• 제목/요약/키워드: Synchronous converter

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동기 정류기를 이용한 고효율 역률보상형 AC/DC 컨버터 (High Efficiency PFC AC/DC Converter with Synchronous Rectifier)

  • 박한웅
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2000년도 전력전자학술대회 논문집
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    • pp.266-269
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    • 2000
  • This paper presents a novel single-stage unity power factor converter which features the reduced switching losses by zero-voltage switching and zero-current switching (ZVZCS). Hence the turn-on and turn-off losses of switches are sufficiently reduced. And the reduced conduction losses are achieved by the elimination of one leg of front-end rectifier. And low on-resistance MOSFETs (Synchronous Rectifier) are used in the rectifier at the secondary side of high frequency transformer instead of diodes. Theoretical analysis simulated results of a AC to DC 150W(5V, 30A) converter are presented.

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전류제어형 PWM컨버터를 이용한 동기발전기용 여자시스템에 관한 연구 (A Study on Excitation System for Synchronous Generator using Current Mode Controlled PWM Converter)

  • 장수진;류동균;서민성;김준호;원충연;이진국
    • 조명전기설비학회논문지
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    • 제17권3호
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    • pp.32-39
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    • 2003
  • 동기발전기 출력전압은 여자시스템의 계자전류 제어에 의해 일정하게 유지된다. 고주파 PWM 컨버터(전류제어 모드 buck 컨버터) 형태의 여자시스템은 부하변동이 발생하였을 때 동기발전기의 계자전류를 제어하게 된다. 이 논문은 정상상태 및 과도상태에서의 안정화를 개선하기 위하여 여자시스템의 설계 및 실험에 대해 다루었다. 시뮬레이션 및 실험 결과는 제안된 여자시스템이 50[kW] 동기발전기의 DVR에 의해 응답시간이 개선되었음을 보여주었다.

단위역률동작을 위한 동기 발전기 여자 시스템용 2단 3상 PWM AC/DC 컨버터 (2-stage 3-phase PWM AC/DC Converter for Unity Power Factor Drive of Synchronous Generator)

  • 이상훈;김태형;이동희;안진우
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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    • pp.187-192
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    • 2007
  • The terminal voltage of a synchronous generator is maintained by the field current control of excitation system Generally AC/DC converter which is component of AVR(Automatic Voltage Regulator) system for excitation current control is connected to diode rectifier and DC/DC converter system In the case of diode rectifier system of phase controlled converter, AC/DC converter has low power factor and some low order harmonics in the line current. In this paper, two-stage three-phase PWM AC/DC converter is studied to solve these problems, The proposed method is verified by the computer simulations and experimental results in prototype generation system.

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AC-DC Zeta Converter for Power Quality Improvement in Direct Torque Controlled PMSM Drive

  • Singh Bhim;Singh B.P.;Dwivedi Sanjeet
    • Journal of Power Electronics
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    • 제6권2호
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    • pp.146-162
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    • 2006
  • This paper deals with the analysis, design and implementation of an AC-DC Zeta converter in discontinuous current mode (DCM) of operation used for power quality improvement at AC mains in direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drives. The designed Zeta converter feeds a direct torque controlled PMSM drive system. Modeling and simulation is carried out in a standard PSIM software environment. Test results are obtained on the developed prototype Zeta converter using DSP ADMC401. The results obtained demonstrate the effectiveness of the Zeta converter in improving power quality at AC mains in the PMSM drive system.

약한 AC 계통에서 동기조상기용 여자 시스템 특성에 따른 HVDC 과도 특성 (Dynamic Performance of HVDC According to Excitation System Characteristics of Synchronous Compensator in a Weak AC System)

  • 김찬기;김정부;심응보
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제49권6호
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    • pp.431-440
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    • 2000
  • This paper analyses the dynamic performance of HVDC System connected to a weak AC system for various exciter characteristics of synchronous machines connected at the converter bus. Conventionally capacitors are used to supply reactive power requirement at a strong converter bus. But the installation of synchronous machine is essential in a isolated weak network to re-start after a shutdown of HVDC and to increase system strength. The dynamic performance of a synchronous machine depends on the characteristics depends of its exciter. In this paper, several exciter types are used to investigate their effect on the dynamic performance of the HVDC system and modifications to standard exciter topologies are suggested to mitigate observed problems.

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GaN FET 기반 동기정류기를 적용한 저전압-대전류 DC-DC Converter 효율예측 (A Study on the Efficiency Prediction of Low-Voltage and High-Current dc-dc Converters Using GaN FET-based Synchronous Rectifier)

  • 정재웅;김현빈;김종수;김남준
    • 전력전자학회논문지
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    • 제22권4호
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    • pp.297-304
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    • 2017
  • The purpose of this paper is to analyze losses because of switching devices and the secondary side circuit diodes of 500 W full bridge dc-dc converter by applying gallium nitride (GaN) field-effect transistor (FET), which is one of the wide band gap devices. For the detailed device analysis, we translate the specific resistance relation caused by the GaN FET material property into algebraic expression, and investigate the influence of the GaN FET structure and characteristic on efficiency and system specifications. In addition, we mathematically compare the diode rectifier circuit loss, which is a full bridge dc-dc converter secondary side circuit, with the synchronous rectifier circuit loss using silicon metal-oxide semiconductor (Si MOSFET) or GaN FET, which produce the full bridge dc-dc converter analytical value validity to derive the final efficiency and loss. We also design the heat sink based on the mathematically derived loss value, and suggest the heat sink size by purpose and the heat divergence degree through simulation.

