A Novel ZCS-PWM Flyback Converter With A Simple ZCS-PWM Auxiliary Circuit

This paper proposed a novel zero-current-switching pulsewidth-modulation (ZCS-PWM) flyback dc/dc converter using a simple ZCS-PWM auxiliary circuit. The main switch and auxiliary switch operate at zero-current-switching turn on and turn off, and the all passive semiconductor devices in the proposed converter operate at zero-voltage-switching (ZVS) turn on and turn off. Besides operating at constant frequency and reducing commutation losses, the proposed converter has no additional current stress and conduction loss in the main switch in comparison to the conventional hard switching flyback converter counterpart. 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