Research of phase-shift full-bridge ZCT converter based on digital control

This paper proposes a novel ZCT (zero-current-transition) PWM full-bridge DC-DC converter. The proposed converter can achieve ZCS (zero-current- switching) for all the active switches in the entire load ranges, also it realizes soft commutation for the output rectifier diodes. Furthermore, the auxiliary circuit also helps to turn on the main switches softly. Soft-switching operational principle is analyzed, and its digital control system was designed based on ARM micro processor LPC2214. A 1 kw,25 kHz prototype based on this proposed topology is developed. Simulation and experimental results verify the theoretical analysis.