A DYNAMIC ELECTROTHERMAL MODEL FOR THE IGBT

A physics-based dynamic electro-thermal model is developed for the IGBT by coupling a temperature-dependent IGBT electrical model with dynamic thermal models for the IGBT silicon chip, packages, and heatsinks. The temperature-dependent IGBT electrical model describes the instantaneous electrical behavior in terms of the instantaneous temperature of the IGBT silicon chip surface. The instantaneous power dissipated in the IGBT is calculated using the electrical model and determines the instantaneous rate that heat is applied to the surface of the silicon chip thermal model. The thermal models determine the evolution of the temperature distribution within the thermal network and thus determine the instantaneous value of the silicon chip surface temperature used by the electrical model. The IGBT electro-thermal model is implemented in the Saber circuit simulator and is connected to external circuits in the same way as the previously presented Saber IGBT model, except that it has an additional thermal terminal that is connected to the thermal network component models for the silicon chip, package, and heatsink. The IGBT dynamic electro-thermal model and the thermal network component models are verified for the range of temperature and power dissipation levels (heating rates) that are important for power electronic systems.