Development Of Phase-Shifted Zero-Voltage And Zero-Current-Switching Full Bridge Converter

Phase-shifted (PS) ZVZCS full bridge converter achieves zero-current switching for the devices due to the eliminated circulating current. The converter reduces the conduction loss and improves the efficiency and power density, so it is suitable for high power application.The paper reviews the research status of the ZVZCS full bridge converter and introduces some kind of method to achieve soft switching by using auxiliary circuit. Two kinds of PS ZVZCS full bridge converter with clamping circuit are studied in detail.The operation principles of the two converters are analyzed, and the parameter equations of state are given. The paper compares the two different operation patterns of the converter.The paper studies the relationship on the circuit loss and the clamp capacitance base on loss analysis in order to optimize the clamp circuit's parameters. The condition to realize the soft switching and the efficient duty cycle are also analyzed. The small signal model of the converter is established to design the compensation network.Two 7kW (270V input and 360V/20A output) DC/DC converters are implemented using the above two kind of methods. The simulation and the experimental result have confirmed the theoretical analysis accuracy.