【目的】屏蔽式永磁同步电机(CPMSM)具有高效率、高功率密度等优异的性能,凭借体积小、重量轻、运行稳定可靠及维护需求低等优点被广泛应用于真空泵等高要求的精密控制工业设备中。真空泵在抽真空工作中可能有空气流入真空环境中,导致真空泵高负载作业,从而使CPMSM过载。【方法】本文通过Simulink和Ansys构建联合仿真模型,对电机的电磁场及温度场进行分析,得出电机过载后的安全运行时间及电磁场的变化规律。以一台1.5 kW CPMSM为例,通过设置不同倍数的过载转矩模拟冲击载荷,采用单向耦合法计算CPMSM在过载状态下绕组绝缘及永磁体的温升。【结果】研究结果表明,CPMSM的绕组绝缘在过载到1.8倍负载后的516 s时达到绝缘温度限制,之后继续工作将造成电机损坏,而永磁体在此负载下仍可继续安全工作,则电机过载后的安全运行时间为516 s。此外,研究表明电机过载后相比于额定负载定子轭部磁密较大的区域增多,气隙磁密基波幅值减小,反电动势基波幅值增强。电机过载后损耗增加,效率和功率因数下降,转矩波动先减小后增大。【结论】本文通过构建仿真模型深入分析了CPMSM在过载状态下的运行特性,为精准确定电机过载状态下温度升高后的安全响应时间提供了科学依据,总结了电机过载后电磁性能的变化规律,对提升CPMSM的性能具有重要意义。

[Objective] Canned permanent magnet synchronous motor (CPMSM) demonstrates excellent performance, including high efficiency and high power density. Due to its compact size, lightweight design, stable and reliable operation, and low maintenance requirements, it is widely used in precision-controlled industrial equipment such as vacuum pumps. During the vacuum pumping process, air may flow into the vacuum environment, causing the vacuum pump to operate under high load conditions and leading to CPMSM overload. [Methods] This study established a co-simulation model using Simulink and Ansys to analyze the electromagnetic and thermal fields of the motor, determining the safe operation duration and the variations in the electromagnetic field under overload conditions. Taking a 1.5 kW CPMSM as an example, different overload torque multiples were set to simulate impact loads. The one-way coupling method was used to calculate the temperature rise in the winding insulation and permanent magnets under overload conditions. [Results] The results showed that the winding insulation of the CPMSM reached its temperature limit after 516 s under 1.8 times the rated load. Continued operation beyond this limit would cause motor damage, while the permanent magnets could still function safely under this load. Therefore, the motor's safe operating time under overload was 516 s. In addition, the study revealed that after overload, regions with higher stator yoke magnetic flux density increased compared to rated load conditions, while the fundamental amplitude of the air gap flux density decreased, and the fundamental amplitude of the back electromotive force increased. After overload, motor's losses increased, while both efficiency and power factor decreased. Additionally, the torque fluctuations first decreased and then increased. [Conclusion] By establishing a simulation model, this paper provides an in-depth analysis of CPMSM's operating characteristics under overload conditions, providing a scientific basis for accurately determining the safe response time after temperature rise. The study summarizes the variations in electromagnetic performance after overloading, which is crucial for improving CPMSM performance.

辽宁省教育厅一般项目(LJ212410167024)