One Zero-Voltage-Switching Voltage-Fed Three-Phase Push-Pull DC/DC Converter for Electric Vehicle Applications

摘要

A simple zero-voltage-switching (ZVS) step-up voltage-fed three-phase push-pull dc/dc converter for electric vehicle applications is proposed in this paper. In comparison with the conventional three-phase topology, only one auxilliary switch is inserted between the input voltage source and the midpoint of the Y-Y connection three-phase transformer. All of three main switches can realize ZVS turn-on in a wide load range and the auxiliary switch could achieve ZVS turn-on under the condition of enough leakage inductance energy, which enables us to reduce the switching loss and improve efficiency. The PWM strategy, steady-state operation and characteristics are discussed, and finally, a prototype was conducted and the test results verified the effectiveness of the proposed topology.