고역률 절연형 DCM 벅-부스트 컨버터에 관한 연구

This paper presents a novel isolated buck-boost converter for high power factor and high efficiency. The switching devices in the proposed converter are operated by soft switching technique using a new resonant circuit, and are driven with discontinuous conduction mode (DCM) according to pulse width modulation. The resonant circuit makes use of a step up-down inductor and a loss-less snubber capacitor. The input ac current waveform in the proposed converter also becomes a quasi sinusoidal waveform in proportion to the magnitude of input ac voltage under constant switching frequency. As a result, the proposed converter make it possible that the switching power losses are low, the efficiency of the converter is high, and the input power factor is nearly unity.