Junction Temperature Prediction of a Multiple-chip IGBT Module under DC Condition

This paper develops a thermal model for a six-pack insulated gate bipolar transistor (IGBT) power module operating as a three phase voltage source inverter. With this model, the temperature of each chip can be derived directly from the losses of the silicon chips and a thermal impedance matrix. The losses of each chip can be calculated through the voltage and current information of the power module. The impedance model can be easily transferred into a micro-processor to predict the online chip temperatures. It largely increases the temperature accuracy when the inverter operates at zero or low output frequency. Theory analysis, simulation and experimental results are provided to verify the effectiveness of this model.