In-Situ Fault Sensing Methods for Degradation Mechanism of SiC Power MOSFETs in Power Supplies Under Power Cycling Stress

This paper investigates a fault sensing method for SiC power MOSFETs in power supply based on voltage transient. The impact of SiC power MOSFETs degradation on voltage transient have been theoretically analyzed. The effect of the degradation is represented by the voltage changing rate measured by a RF voltage probe with a noninvasive manner. The degraded devices were obtained through the power-cycling test, and a BOOST circuit is used to simulate the real working environment and conditions. We extracted voltage changing rate of SiC power MOSFETs when SiC power MOSFETs were working, and compared the changes in voltage changing rate before and after degradation. The feasibility of the fault sensing method was verified by experimental results. The results may aid in the degradation monitoring of SiC power MOSFETs in power supply, thereby improving the safety of power supply operations.