Temperature Field Analysis And Heat Dissipation Optimization Of Permanent Magnet Synchronous Motor For Electric Vehicle

Eelectric vehicles are the future of automobile.The driving system of an electric vehicle is motor drive system,and the motor is a core component of the motor drive,and its performance directly affects the stability of the vehicle operation.The temperature increment of the drive motor has a great influence on the performance of the motor.Therefore,it is necessary to study and analyze the temperature field inside the motor,and reasonably design the cooling structure of the motor to make the motor run reliably.This paper studies the motor loss,temperature field and cooling structure based on A00 class mini car that use a permanent magnet synchronous motor as drive motor.Firstly,the basic performance parameters of the motor were determined according to the design requirements.The electromagnetic structure designing of the product was based on the appropriate selection of stator and rotor punching plate;The electromagnetic simulation calculation of the motor was conducted by the motor path coupling algorithm with MotorCad software;the main loss of the motor was optimized based on the basic calculation method of motor loss And the motor body structure was optimized accordingly.Secondly,the heat circuit diagram of the permanent magnet synchronous motor is established according to the heat exchange theory.The motor thermal analysis model and the thermal resistance network diagram are established by the principle of the equivalent thermal network method in MotorCad,and the basic flow of the motor thermal analysis is determined.Combined with the operating conditions of the permanent magnet synchronous motor for Eelectric vehicles,the permanent magnet synchronous motor is subjected to the transient temperature field analysis of steady state and actual operating conditions,and the temperature rise law of the motor and various working conditions are obtained through simulation.The motor temperature rise curve provides a theoretical basis and a practical analysis flow for temperature rise analysis in the motor design process.According to the temperature rise curve,it is judged that the temperature rise of the motor is high,and the cooling structure of the motor needs to be further optimized.Thirdly,in order to reduce the temperature rise of the motor and obtain a better heat dissipation effect,the cooling structure of the motor is studied;Through the analysis method of fluid-solid coupling,the heat transfer effect of the motor shell structure is analyzed.The heat transfer effect of the spiral water channel and the axial water channel is compared,and the number of water channels is adjusted and analyzed.The structure of the motor casing is optimized by analysis to improve the heat dissipation performance of the motor and meet the design requirements.Finally,a motor test platform was established to test the performance,back EMF and temperature rise of the motor.based on the actual motor design experience.Comparing the simulation results with the measured data,the data is basically consistent,and the error is within 5%,which determines the rationality of the whole design process.In the case of meeting the design requirements,the product development cycle is shortened,the reliability of the motor is improved,and the theoretical basis and design flow are provided for the development of subsequent products.