the generator angle and the DC power Pdc under the case 1 fault; and Figs. 6 and 7 show the system dynamic to be Pd dc � 0:4 in order to minimize the change of DC line power and to keep the pre-fault generatorA nonlinear robust HVDC control for a parallel AC/DC power system Hongzhi Cai a , Zhihua Qu b

A Telecom power supply is studied and analyzed from control system viewpoint. It consists of three stages: AC/DC rectifier, a backup battery, and a Telecom load. The AC/DC rectifier stage can be composed of paralleled DC/DC converters preceded by parallel...

A Telecom power supply is studied and analyzed from control system viewpoint. It consists of three stages: AC/DC rectifier, a backup battery, and a Telecom load. The AC/DC rectifier stage can be composed of paralleled DC/DC converters preceded by parallel...

With the increasing use of dc transmission in existing ac networks, the possibility of ac and dc circuits running parallel to each other and sharing the same right-of-way or even the same tower is increasing. It is important from the point of view of design of such hybrid ac/dc transmission lines to determine the nature and extent of field and ion ...

A mathematical model is developed to investigate the dynamic stability dc system in parallel with an ac transmission system. The dynamic stability model for a one machine infinite bus system is developed first. This model is used to determine the dynamic stability of the parallel ac - dc power system under ...

A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of ...

A novel approach is presented to improve the dynamic stability of a parallel AC-DC power system. The developed scheme employs a proportional-integral-derivative (PID) power system stabilizer (PSS) and a PID rectifier current regulator (RCR) to enhance the damping for the electromagnetical mode of the system. The parameters of the proposed PID controllers ...

An AC-DC converter based on a parallel drive of two piezoelectric ceramic transformers was investigated. The transformers operate in a fundamental contour extensional vibration mode which has a large electromechanical coupling factor notwithstanding the use of a piezoelectric transversal effect. The converter includes Al electrolytic capacitors for smoothing circuits and metal ...

... TECHNIQUES FOR DETERMINING PERFORMANCE AND RATINGS OF CASED CAPACITORS UNDER COMBINED AC-DC OPERATION AS A ...

A new static AC/DC portable military power source providing either 115 V, 400 Hz, AC or 28 V DC, or a combination of both, is described. The primary power source for the AN/GSQ-152( ) Power Supply Set is a thermoelectric generator operating in parallel wi...

Considerable incentives exist for utilities to place hvdc transmission lines along the same right of way as ac lines. One consequence of such an application is steady state induction of fundamental frequency voltages into the dc circuit. The resulting current ripple on the dc converter can cause continuous offset transformer saturation, with many consequent impacts upon system performance and ...

The power system dynamic instability problem on the Pacific AC/DC Intertie was solved by modulating the converter power of the HVDC tie line. An alternate control approach using magnetic energy storage is explored for more general power systems without HVDC lines. Dynamic equivalents of power systems are first formulated using a ...

leg regulates the voltages on their capacitors independently of the others. Main Features #12;AC/DC/AC C: value of the DC-link capacitors Voltage Oscillation Amplitude #12;AC/DC/AC Converters: TwoAC/DC/AC Converters: Two-Level and Multilevel VSI Page 1 Socrates � Erasmus Visit AC/DC/AC

For a parallel ac--dc power system, the effect of a controlled dc link on system stability and damping depends on the system operating conditions. Thus, a controller which improves stability at one operating condition may have a detrimental effect at other system operating conditions. Further, when the machine power angle to the ac line angle is high, ...

This patent describes a static converter system operating between opposite ones of respective AC and DC buses. It comprises: at least three rectifier bridges connected in parallel to the DC buses, each rectifier bridge having three AC lines connected to the middle point of two rectifier devices in series between the two DC buses, the AC lines of one rectifier bridge being ...

... Extension of the NIST AC-DC Difference ... The NIST primary standards of ac-dc difference for current are multijunction thermal converters (MJTCs). ...

The $1 million ac-dc system operation laboratory of Edison Electric Institute on the campus of the University of Pennsylvania is described.

This paper proposes a new harmonic current-free ac/dc power conversion system characterized by the integration of a small-rated series active filter with a large-rated double-series diode rectifier. The dc terminals of the active filter are directly connected in parallel with those of the diode rectifier, thereby forming a common dc bus. The active filter ...

It is well known that power system transient stability can be improved by utilizing the effects of the power flow in a dc transmission link in a parallel ac--dc power system. The literature describes various control schemes that have been used for this purpose. In a recent experimental study it was determined that a sudden increase in the dc power level ...

By making use of the power flow control of dc system, the disturbance in a paralleling ac system may be removed without delay. The control system developed is used to prevent the generator from falling out of step. It was clear that the control system was adoptable for the improvement of the transient stability in the ac system as well. If the dc power is rapidly increased in ...

In distribution system, Distributed Generation (DG) is expected to improve the system reliability as its backup generation. However, DG contribution in fault current may cause the loss of the existing protection coordination, e.g. recloser-fuse coordination and breaker-breaker coordination. This problem can drastically deteriorate the system reliability, and it is more serious and complicated when ...

A novel method we refer to as the tie-line field (TLF) method has been developed to globally determine the tie-lines of any three-component two-phase coexistence region by fitting electron-spin resonance (ESR) spectra obtained from compositions on the coexistence curve and within the coexistence region. The TLF method is illustrated by applying it to the liquid-ordered (L_o) ...

Bidirectional dc current flow is not a natural feature of the buck (step-down) switch-mode rectifier, which leaves it at a disadvantage to boost (step-up) designs. A circuit topology is presented that allows bidirectional flow and which, by dual use of components, uses fewer devices than anti-parallel bridges. Sinusoidal current, controlled displacement factor, and variable ...

This article analyzes the electrical behavior of an array of piezoelectric energy harvesters endowed with several interfacing circuits, including the standard AC/DC circuit and parallel/series SSHI (synchronized switch harvesting on inductor) circuits. The harvesters are classified according to the connection to a single or multiple rectifiers. The ...

