Realization of an Online Junction Temperature Monitoring Scheme of SiC MOSFET Based on On-state Voltage Drop

The extensive use of SiC MOSFET devices in the rail and new energy automotive sectors has obviously had a positive impact, particularly in terms of increasing converter power density. Nevertheless, performance degradation and failures due to junction temperature T
j
fluctuations of SiC MOSFET pose a challenge to the reliability of power electronic systems. To address this issue, we propose a scheme for monitoring T
j
based on on-state voltage drop (OVD). Additionally, an online measurement circuit for OVD using shunt regulator clamping is proposed. The accuracy of the OVD measurement circuit is initially verified by experiment. Finally, a T
j
estimation model is developed using experiment data to prove the feasibility of the recommended T
j
monitoring scheme.