【目的】本文以一台1.5 kW的屏蔽式永磁同步电机(CPMSM)为研究对象，旨在揭示三相短路故障下屏蔽套材料对CPMSM退磁特性与电磁性能的影响规律。【方法】首先，采用场路耦合计算方法，对比分析屏蔽套材料为SUS430、SUS316、SUS304的CPMSM的三相短路电流、永磁体退磁系数、气隙磁密、感应电动势以及输出转矩等关键电磁性能指标。然后，通过空载漏磁系数与永磁体工作点揭示抗退磁机理。最后，制作样机并开展试验，验证仿真模型准确性。【结果】三相短路故障下，屏蔽套材料为SUS430的CPMSM的d、q轴电流峰值明显更低，永磁体退磁程度极轻，短路前后气隙磁密、定子磁密、感应电动势与输出转矩基本保持稳定，转矩波动小幅上升；屏蔽套材料为SUS304、SUS316的CPMSM的永磁体严重退磁，空载感应电动势降幅超64%，平均转矩下降54.6%，转矩波动大幅加剧。【结论】SUS430磁性不锈钢屏蔽套可有效提升CPMSM在三相短路下的抗退磁能力，屏蔽套磁导率是影响CPMSM退磁特性的核心参数。本文研究结果可为真空泵等领域CPMSM的屏蔽套选材与抗退磁设计提供参考。

[Objective] This paper takes a 1.5 kW canned permanent magnet synchronous motor (CPMSM) as the research prototype to reveal the influence laws of can materials on the demagnetization characteristics and electromagnetic performance of CPMSM under three-phase short-circuit fault conditions. [Methods] First, the field-circuit coupling calculation method was adopted to comprehensively compare and analyze the key electromagnetic performance indices of CPMSM with SUS430, SUS316, and SUS304 can materials, including three-phase short-circuit current, permanent magnet demagnetization coefficient, air-gap flux density, induced electromotive force, and output torque. Subsequently, the anti-demagnetization mechanism of the motor was revealed by combining the no-load leakage flux coefficient and the operating point of permanent magnets. Finally, a prototype motor was manufactured, and experimental tests were conducted to verify the accuracy and reliability of the established finite element simulation model. [Results] Under three-phase short-circuit fault conditions, the CPMSM with SUS430 can exhibited significantly lower peak d-axis and q-axis currents and extremely slight demagnetization of permanent magnets. Its air-gap flux density, stator flux density, back electromotive force, and output torque remained basically stable before and after the short-circuit fault, with only a slight increase in torque ripple. In contrast, CPMSMs adopting SUS304 and SUS316 cans suffered severe permanent magnet demagnetization. Specifically, the back electromotive force dropped by more than 64%, the average output torque decreased by 54.6%, and the torque ripple was drastically aggravated after the short-circuit fault. [Conclusion] The magnetic SUS430 can effectively improves the anti-demagnetization capability of the CPMSM during three-phase short-circuit faults. The can permeability is identified as the core parameter dominating the demagnetization characteristics of the CPMSM. The research results of this paper can provide a reliable reference for can material selection and anti-demagnetization design of CPMSMs applied in vacuum pumps and other relevant fields.

渤海大学 控制科学与工程学院,辽宁 锦州 121210 School of Control Science and Engineering, Bohai University, Jinzhou 121210, China