【目的】屏蔽式永磁同步电机(CPMSM)因其优异的安全性与密闭性，被广泛应用于高要求的工业领域，并多采用变频器供电。然而，变频器产生的时间谐波电流会引发电机内部的电磁扰动，改变多物理场的耦合特性，使屏蔽套产生受迫形变，长期运行可能导致结构疲劳甚至电机损坏。因此，深入研究谐波电流对屏蔽套电磁力线密度分布及结构响应的影响，对于揭示变形机理、优化电机设计、提升运行可靠性具有重要意义。【方法】本文以一台1.5 kW、9 000 r/min的CPMSM为研究对象，开展电磁场与结构场联合仿真。首先，基于电磁场理论推导考虑时间谐波电流的径向电磁力解析式，然后构建CPMSM的仿真模型，通过施加不同参数的谐波电流，对屏蔽套内侧电磁力线密度进行了计算，并分析屏蔽套采用SUS304、SUS316和SUS430三种不锈钢材料时的受迫形变响应。【结果】仿真结果表明:电磁力线密度随时间谐波电流幅值增加而增强，随时间谐波电流次数增加电磁力线密度频率升高但幅值基本不变；电磁力线密度与相位角之间呈余弦变化关系，具有明显调制特性；其中，SUS430材料因磁导率较高，在相同激励下产生的电磁力线密度与形变量最大。【结论】本研究揭示了时间谐波电流对电机电磁力线密度分布及屏蔽套受迫形变的影响规律，为电机结构优化、谐波抑制提供理论依据，对提升电机运行稳定性有工程意义，也为屏蔽套设计与选材提供参考。

[Objective] Canned permanent magnet synchronous motor(CPMSM) is widely used in high-demand industrial fields due to its excellent safety and tightness, and is mostly powered by frequency converter. However, the time harmonic current generated by the frequency converter will lead to electromagnetic disturbance inside the generator, change the coupling characteristics of multi-physical fields, and cause forced deformation of the shielding can. Long-term operation may lead to structural fatigue and even motor damage. Therefore, in-depth study of the influence of harmonic current on the electromagnetic force per unit length distribution and structural response of the can is of great significance for revealing the deformation mechanism, optimizing the motor design and improving the operational reliability. [Methods] In this paper, a 1.5 kW, 9 000 r/min CPMSM was taken as the object to carry out the joint simulation of electromagnetic field and structural field. Firstly, based on the electromagnetic field theory, the analytical formula of radial electromagnetic force considering time harmonic current was derived. Then, the simulation model of CPMSM was constructed. By applying harmonic currents with different parameters, the electromagnetic force per unit length on the inner side of the can was calculated, and the forced deformation response of the can of three stainless steel materials of SUS304, SUS316, SUS430 was analyzed. [Results] The simulation results showed that the electromagnetic force per unit length increases with the increase of the amplitude of the time harmonic current, and the frequency of the electromagnetic force increases with the increase of the number of time harmonic current, but the amplitude was basically unchanged. There was a cosine relationship between the electromagnetic force per unit length and the phase angle, which has obvious modulation characteristics. Among them, SUS430 material had the largest electromagnetic force per unit length and deformation under the same excitation due to its high permeability. [Conclusion] This study reveals the influence of time harmonic current on the electromagnetic force per unit length distribution of the motor and the forced deformation of the can. It provides a theoretical basis for motor structure optimization and harmonic suppression. It is of engineering significance to improve the operation stability, and also provides a reference for the design and material selection of the can.

国家自然科学基金项目(62473061);辽宁省教育厅一般项目(LJ212410167024)