A hybrid PWM resonant converter suitable for wide input variation

Abstract

A resonant converter suitable for applications having a wide input range is proposed. The proposed converter is a hybrid combination of a half bridge converter and a phase-shift full-bridge converter and they use one leg of switches in common. The secondary sides of two transformers are connected in series with a resonant capacitor in between which forms a resonant tank with the leakage inductances. By generating a controllable four-level voltage, the proposed converter can handle input voltage variation with reduced output filter size. The proposed converter achieves zero voltage switching easily along wide load range without noticeable increase in a circulating current and an effective duty loss. The analysis of the resonant converter and experimental results of 400 W prototype is presented to verify the features of the converter.