• Title/Summary/Keyword: Synchronous converter

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A Study on Efficiency and Characteristic of Zero Voltage Switched Half-Bridge Converter and Forward Converter (영전압 스위칭 하프브리지 컨버터와 포워드 컨버터의 효율 및 특성에 관한 연구)

  • Seo, J.K.;Kim, Y.;Baek, S.H.;Kwon, S.D.
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.147-149
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    • 1998
  • In this paper, zero voltage switched half bridge converter and an active-clamped, zero voltage switched forward converter equipped with self-driven synchronous rectifier is designed and investigated for high efficiency BC-DC converter. A synchronous rectifier is has a lower conduction power loss than shottky diode rectifier. The purpose of this paper is to investigate the effect of parasitic inductance in a synchronous rectifier of DC-DC converters and examine overall efficiency of zero voltage switched DC-DC converters.

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A Study on Switching Characteristics of Active Clamp Type Flyback Converter with Synchronous Rectifier Driving Signals Controlling Auxiliary Switch (보조스위치가 동기정류기 구동 신호로 제어되는 능동 클램프형 플라이백 컨버터의 스위칭 특성에 관한 연구)

  • Ahn, Tae Young
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.3
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    • pp.21-26
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    • 2018
  • In this paper, the switching characteristics of the active clamp type flyback converter, which is deemed suitable for the miniaturization of the external power supply for home appliance, were analyzed and the process of reducing the switching loss was explained. The active clamp type flyback converter operating in the DCM has confirmed that the surge voltage of the main switch does not occur and the turn-off / on loss of the switch do not occur in principle. Also, in the case of the switch for synchronous rectifier, it was showed that the switch current showed half-wave rectified sinusoidal characteristic, and the switching loss was reduced. The switching characteristics of the experimental results gathered from 120 W class prototype were compared with the theoretical waveform in the steady-state and it was confirmed that the power conversion efficiency of the active clamp type flyback converter was maintained high due to the reduction of the switching loss.

High Efficiency Active Clamp Forward Converter with Synchronous Switch Controlled ZVS Operation

  • Lee Sung-Sae;Choi Seong-Wook;Moon Gun-Woo
    • Journal of Power Electronics
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    • v.6 no.2
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    • pp.131-138
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    • 2006
  • An active clamp ZVS PWM forward converter using a secondary synchronous switch control is proposed in this paper. The proposed converter is suitable for low-voltage and high-current applications. The structure of the proposed converter is the same as a conventional active clamp forward converter. However, since it controls the secondary synchronous switch to build up the primary current during a very short period of time, the ZVS operation is easily achieved without any additional conduction losses of magnetizing current in the transformer and clamp circuit. Furthermore, there are no additional circuits required for the ZVS operation of power switches. Therefore, the proposed converter can achieve high efficiency with low EMI noise, resulting from soft switching without any additional conduction losses, and shows high power dens~ty, a result of high efficiency, and requires no additional components. The operational principle and design example are presented. Experimental results demonstrate that the proposed converter can achieve an excellent ZVS performance throughout all load conditions and demonstrates significant improvement in efficiency for the 100W (5V, 20A) prototype converter.

High Efficiency Active Clamp Forward Converter with Synchronous Switch Controlled ZVS Operation (동기 스위치 제어를 통한 영전압 동작 고효율 능동 클램프 포워드 컨버터)

  • Lee, Sung-Sae;Cho, Seong-Wook;Moon, Gun-Woo
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.266-268
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    • 2005
  • A new synchronous switch controlled transient current build-up zero voltage switching (TCB-ZVS) forward converter is proposed. The proposed converter is suitable for the low-voltage and high-current applications. The features of the proposed converter are low conduction loss of magnetizing current, no additional circuit for the ZVS operation, high efficiency, high power density and low EMI noise throughout all load conditions.

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A study on the efficiency characteristics for LLC resonant half-bridge converter with synchronous rectifier (동기정류기를 적용한 공진형 하프브릿지의 효율특성에 관한연구)

  • Lee, Gwang-Taek;Ahn, Tae-Young
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.289-291
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    • 2005
  • In this paper results of the experiment which used LLC resonant half bridge DC-DC converter to a portable electrical equipment. LLC resonance Half Bridge DC-DC converter which was used in this experiment improved an efficiency because it reduced switching, conduction losses and with synchronous rectifier. As a result of the experiment, this proposed converter could verified an increase of 2% to the efficiency more than diode rectifier.

