Dynamic Redistribution of Switching Losses in Parallel Connected SiC MOSFETs for Active Thermal Balance

SiC MOSFETs are quickly replacing silicon-based devices in high-power applications because of their enhanced electrical and thermal performance. However, due to fabrication limitations, commercial SiC dies have lower current ratings compared to their silicon counterparts. Consequently, multiple Si C MOSFETs need to be connected in parallel for high-current applications. This leads to thermal imbalances among the devices, caused by asymmetrical layouts and parameter mismatches. To tackle this problem, this paper presents an active thermal balancing control strategy that monitors the case temperatures of parallel-connected Si C MOSFETs and dynamically redistributes the switching losses among the power devices. The proposed solution enables optimal utilization of each device, eliminating the need for current derating that is commonly necessary in parallel-connected switching devices. Experimental results are provided to verify the proposed approach.