ZVZCS PSFB converter with minimized primary circulating losses and secondary voltage stresses using auxiliary winding and circuit

In order to solve the efficiency loss problem of phase shifting full bridge converters and maintain the excellent characteristics of wide range adjustment, this paper proposes an improved ZVZCS phase shifting full bridge converter. Through the auxiliary winding of the transformer and the secondary auxiliary circuit, the full-bridge converter achieves zero-voltage switching on the leading arm and zero-current turnoff on the lagging arm, minimizing the primary circulating current; the secondary rectifier diode achieves zero-current switching and minimizes the voltage stress of the rectifier diode; the energy transmission efficiency is significantly improved under the same effective duty cycle. Finally, a DC/DC experimental prototype with an input of 390VDC, an output of 120VDC, and a power of 1.2 kW was built to verify the above characteristics and the peak efficiency reached 97.44%.