• Title/Summary/Keyword: Voltage source converter

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Comparison and Study of Active and Hybrid Power Filters for Compensation of Grid Harmonics

  • Gutierrez, Bryan;Kwak, Sang-Shin
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1541-1550
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    • 2016
  • This paper presents a theoretical analysis and comparisons of active power filter (APF) and hybrid power filter (HPF) systems, given terminal constraints of harmonic compensations in nonlinear loads. Despite numerous publications for the two types of filters, the features and differences between them have not been clearly explained. This paper presents a detailed analysis of the operations of a HPF inverter along with those of passive power filters (PPFs). It also includes their effects on the power factor at the grid. In addition, a theoretical analysis and a systematic comparison between the APF and HPF systems are addressed based on system parameters such as the source voltage, output power, reactive component size, and power factor at the grid terminals. The converter kVA ratings and dc-link voltage requirements for both topologies are considered in the presented comparisons

Multi-Level Operation with Two-Level Converters through a Double-Delta Source Connected Transformer

  • Park, Yongsoon;Ohn, Sungjae;Sul, Seung-Ki
    • Journal of Power Electronics
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    • v.14 no.6
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    • pp.1093-1099
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    • 2014
  • This paper proposes a power conversion topology involving a multi-winding transformer and converters. The fundamental idea is described with circuit diagrams, and the voltage output of the proposed topology is analyzed mathematically. The effectiveness of the topology is discussed with test results from a small-scale power conversion system. When conventional hardware consisting of two-level converters and a transformer is employed, multi-level voltage outputs can be applied to the transformer windings by the proposed method.

Average Current Controlled X-Y Channel Driving White LED Backlight System for 46" LCD TV

  • Cho, Dae-Youn;Oh, Won-Sik;Cho, Kyu-Min;Moon, Gun-Woo;Yang, Byung-Choon;Jang, Tae-Seok
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.271-273
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    • 2008
  • A novel white-LED (light emitting diode) backlight system for 46"LCD TVs which involves the average current controlled X-Y channel driving method is proposed, which is composed of 1 converter and row and column channel switches. In the conventional X-Y channel driving driven with a constant voltage source, the driving current of LED increases because the threshold voltage of LED decreases when LED temperature goes up. To maintain the luminance of backlight constant, the average current controlled X-Y channel driving will be employed. Finally the results are confirmed by experimental results.

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An optimization approach for generation rescheduling with VSC-MTDC and battery energy storage systems (VSC-MTDC와 BESS 통합 시스템을 통한 발전기 리스케줄링 최적화 기법)

  • Kim, Ho-Young;Kim, Mun-Kyeom
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.147-148
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    • 2015
  • 현재 발전기 스케줄링은 제한된 발전 자원, 에너지 수요 및 연료비용 증가, 그리고 불규칙적인 부하 등 최적리스케줄링에 있어 많은 문제들을 해결하기 위한 새로운 변화가 요구된다. 본 논문에서는 Multi-Terminal Voltage Source Converter High Voltage Direct Current (VSC-MTDC)와 Bettary Energy Storage System (BESS)가 결합된 Hybrid Integrated system (HIS)를 통해 발전기 리스케줄링을 위한 최적화 기법을 제안한다. 최적 발전기 리스케줄링을 위한 HIS 퍼포먼스를 위해 VSC station limit과 충 방전을 기반으로 하는 최적화 과정을 수행한다. 최적조류계산 문제는 VSC-MTDC 시스템과 BESS룰 고려하여 정식화되며, 충 방전 전략은 24시간 수요 정보를 사용하여 발전기 리스케줄링을 위한 하이브리드 통합 시스템의 최적알고리즘을 보여준다. 제안된 최적 리스케줄링 기법을 수정된 IEEE 14 모선에 적용하여 효율성을 입증하고자 한다.

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A Study on the Analysis of the Output Waveform of Three-Phase Regular Sampling PWM Inverter (3상 레귤러 샘플링 PWM 인버터의 출력파행 분석에 관한 연구)

  • 노창주
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.28 no.3
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    • pp.274-285
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    • 1992
  • Among various Power converters, a variable voltage variable frequency (VVVF) three-phase PWM inverter is regarded as most promising power converter due to its capabilities, which permits the control of voltage, frequency and harmonic contents in a single power stage employing only on DC source. As a modulating technique of the PWM inverter, the regular sampling technique has rendered possible the on-line computation and generation of PWM control waveforms with a reasonably high switching frequencies. In this paper, microprocessor based three-phase regular samping PWM inverter with real-time control algorithm and control circuits for driving three phase AC motor has been developed. Harmocic components of PWM waveform were analized theoretically in terms of Bessel function series and then calculated by digital computer and observed with spectrum analyzer.

