A New Family of Full-Bridge ZVS Converters

Abstract

A family of soft-switched, full-bridge (FB) pulse-width-modulated (PWM) converters that feature zero-voltage-switching (ZVS) of all bridge switches over a wide range of input voltage and output load with minimal duty cycle loss and circulating current is described. The ZVS of primary switches is achieved by employing two magnetic components whose volt-second products change in the opposite directions with a change of phase shift between the two bridge legs. One magnetic component is a transformer while the other magnetic component is either a coupled inductor or a single-winding inductor. The transformer is used to provide isolated output(s), whereas the inductor is used to store energy for ZVS.