Design and Realization of High Power Density EV Charging Module

DC charging module consists of AC/DC converter circuit and DC/DC converter circuit. In view of the requirement of charging module high power density and good output characteristic of EV’s charger, AC/DC adopts the three-phase VIENNA rectifier design, and DC/DC adopts the full bridge LLC resonant circuit, in which the former can meet the requirements of high power density and high power factor, while the latter can meet the requirements of high efficiency and soft switch. The working principle of three-phase VIENNA rectifier and all bridge LLC resonant conversion circuit are analyzed. Then, the parameters of the front-end and back-end circuits are calculated, and the output voltage and efficiency of the charging module at full load, no-load and half load are tested. The experimental results show that the output voltage of the front-end circuit is stable, the output DC capacitance can be automatically compressed, the back-end circuit can realize ZVS shut off, the module features high efficiency and good output.