In this dissertation, two major accomplishments are achieved. First, the feasibility of a proposed Wyoming to California HVDC system having the ratings of 1000 MW, �500 kV, 2 kA, 860 miles and 12-pulse bipolar lines is shown for exporting Wyoming's electrical power resources to the heavy loaded western states. The second and the main objective of this dissertation is the development of a Kalman ...

The objective of this study is to develop a parallel ac-ac converter that can be implemented as a means of connecting ac generators in parallel. The most important goal of the parallel converter in this study is to obtain equal current sharing performance among the paralleled generators such that an economically ...

... b. Fluke 803B AC/DC Differential Voltmeter, Serial number 2797- c. Fluke 823A AC/DC Differential Voltmeter, Serial number 274. ...

... AC/DC, demmies, dillies, hillbilly heroin, oxy, percs, vics � whatever you call prescription pain relievers, always remember they can be killers when misused ...

... Accession Number : ADA211612. Title : Investigation of Resonant AC-DC Magnetic Field Effects. Descriptive Note : Final rept. May 1986-Jul 1989. ...

... Search, All Collections, ... Title : Electronic-Commutator AC/DC Motor-Driven Tracked All-Terrain Vehicles with Extremely High Mobility,. ...

This website serves as an excellent tutorial on basic AC & DC electronics, semiconductor operation and digital theory. Experiments are included to illustrate these concepts. The material is sufficiently comprehensive and is highly recommended as a starting point for students interested in learning about basic electronics.

The procedure describes the calibration of the Radio Frequency Laboratories, Inc. Model 33 AC-DC- Meter Calibrator. The test instrument is a self contained unit providing accurate av, dv, ac, or dc outputs. (Author)

... heat sinking of the electronic components was ... conception of the mechanical packaging was established. ... not react instantaneously to short circuits. ...

... CIRCUITS, COMPUTER PROGRAMMING, SEMICONDUCTOR DEVICES, ALTERNATING CURRENT, DIRECT CURRENT, TRANSIENTS, LOGIC ...

The feasibility for implementation of a concept for direct ac/dc multikilowatt power conversion with

An efficient and simple hierarchical state estimation method, suitable for real-time monitoring of large-scale power systems is investigated in detail. This method exhibits inherent parallelism; it treats all sub-systems of the large system and all tie lines coupling these sub-systems separately and independently. Thus, it is very ...

A new hybrid stochastic search technique is proposed to design of suboptimal AGC regulator for a two area interconnected non reheat thermal power system incorporating DC link in parallel with AC tie-line. In this technique, we are proposing the hybrid form of Genetic Algorithm (GA) and simulated annealing (SA) based regulator. GASA has been successfully ...

The paper presents a Hybrid-computer simulation study of the damping effectiveness of static phase shifters. Control strategies based on tie line power and frequency deviations feedback and utilizing fast acting static phase shifters to modulate tie line power flow are effective in damping power and frequency ...

Between October 23 and November 9, 1978, Aero Service Division Western Geophysical Company of America conducted a high sensitivity airborne gamma-ray spectrometer and magnetometer survey over the 2/sup 0/ x 1/sup 0/ NTMS quadrangle of Cortez, Colorado and Utah. The survey area is bounded by the 108/sup 0/ W and 110/sup 0/ W meridians and the 37/sup 0/ N and 38/sup 0/ N ...

This report contains a work statement for a study in which the objective is to examine the dynamic relationships of integrated ac/dc power systems containing high voltage direct current circuit breakers; a one-page discussion of the effects of a planned HVDC system on interconnected ac systems located in the general vicinity; and a quarterly progress report for a study aimed ...

Results achieved by the intermediate power level ac-dc model in Philadelphia demonstrate the unusual features and advantages of this research tool for working toward accomplishment of over-all aims of the project. Insofar as can be determined, it is presently the only facility capable of evaluating the dynamic interactions between ac-dc converter terminals ...

... 555 PRECISION DC VOLTAGE STANDARD 559 400-CYCLE OSCILLATOR 560 AC - DC CONVERTER 565 TRUCK, HAND, AUTONAVIGATOR ...

... Operational Requirements Document (ORD) for the Alternating Current/Direct Current (AC/DC) Clamp-on CARDS ORD 16039 ...

... Title : Operational Requirements Document (ORD) for the Alternating Current/ Direct Current (AC/DC) Clamp-on Ammeter, ME-563. ...

The most cost-effective AC/DC and DC systems are evaluated, specifically to develop system details which lead to technology goals, including: array; ...

... We chose planar black lipid mem- branes for experimental studies of magnetic field effects on membranes because they are the simplest known ...

... DC propulsion systems using silicon rectifier conversion equipment with the following objectives: Discussion of the AC - DC propulsion system with ...

... Title : Hardware Model of a Shipboard Zonal Electrical Distribution System (ZEDS): Alternating Current/Direct Current (AC/DC). ...

... Title : Hardware Model Of A Shipboard Zonal Electrical Distribution System (ZEDS): Alternating Current/Direct Current (AC/DC). ...

... of the dry disk brake on the induction motor is ... ME AC DC), and the DC generator (ME DC ... DC generators can take three basic forms; a commutated ...

Build circuits with capacitors, inductors, resistors and AC or DC voltage sources, and inspect them using lab instruments such as voltmeters and ammeters.

This new version of the CCK adds capacitors, inductors and AC voltage sources to your toolbox! Now you can graph the current and voltage as a function of time.

... Characterizing the degradation of Army primers by the AC-DC-AC accelerated test method ... DC AC-DC-AC accelerated testing method Page 5. ...

... SUPPLIES), (*RADAR TRANSMITTERS, (*PHASED ARRAYS, POWER SUPPLIES), ALTERNATING CURRENT, DIRECT CURRENT, CIRCUITS ...

... and a pair of positive and negative switching DC/DC converter sections connected to said AC/DC converter section and receiving a pair of positive ...

... air-cooling function of the air-conditioning system is ... An air conditioner that is capable of supplying a ... ohm multimeters; one differential ac-dc vacuum ...

