A precise ZVS range calculation method for full bridge converter

This paper presents a more precise ZVS range calculation method for ZVS full-bridge converter. Primary current downward step during the leading leg transition is mainly analyzed. This downward step often ignored, caused by the rectifier junction capacitance discharging, will significantly influence the ZVS range of the lagging leg power switch. An 800 W ZVS full bridge converter prototype is constructed and experimental results verified the validity of the proposed method.