Soft-Switching Full-Bridge PWM DC–DC Converter With Controlled Output Rectifier and Secondary Energy Recovery Turn-Off Snubber

A zero-voltage and zero-current switching full-bridge pulse-width modulated dc-dc converter with controlled secondary-side rectifier using a novel nondissipative energy recovery turn-off snubber is presented in this paper. Using a controlled rectifier, a turn-off snubber, and an innovative control algorithm, the circulating current of the converter is eliminated and soft switching for all power switches of the inverter is achieved for full-load range from no-load to short circuit. The principle of converter operation is explained and analyzed and the experimental results on a 4.5 kW, 100 kHz laboratory model of the converter are presented.