【目的】屏蔽式永磁同步电机(CPMSM)因屏蔽套的密封性，被广泛应用于核电、化工等恶劣环境。但屏蔽套的涡流损耗会导致电机温升，影响性能。为降低损耗与温升，本文系统研究了非金属陶瓷屏蔽材料的电磁热耦合效应，探索其应用潜力。【方法】本研究以一台额定功率1.5 kW、转速9 000 r/min的CPMSM为研究对象，构建二维有限元模型，采用电磁场与温度场的双向耦合迭代算法，对三种不同物理性质材料的屏蔽套进行对比分析。研究了屏蔽套材料物理特性对电机感应电动势、气隙磁密、损耗、转矩及效率的影响，并深入分析了其温度分布特性。【结果】研究结果表明，氮化硅(Si3N4)材料作为电机屏蔽套时，凭借其绝缘性特征，有效抑制了涡流损耗，提高了电机效率与输出转矩，且感应电动势基波幅值提升超过11%。与SUS316和SUS430材料相比，Si3N4使电机的温度分布更加均匀、温升更低，永磁体温度相比采用SUS316作为屏蔽套材料时降低了30%。【结论】Si3N4作为新型高性能屏蔽套材料，兼具电绝缘性、非磁性与高热导率等优异特性，能有效抑制涡流损耗、优化电磁特性并增强电机热稳定性，在高效、可靠、低损耗电机设计中具有重要应用前景。

[Objective] Canned permanent magnet synchronous motor (CPMSM) is widely used in nuclear power, chemical, and other harsh environments due to the sealing properties of its shielding can. However, eddy current losses in the shielding can lead to significant temperature rise, adversely affecting motor performance. To mitigate these losses and thermal effects while enhancing electromagnetic performance and thermal stability, this paper systematically investigates the electromagnetic-thermal coupling effects of shielding can materials, with a focus on exploring the application potential of non-metallic ceramic materials in canned motors. [Methods] In this study, a CPMSM with rated power of 1.5 kW and a speed of 9 000 r/min was selected as the research object, and a two-dimensional finite element model was constructed, and the shielding can of three materials with different physical properties, were compared and analyzed by using the two-way coupling iterative algorithm of electromagnetic field and temperature field. The effects of physical properties of shielding can materials on the induced electromotive force, air gap magnetic density, loss, torque and efficiency of motors were studied, and their temperature distribution characteristics were deeply analyzed. [Results] The research results demonstrated that when silicon nitride (Si3N4) material was used as the motor shielding sleeve, its insulating properties effectively suppressed eddy current losses, improved motor efficiency and output torque, and increased the fundamental amplitude of the induced electromotive force by more than 11%. Compared to SUS316 and SUS430 materials, Si3N4 ensured more uniform temperature distribution and lower thermal rise in motors. Notably, permanent magnet temperatures were reduced by 30% when using Si3N4 as the shielding material compared to SUS316. [Conclusion] As a new high-performance shielding can material, Si3N4 has excellent characteristics such as electrical insulation, non-magnetism and high thermal conductivity. It can effectively suppress eddy current, optimize electromagnetic characteristics and enhance the thermal stability of motor. It has an important application prospect in the design of efficient, reliable and low loss motor.

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