The authors have shown that 50 Hz sinusoidal magnetic fields within the 5--10 microTesla ({micro}T) rms range cause an intensity-dependent reduction in nerve growth factor (NGF) stimulation of neurite outgrowth (NO) in PC12- cells. Here they report on the frequency dependence of this response over the 15--70 Hz range at 5 Hz intervals. Primed PC-12 cells were plated in collagen-coated, 60 mm ...

A semiautomatic ac/dc difference calibration system is described. The system operates over a frequency range of 20 Hz to 100 kHz, covering the voltage range from 0.5 V to 1 kV. For all voltages at frequencies in the range from 20 Hz to 20 kHz, the total u...

The assimilation of large numbers of large wind turbine generators into utility grids posses significant operational questions. This paper explores design and operational issues associated with the interconnection of wind farms using a controllable AC/DC/AC series-connected interface. The study is in terms of steady-state operation of and transient effects on both the power ...

Development of techniques and analytical tools for utilizing the inherent controllability of multiterminal hvdc transmission to enhance the performance of an integrated ac/dc power system were explored. Specific investigations that were performed during the course of the project were described, including steady state operation of ac/dc systems, and multiterminal power ...

This paper analyzes the interactions between the ac voltages and the dc current in weak ac/dc interconnections. The response of the voltage is expressed in terms of the basic parameters of the interconnection and the impact of these parameters on the voltage waveshapes is analyzed. Finally, indexes describing the distortion of the magnitude and phase of the ac voltage during ...

AC/DC voltage standards based entirely on solid-state references used as secondary, working, or transfer standards is widespread, although metrological performance is typically defined only via comparison with a higher level standard. The present report shows the improvements of the output metrological characteristics of an ac/dc calibrator by establishing three internal ...

Optimal Modulation Controllers for multiarea ac/dc systems are designed by a recursive algorithm that determines the state weighting matrix Q of a linear quadratic performance criterion. The basic feature of the proposed method is the reduction of the number of iterations as well as minimization of the calculations involved. This method is applied for eigenvalue assignment of ...

Conventional ac-dc converters present two important disadvantages: they create harmonic currents and require reactive power. To reduce these drawbacks, a diode rectifier is directly connected in series with a chopper controlled by pulsewidth modulation. Both are preceded by a series inductance (added to the equivalent one of the power system) and a shunt capacitor. This study ...

Calibration of welding systems and parameter monitoring data acquisition systems (DAS) assures transfer of identical welds between similar welders as well as assuring continued quality control of the welding process. A 1000 amp ac/dc current source was de...

The aim of Load Frequency Control (LFC) is to regulate the output powers of generating plants so as to maintain the deviations of frequency and tie line load within allowable limits. Various control schemes such as FEC and TBC have been developed for this purpose. In recent years, this problem has been studied from viewpoints of optimal control. In ...

... Nitrogen-10, (Iron, Cobalt, Nickel, Copper, Zinc)-500, ... the thermodynamic behavior of such alloys with these ... the tie line distribution in the base Ti-Mo ...

... Acoustic surveys using CHIRP and dual- frequency echo sounder were carried out along the two transect lines with additional along-shore tie- lines ...

... Title : A SERIES OF NICKEL-BASE SUPERALLOYS ON GAMMA-GAMMA PRIME TIE LINE OF ALLOY INCONEL 713C,. Corporate Author : ...

During the three austral summers that occurred in the period October, 1998 to February, 2001, the Support Office for Aerogeophysical Research (SOAR) of the University of Texas Institute for Geophysics (UTIG) conducted aerogeophysical campaigns for eight separate projects in both East and West Antarctica. Measurements were made of magnetic and gravitational fields, surface elevation and sub-glacial ...

The use of a thin film or a planar multijunction thermal converter (PMJTC) for the ac-dc transfer of voltage and current is well established. In general, a three dimensional multijunction thermal converter (MJTC) has the advantage of accuracy and a single junction thermal converter (SJTC) has that of low cost. PMJTCs provide a long-term stability, a high sensitivity and a high-dynamic-frequency ...

The room-temperature and 700 deg C tie lines of the early transition metal-Si-Cu ternary systems have been calculated for the metals Cr, Mo, Nb, Ta, V, and W. The tie lines are determined by considering only binary and elemental phases in observance of st...

Abstract�This paper discusses the basic construction procedure and topological possibilities of creating ac/dc converters out of simple dc/dc converters. It is shown that two separately controlled dc/dc converters are sufficient for producing a regulated dc output and shaping the input current, from an ac voltage source, without the need for input rectifiers. Some design ...

This paper develops a new technique for the design of optimal modulation controllers for multi-area ac/dc systems. The technique is based on optimal pole assignment using eigenvalue sensitivities. The basic feature of the proposed method is that both the diagonal and the off-diagonal elements of the weighting matrices are used for the eigenvalue assignment which results in ...

Existing 34, ac-dc low-harmonic rectiifiers are costly and require complex control schemes to minimize input current harmonics. Introduced here are three new classes of low cost 34, ac-dc high power factorllow harmonic controlled rectifiers. These are derived from parent dc-dc convrter topologies containing boost-type inputs, buck-type inputs and qwsi ...

This applet helps in understanding the operation of an NMOS transistor as a diode.There are various options to simulate this circuit including AC,DC and transient analysis to give a good understanding of the overall circuit operation

Undersea transmission lines and shoreline AC-DC conversion stations and near-shore transmission lines are being considered as part of a system for transporting energy between the Hawaiian Islands. These facilities will need to be designed so that they wil...

This research project was focused on the development of a quantum mechanical balance equation based device simulator that can model advanced, compound, submicron devices, under all transport conditions (AC, DC, and transient response). This report documen...

This paper presents the results of theoretical and experimental development of a new dc-ac-dc converter for superconducting magnet power supplies. The basic operating principles of the circuit are described followed by a theoretical treatment of the dynam...

The publication collects and summarizes the specialized information needed to operate the ac-dc difference laboratory and calibration service at the National Institute of Standards and Technology (NIST) in Gaithersburg. It also serves as a convenient refe...

The most cost-effective AC/DC and DC systems are evaluated, ..... In the past, traditional AC systems weighed and cost much more and were less ...

