction, with 4 cases of renal failure and 2 deaths. In spite of these differences, high and low voltage groups experienced similar rates of neuropsychiatric sequelae, limited return to work and delays in return to work. Final impairment ratings for the high and low voltage groups were 17.5% and 5.3%, respectively. Electrical injuries often incur severe morbidity despite relatively small burn size and/or low voltage. When comparing high and low voltage injuries, similarities in endpoints such as neuropsychiatric sequelae, the need for late reconstruction, and failure to return to work challenge previous notions that voltage predicts outcome. PMID:20395807

Chudasama, Shruti; Goverman, Jeremy; Donaldson, Jeffrey H; van Aalst, John; Cairns, Bruce A; Hultman, Charles Scott

2010-05-01

446

Simple low-noise power supply for electrical transient measurements.  

PubMed

A very simple means is described for rapidly applying and briefly maintaining a large, essentially noiseless, dc voltage across a capacitive load. The technique is suitable for various nonrepetitive electrical transient measurements, such as carrier mobility determination, occurring over timescales ranging from tens of microseconds to several seconds; it essentially eliminates capacitive currents caused by noise in the power supply voltage, which can interfere with measurement of the true transient current. In an example, the noise on a 10-ms transient current (driven by 2000 V dc, and observed as a voltage across a 100-kOmega load resistor) was barely more than the Johnson noise ( approximately 2x10(-11) A rms) to be expected from the resistor. PMID:18699416

Vincett, P S

1979-11-01

447

A novel self-generated low-voltage power supply for the gate-driver of high-voltage off-line SMPS  

Microsoft Academic Search

A novel self-generated low-voltage power supply for the gate-driver of high-voltage off-line switching model power supply IC is described. The structure and properties of the device are analyzed and simulated. The experimental results have verified that the structure can realize the self-generated function, be controlled by the low-voltage logic signal and get 14 V of the low-voltage power supply. Using

Liu Jizhi; Chen Xingbi

2009-01-01

448

High voltage bulk GaN-based photoconductive switches for pulsed power applications  

NASA Astrophysics Data System (ADS)

Switches are at the heart of all pulsed power and directed energy systems, which find utility in a number of applications. At present, those applications requiring the highest power levels tend to employ spark-gap switches, but these suffer from relatively high delay-times (~10-8 sec), significant jitter (variation in delay time), and large size. That said, optically-triggered GaN-based photoconductive semiconductor switches (PCSS) offer a suitably small form factor and are a cost-effective, versatile solution in which delay times and jitter can be extremely short. Furthermore, the optical control of the switch means that they are electrically isolated from the environment and from any other system circuitry, making them immune from electrical noise, eliminating the potential for inadvertent switch triggering. Our recent work shows great promise to extend high-voltage GaN-based extrinsic PCSS state-of-the-art performance in terms of subnanosecond response times, low on-resistance, high current carrying capacity and high blocking voltages. We discuss our recent results in this work.

Leach, J. H.; Metzger, R.; Preble, E. A.; Evans, K. R.

2013-03-01

449

Module Five: Relationships of Current, Voltage, and Resistance; Basic Electricity and Electronics Individualized Learning System.  

ERIC Educational Resources Information Center

|This module covers the relationships between current and voltage; resistance in a series circuit; how to determine the values of current, voltage, resistance, and power in resistive series circuits; the effects of source internal resistance; and an introduction to the troubleshooting of series circuits. This module is divided into five lessons:…

Bureau of Naval Personnel, Washington, DC.

450

Module Five: Relationships of Current, Voltage, and Resistance; Basic Electricity and Electronics Individualized Learning System.  

ERIC Educational Resources Information Center

This module covers the relationships between current and voltage; resistance in a series circuit; how to determine the values of current, voltage, resistance, and power in resistive series circuits; the effects of source internal resistance; and an introduction to the troubleshooting of series circuits. This module is divided into five lessons:…

Bureau of Naval Personnel, Washington, DC.

