Analysis, design and implementation of a wide ZVS full-bridge converter

This paper presents a DC/DC converter integrated a full-bridge converter and a half-bridge converter. Compared to the conventional full-bridge converter, the advantages of the proposed converter are low circulating loss, wide ZVS range of the lagging-leg switches and low output inductor size. A resonant capacitor is adopted in the transformer primary side to reduce the primary current to zero during the freewheeling interval. Thus, the circulating loss in conventional full-bridge converter is removed. Half-bridge circuit shares the same lagging-leg switches of full-bridge circuit in order to extend the ZVS range of lagging-leg switches. The transformer secondary windings of two converters are connected in series. Two positive voltage levels are generated at the secondary rectified voltage and the output inductance of the proposed converter is reduced. Finally, experimental results with a 1.44kW laboratory prototype are provided to verify the effectiveness of the proposed converter.