Snubber capacitors optimization for super-junction MOSFET in the ZVS full-bridge inverter

摘要

A zero-voltage switching (ZVS) full-bridge inverter and its modulation schemes have been investigated in previous literatures. Parallel snubber capacitors are utilized to reduce the turn-off loss of super-junction MOSFETs in the ZVS full-bridge inverter. However due to the MOSFET's nonlinear output capacitance together with the parallel snubber capacitor, the ZVS commutation is unable to be realized and high voltage spike occurs on switching devices under light load condition. The problem is solved by changing the position of the snubber capacitors to reduce the turn-off rising time of drain-source voltage. The validity of snubber capacitors optimization is verified by experiments on a ZVS full-bridge inverter prototype.