In recent decades, switched reluctance motors (SRMs) have been attracting increasing attention as a promising type of traction motors for electric vehicle propulsion, owing to their robust construction, elimination of permanent magnets. However, their phase inductance profile contains significant high-order harmonics, which generates input-current and torque ripples under SRM drive with the conventional square phase-current waveform. This study solves this problem by proposing a novel phase-current waveform in replacement of this square waveform. The proposed waveform is a predetermined waveform that can be stored as a look-up table in the inverter controller and can be magnified or attenuated to adjust the output torque, similarly as the conventional square waveform. Certainly, SRMs generally exhibit magnetic non-linearity due to magnetic saturation, which complicates the analysis. Therefore, the proposed waveform is analytically derived under the assumption that the magnetisation of the motor remains below the saturation level because vehicle propulsion tends to require a torque output far smaller than the maximum rating of the motor in normal vehicle travel. The proposed phase-current waveform is experimentally tested in comparison with the conventional square phase-current waveform. Consequently, the proposed waveform revealed smaller ripples in both the input-current and torque, supporting the effectiveness of the proposed phase-current waveform.

中文翻译：

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开关磁阻电动机的相电流波形，可消除磁饱和以下的低功率推进中的输入电流纹波和转矩纹波

近几十年来，开关磁阻电动机（SRM）作为一种有前途的电动车辆推进牵引电机，由于其坚固的结构和永磁体的应用而受到越来越多的关注。但是，它们的相位电感曲线包含大量的高次谐波，这些谐波在SRM驱动下以传统的方相电流波形产生输入电流和转矩纹波。本研究通过提出一种新颖的相电流波形来代替该方波波形来解决此问题。提出的波形是预定波形，其可以存储为逆变器控制器中的查找表，并且可以被放大或衰减以调节输出扭矩，这与常规方波相似。当然，由于磁饱和，SRM通常表现出磁非线性，这使分析变得复杂。因此，在假设电动机的磁化强度保持在饱和水平以下的前提下，通过分析得出建议的波形，因为车辆的推进趋向于要求扭矩输出远小于正常车辆行驶中电动机的最大额定值。与传统的方相电流波形相比，对所提出的相电流波形进行了实验测试。因此，建议的波形显示出输入电流和转矩中的波动较小，从而支持了建议的相电流波形的有效性。建议的波形是在假设电动机的磁化强度保持在饱和水平以下的前提下分析得出的，因为车辆的推进趋向于要求扭矩输出远小于正常车辆行驶中电动机的最大额定值。与传统的方相电流波形相比，对所提出的相电流波形进行了实验测试。因此，建议的波形显示出输入电流和转矩中的波动较小，从而支持了建议的相电流波形的有效性。建议的波形是在假设电动机的磁化强度保持在饱和水平以下的前提下分析得出的，因为车辆的推进趋向于要求扭矩输出远小于正常车辆行驶中电动机的最大额定值。与传统的方相电流波形相比，对所提出的相电流波形进行了实验测试。因此，建议的波形显示出输入电流和转矩中的波动较小，从而支持了建议的相电流波形的有效性。