An improved ZVZCS PWM FB DC/DC converter using the modified energy recovery snubber

Abstract

The conventional high frequency phase-shifted full bridge DC/DC converter has a disadvantage that a circulating current flows through transformer and switching devices during the freewheeling interval. Due to this circulating current, RMS current stress, conduction losses of transformer and switching devices are increased. To alleviate that problem, the paper proposes a circulating current free type high frequency soft switching phase-shifted full bridge (FB) DC/DC converter with the modified energy recovery snubber (ERS) attached at the secondary side of transformer. The modified energy recovery snubber (ERS) adopted in this study consists of four fast recovery diodes and two resonant capacitors.