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Power Standard System for the Calibration and Test of Precision Power Meters (정밀전력계의 교정과 시험을 위한 전력표준시스템)

  • Park, Young-Tae;Ryu, Kwon-Sang;Yu, Kwang-Min;Jang, Seok-Myeong
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.11
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    • pp.622-627
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    • 2002
  • The power comparison techniques have implemented power measurements, in which a power comparator is used to balance ac against a dc power obtained from known values. The developed power standard system using the comparison techniques consists of dc sources, ac source, control switches, resistive voltage dividers, resistive shunts and a power comparator. The total uncertainty of the power standard system was proved by analysis of the component instruments. Its expanded(k=2) uncertainty is evaluated to be less than 30 uW/VA at unit power factor and 42 uW/VA at power factor 0.5

Multi-Step Commutation and Control Policies for Matrix Converters

  • Hofmann, Wilfried;Ziegler, Marcus
    • Journal of Power Electronics
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    • v.3 no.1
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    • pp.24-32
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    • 2003
  • The commutation and control in matrix converters is more complicated as in voltage source converters. Natural freewheeling paths do not exist and the theoretic absent storage elements result in a direct coupled system of load and line currents as well as voltages. The paper offers an overview about staggered commutation and control policies in matrix converters. Based on the knowledge about load current direction and the signs of the line to line input voltages different multi-step commutation policies were derived. This paper examines the application of that policies in the case of space vector modulation and direct control methods with the focus on the resulting effects to the reference output voltage deviation.

A Quasi Z-Source AC-AC Converter for Low Voltage Smart Distribution System (저전압 스마트 배전시스템을 위한 Quasi Z-소스 AC-AC 컨버터)

  • Yoo, Dae-Hyun;Eom, Jun-Hyun;Jung, Young-Gook;Lim, Young-Cheol
    • Proceedings of the KIPE Conference
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    • 2013.07a
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    • pp.273-274
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    • 2013
  • 본 논문에서는 저전압 스마트 배전시스템을 위한 Quasi Z-소스 AC-AC 컨버터를 제안하였다. 제안된 시스템은 Quasi Z-소스 AC-AC 컨버터의 교류 입력 전압에 대하여, 동상의 출력 전압을 부스트 하고, 역상의 출력 전압을 벅-부스트하는 고정 주파수 가변 전압 VVCF(Variable Voltage Constant Frequency)의 출력특성을 가지고 있다. 또한 Quasi Z-소스 AC-AC 컨버터의 shoot-through 스위치 단에 벅-컨버터를 연결하여 Quasi Z-소스 AC-AC 컨버터의 동작과 함께 저압의 직류 전압을 출력 할 수 있다. PSIM 시뮬레이션과 실험에 의하여, 제안된 시스템이 동상 부스트 모드로 동작하는 경우, PI 제어된 벅 컨버터에 의하여 직류 전압을 출력할 수 있음을 확인하였다.

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Drive system for 500MVA high-power testing facility (500MVA 대전력시험설비의 모터구동시스템)

  • Jung, Heung-Soo;La, Dae-Ryeol;Kim, Sun-Koo;Roh, Chang-Il;Kim, Won-Man;Lee, Dong-Jun
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.858-860
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    • 2003
  • This paper introduces the drive system for 500MVA short-circuit generator. Drive system is usually low-voltage, but this system is 2300V high-voltage using Insulated Gate Bipolar Transistor(IGBT). Drive system consists of switchgear, 18-pulse transformer, converter(source bridge), inverter(load bridge) and control rack. In this paper, It describes the function and construction of each part.

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Detection of DC-Cable Fault Location for HVDC Transmission Systems Integrated with Wind Farm

  • Nguyen, Thanh Hai;Lee, Dong-Choon
    • Proceedings of the KIPE Conference
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    • 2014.07a
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    • pp.71-72
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    • 2014
  • This paper presents a method to find the fault location on the DC cables for the HVDC transmission systems which utilizes a hybrid topology of the diode rectifier and the voltage-source converter (VSC) in the wind farm (WF) side. First, the DC-cable fault occurring in this HVDC system is analyzed in detail. Then, the DC-cable fault location is detected from the two relative voltages located on the same section of the cable, which are estimated from a pair of DC-cable voltage and current measurements. The effectiveness of the method is verified by the simulation results.

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