ZVS PWM scheme to suppress ground leakage currentof full-bridge grid inverter

The common mode (CM) model of the full-bridge inverter with active-clamping technique is derived and the ground leakage current of the existing Zero-Voltage-Switching (ZVS) PWM scheme is analyzed. In order to minimize the ground leakage current of the ZVS inverter, a novel ZVS PWM scheme is proposed. Firstly, the ZVS condition is analyzed and then the ZVS PWM scheme is designed to realize the zero voltage switching for both main switches and auxiliary switch in a large power range. After that, the CM characteristic of the proposed PWM scheme is analyzed. The experiment on a 3kW prototype shows the realization of ZVS operation and the significant reduction of the ground leakage current.