【目的】屏蔽式永磁同步电机(CPMSM)因其高功率密度、高效率和动态性能优异等特点，被广泛应用于化工、核能及医疗等关键领域。然而，批量生产永磁体性能差异对电机长期稳定性的影响研究不足。因此，本文旨在分析永磁体差异对CPMSM性能的影响，并揭示其多物理场耦合机理。【方法】首先，提出一种基于负载反电动势的永磁体磁性能实时检测方法，无需额外传感器即可实现装机后动态监测。然后，利用有限元模型分析了永磁体性能差异对CPMSM电磁场、温度场和屏蔽套热应力及其形变的影响。最后，通过试验验证所提方法的性能。【结果】结果表明，永磁体等级为N38的电机与N30相比，功率因数相差2.56%，效率相差1.76%，绕组温度相差5 ℃，机壳温度相差5.82 ℃。【结论】永磁体磁性能下降会导致电机指标非线性恶化，且性能差异仅与永磁体数量相关，与分布无关。该研究为CPMSM的优化设计、永磁体偏差影响评估及严苛环境下的可靠性提升提供了理论参考。

[Objective] The canned permanent magnet synchronous motor (CPMSM) is widely used in critical fields such as chemical processing, nuclear power, and medical applications due to its high power density, superior efficiency, and excellent dynamic performance. However, research on the impact of batch-produced permanent magnet performance variations on long-term motor stability remains insufficient. Therefore, this study aims to analyze the influence of permanent magnet variations on CPMSM performance and reveal its multi-physics field coupling mechanisms. [Methods] Firstly, a load backs electromotive force-based real-time detection method for permanent magnet magnetic properties was proposed, enabling dynamic post-assembly monitoring without additional sensors. Then, the influence of permanent magnet performance variations on CPMSM electromagnetic fields, temperature distribution, and shield-can thermal stress/deformation was analyzed using finite element models. Finally, experimental validation of the proposed method was subsequently conducted. [Results] The results demonstrated that when compared with the N30-grade, the motor with N38-grade permanent magnets exhibited a 2.56% difference in power factor, a 1.76% difference in efficiency, a 5 ℃ difference in winding temperature, and a 5.82 ℃ difference in casing temperature. [Conclusion] A decline in the magnetic performance of permanent magnets leads to nonlinear deterioration in motor performance metrics, and the performance difference is solely related to the quantity of permanent magnets, independent of their distribution. This study provides theoretical references for the optimized design of CPMSM, the evaluation of permanent magnet deviation impacts, and the enhancement of reliability in harsh environments.

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