Online monitoring of IGBT junction temperature based on V ce measurement

In this paper, an online junction temperature monitoring method based on the on-state voltage under high collector current density measurements for IGBT power modules is proposed. Unlike the conventional junction temperature monitoring method, the presented method can extract the junction temperature during operation without altering the modulation strategy or topology of the converter. The proposed method is verified by simulations and the JEDEC-51 standard recommended approach. To accurately extract the on-state voltage during operation, a measurement circuit that combines the advantages of both the active MOSFET clamp and the diode clamp is designed and tested. It has been shown to have good accuracy and a rapid response time. After the calibration results are obtained, the presented method is applied to a three-phase voltage source converter controlled by a closed-loop SVPWM modulation strategy.