Efficient Electromagnetic Optimization Design and Performance Analysis of Permanent Magnet Synchronous Motor Based on Multi Physics Field Coupling

Synchronous motors face the problem of how to control vibration amplitude, temperature sensitivity and magnetic field stability while ensuring good speed regulation performance. This paper adopts the method of multi-physics field coupling for research. In the specific implementation process, it is first clear that the motor design needs to meet the requirements of electromagnetic performance, mechanical strength and temperature rise control. Through multi-physics field coupling analysis, the interaction and influence between electromagnetic field, temperature field and mechanical stress field are comprehensively considered. In terms of electromagnetic design, the partial differential equation of the vector magnetic potential or scalar magnetic potential of the motor is established by analytical method and the corresponding boundary constraints are substituted to solve the parameters such as magnetic induction intensity distribution, induced electromotive force, electromagnetic torque, etc. Then, the motor is three-dimensionally modeled by finite element method to further analyze the influence of permanent magnet end effect, stator skew slot and other factors on the magnetic circuit distribution of the motor. The motor circuit is coupled with the magnetic field to obtain the output torque performance characteristics. At the same time, considering the heat exchange phenomenon inside the motor, the heat dissipation coefficient of each part in the heat exchange process is determined, the electromagnetic loss is loaded into the motor temperature field, and the magnetothermal coupling temperature rise finite element model is established. Based on the analysis results, the structure of the motor is optimized. The vibration amplitude of the optimized motor is reduced in different scenarios. The average temperature rise rate before optimization is 7.076 °C/h, and after optimization it is reduced to 3.272 °C/h. The air gap magnetic flux fluctuation rate is also optimized.