Using the Zth(t) – power pulse measurement to detect a degradation in the module structure

Inhalt:
The electrification in the field of vehicles is progressing immensely. Therefore, power electronics plays an increasingly role. To guarantee a high reliability of the devices, health monitoring functions included into the inverter block are of interest. This paper describes a short pulse quasi-Zth-method to measure the state-of-health of the power switches in the vehicle without any external equipment. The method, which will be presented, just needs an optimized driver circuitry.