Digital Control of Secondary Active Clamp Phase-shifted Full-bridge Converter

A DSP-based self-adaptive proportional-integral (PI) controller to control a DC-DC converter is proposed in this paper. Full-bridge topology is adopted here to obtain higher power output capability and higher conversion efficiency. The converter adopts zero-voltage-switching (ZVS) technique to reduce conduction losses. A parallel secondary active clamp circuit is added to deal with voltage overshoot and ringing effect on transformer’s secondary side. A self-adaptive PI controller is proposed to replace the traditional PI controller. Moreover, the designed converter adopts a constant-current and constant-voltage (CC-CV) output control strategy. The secondary active clamp mechanism is discussed in detail. The effectiveness of the proposed converter was experimentally verified by an IGBT-based 10kW prototype.