A Study on Insulation Components of High Voltage Electrical Machines Used in Electric Vehicles

This paper deals with the primary insulation components for the 800 V traction motors used in e-mobility applications. Challenges with the increased voltage level as well as employing SiC converters and oil cooling system are discussed. Focus in this paper is placed on the conductor insulation and slot liners avoiding short-circuit between the conductors, and also between the conductors and lamination, respectively. The study done is based on an extensive laboratory measurement. For each insulation component both voltage endurance and partial discharge inception voltage measurements are carried out, and a comparison between different insulation alternatives is presented and discussed. The measurement results presented in this paper can be well used for proper selection of insulation system depending on the voltage differences between different components and also the expected life-time of the electrical machine.