Research on Thermal Analysis of Permanent Magnet Electric Traction Motor for Electric Vehicle

Due to the high efficiency and high power density, permanent magnet synchronous motors are good candidates as traction motors in the electric vehicle application. However, they easily undergo irreversible demagnetization and insulation failure of coils under severe thermal load condition. It is important to quickly and accurately evaluate the temperature rise in the first design stage. Besides, the cooling system plays a crucial role in the electric motor design, which contributes to heat dissipation and decides the maximum temperature rise in the motor. In this paper, the temperature rise in key parts of the electric motor is quickly calculated by lumped parameter theimal model. The influences of thermal contact and flow rate on temperature rise are discussed respectively. The design principle of the efficient cooling system is presented.