An intelligent medium voltage gate driver with enhanced short circuit protection scheme for 10kV 4H-SiC MOSFETs

Abstract

Designing of gate drivers for high voltage SiC power devices in medium voltage applications is challenging due to high dv/dt and di/dt at the switching instants. During short circuit fault, the device current rises with high di/dt, and eventually the device fails within few of micro seconds if not protected. Short circuit protection of power devices is an essential feature to improve reliability of converters. In this paper, a novel gate driver is developed with short circuit protection scheme, suitable for 10kV, 10A 4-H SiC MOSFETs. It utilizes the de-sat sensing scheme to detect the fault, and clears the fault by turning off the gate pulse in two stages. The trip time at the short circuit fault is much smaller than the short circuit withstanding time of 10kV 4H-SiC MOSFETs. The gate driver is qualified with appropriate experimental test bench for validation of short circuit protection feature, over-current limit and continuous operation for the 10kV MOSFETs.