A Cost-Effective Series-Connected Gate Drive Circuit for SiC MOSFET

Compared with Si power devices, SiC power devices have obvious performance advantages. Despite that the development of SiC device manufacture is developing rapidly in recent years, the maximum voltage rating of the existing commercial SiC MOSFET is still only 1.7kV. In some high voltage applications, the series-connected SiC MOSFET is required to increase the rated voltage of SiC MOSFETs. Fast turn-on and turn-off speed of SiC MOSFETs reduce switching losses, but also makes the dynamic voltage imbalance problem of series SiC MOSFETs more serious. In this paper, to solve this problem, a cost-effective gate drive circuit for series-connected SiC MOSFET is proposed. Only an external gate driver, several passive components and a controllable voltage source are needed to drive the series-connected SiC MOSFETs. The operation principles of the proposed gate drive circuit for series-connected SiC MOSFETs are theoretically analyzed. Finally, experimenttal studies are carried out to verify the effectiveness of the proposed series-connected gate drive circuit for SiC MOSFETs.