Analysis of the Temperature Field of a High-Speed Permanent Magnet Motor

Abstract

When the high-speed motor is running, due to its ultra-high speed and the current frequency of thousands of hertz, the loss value of each part will increase greatly. High loss will inevitably lead to high temperature rise. Excessive temperature rise may cause problems such as motor insulation failure, permanent magnet demagnetization, and insufficient mechanical strength. This paper establishes a lumped parameter thermal network model of a 20 kW, 10 Wrpm surface-mount 2 pole 6 slot high speed permanent magnet motor, and conducts a finite element analysis, and analyzes the effect of a cooling method in the stator conductor. The final finite element analysis results show that the copper conductor temperature rise of this high-speed motor is 254.49 °C, and the maximum temperature rise of the motor is 258.71 °C. When the copper conductor has an internal cooling structure and cooling water is passed, the copper conductor temperature rise almost drops to 0 °C, and the maximum temperature rise of the motor has also dropped to 80.27 °C.