A Study on Heat Dissipation of Electric Vehicle Motor Based on Heat-Pipe Heat Transfer Analysis

With the increasingly serious problems of environmental pollution and energy shortage, electric vehicles have a promising future. As a core component of electric vehicles, the drive motor is developing towards high power density of which remains temperature rise problems, which affects the performance, efficiency and service life of the drive motor. Liquid cooling has high energy consumption and poor reliability. The heat-pipe has excellent heat conduction and temperature uniformity capabilities. Therefore, this paper proposes a heat pipe-based drive motor heat dissipation system to make the heat-pipe act on the inside of the motor to reach a specified range of driving conditions. The drive motor can better dissipate heat through the heat-pipe. Firstly, analysis of the internal heat generation mechanism of the motor, heat transfer characteristics of the heat-pipe and the heat-pipe layout plan was established. The motor heat transfer model and the vehicle dynamics model is designed to simplify the driving condition of the car to a constant driving speed condition and improve the heat dissipation efficiency, as well as the overall motor analysis of the heat dissipation performance. The results demonstrate that the use of the heat dissipation method in this paper improved the reliability of the drive motor cooling system and the overall efficiency of the drive motor under the same operating conditions. By comparing the temperature values of motors with and without heat pipes at certain vehicle speeds, it is found that the temperature of each node of the internal thermal network of the motor with heat pipe cooling is reduced by about 5-7° at the highest. Under the same working conditions of the vehicle, the heat pipe can make the electric vehicle work at a higher speed at a constant speed, which can increase the vehicle speed by 6.0 km/h. This paper considers the heat dissipation of permanent magnet synchronous motors for vehicles based on heat-pipe heat transfer. It shows that the extra heat-pipes heat dissipation scheme can effectively reduce the internal temperature of the motor during operation and provide a reference for improving the stability of the motor heat dissipation system.