Electrothermal Coupling Model of IGBT Power Module Considering Thermal Coupling

Power device is the core of power electronic system, and its failure is mainly caused by temperature factors. Therefore, in order to predict the junction temperature of the chip as accurately as possible, this paper studies the junction temperature estimation method of IGBT power module. Firstly, considering the influence of temperature, driving resistance, voltage and other factors on the loss, an instantaneous power loss model is established and its results are applied to the thermal model. Then, two kinds of thermal network models are compared and studied, and the steps of extracting parameters from the thermal network model to obtain accurate temperature estimation are given. Finally, the effectiveness of the electrothermal coupling model is verified under different conditions. These two methods are significantly improved compared with the values provided in the data manual, which can reflect the temperature fluctuation under different load conditions and lay a foundation for monitoring the health status of equipment in the future.