451

Outline of CCVT (Coupling Capacitor Voltage Transformer) calibration procedure, EPRI-NBS (Electric Power Research Institute/National Bureau of Standards) prototype system. Supplement to EPRI report EL-890 (Field Calibration System for CCVTs, April 1978)  

NASA Astrophysics Data System (ADS)

The step by step procedure for use of the EPRI-NBS Prototype field Calibration System for Coupling Capacitor Voltage Transformers (CCVTs) in the calibration of CCVTs in the substation is presented. All details are not given, but references are presented which contain the detailed procedures.

Hillhouse, D. L.

1984-08-01

452

Novel Multiple DC-Inputs Direct Electric-Power Converter  

NASA Astrophysics Data System (ADS)

A new multiple dc-inputs direct electric-power converter (D-EPC) has been developed. It is placed between multiple dc power sources and an ac motor, thereby eliminating the need for a dc/dc converter that is generally used in conventional converter/inverter systems. D-PEC can improve the efficiency of a motor drive system with a more compact size. Its power distribution control is carried out by allotting voltage ratios to each of the two different dc power sources on a time average basis. A new pulse width modulation (PWM) generation technique to drive the switching devices in D-EPC has also been developed. Tests have verified that the three-phase ac motor can be operated by controlling the power distribution between the two power sources.

Yoshimoto, Kantaro; Takahashi, Kouji; Okushima, Keiji; Tani, Kazuhiko

453

Voltage control in power system using expert system based on SCADA system  

Microsoft Academic Search

This paper presents the type of expert system for controlling the 22 kV voltage levels of a power system in the northern region of Thailand based on the SCADA system. At present, for the operation, the operators have to make decisions by their knowledge and experience to control the voltage. This expert system is obtained for alleviation of voltage violation

C. Pimpa; S. Premrudeepreechacharn

2002-01-01

454

Voltage Stability Evaluation of The Khouzestan Power System in Iran Using CPF Method and Modal Analysis  

Microsoft Academic Search

Voltage stability is an important factor that needs to be taken into consideration during the planning and operation of power systems in order to avoid voltage collapse and subsequently partial or full system blackout. The study of the voltage collapse phenomenon can provide a way to prevent this event from happening. There have been many methods developed to study the

Farbod Larki; Mahmood Joorabian; H. M. Kelk; M. Pishvaei

2010-01-01

455

Parallel flow to analyze the impact of the voltage regulator model in nanoscale power distribution network  

Microsoft Academic Search

In this paper, an efficient parallel flow for the design of the full power distribution network (PDN) is proposed. The analysis demonstrates the impact of the voltage regulator model in both frequency and time domain response. Based on the experimental results, it is observed that including the voltage regulator model in the PDN model increases the transient voltage drop and

Amirali Shayan Arani; Xiang Hu; He Peng; Wenjian Yu; Wanping Zhang; Chung-kuan Cheng; Mikhail Popovich; Xiaoming Chen; Lew Chua-eoan; Xiaohua Kong

2009-01-01

456

A new power flow method for radial distribution systems including voltage dependent load models  

Microsoft Academic Search

This paper presents a simple and efficient method to solve the power flow problem in radial distribution systems. The proposed method takes into account voltage dependency of static loads, and line charging capacitance. The method is based on the forward and backward voltage updating by using polynomial voltage equation for each branch and backward ladder equation (Kirchoff's Laws). Convergence ability

Ulas Eminoglu; M. Hakan Hocaoglu

2005-01-01

457

Profile-based Optimization of Power Performance by using Dynamic Voltage Scaling on a PC cluster  

Microsoft Academic Search

Currently, several of the high performance processors used in a PC cluster have a DVFS (Dynamic Voltage and Frequency Scaling) architecture that can dynamically scale processor voltage and frequency. Adaptive scheduling of the voltage and frequency enables us to reduce power dis- sipation without a performance slowdown during commu- nication and memory access. In this paper, we propose a method

Yoshihiko Hottay; Mitsuhisa Sato; Hideaki Kimura; Satoshi Matsuoka; Taisuke Boku; Daisuke Takahashi

