Silicon MOSFETs Evaluation in Auxiliary DC-DC Converters for HEV/EV Applications

Abstract

The paper deals with the last generation silicon MOSFETs application in an auxiliary power supply for HEV and EV applications. In the paper, the converter high- efficiency target is achieved by a suitable selection of the MOSFETs in the primary side and secondary side of an isolated DC-DC converter applied to interface the high-voltage to the low-voltage battery pack. The primary side is a high voltage full-bridge topology with super-junction MOSFETs, while the secondary is arranged with a low voltage trench-gate MOSFETs in synchronous rectifier operation. Experimental evaluation of the primary and secondary side of MOSFETs devices has been carried out to give correct guidelines to choose the power switches devices. Furthermore, an active clamp stage circuit on the secondary side is evaluated to reduce the drain-source MOSFET voltage spike.