Inverter Power Module Lifetime Estimation for HEV and EV

Inhalt:
In Hybrid Electric Vehicle(HEV) and Electric Vehicle(EV) operation, a three phase inverter of PWM switching method generates the power dissipation that causes a junction temperature increase. Power electronic modules usually dissipate large amount of heat and operated under severe environmental condition, so that the stresses caused by the thermal behavior affect the long term reliability. In this paper, thermal model is developed to estimate the junction temperature irrespectively of various driving conditions such as high speed driving, regenerative braking, and hill-holding. After then this model is a bit more effectively used to estimate the reliability of power module with the thermal stress conditions over the HEV lifetime. The lifetime evaluation is implemented through the vehicle mission profile with thermal model and thermal stress counting algorithm.