A ZVS PWM full bridge converter with self-regulating auxiliary current

A zero-voltage-switching (ZVS) phase-shift full-bridge converter with self-regulating auxiliary current is proposed. ZVS of lagging-leg switches can be achieved in full load range due to the introduced active auxiliary circuit. Meanwhile, the auxiliary circuit that features simple control of the auxiliary switches has no effect on the main power transferring path and the auxiliary energy stored for the ZVS of lagging-leg can be regulated by the load current without significantly increasing conduction loss over the entire load range. The principle of the proposed converter is discussed in detail and design method of key parameters is carefully depicted. Finally, the operation and performance of the proposed converter is verified on a 1kW/54V, 100 kHz prototype.