Online Junction Temperature Measurement of Power Semiconductor Devices

Monitoring the junction temperature of power electronic devices enables over-temperature protection, health monitoring, online lifetime estimation or junction temperature control to extend the expected lifetime. A method for online junction temperature estimation in power semiconductor devices based on the temperature sensitive reverse-recovery behavior of pin-diodes is presented in this paper. Since the reverse-recovery time of diodes is a function of their junction temperature, it can be used for junction temperature measurement. Therefore, a simple measurement circuit is developed to determine the duration between the start of the load current commutation and the instant of time when the diode is in blocking mode. This duration, which is related to the reverse-recovery-time, is defined as the quasi-reverse-recovery time.