• Journal of Power Electronics
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• 제18권2호
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• pp.323-331
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• 2018

Buck power factor correction (PFC) converters, compared with conventional boost PFC converters, exhibit high efficiency performance in the entire range of universal line voltage. This feature has gotten more attention for eliminating the zero crossing dead angle of buck PFC rectifiers. Furthermore, bridgeless structures for the reduction of conduction losses have been proposed. The aim of this paper is to introduce a single-phase buck rectifier that simultaneously has unity power factor (PF) and bridgeless structure while operating in the continuous conduction mode (CCM). For this purpose, two auxiliary flyback converters without any active switches are applied to a bridgeless buck rectifier to eliminate the zero crossing dead angle and achieve unity power factor, low total harmonic distortion (THD) and high efficiency. The operation and design considerations of the proposed rectifier are verified on a 150W, 48V prototype using a conventional peak-current-mode control. The measurement results show that the proposed rectifier has nearly unity power factor, THD less than 7% and high efficiency.

• 전력전자학회논문지
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• 제16권3호
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• pp.293-301
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• 2011

본 논문에서는 정류용 브릿지 다이오드가 없는 고효율 하프 브릿지 AC-DC 컨버터를 제안한다. 제안하는 컨버터는 비대칭 펄스 폭 변조 방식의 하프 브릿지 DC-DC 컨버터와 정류용 브릿지 다이오드가 없는 역률 개선 회로가 통합된 회로 구조를 지닌다. 제안하는 컨버터는 정류용 브릿지 다이오드를 사용하지 않고 교류 입력 전압으로부터 절연된 직류 출력 전압을 공급한다. 간단한 회로 구조와 함께 도통 손실을 줄일 수 있다. 또한 스위칭 소자들의 영전압 스위칭을 통하여 스위칭 손실을 줄일 수 있다. 두 개의 직렬 연결된 트랜스포머를 구비함으로서 프로파일을 낮추고 전력밀도를 높일 수 있다. 250 W (48 V / 5.2 A) 회로 설계 및 실험을 통하여 제안된 컨버터의 성능을 $90 \;V_{rms}$ 교류 입력 전압에 대하여 입증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.232-233
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• 2012

This paper presents an effective control scheme for an electric vehicle battery charger where a symmetrical bridgeless power factor-corrected converter and a buck converter are cascaded. Both converters have been popular in industries because of their high efficiency, low cost, and compact size, hence combining these converters makes the overall battery charging system strongly efficient. Moreover, this charger topology can operate at universal input voltage and attain a desired battery current and voltage without ripple. In order to achieve a unity input power factor and zero input current harmonic distortion, the proposed control scheme adopts duty ratio feed-forward control technique in both current and voltage control loop. Additionally, in the current loop, its reference is created by a phase-locked loop (PLL) block, leading to a pure sinusoidal input current although the input voltage waveform is being distorted. The feasibility and practical value of the proposed approach are verified by simulation and experiment with an 110V/60Hz ac line input and 1.5kW-72V dc output of the battery charging system.