A Novel ZCS-PWM Flyback Converter With a Simple ZCS-PWM Commutation Cell

This paper proposes a novel zero-current-switching pulsewidth-modulation (ZCS-PWM) flyback dc/dc converter using a simple ZCS-PWM commutation cell. The main switch and auxiliary switch operate at ZCS turn-on and turn-off conditions, and all uncontrolled devices in the proposed converter operate at zero-voltage-switching (ZVS) turn-on and turn-off. In addition, given constant frequency and decreasing commutation losses, the proposed converter has no additional current stress and conduction loss in the main switch compared to the conventional hard switching flyback converter. The averaging approach is used to estimate and examine the steady-state of the proposed converter. The principle of operation, theoretical analysis, and experimental results of the new ZCS-PWM flyback converter, rated 150 W and operating at 80 kHz, are provided in this paper to verify the performance of the proposed converter.