Analysis and Implementation of a Novel Full-Bridge ZVS Converter with Adaptive Auxiliary Circuit

A new adaptive auxiliary circuit scheme is proposed for the phase-shift full-bridge converter that provides zero-voltage-switching (ZVS) for all switches for a wide variation in load and input range. Complementary voltage seconds works on the auxiliary inductor to provide adaptive energy for the lagging leg switches. Therefore, ZVS operation over a wide load conversion range is achieved without significantly increased conduction loss. Stages of operation are presented and analyzed. Base on the analysis, design procedure and optimum design are presented. Experimental results obtained from a 1-kW/100kHz prototype are given to verify the performance of the proposed converter for varing load as well as input voltage.