A novel zero-voltage and zero-current-switching full-bridge PWM converter

A novel zero voltage and zero current switching full bridge pulse width modulation (ZVZCS-FB-PWM) converter is proposed and analyzed. An auxiliary circuit, which consists of a diode and auxiliary winding coupled with output inductor, are added to provide zero current switching (ZCS) conditions. The ZCS of lagging-leg switches is achieved by resetting the primary current with induced EMF of auxiliary winding during the freewheeling period. Many advantages including low current pressure, simple circuit topology and low cost make the new converter very attractive for high power applications. The operation, analysis and design considerations are illustrated and verified on a 3 kW 100 kHz IGBT based experimental circuit.