Novel soft-commutation DC-DC power converter with high-frequency transformer secondary side phase-shifted PWM active rectifier

This paper presents a novel circuit topology of the voltage source type zero voltage soft-switching (ZVS) full bridge DC-DC power converter with an isolated high-frequency transformer, which incorporates zero-current soft-switching (ZCS) phase-shifted (PS)-PWM active power switches in series with diodes of two bridge arms of a full-bridge rectifier on the high-frequency transformer secondary side. This high-frequency linked DC-DC power converter can achieve ZVS for noncontrolled active power switches on the primary side of the transformer and ZCS for PS-PWM active switches on the secondary side of the transformer under wide load variations as well as a wide PS-PWM regulation range. The switching power losses and conduction power losses of the active devices of the proposed DC-DC converter can be considerably reduced. The proposed DC-DC converter blocks circulating current flowing through the semiconductor switching devices on the transformer primary side as compared to the lossless snubbing capacitor and transformer leakage and magnetising inductor-assisted soft-switching full-bridge DC-DC converter with ZVS PS-PWM scheme on the transformer primary side. The steady-state operating principles of the proposed DC-DC converter are evaluated and discussed, based on the simulation and experimental results obtained from a 2 kW-40 kHz breadboard set-up using IGBTs.