Temperature Fields Analysis On A Permanent Magnet Synchronous Motor Of Electric Vehicle

The permanent magnet synchronous motor (PMSM) has not the electromagnetic loss,and has high instantaneous power and efficiency, so it has been widely used in recent years.In the permanent magnet synchronous motor, the performance of a permanent magnet,winding resistance etc. have close relationship with temperature, which directly affects theoutput of the motor efficiency and overload capacity etc., even in the safe operation of amotor. If the whole temperature of motor or the local temperature is too high, the irreversibledemagnetization of permanent magnet in permanent magnet motor may be caused, thewinding insulation damage may also be caused by inter turn short-circuit. If materials chosenare too expensive in order to resist high temperature it will increase the cost of motormanufacturing. Therefore, accurate analysis of temperature rise amplitude of various parts ofthe motor is very necessary.The research object of this paper is a5.5KW electric vehicle permanent magnetsynchronous motor. At first, CATIA V5R20of3D software is used for establishingthree-dimensional models of the motor. Secondly, the thermal conductivity of motor parts andthe heat transfer coefficient of the radiating surfaces are calculated according to the theoriesof the basic heat transfer. Thirdly, simulation analysis of temperature field of the motor arecarried out by using finite element method, the three-dimensional temperature field of themotor and the space streamline distribution figure are obtained. According to the results ofanalysis, the cooling wind path of the original motor is optimized. To verify the rationality ofthe optimization, A experimental on the thermal system of the prototype is conducted, which luse thermoelectric coupling method to monitor each motor parts of temperature rise when themotor is running, the experimental values are compared with the analysis values. The work ofthis paper provides a basis to optimize the design of permanent magnet synchronous motor inorder to balance temperature field and reduce the highest temperature points of the motor.