Phase-shift full-bridge ZCT converter based on digital control

Based on the study of many full-bridge ZCT(zero current transition) converters, a novel ZCT PWM full-bridge DC/DC converter was proposed. The soft-switching of main switches is completed by using the resonant inductor auxiliary circuit. The ZCS(zero current switching) of all active switches and output rectifier diodes soft commutation is realized in entire load ranges. The digital control system was designed by using ARM chip LCP2214. A 1 kW, 25 kHz soft-switching power supply was developed and the circuit experiments were carried out. The results show that this digital control PWM full-bridge converter which employs the proposed topology has lower loss and lower cost, and the maximum efficiency exceeds 91%, which shows a great prospect for future applications.