An electro-thermal parametric degradation model of insulated gate bipolar transistor modules

Insulated gate bipolar transistor (IGBT) is widely used in a variety of applications, many of them are safety-critical. The failure of the IGBT accounts for a significant portion of the failures in the converter. An electrothermal model is useful for predicting the junction temperature in power electronic components and modules. The model parameters change with degradation, but parameters of such models are not readily available in the literature or in the parts documentation. In this work, various combinations of parameters, source voltage, junction temperature, gate voltage, collector current, gate resistance, and frequency are developed and executed, and the electro-thermal model parameters are derived from these experimental results. The change of switching power loss and thermal resistance with degradation is derived from accelerated aging experiments that combine temperature and current. The results show that degradation in the thermal resistance over a period of 9000 cycles can increase the junction temperature by more than 20% compared with the original junction and case temperature difference. Degradation at the die level can cause a 50% increase in the switching power loss compared with the original switching power loss under the same working conditions. The electro-thermal model and parametric degradation model are applied in the sine pulse width modulation (SPWM) simulate circuit to improve the accuracy of temperature prediction after degradation.