ZVS-PWM half-bridge converter using active current clamping with an auxiliary winding of a transformer

A ZVS-PWM half-bridge converter which achieves active current clamping by using an auxiliary winding of a transformer is presented and evaluated in detail. This converter does not need the complicated drive circuit for the active-clamping switches. In the experiment, high efficiency of 86.5% is achieved for the low output voltage of 3.3 V, an output current of 30 A, and an input-voltage range of 300 V to 400 V at the switching frequency of 200 kHz.