Junction Temperature Estimation of SiC MOSFETs During Inverter Operation Using Switching Times and On-State Voltages

Temperature-sensitive electrical parameters (TSEPs) can be used for on-line determination of the junction temperature of semiconductors and as key parameters for degradation detection. Typical TSEPs are on-state voltages and switching times. Measuring these TSEPs of fast switching SiC power modules with high switching frequencies is challenging in terms of circuit design. This work presents TSEP measurement hardware for SiC modules capable of measuring switching times and on-state voltages during PWM operation. The system is evaluated in double-pulse experiments as well as in regular inverter operation. Finally, the power module’s thermal impedance system is artificially increased and the system’s capability to detect this change is shown.