458

Reactive reserve-based contingency constrained optimal power flow (RCCOPF) for enhancement of voltage stability margins  

Microsoft Academic Search

This paper presents a new concept of reactive reserve-based contingency constrained optimal power flow (RCCOPF) for voltage stability enhancement. This concept is based on the fact that increase in reactive reserves is effective for enhancement of voltage stability margins of post-contingent states. In this paper, the proposed algorithm is applied to voltage stability margin of interface flow. Interface flow limit,

Hwachang Song; Byongjun Lee; Sae-Hyuk Kwon; Venkataramana Ajjarapu

2003-01-01

459

DC power system having battery voltage equalizer circuit  

SciTech Connect

An equalizer circuit is disclosed for permitting two series 12 volt batteries to supply both 24 volts and 12 volts and which maintains the batteries charged to equal voltages. The equalizer circuit is a regulated DC to DC converter with its output connected across the 12 volt battery which is connected to 12 volt loads and its input connected across either the other battery or the 24 volts of the input series pair of batteries. The reference voltage for the regulator is derived from a voltage dividing circuit which is connected across the 24 volt terminals of the two batteries. The voltage dividing circuit provides a reference voltage which is equal to half the voltage across the sum of the voltages of the two batteries.

Sullivan, J.D.

1984-10-23

460

Industrial high-voltage electrical burn of the skull, a preventable injury.  

PubMed

Deep burns of the scalp and skull are often caused by high-voltage electrical injuries. Patients with such injuries should be referred to regional burn centers that are prepared to excise necrotic burn tissue and cover the devitalized bone with a well-vascularized flap. Strategies for prevention of these electrical burns are discussed. PMID:9258785

Wright, H R; Drake, D B; Gear, A J; Wheeler, J C; Edlich, R F

461

Construction and performance of a high voltage zinc bromine battery in an electric vehicle  

Microsoft Academic Search

This paper describes the design, construction, testing and installation of a 391 volt, 35 kWh zinc bromine battery in an electric vehicle. This research project, was referred to as the “Endura project” and resulted in the construction of the highest voltage zinc bromine battery ever to be used in an electric vehicle. The zinc bromine battery is a high energy

David H Swan; Blake Dickinson; Murali Arikara; Manohar Prabhu

1995-01-01

462

Numerical determination of electric field induced currents on human body standing under a high voltage transmission line  

Microsoft Academic Search

In this paper, biological effects of high voltage transmission line electric field on biological systems especially on a grounded human body standing under a high voltage transmission line have been studied. The electric field distribution on a human body standing underneath extra high voltage overhead transmission lines has been calculated by using Boundary element method (BEM). Induced currents and current

S. M. El-Makkawy

2007-01-01

463

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

464

46 CFR 28.850 - Main source of electrical power.  

Code of Federal Regulations, 2011 CFR

... Main source of electrical power. 28.850 Section 28... Main source of electrical power. (a) Applicability...that relies on electricity to power any of the following essential...have at least two electrical generators to supply: (1) The...

2011-10-01

465

46 CFR 28.355 - Main source of electrical power.  

Code of Federal Regulations, 2011 CFR

... Main source of electrical power. 28.355 Section 28... Main source of electrical power. (a) Applicability...that relies on electricity to power any of the following essential...have at least two electrical generators to supply these loads:...

2011-10-01

466

10 CFR 434.401 - Electrical power and lighting systems.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Electrical power and lighting systems. 434...Equipment § 434.401 Electrical power and lighting systems. Electrical...for the sale of accessories, clothing, dry goods, electronics...mechanical buildings, electric power buildings, and similar...

2009-01-01

467

10 CFR 434.401 - Electrical power and lighting systems.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Electrical power and lighting systems. 434...Equipment § 434.401 Electrical power and lighting systems. Electrical...for the sale of accessories, clothing, dry goods, electronics...mechanical buildings, electric power buildings, and similar...

