Zero voltage switching double ended Cuk converter

This paper presents a zero voltage switching (ZVS) Cuk converter with double ended rectifier to reduce switching losses on power semiconductors, decrease voltage stresses on rectifier diodes and achieve power delivery to output load in positive and negative half cycle of the secondary winding voltage. An auxiliary switch and a clamp capacitor are connected in parallel with the primary side of the transformer to absorb all the energy stored in the transformer leakage inductance. The resonant inductance and the clamp capacitance are resonant to achieve zero-voltage switching (ZVS) of auxiliary switch. On the other hand, the resonant inductance and output capacitance of main switch are resonant to achieve ZVS turn-on of main switch. Experimental results for a 300 W prototype circuit operating at 73 kHz are given to demonstrate the effectiveness of the proposed converter.