【目的】本文旨在解决直驱永磁同步电机(PMSM)在变频器供电条件下损耗特性研究不足的问题。【方法】基于Simplorer搭建PMSM矢量控制系统，结合Maxwell建立的电机二维瞬态电磁场有限元模型，搭建场路耦合联合仿真模型，探究了工业磨机直驱PMSM在变频器供电下的铁心损耗与永磁体涡流损耗特性。【结果】在保持变频器其他参数不变的情况下，仅改变载波频率，PMSM气隙磁密中的5次和11次谐波幅值以及永磁体涡流损耗均随载波频率升高而降低；同时，定转子铁心磁密峰值随载波频率上升而减小，仿真所得铁耗亦呈现下降趋势。【结论】对比分析表明，当载波频率提升至5 kHz以上时，损耗对频率变化的敏感度下降。因此，选定5 kHz作为现场变频器的最佳载波频率。理论计算得到的系统效率与磨机现场实测运行效率具有良好一致性，从而验证了所建立理论模型与分析方法的准确性。

[Objective] This paper aims to address the insufficient research on the loss characteristics of direct drive permanent magnet synchronous motor (PMSM) under inverter power supply conditions. [Methods] A field-circuit coupled joint simulation model was constructed by establishing a PMSM vector control system in Simplorer and combining it with a two-dimensional transient electromagnetic field finite element model of the motor in Maxwell. The iron core loss and permanent magnet eddy current loss characteristics of a direct drive PMSM for an industrial mill under inverter power supply were investigated. [Results] With other inverter parameters kept constant, only the carrier frequency was varied, the results showed that the 5th and 11th harmonic amplitudes in the PMSM air-gap magnetic flux density, as well as the permanent magnet eddy current loss, decreased as the carrier frequency increased. Simultaneously, the peak magnetic flux density in the stator and rotor cores decreased with the rising carrier frequency, and the simulated iron loss also exhibited a downward trend. [Conclusion] Comparative analysis indicates that when the carrier frequency exceeds 5 kHz, the sensitivity of loss to frequency variation decreases. Therefore, 5 kHz is selected as the optimal carrier frequency for the field inverter. The theoretically calculated system efficiency shows good consistency with the measured operational efficiency of the mill, thereby validating the accuracy of the established theoretical model and analysis method.