Flash-over along solid insulators in SF6 was studied experimentally. The breakdown voltage was measured under different experimental conditions; the parameters varied were: the voltage source (AC, DC and lightning impulse), gas pressure, electrode distanc...

The procedure describes the calibration of direct and alternating (60 or 400 Hz) voltage and current meters. The measurement range and accuracy for the procedure is limited only by the range and accuracy of the equipment that is used. (Author)

... Heerbrugg, Switzerland) and connected to a high-input impedance (1012 ? AC/DC micro-amplifier model UN-06, Syntech, Hilversum, ... ...

Laminate structures composed of alternating thin layers of conductor and dielectric material are commonly used in energy storage and transmission components. The failure of the dielectric layers in regions of high field stress, with applied 60 Hz ac, dc a...

The NIST calibration service for ac-dc difference of thermal current converters relies on multijunction thermal converters as the primary standards, and various thermal converters and thermoelements (TEs) as the reference and working standards. The paper ...

The NIST calibration service for ac-dc difference of thermal current converters relies on multijunction thermal converters as the primary standards, and various thermal converters and thermoelements (TEs) as the reference and working standards. Calibratio...

... the ac-dc difference of a customer's thermal current converter to the ac-dc difference of a ... range from 50 kHz to 100 kHz at currents from 1 mA to 20 A ...

Contents: Welcome; Division Programs; Electricity Highlights; The Electronic Kilogram; Voltage Metrology; Metrology of the Ohm; Single Electron Tunneling; AC-DC Difference Standards and Measurement Techniques; Farad and Impedance Metrology; Pulse Metrolog...

The inaugural ceremony of EEI's new ac-dc system operation laboratory, the problems to be studied, and the cost of the installation are described.

For the transfer of alternating voltage and current to the equivalent direct units, Multijunction Thermal Converters (MJTC's) have been developed, the uncertainty of which are in the range of the uncertainty of the maintenance of the electrical units. A n...

This website, presented by India Netzone Electronics, explains the common concepts in electronics from AC/DC circuits, digital logic, magnetism, diode, junction transistor, JFET, and opamps. There are many other electronics related topics covered on this website as well.

The activity reported herin is the proposed system study to examine the dynamic relationship of integrated ac/dc systems wherein the existence of direct current circuit breakers is postulated.

9 month skymap in cts/s/pixel with 95% C.L. error circles for BSL sources (0.3? pixel) ... Variability studies in the BSL paper finds marginal variability ...

The objective of this project is to establish the best power conversion technology (technologies) applicable to a number of advanced energy storage conversion technologies, including a study of common conversion technology, modular approach to constructio...

... DTIC's PDF and Excel spreadsheet versions of Congressional ... 208 30 50/60/400Hz power source. ... thyristor series LC resonant inverter power stage ...

This animated essay from the American Experience Web site explains the difference between alternating and direct electric current and offers in-depth explanations about the role played by a battery, light bulb, wire, and generator.

... were designed and constructed, employing three methods of excitation (60-c/s ac, dc, and rf) and a ... making use of the 3.39-micron He-Ne line, was ...

Enhancement of the overall system dynamic performance of an existing ac/dc scheme is possible by minor modifications in the NVDC controls. The paper presents some control modifications for the Chateauguay HVDC back-to-back 1000 MW scheme with interconnections to the Beauharnois generators and to the 765 kV intertie to NYPA. These modifications lead to a remarkable improvement ...

Free-wheeling power plants using free replenishable hydraulic forces of winds and water currents would consist of most or all of the following: fore and after cones to increase throughput; duplex impellers; rotors with dc/ac excitation, ac/dc inverters and dc field coils; stators with ac output of varying frequency, voltage and power; solid-state ac/dc ...

Variable frequency drives typically have employed dc voltage or current links for power distribution between the input and output converters and as a means to temporarily store energy. The dc link based power conversion systems have several inherent limitations. One of the important limitations is the high switching loss and high device stress which occur during switching intervals. This severely ...

Adding an HVDC transmission line to an existing right-of-way with an HVAC line can increase power transfer for a given right-of-way width. However, interaction between the two line types can change some electrical effects unless a critical distance is exceeded. Researchers conducted full-scale, two-phase tests using an HVAC test span paralleled by a two-pole HVDC test span to ...

This electricity/electronics guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 35 modules on the following topics: electrical energy and work; general safety and the electronics ...

This report describes Utility Power Group's (UPG's) technical progress for Phase 1 of a two-phase effort to focus on the design, assembly, and testing of a fully-integrated residential PV power system, including storage. In the PV Array Task, UPG significantly improved the conventional means and methods required to structurally interface PV modules to the roofs of single-family ...

In order to keep power supply reliability at a certain level, electric power utilities have a certain amount of reserved capacity. When no generator outage or no unexpected large power demand occurs, however, the reserved capacity is regarded as surplus facility. To reduce the reserved capacity, some margin is reserved in tie lines between utilities. This ...

... pathways, and play types. In addition, a 2D tie line survey has been designed as a second ... 420 mi or 675 km) are designed to tie the details of the new high resolution 3D ... ...

Progress is reported on system definition and performance analysis of a 100-MWe solar power system; user application analyses of direct hydroelectric integration, tie-line integration, and industrial augmentation systems; and meteorological analyses to mo...

ever, the plagioclase data fall far off this isochron. The pyroxene plagioclase tie-line yields ... is possible that only the plagioclase has been affected. ...

The proposed Happy Valley project consists of construction of a new BPA customer service 69-kV substation south of Sequim in Clallam County, Washington. A tie line, to be constructed by the customer as part of this project, will link the new BPA facility ...

The problem addressed by the capacity - building project arose in the development of a statewide information and referral (I and R) system known as TIE LINE. Since the Georgia Department of Human Resources (DHR) was in the process of reorganization and co...

Volume 2-B contains the radiometric profiles (all tie lines and profile lines 1 to 100) for the Sierra Madre detail area of Wyoming.

