On-line junction temperature measurement of IGBTs based on temperature sensitive electrical parameters

This paper deals with a method to derive the junction temperature of an IGBT while the device is in operation. In order to achieve this the gate-emitter voltage, the collector current and the collector-emitter voltage are digitized on the driver board. Due to the fact that material parameters vary with temperature, the waveforms of the switching transients vary with temperature, too. Thus, there is a correlation between the temperature and the switching waveforms. Evaluating temperature sensitive electrical parameters (TSEP), the working temperature of the device can be estimated.