Analysis and implementation of a novel soft-switching pulse-width modulation converter

A soft-switching pulse-width modulation (PWM) converter with parallel connection to realise the zero voltage switching (ZVS) and achieve load current sharing is presented. The leakage inductance of the transformer and output capacitances of power switches are adopted to realise the resonance at the transition interval of switches such that the ZVS turn-on can be achieved. The energy stored in the transformer leakage and magnetising inductances can be released to limit the peak voltage stress of switching devices. To reduce the ripple current on the output capacitor and reduce the current stress on the secondary windings of the transformer, the parallel-connected circuit with an interleaved PWM scheme is used at the output side to share the load current and reduce the output ripple current. The operation principles, steady-state analysis and design equations of the proposed converter are provided in detail. Finally, experiments based on a 1 kW (12 V/84 A) prototype are provided to verify the theoretical analysis and the effectiveness of the proposed converter.