Analysis and design considerations of an improved ZVS full-bridge DC-DC converter

An improved full-bridge (FB) pulse-width-modulated (PWM) converter is proposed featuring zero-voltage-switching (ZVS) of all primary switches in the entire line and load range. Compared to the conventional full bridge dc/dc converter, the proposed converter achieves ZVS with substantially reduced duty-cycle loss and circulating current. The operation principle of the circuit is described and design considerations of the converter are discussed. Finally, the operation and performance of the proposed converter is verified on a 1-kW (54-V/20-A) experimental PWM FB converter prototype operating at 100 kHz from a 300-400 V dc input.