Interleaved DC-DC zero-voltage switching converter with series-connected in the primary side and parallel-connected in the secondary side

An interleaved zero-voltage switching (ZVS) forward converter is presented in this study. Two forward converter circuits with active snubber are used in the proposed circuit to share the load current. The interleaved pulse-width modulation (PWM) scheme is adopted to achieve current ripple reduction in the output capacitor. Thus, the size, weight and conduction losses of the output chokes are reduced. Only two switches instead of four switches in the conventional parallel ZVS forward converter are used in the proposed converter. Thus, the switch counts are reduced in the proposed circuit. The PWM signals of two switches are complementary each other with a small delay time in order to realise the ZVS turn-on at the transition interval. Thus, the switching losses and thermal stresses of the power switches are reduced. Experiments based on a 650 W prototype were provided to verify the theoretical analysis and the effectiveness of the proposed converter.