Over Temperature Protection of Power Module under Electric Water Pump Failure Condition in EV

Abstract:
In Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV), the thermal characterization of power module is important feature for the performance and reliability. It is required that the junction temperature does not exceed defined limit irrespectively of various driving conditions. In this paper, the thermal model is developed to estimate the junction temperature within various driving conditions so that it is safely protected from overheating and be guaranteed its lifetime. However, the thermal model is no longer valid in case of abnormal cooling state due to heatsink temperature misreading. Therefore, IGBT on-chip temperature sensor inside of power module is effectively used to estimate the actual heatsink temperature after then the junction temperature can be accurately estimated so that it can be protected from over-heating condition not only normal cooling condition but also abnormal cooling condition such as Electric Water Pump (EWP) failure condition.