Efficiency Optimization of the Active Auxiliary Network in the Phase-Shifted Full-Bridge DC/DC Converter

Phase-shifted full-bridge DC/DC converter is widely used in the medium and high power DC/DC conversion, and its efficiency is an important index to evaluate the performance of the converter. Phase-shifted full-bridge circuit can easily realize the zero voltage switching (ZVS) of the power devices, but there are also problems such as duty-cycle loss and lagging bridge arms that make it difficult to achieve a wide range of ZVS. The application of active auxiliary network can effectively solve the above problems, but it introduces additional loss. This paper analyzes the phase-shifted full-bridge DC/DC converter with active auxiliary network, the duty cycle-loss suppression and the additional circuit loss, optimizes the circuit parameters to reduce the loss and improve the overall efficiency of the converter, verifies the theoretical analysis through experiments. Finally, the efficiency advantages of the study for high current output applications are clarified.