Research On The High-Power Permanent Magnet Motor For Electric Racing Car

Permanent magnet synchronous motor is widely used in Electric racing cars for its high efficiency, high torque density and high controlling precision. The car race requires high power and light weight. And improving cooling system and increasing the amount of permanent magnet can enhance the power mass rate. However, long-time high power output leads to difficulty in heat dissipation, excessive temperature rise, which are likely to result in motor fault or even motor damage. This problem is the limiting factor of motor output.This paper is aimed at solving how to achieve high power while maintaining the small size and light weight of the motor. First of all, this thesis analysis the advantages and disadvantages of the motor in different rotor magnetic circuit structures. According to car design parameters provided by university racing car technology center, the author set up the 3D model. And based on basic theory of temperature field and electro mechanics, the author analyzed the main sources of loss inside motor with the emphasis on calculating the loss value of each part. Then comes setting up of the two-dimensional model with motor analysis software Ansoft Maxwell to conduct simulation verification of loss value. The loss value was put into software of finite element analysis ANSYS to conduct the steady temperature field simulation of the water-cooling system and the temperature distribution was generated.After designing a common air-cooling system for heat dissipation, the maximum output was calculated after repeated loss simulation and thermal simulation. Finally, with the application of micro heat pipe cooling technology, the original design was maximized into a new air-cooling system. With temperature field simulation via software of finite element analysis, the heat dissipation performance of the new structure was proved.The result indicates that using the motor equipped with the new structure, the peak power can be improved by 7kW while the power mass rate can be improved from 0.95kW/kg to 1.25kW/kg compared with common structure of the same weight. The new structure can enhance the performance of the motor with outstanding heat dissipation. This paper provides insight on further optimization of permanent magnet synchronous motor in FSE and explores the application of micro heat pipe cooling technology in the motor.