ZVS Double-Ended Ćuk Converter

This brief presents a zero-voltage switching (ZVS) Ćuk converter with double-ended rectifier to reduce switching losses on power semiconductors, decrease voltage stresses on rectifier diodes, and achieve power delivery to the output load in both the positive and negative half cycles 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 ZVS of the auxiliary switch. On the other hand, the resonant inductance and output capacitance of the main switch are resonant to achieve ZVS turn-on of the main switch. Experimental results for a 300-W prototype circuit operating are given to demonstrate the effectiveness of the proposed converter.