Volume 2-B contains the radiometric profiles (all tie lines and profile lines 1 to 100) for the Sierra Madre detail area of Wyoming. (ERA citation 08:055475)

The room-temperature and 700 deg C tie lines of the early transition metal-Si-Cu ternary systems have been calculated for the metals Cr, Mo, Nb, Ta, V, and W. The tie lines are determined by considering only binary and elemental phases in observance of strict stoichiometry and zero solid solubility. The authors ...

This dissertation is a systematic study of artificial neural networks (ANN) applications in power system restoration (PSR). PSR is based on available generation and load to be restored analysis. A literature review showed that the conventional PSR methods, i.e. the pre-established guidelines, the expert systems method, the mathematical programming method and the petri-net method have limitations ...

Existing 3{phi} ac-dc low-harmonic rectifiers are costly and require complex control schemes to minimize input current harmonics. Introduced here are two new classes of low cost 3{phi} ac-dc high power factor/low harmonic controlled rectifiers. These are derived from parent dc-dc converter topologies containing boost-type inputs and buck-type inputs. With ...

Each of the twelve Booster Main Magnet Power Supply modules consist of two three-phase, full-wave rectifier bridges in series to provide a 560 VDC maximum output. The harmonic contents of the twelve-pulse ac-dc converter output are multiples of the 60 Hz ac power input, with a predominant 720 Hz signal greater than 14 dB in magnitude above the closest harmonic components at ...

This paper proposes a novel control method based on the virtual AC/DC/AC conversion for the matrix converter. The virtual AC/DC/AC conversion method is a very simple strategy to control the input current and the output voltage for the matrix converter. There are two new topics proposed in this paper. Firstly, this paper proposes the minimum switching loss ...

This paper describes the implementation of both Point of Collapse (PoC) methods and continuation methods for the computation of voltage collapse points (saddle-node bifurcations) in large ac/dc systems. A comparison of the performance of these methods is presented for real systems of up to 2,158 buses. The paper discusses computational details of the implementation of the PoC ...

This paper describes the result of work performed at the Laboratoire National de M�trologie et d'Essais (LNE) aiming at characterizing the metrological performance of analogue-to-digital converters of a commercial digital voltmeter in the 20 Hz to 400 Hz frequency range. In order to reach uncertainties at the 10?6 level, ac-dc thermal transfer techniques have been used to ...

Calibration of welding systems and parameter monitoring data acquisition systems (DAS) assures transfer of identical welds between similar welders as well as assuring continued quality control of the welding process. A 1000 amp ac/dc current source was developed to aid in the calibration of these welding systems. The equipment used to create the current source is discussed. ...

This paper presents a new method for solving the Multi-Area Economic Dispatch (MAED) problem with tie line constraints. This formulation extends the traditional economic dispatch methods used in study applications such as Unit Commitment to include area demand constraints, area reserve constraints, and tie line ...

In many situations of power system restoration or emergency control load flow, often dynamic load flow, results are needed at a time scale which makes regular load flow computations impractical. In this paper a low order dynamic model is introduced which retains fully detailed and precise representation of the critical components (such as strong backbone lines like EHV or weak ...

In recent years, a lot of distributed generations such as photovoltaic and wind power generations are going to be installed in power systems. However, the fluctuation of these generator outputs affects the system frequency. Therefore, introduction of battery system to the power system has been considered in order to level the fluctuation of the total power output of the distributed generations. ...

The U.S. Geological Survey has recently collected high-resolution Boomer and CHIRP seismic-reflection profiles along the inner continental shelf of North Carolina between False Cape, VA and Cape Hatteras, NC. The two systems were used concurrently on a dense survey grid with shore parallel lines spaced about 300 m apart. Tie lines were ...

We conducted a ground penetrating radar (GPR) survey of several fault traces from the Warm Springs Valley fault system in western Nevada. Several trenches have been excavated along the southern part of the fault system, in an ideal setting to experiment with GPR. Our survey was conducted with a pulseEKKO 100 GPR system, using a 1000v transmitter, at an antenna frequency of 200 MHz, with an ...

of equipment. The power supplies in the lab are capable of delivering very high current. High current can lead and Laboratory Rules Sample Title Page for Lab Reports Lab-1: AC/DC Circuits and Measurements Lab-2: AC Transformers Lab-3: Brushed DC Motors Lab-4: Squirrel-Cage Induction Motors and VFDs Lab-5: Synchronous

This working group report presents dc benchmark models tailored to ac/dc interaction. This is to encourage comparisons of the performance of different control strategies or computational tools related to various ac/dc interaction phenomena and system dynamic performance. System data and results are available on diskette or through e-mail.

This paper presents a general and efficient method for transient simulation of HVDC converters. The proposed method utilizes a new algorithm, based on network topological concepts, which provides an efficient solution to the problem of modeling the inherently nonlinear characteristics and time varying topology of static power converters caused by the switching action of the thyristor valves.

The purpose of this project is to develop a comprehensive treatment of the Compound HV-AC-DC System, that is the up-to-date large power system in all its aspects: Analysis and operation with at least some aspects of planning, normal operating conditions, ...

The nondestructive wire rope tester, MT 75, was investigated, tested, and evaluated in order to fill the gap between the hand-held rag inspection and the large unitized AC/DC wire rope inspection device. The MT 75 can provide better information on the con...

to produce hydrogen by electrolyzing water � Characterize electrolyzer performance under variable input power Bridge Current Wind-Electrolysis Project AC Source (Wind Turbine) Simulator 10kW Wind Turbine AC-DC Power � Power electronics (PE) regulating voltage � 50A avg. current � No added benefit of high winds

This paper is concerned with modeling the reliablity characteristics in both probability and frequency of large electric utility application wind turbine generators together with their associated utility interface equipment. A computationally efficient algorithm is developed and applied to a wind farm with a special AC/DC/AC interface currently under design. The effects of ...

This program introduces the technician to three phase a-c power and its relationship to rectifier power conversion systems. A brief introduction is given as to the engineering significance of various parameters such as, phase rotation, ac power relationsh...

A power factor analysis of the input part of an advanced AC/DC/AC converter for variable speed wind turbines is presented. Two types of rectifying input converters are compared: the boost rectifier, consisting of three AC inductors, a three-phase diode br...

