Input Series Output Parallel Phase-Shifted Full-Bridge Converter Design for Full Range Soft-Switching Effect and Minimum Output Current Ripple

This paper proposes a DC-DC converter with input series and output parallel structure, which consists of three phase-shifted full-bridge converter modules and three auxiliary LC networks implemented in the lag bridge arm for soft switching. The three LC networks are connected to the midpoint of the leading bridge arm and lagging bridge arm of different modules, respectively. By utilizing the current provided by the LC network, zero-voltage switching (ZVS) of the lagging bridge arm under light load is implemented for each of the three modules, and the amplitude of the current source network is negatively correlated with duty cycle and load to reduce the circulating current loss. The three modules achieve overlapping of the output current through interleaved control. By comparing the 180° phase shift of two modules, the output current ripple is effectively suppressed so that a smaller filter capacitor can be selected. The characteristics of the converter are analyzed, and the feasibility of this scheme is verified through simulation.