Analysis of a Zero Voltage Switching Cuk Converter

A boost type zero voltage switching (ZVS) isolated Cuk converter is presented in this paper to reduce the switching losses of main switch. An auxiliary switch and a clamp capacitor are connected in parallel with the main switch to absorb all the energy stored in the leakage inductance of the transformer. The ZVS operation of main switch is achieved by the resonance with the resonant inductor and output capacitor of main switch. The ZVS operation of auxiliary switch is achieved by the resonance with the resonant inductor and the clamp capacitor. Therefore both switches are turned on at ZVS. The principle of operation, system analysis and design consideration are presented Finally, experiments based on an 180 W (12 V/15 A) prototype are provided to demonstrate the effectiveness of the proposed converter.