A Drive Cycle Based Electro-Thermal Analysis of Traction Inverters

This paper presents an electro-thermal simulation model to estimate the power devices junction temperatures of traction inverter. The model includes four sub-systems: hybrid electric vehicle simulation, model of traction motor, temperature dependent power loss model, and the thermal model of traction inverter. Firstly, load profile of the traction inverter is obtained considering the vehicle dynamic, the traction motor, and the drive cycle of the vehicle. Then, instantaneous power loss is calculated by using the load profile of the inverter. Based on the power loss and developed thermal models, junction temperatures of power devices are estimated. With the feedback of the junction temperatures into the power loss model, the temperature dependent power losses are obtained. Therefore, the electro-thermal simulation of traction inverter can be conducted. The electro-thermal model presented in this paper is simulated for the Urban Dynamometer Driving Schedule (UDDS) drive cycle, and the junction temperatures of power devices are obtained.