The ammeter shall operate in a frequency range of 45 Hertz (Hz) to 500 Hz with a resolution of no more than 100 mAMP on the low range scale and no more than 1 AMP on the high range scale. It will have a maximum AC current range to 300 AMP and a DC current...

This paper presents the results of theoretical and experimental development of a new dc-ac-dc converter for superconducting magnet power supplies. The basic operating principles of the circuit are described followed by a theoretical treatment of the dynamics and control of the system. The successful results of the first experimental operation and control of such a circuit are ...

Electrical Penetration Graph (EPG) monitoring is the most rigorous means of observing and quantifying the feeding of any piercing-sucking arthropod. However, until now, most studies have emphasized a relatively small number of insects, mostly small-bodied aphids (Hemiptera: Aphididae) and leafhopp...

Matrix converters offer certain advantages over conventional AC-DC-AC conversion such as elimination of reactive elements, inherent bi-directional power flow capability, increased reliability and compactness. This paper explores the reactive and harmonic compensation capability of a matrix converter. Space vector modulation technique has been used for controlling the matrix ...

In general, high voltage direct current (HVDC) systems are used to transmit energy between two alternating current (HVAC) systems and require, in addition to a transmission line, two ac/dc conversion stations. In describing the basic design criteria, comp...

LLNL personnel have designed and constructed a special purpose electrical test stand to evaluate CFCs and CFC replacement fluids under simulated AC, DC, and pulsed breakdown conditions. The test stand includes an electrical diagnostic system which allows ...

Recently reported observations by others indicates that a combination of a weak dc magnetic field and extra-low-frequency ac magnetic fields can produce resonant effects in biological systems. This study of resonant magnetic fields that consists of two pa...

, power electronic circuits can be configured as: 1. Diode rectifiers( )ac dc 2. Controlled rectifiers the operation of a few circuits to understand how they are used in wind power. The first is the diode rectifier: Fig. 3.14 Diode Rectifier Fig. 3.15 Output Voltage When sV is +, D1 conducts and D2 is off, so o

DoublyFed Induction Generator (variable speed) Plant Feeders ac dc partial power dc ac Type 4 10 generator full power ac to dc dc to ac Fullconverter interface #12;2. What is a wind plant? Type 3 Doubly Fed/3 of full power rating � Eliminates wind gustinduced power spikes � More efficient over wide wind speed

"This is an educational module dedicated to basic power electronic circuits. The module includes DC/DC converters, basic diode and thyristor converter systems, AC/DC inverter, space vector modulation and basic signal theory. In the future there will be minor changes (mainly additions and corrections). The material currently is available in German, English, Japanese, Korean, ...

with rectifiers to form RF-to-dc converters having narrow-range resistive input characteristics is also treated�dc converter, comprising an inverter stage, a transformation stage, and a rectifier stage [1]�[10]. Manuscript an inverter (dc�ac) circuit, a transformation/matching circuit, and a rectifier (ac�dc) circuit. The inverter

loss versus specific deposit from Veerapaneni (23). Mo ) 6(1 - )/dc (4) Ac ) dc 2 + NAp 2 (5) 578 9- parameter model suggests that a velocity-dependent parameter representing deposit morphology must also Permeability reduction caused by particle deposition in porous media, or clogging, is important in several

Featured Articles: Hitachi's New Technologies for Railway Systems; High-Speed Train for Next Generation Shinkansen; High-Performance AC/DC Dual Mode 4-Axle Type Inverter Controlled Locomotive; Advanced Inverter Control System Using a High-Voltage IGBT; Au...

A hardware model of a shipboard electrical distribution system based on aspects of the DDG 51 Flight IIA, Arleigh Burke class, 60Hz Alternating Current (AC) and the future direct current (DC) zonal electrical distribution system (ZEDS). These distribution...

A hardware model of a shipboard electrical distribution system based on aspects of the DDG 51 Flight IIA, Arleigh Burke class, 60Hz Alternating Current (AC) and the future direct current (DC), zonal electrical distribution system (ZEDS). These distributio...

amplifier, DC-DC convert- ers and high performance AC, DC and step-motor control appli- cations. Many+. Capacitor, C1, integrates in a direction to satisfy the reference current signal at IN. The IN- input will be a function of the amount of dc hysteresis gain, R3/R1 and the size of capacitor, C1. As the capacitor, C1

The possibility of abnormal harmonic generation in an ac system feeding a converter load is examined from the standpoint of automatic control systems used in modern hvdc transmission systems. It is shown that with certain types of automatic controls, the firing angles of converter valves may sustain some errors, which in turn could generate abnormal harmonic currents in the three phase ac system ...

An automatic ac/dc difference calibration system is described which uses direct measurement of thermoelement emfs. In addition to ac/dc difference testing, the system can be used to measure some important characteristics or thermoelements, as well as to c...

that comes barreling down a string line shaft towards the unwelcome intruders. This is an example of a purely). Bill of Materials: - 1 Arduino Duemilanove micro controller - 1 AC/DC adapter for the Arduino (or any's who own guns and have children. Every year, tragic deaths result for families with gun owners

The authors discuss field experience with three ac-dc converter installations. A rectifier and two self-commutated inverters comprise the evaluated equipment. Each case deals with slightly different aspects in the application of converters on power systems. The three cases compliment each other to provide insight into a majority of the problems and solutions associated with ...

An inductor-converter bridge (ICB) is a solid state DC-AC-DC power converter system for bidirectional, controllable, energy transfer between two coils. The ICB is suitable for supplying large pulsed power to such magnets as the superconducting equilibrium field coil of the proposed tokamak power reactors from another superconducting energy storage coil.

... hal ~~~C s�:""' ihpecial exporpcnro lsl o =4 N- 2 goer~st s oro~g ... to$e ,x 'o X~Z .V. 6 ::1OJ Id6 ;6 186 16 1 616 16'd16 X t~XC X Xzit M Ix I -Aio ...

