A Cost Effective Gate Drive Circuit for Improved Switching Performance in SiC Traction Inverters

With the growing utilization of wide bandgap (WBG) devices that switch significantly faster than conventional devices like Si MOSFETs and IGBTs, there is an ever-increasing focus on extracting the highest performance out of these devices by increasing the switching frequency while minimizing the switching losses. While the fast switching in WBG devices reduces switching losses, it aggravates unwanted second-order effects such as overshoots and ringing which limits the performance of these devices. Existing solutions in the literature either require a trade-off between the second-order effects and the switching losses or a complex and expensive implementation to minimize both the switching losses and the second-order effects simultaneously for achieving optimum switching performance. The primary contribution of this paper is a simple and inexpensive gate drive circuit using passive components to reduce turn-off switching losses. The proposed circuit independently controls the drain-source voltage and the drain current slew rate during a turnoff event to minimize switching losses without simultaneously increasing the drain voltage overshoot. Hardware experiments validate that the turn-off switching losses reduce by about 16.5 % using the proposed circuit.