2010-01-01

468

Effect of semiconductor-controlled voltage injection by UPFC and ULTC on power system stability  

NASA Astrophysics Data System (ADS)

Commercial availability of various power semiconductor switches indicates proliferation of power electronic based apparatus in utility power systems. Furthermore, existing power system apparatus, e.g. mechanical phase shifters and mechanical tap changing transformers, will be retrofitted to utilize higher switching speed of semiconductor switches. A group of these apparatus, i.e., unified power flow controller (UPFC), static phase shifter (SPS), under-load tap-changing (ULTC) transformer and static series capacitor (SSC), perform their respective functions by means of injecting series controlled voltages in power systems. This thesis demonstrates that fast series voltage injection, for dynamic power flow regulation, can result in voltage dynamics and even voltage instability. This indicates that fast voltage injection by means of power electronic based apparatus can couple voltage stability and angle stability phenomena. To investigate this coupling phenomena, the voltage dependency of the load must be adequately represented in the load model. The reported studies in this work are based on representing the load by a combination of static and dynamic loads. This thesis primarily investigates impacts of UPFC and semiconductor-controlled ULTC on voltage stability and angle stability phenomena. An eigen analysis approach is used for the studies. The eigen analysis results are validated by digital time-domain simulations using a transient stability software. Both the eigen analysis and the transient stability software tools are tailored to account for angle and voltage stability phenomena.

Alavian Mehr, Alireza

469

Power Sharing Control between Load-Side Inverters in DC Microgrid for Super High Quality Electric Power Distribution System  

NASA Astrophysics Data System (ADS)

DC microgrid is a novel power system using dc distribution in order to provide a super high quality electric power. The dc distribution system is suitable for dc output type distributed generations such as photovoltaic and fuel cells, and energy storages such as batteries and electric double layer capacitors. Power is distributed through dc distribution line and converted to required ac or dc voltage by converters placed near loads. Load-side single phase inverters are connected through transformers in order to share active and reactive power. In this paper, a power sharing control scheme was proposed, and the power sharing characteristics were demonstrated by experimental results.

Kakigano, Hiroaki; Nada, Kaho; Miura, Yushi; Ise, Toshifumi; Uchida, Ryohei

470

Voltage Regulation Performance of a Shunt Active Filter Intended for Installation on a Power Distribution System  

NASA Astrophysics Data System (ADS)

This paper discusses control characteristics of line-voltage regulation by a shunt active filter intended for installation on a power distribution system. Since the power circuit configuration of the active filter is the same as a static synchronous compensator (STATCOM), it is possible to regulate the line voltage by means of controlling an adequate amount of a reactive power. In this case, no harmonic voltage affects a feedback controller for the line-voltage regulation, because the active filter eliminates harmonic components from the line voltage at the installation bus. The dynamic performance is also investigated by computer simulation and experimental results. This paper proposes a new compensation scheme capable of reducing transient voltage fluctuations caused by a phase angle change in the installation bus voltage.

Yamashita, Hiroshi; Jintakosonwit, Pichai; Fujita, Hideaki; Akagi, Hirofumi; Shinohara, Junya; Hakoda, Hirotoshi

471

A closed-loop selective harmonic compensation with capacitor voltage balancing control of cascaded multilevel inverter for high-power active power filters  

Microsoft Academic Search

This paper proposes a closed-loop selective harmonic compensation with capacitor voltage balancing control of cascaded multilevel inverter for high-power active power filters (APF). Firstly, the sum of each phase capacitor voltage is built through absorbing the fundamental active power current from the power system. Further, the capacitor voltage regulation method is presented to balance the voltages of flying capacitor of

Chen Junling; Li Yaohua; Wang Ping; Yin Zhizhu; Dong Zuyi

2008-01-01

472

Solar thermal electricity - Power tower dominates research  

Microsoft Academic Search

The Energy Research and Development Administration (ERDA) has tended to favor development of centralized solar thermal generating plants at the expense of smaller scale intermediate-temperature systems, though, according to a report from the Office of Technology Assessment (OTA), the large solar electric plant, such as the 'power tower' presently being promoted by ERDA and the Electric Power Research Institute (EPRI),

W. D. Metz

1977-01-01

473

High voltage, high power operation of the plasma erosion opening switch  

SciTech Connect

A Plasma Erosion Opening Switch (PEOS) is used as the opening switch for a vacuum inductive storage system driven by a 1.8-MV, 1.6-TW pulsed power generator. A 135-nH vacuum inductor is current charged to approx.750 kA in 50 ns through the closed PEOS which then opens in <10 ns into an inverse ion diode load. Electrical diagnostics and nuclear activations from ions accelerated in the diode yield a peak load voltage (4.25 MV) and peak load power (2.8 TW) that are 2.4 and 1.8 times greater than ideal matched load values for the same generator pulse.