The band AC/DC is considered one of the seminal hard rock bands, often compared to Led Zeppelin and Black Sabbath in influencing many subsequent hard rock and heavy metal bands. The band was formed in 1973 by Angus and Malcolm Young who took the band�s moniker from the back of their sister�s sewing machine. In its 35

, transportation systems, and etc., which requires a rectifier, a DC bus, and an inverter to obtain arbitrary AC parts, i.e., a virtual front-end AC/DC rectifier and a virtual DC/AC inverter, and synthesizes the switching state of the matrix converter from the both switching states of the virtual rectifier

The paper presents a formulation for coordinating all controllable reactive power sources, including the DC converters of a multiterminal DC system, to correct bus voltage violations. Based on the formulation, an algorithm using Linear Programming solution technique has been developed. The effectiveness of this algorithm to correct bus voltage violations in a 30 bus, 5 DC terminal ...

Conventional methods for calculating electricity losses in pipe-type cable systems rely heavily on data measured in lower-voltage systems in the 1950s. With the new technique developed in this study, engineers can compute power losses more precisely for cables of various configurations and voltage ratings.

The feasibility for implementation of a concept for direct ac/dc multikilowatt power conversion with bidirectional transfer of energy was investigated. A 10 kHz current carrier was derived directly from a common 60 Hz three phase power system. This carrie...

The identification of hardware developments and system applications which exemplify cost and operational advantages of integrated ac/dc power systems is discussed. The three principal tasks undertaken were: assessment of equipment developments; quantification of operational advantages; and interaction with system planners. The dissemination of information about high voltage ...

The hardware development and systems applications are described for high voltage direct current (HVDC) power systems. Particular emphasis is given to exemplifying cost and operational advantages of integrated ac/dc power systems. Progress is reported in the development of the following: HVDC converters; computerized simulation of HVDC systems; circuit breakers; and long range ...

The activity reported herin is the proposed system study to examine the dynamic relationship of integrated ac/dc systems wherein the existence of direct current circuit breakers is postulated. (ERA citation 05:033608)

The bibliography contains citations concerning types and applications of adjustable speed drives (ASD). Uses in heat pumps, fans, compressors, electric motors, boiler feed systems, and power transmission are described. Coverage includes AC-DC motors, induction motors, and brushless electric motors. Energy cost savings are also examined. (Contains a minimum of 102 citations and ...

Co and a current source n ir (n is the transformer turn ratio) [7]. A halfway rectifier Rect and an inductor Lo value of the capacitor Co current ( Coi ) the rectifier will operate under overlapping conditions = 4 = n ir OLi 1Di 2Di OCi OCv 1Di 2Di (b) Fig. 2. The rectifier's current and voltage waveforms

In response to the current imbalance phenomenon and its harmfulness, a current sharing circuit model is built up, which reveals the underlying causes for the current imbalance through a quantitative analysis. Then, a feasible approach of improvement, namely enlargement of the length of connection busbars, is proposed. After the amendment, it can be seen that the current sharing coefficient is ...

Increasing complexity of high-voltage direct current (HVDC) transmission systems places new demands on alternating current/direct current (ac/dc) power converters. The possibility of using advanced power conversion techniques, specifically force-commutate...

ABSTRACT The Power Systems branch at JSC faces a number of complex issues as it readies itself for the President's initiative on future space exploration beyond low earth orbit. Some of these preliminary issues - those dealing with electric power generati...

The final report concludes that the two most likely long-range candidates for converting dc to ac power from batteries and fuel cells are the basic current-fed line commutated inverter (a derivative of HVDC technology), and the voltage-fed conduction angl...

The AC-DC Power Processor Type I Power Module furnishes O-100ADC over an output voltage range of 24 to 32VDC from a 120/208 30 50/60/400Hz power source. Remote output voltage sensing at the load circuit is provided to eliminate the IR drop of the power di...

An 8-meter-long, versatile gas laser and associated equipment were designed and constructed, employing three methods of excitation (60-c/s ac, dc, and rf) and a Brewster-angle prism method of intracavity wavelength selection. The high gain resulting from ...

. However, reducing the CMV via PWM pulse pattern typically degrades the other modular performance supply AC-DC-AC power converter units. Pulse Width Modulation (PWM) is the standard approach to operate controlling the PWM pulse patterns is the most economical method as it requires no extra components and cost

This is volume 2 of the proceedings of the IEEE International Conference on Power Electronics, Drives and Energy Systems for Industrial Growth held during January 1996, in New Delhi, India. The topics of this volume include AC/DC and AC/AC converters, induction generators, traction and electric vehicle drives, application of neural networks and fuzzy logic systems, power ...

This report covers effort under Contract DAAK70-77-C-0035 to further develop the ac-to-dc section or converter portion of a 15 kW general purpose power conditioner or frequency changer. Previous Delco effort under Contract DAAK02-72-C-0210 had provided a ...

This paper reviews relevant operating objectives established by the North American Electric Reliability Council, NERC. It shows that the present definition for Area Control Error (ACE) is somewhat subjective. It further argues that unconditional reaction to small ACE does not optimize interconnection objectives. This paper evolves tie-line bias control objectives into a ...

Results of calorimetric, differential thermal analysis, and structural measurements are presented for a series of bulk metallic glass forming compositions in the Zr{endash}Ti{endash}Cu{endash}Ni{endash}Be alloy system. The calorimetric data for five alloys, prepared along the tie line between phase separating and nonphase separating compositions, show that ...

Results of calorimetric, differential thermal analysis, and structural measurements are presented for a series of bulk metallic glass forming compositions in the Zr[endash]Ti[endash]Cu[endash]Ni[endash]Be alloy system. The calorimetric data for five alloys, prepared along the tie line between phase separating and nonphase separating compositions, show that ...

This report outlines progress in the first quarter of the second year of the DOE project ''High Resolution Prediction of Gas Injection Process Performance for Heterogeneous Reservoirs''. The application of the analytical theory for gas injection processes, including the effects of volume change on mixing, has up to now been limited to fully self-sharpening ...

The isotopic substitution method in neutron diffraction is applied to two chalcogenide glasses on the (Ag2S)x(As2S3)1-x (0<=x<=1) tie line of the Ag-As-S system. It is shown that there is a reduction from ~=4 to ~=3 in the average number of S atoms covalently bonded to Ag as x is increased from 0.096 to 0.500, but that As remains threefold ...