2단 3상 PWM AC/DC 컨버터를 이용한 동기발전기 여자제어시스템 (A Study on Excitation System for Synchronous Generator Using Two State Three Phase PWM AC/DC Converter)

  • 이상훈;이동희;안진우
    • 조명전기설비학회논문지
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    • 제21권3호
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    • pp.96-106
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    • 2007
  • 동기발전기의 출력전압은 여자 시스템의 계자 전류 제어에 의해 일정하게 유지된다. 현재 대부분의 발전기 여자기의 여자전류제어를 위해 사용되는 AVR 시스템의 AC/DC 컨버터 부는 출력전압 제어가 가능한 위상제어 컨버터나 출력전압을 제어할 수 없는 다이오드 정류기와 DC/DC 컨버터를 결합하여 사용하고 있다. AC/DC 전력 변환장치로서 위상제어 컨버터나 출력전압을 제어할 수 없는 다이오드 정류기의 경우, AVR시스템의 전력을 공급하는 모선의 역률저하 및 저차 고조파 발생의 문제점을 야기 시키게 된다. 본 논문에서는 동기발전기의 여자전류 제어를 위해 사용되는 AVR 시스템 설계에 있어 단위역률 동작이 가능한 Boost형 AC/DC 컨버터와 모선의 부하변동에 속응성 있게 동작할 수 있는 전류 제어형 Buck 컨버터를 결합한 2단 3상 PWM AC/DC 컨버터에 대해 연구하였다. 제안된 AC/DC 컨버터를 시뮬레이션 한 결과 Boost 컨버터의 경우 단위 역률 동작 및 출력 DC 전압의 Boost 동작이 원할히 이루어졌으며, Buck 컨버터의 경우 다른 위상제어 컨버터에 비해 응답시간이 개선되었음을 알 수 있었다.

저전압 대전류용 개방형 DC-DC 컨버터 모듈에 관한 연구 (A Study on Open-frame Type DC-DC Converter Module for Low-Voltage High-Current Applications)

  • 안태영;황선민;조인호
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제52권4호
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    • pp.183-190
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    • 2003
  • We report the performance of an open-frame type low-voltage high-current DC-DC converter module developed using an active clamp forward converter circuit and current doubler rectifier. The converter module is designed with the specifications of an 1.8V output voltage, 25A output current, and 36-75V input voltage. The synchronous rectifier is used to reduce the conduction fuss at high current level and current-mode control is adapted to enhance the flexibility in the system configuration. A prototype converter module is successfully implemented within 10mm height and half brick size (58${\times}$61mm), and recorded an 84% efficiency and 4% voltage regulation for the entire input voltage range, thereby demonstrating its application potentials to future telecommunication electronics.

저전압 대전류용 개방형 DC-DC 컨버터 모듈에 관한 연구 (A Study on Open-frame Type DC-DC Converter Module for Low-Voltage High-Current Applications)

  • 안태영;황선민;조인호
    • 대한전기학회논문지:전력기술부문A
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    • 제52권4호
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    • pp.183-183
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    • 2003
  • We report the performance of an open-frame type low-voltage high-current DC-DC converter module developed using an active clamp forward converter circuit and current doubler rectifier. The converter module is designed with the specifications of an 1.8V output voltage, 25A output current, and 36-75V input voltage. The synchronous rectifier is used to reduce the conduction fuss at high current level and current-mode control is adapted to enhance the flexibility in the system configuration. A prototype converter module is successfully implemented within 10mm height and half brick size (58×61mm), and recorded an 84% efficiency and 4% voltage regulation for the entire input voltage range, thereby demonstrating its application potentials to future telecommunication electronics.

Cost-Effective Converters for Micro Wind Turbine Systems using PMSG

  • Park, Hong-Geuk;Lee, Dong-Choon;Kim, Heung-Geun
    • Journal of Power Electronics
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    • 제8권2호
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    • pp.156-162
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    • 2008
  • This paper proposes a low-cost power converter for micro wind turbine systems using permanent magnet synchronous generators (PMSG). The proposed converter consists of a two-leg three-phase PWM inverter for the generator control and a single-phase half-bridge PWM converter which is connected to the utility grid. For the two separate DC-link voltages, a balancing control is added and the adverse effect of the DC-link voltage ripples on the inverter output voltage is compensated. The control performance of the proposed converter topology for the micro wind turbine system is shown by the simulation results using PSIM software.