Insulation system sesign for 800 V traction motors used in E-mobility applications

This paper proposes an insulation solution for the traction motors developed and used in 800 VDC propulsion systems of battery electric vehicles. First, challenges with the increased voltage level as well as employing SiC converters and oil cooling system are discussed. Then a modelling methodology for voltage distribution in the winding system taking into account the high switching frequency, and as a result short rise-time, is presented and the corresponding simulation results are elaborated. Additionally, experimental tests are carried out to evaluate the voltage distribution in the winding, and also measure partial discharge inception voltage of different possible conductor insulations. Based on the simulation and test results, a complete insulation system from primary conductor insulation to slot liner and impregnation resin is recommended that addresses the needs for the discussed propulsion system.