Neri, J.M.; Boller, J.R.; Ottinger, P.F.; Weber, B.V.; Young, F.C.

1987-04-07

474

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

475

Electric power monthly, March 1995  

SciTech Connect

This report for March 1995, presents monthly electricity statistics for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. 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.

NONE

1995-03-20

476

Measurements of electrical conductivity of ceramics under electron irradiation in a high voltage electron microscope  

Microsoft Academic Search

A specimen holder for in-situ measurements of electrical conductivity in a high voltage electron microscope (HVEM) was developed. The performance of newly developed holder was checked by measuring the temperature dependence of the electrical conductivity in ZrO23mol%Y2O3 (YSZ) and the radiation induced conductivity was subsequently measured in YSZ, ?-Al2O3 and MgAl2O4 during irradiation with 1 MeV electrons. The electrical conductivity

Kenichi Shiiyama; Tadahiro Izu; Chiken Kinoshita; Masanori Kutsuwada

1996-01-01

477

Analysis of Near Field Noise Voltage Caused by Pulse Current on Power Electronics Circuits  

NASA Astrophysics Data System (ADS)

Recently, the design procedure of a power electronics circuit structure is discussed for high power density circuits or thin structure converters. Control circuits of the converter circuit may connect close to the power circuit. When the pulse current flows into the power circuit, it radiates the magnetic field and may generate near field noise voltage to the control circuit. Therefore, it is important for the power electronics circuits to evaluate the near field noise voltage by experiment. This paper shows the measurement results of the near field noise voltage and the electromagnetic force voltage of a small area loop antenna from the 15A, 100kHz buck chopper circuit. Moreover, this paper discusses that the noise voltage may affect the control circuits in the high power density circuits.

Ariga, Zen-Nosuke; Wada, Keiji

478

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

479

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

480

Analyzing Techniques for Increasing Power Transfer in the Electric Grid  

NASA Astrophysics Data System (ADS)

The worldwide demand for electric energy is slated to increase by 80% between the years 1990 and 2040. In order to satisfy this increase in load, many new generators and transmission lines are planned. Implementations of various plans that can augment existing infrastructure have been hindered due to environmental constraints, public opposition and difficulties in obtaining right-of-way. As a result, stress on the present electrical infrastructure has increased, resulting in congestion within the system. The aim of this research is to analyze three techniques that could improve the power transfer capability of the present electric grid. These include line compaction, use of high temperature low sag conductors and high phase order systems. The above methods were selected as they could be readily employed without the need for additional right-of-way. Results from the line compaction tests indicate that line compaction up to 30% is possible and this increases the power transfer capability up to 53%. Additional advantages of employing line compaction are the reduction in electric and magnetic fields, increase in system stability and better voltage regulation. High temperature low sag conductors that were applied on thermally limited lines were seen to increase the power transfer capability. However, a disadvantage of this technique was that the second most congested line, limits the power transfer capability of the system. High phase (six phase) order system was noted to have several advantages over three phase system such as lower voltage requirement to transfer equal amount of power and lower electric and magnetic field across the right of way. An IEEE 9 and 118 bus test system were used to evaluate the above mentioned techniques.

Dave, Kushal

481

Control of shunt unbalanced power active compensators for reactive and asymmetry elimination in four wire electrical systems using symmetrical components  

Microsoft Academic Search

The paper presents a new method for obtaining the reference currents for a shunt unbalanced power active compensator (SUPAC), working under unbalanced voltages and asymmetrical l