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

The conventional high frequency phase-shifted full-bridge DC/DC power converter has a disadvantage that a circulating current flows through the 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 this problem, this paper provides a circulating current free-type high-frequency ZVZCS phase-shifted full bridge (FB) DC/DC power converter with an energy recovery snubber attached at the secondary side of transformer. The energy recovery snubber adopted in this study is consisted of three fast recovery diodes and two resonant capacitors.