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Passive Current Sharing Characteristics of Multi-Phase Synchronous Buck Converter (다상 동기 벅 컨버터의 Passive Current Sharing 특성)

  • Kim, Jeong-Hoon;Cho, Kyung-Sig;Chung, Se-Kyo
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.175-177
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    • 2007
  • An analysis on a passive current sharing characteristics of a multi-phase synchronous buck converter is presented. The passive current sharing method is simple but its characteristics depend on the converter equivalent resistance and PWM uniformity. In this paper, the load sharing and power consumption of the passive current sharing system for the converter equivalent resistance and duty ratio inequalities are investigated through the simulation and experiment.

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LLC resonant half-bridge DC-DC converter with synchronous rectifier (동기정류기를 적용한 LLC 공진형 하프브릿지 DC-DC 컨버터)

  • Lee, Gwang-Taek;Ahn, Tae-Young
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1392-1394
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    • 2005
  • In this paper results of the experiment which used LLC resonant Half Bridge DC-DC converter to a portable electrical equipment. LLC resonant Half Bridge DC-DC converter which was used in this experiment improved an efficiency because it reduced switching, conduction losses and with synchronous rectifier. As a result of the experiment, this proposed converter could verified an increase of 2% to the efficiency more than diode rectifier.

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A Study on the Efficiency Improvement of TTFC(Two Transistor Forward Converter) using Synchronous Rectifier of Compulsory Control-driver (동기정류기 강제구동 방식을 이용한 TTFC의 효율 향상에 관한 연구)

  • Bae, Jin-Yong;Kim, Yong;Lee, Eun-Young;Kwon, Soon-Do;Han, Kyung-Tae;Han, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2003.10b
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    • pp.166-170
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    • 2003
  • This paper presents the TTFC(Two Transistor Forward Converter) using Synchronous Rectifier of Compulsory Control-driver. The two transistor forward circuit is used to decrease voltage stress of primary side and the synchronous rectifier is used to reduce current stress of secondary side. Previous synchronous rectifier's MOSFET of TTFC have long dead time This paper presents synchronous rectifier of compulsory control-driver for minimized dead time. This paper compared with diode rectifier, self-driven synchronous rectifier and compulsory control-driver synchronous rectifier of TTFC. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 200W 100kHz MOSFET based experimental circuit.

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Design of a High Frequency PWM Converter for Synchronous Generator Excitation System (동기발전기 여자시스템용 고주파 PWM 컨버터 설계)

  • Jang Su-Jin;Ryu Dong-Kyun;Won Chung-Yuen;Lee Jin-Kuk;Bae Kee-Hun;Kim Soo-Suck
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.515-518
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    • 2002
  • A synchronous generator is equipped with an automatic voltage regulator(AVR), which is responsible for keeping the output voltage constant under normal operating conditions at various levels. The output voltage of Synchronous Generator is regulated constantly by field voltage control in excitation system. High frequency PWM converter (Buck converter) type excitation system for synchronous generator that can sustain prefer output voltage level even at the fault condition happened. The proper operation of the proposed excitation system was verified through the simulations and the experiments.

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A Single-Stage Single-Switch Flyback Converter with Synchronous Rectifier (단일단 단일스위치 동기정류기형 플라이백 컨버터)

  • Lim, Ik-Hun;Lee, Joo-Hyun;Ryu, Ho-Seon;Kwon, Bong-Hwan;Kim, Bong-Suck
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.4
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    • pp.361-370
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    • 2006
  • A single-stage single-switch flyback converter with synchronous rectifier is proposed. The proposed single-stage single-switch technique meets the IEC 61000-3-2 harmonic requirements. The proposed SR is the voltage driven synchronous rectifier (VDSR) which operates depending on the voltage drop across the drain and source of the MOSFET. Experimental results for the 85W (12V /7.1A) proposed converter are shown.