A full-bridge SR-PWM DC-DC converter operating at reduced conduction and commutation losses and working with three different transformers

This paper presents a SR-PWM Full-Bridge DC-DC converter operating at reduced conduction and commutation losses working with three different transformers and using phase-shift control. This converter employs a self-resonant circuit and a tapped inductor for minimizing a circulating current flowing through the transformer and switching devices. The principle of the self-resonant circuit provides the soft switching. It is based in an auxiliary voltage source that feeds the resonant circuit, charging a capacitor which provides the condition for zero voltage switching (ZVS) of the main switches. The proposed approach allows building a converter with high frequency of operation. A detailed analysis of the operation is presented. The output voltage is controlled by PWM. The complete theoretical analysis, operating principles, simulation and experimental results are presented.