Energy recovery snubber circuit for a dc-dc push-pull converter

This study presents an active snubber recovery circuit for a dc-dc push-pull converter. Detailed waveform analysis and associated mathematical equations are presented, supported by PSpice simulations and experimentation. More importantly, unlike previous snubbers for the push-pull converter, the presented active recovery circuit remains fully functional over the complete duty cycle range. The proposed snubber technique is practically demonstrated on a 1-kW voltage-fed 48V_dc/560V_dc step-up push-pull converter. The experiments are conducted with a low-voltage and high-current source, typical of battery, supercapacitor, and photovoltaic source applications.