The viability crisis in a power system is defined, and three consecutive tasks are identified for the viabilizing control. A newly formulated criterion is proposed, and a complete set of approaches for viabilization is presented in both Tasks II and III, an implementable least-disruptive solution is obtained, which ensures that the transient state of the system is in the safe region. A reduced ...

The report describes a proposed solution for the generation control problem which unifies economic dispatch, load frequency control and statistical load forecasting. This solution retains the decentralized character of the Area Control Principle but updates the concept of the Area Control Error to fully account for dynamic effects. Thus, the control remains areawise, using only measurements of ...

It is shown that measurements of microhardness can be used for plotting conades (Tie Line) of the alpha + Cu/sub 3/Ti region in the Al--Cu-- Ti constitution diagram at 500 to 850 deg C. (R.V.J.)

An imitation of quaternary eutectic point searching techniques by means of two-dimensional sections set construction (tie-lines method) was made, using the model of T-x-y-z diagram of eutectic type without solid-phases solubility as an example. The errors, appearing in sections graphics of experimentally studied systems, are analyzed.

Certain ternary mixtures of ethoxylated alcohols, n-alkanes, and water at 25/sup 0/C separate at equilibrium into three liquid phases. The development of an amphiphile-rich middle phase is sensitive to alcohol molecular weight, alkane carbon number (ACN), and temperature. A middle phase arises when all three variables are adjusted such that the alcohol has no preference to partition into either an ...

with smectite, smectite�chlorite mixed layer minerals, or chlorite calcite zeolite sulfide Fe-oxyhydroxide. We. Different symbols are: squares, chlorite; circles, chlorite/smectite mixed-layer phases; triangles, smectite and chlorite/smectite mixed-layer phases. Tie lines with shallower slopes indicate significant fractions

to merge to a 32.5 hour block. The Sunday of week 13 and Monday of week 14 are being proposed to merge for April 2010 for weeks 13 - 15. DSS-14 downtime for Life Extension beginning 09/28/2009. It was requested for 14 hour complex downtimes are requested by GDSCC. Corrective maintenance "Apollo Tie-Line CB 22

This volume contains all the graphic data for Area III, which includes lines 3420 to 5320 and tie lines 6080, 6100, and 6140. Due to the large map scale of the data presented (1:62,500), this area was further subdivided into eleven 7-1/2 min quadrant sheets.

In the months of August, September, and October 1978, EG and G geoMetrics collected 4231 miles of high sensitivity airborne radiometric and magnetic data in southwestern Colorado. Data were collected on traverse lines 1/4 mile apart and on tie lines of ap...

This volume contains all of the graphic data for Area II, which include map lines 1660 to 3400 and 5360 to 5780 and tie lines 6100, 6120, and 6160. Due to the large map scale of the data presented (1:62,500), this area was further subdivided into eleven 7...

Two-dimensional electrical resistivity tomography (ERT) has been established in the previous decade as a widely applied tool for the mapping and characterization of permafrost in the shallow subsurface of mountain environments. Using the marked increase in electrical resistivity at the freezing point, this method delivers information about subsurface structures that contain ice and furthermore ...

The phenomenon of torsional oscillations as a result of series capacitor compensation and HVDC converter controllers of an AC/DC system is investigated. A feasible approach for damping the torsional modes based on coordinating the controllers of an SVC unit with the supplemental subsynchronous damping control (SSDC) of the HVDC rectifier, is presented. An eigenvalue method is used for the studies ...

Increasing demand for low power consumption in electronics combined with continued miniaturization of electronic device components in today's analogue/digital circuits have reduced the supply voltage to sub-one volt levels. The supply voltage to integrated circuit devices are provided by AC-DC converters, which converts high frequency ac voltage to a conditioned dc output voltage at a given power ...

A semiautomatic ac/dc difference calibration system is described. The system operates overa frequency range of 20 Hz to 100 kHz, covering the voltage range from 0.5 V to 1 kV. For all voltages at frequencies in the range from 20 Hz to 20 kHz, the total uncertainty is 50 parts per million (ppm), and 100 ppm for voltages at frequencies between 20 kHz and 100 kHz. In addition to ...

This paper addresses the design of efficient switched-capacitor power converters. The discussion starts with a review of the fundamental limitation of switched-capacitor circuits which shows that the topology of such circuits and the ``forced`` step changes of capacitor voltages are the inherent attributes of power loss. Although the argument follows from a rather trivial result from basic circuit ...

We report here on the design, construction and testing of a vacuum compatible AC-DC amplification system for low signal measurements with scanning probes. The most important feature of this new amplification system is incorporated within the head of a scanning tunneling microscope (STM). This is achieved with a very low thermal dissipation radio frequency amplifier at the STM ...

The power system of Hydro-Quebec has a peak load of approximately 27 GW. The great distance between the production sites and the load centers introduces stability limitations, which is the reason why the Quebec grid cannot be economically synchronized (through ac transmission with limited capacity) with the U.S. northeastern network. Power exports are therefore dependent on the use of HVDC links ...

This paper describes breakdown characteristics of an oil-pressboard insulation system to a superposition voltage of AC and DC voltages. Although AC electric field is decided by the ratio of the relative permittivity of a pressboard and insulating oil, DC electric field is decided by ratio ? of volume resistivities. From the measurement in this study, 13�78 and 1.8�5.7 are obtained as the ...

Using electromatic field theory, a new method is developed for calculating alternating current in power cables installed in pipes of carbon steel (magnetic pipes). The technique for evaluating these losses is based on the method of images which replaces complicated distribution of currents in the system with a sequence of thin conductors. The method not only gives a mathematical framework for the ...

This paper develops an incremental transformer model suitable for slow transient studies. A typical application is the study of temporary harmonic overvoltages in ac/dc systems caused by transformer saturation. The proposed model represents in detail the nonlinear magnetic circuit of the transformer and is, therefore, more complex than the piecewise linear models often used to simulate saturation. ...