This article compares two methods for computing high-frequency harmonic currents (HFHCs) and losses in permanent magnet synchronous machines (PMSMs) driven by pulsewidth modulation (PWM) voltage-source inverters (VSIs). The first method uses the currents containing HFHCs, which are obtained from the SIMULINK-based inverter–motor simulation system, as input for time-stepping finite-element analysis (TSFEA) to compute the PWM effects, while the second method directly uses PWM voltage sources as input for conducting the coupled field-circuit TSFEA. It is pointed out that the HFHCs are underestimated with the first method due to neglecting the eddy current reaction effect. Hence, both the iron and permanent magnet losses will be underestimated with the first method. On the contrary, the second method is better for computing the PWM effects because high-frequency harmonic voltages are independent on the eddy current reaction effect under PWM VSI supply and are directly related to high-frequency flux density variations, which determine high-frequency losses. Experiment on an interior PMSM was conducted to validate the simulation in this article.

中文翻译：

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考虑涡流反应的永磁电机PWM效应计算中不同源计算方法的比较

本文比较了两种计算脉冲宽度调制（PWM）电压源逆变器（VSI）驱动的永磁同步电机（PMSM）中的高频谐波电流（HFHC）和损耗的方法。第一种方法使用包含基于HFHC的电流（从基于SIMULINK的逆变器-电动机仿真系统中获得）作为时间步进有限元分析（TSFEA）的输入来计算PWM效果，而第二种方法直接使用PWM电压源用作传导耦合场电路TSFEA的输入。需要指出的是，由于忽略了涡流反应的影响，HFHCs被第一种方法低估了。因此，第一种方法会低估铁和永磁体的损耗。相反，第二种方法更适合于计算PWM效果，因为高频谐波电压与PWM VSI供电下的涡流反应效果无关，并且与确定高频损耗的高频磁通密度变化直接相关。本文对室内PMSM进行了实验以验证仿真。