The recent emergence of wide bandgap power devices enables higher switching frequencies in electric motor drives. The subsequent possibility for higher efficiency and smaller size requires accurate prediction of harmonic losses in motors. Therefore, in this article, an original analysis of harmonic losses arising in inverter-fed two-pole slotless permanent-magnet machines with axially segmented ring magnets is presented. The developed three-dimensional time-efficient numerical model is successfully validated under high-speed no-load operation using a silicon carbide based three-phase inverter and rotors carrying a broad range of magnet segment thicknesses (3-12.6 mm). The model enables harmonic loss prediction capability (including loss separation) with an accuracy of 15% over a wide frequency range (8-120 kHz), which is a unique contribution. The sensitivity analysis primarily emphasizes the importance of taking into account the axial segmentation, and secondarily the rotor-shaft magnetoelasticity effects for accurate modeling of harmonic losses. The conducted case study demonstrates that wide bandgap transistors effectively can contribute to eliminating the need for inductive filters in motor drives.

中文翻译：

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宽带隙逆变器电源引起的两极无槽永磁电机谐波损耗的研究


最近出现的宽带隙功率器件可以在电动机驱动器中实现更高的开关频率。随后实现更高效率和更小尺寸的可能性需要准确预测电机中的谐波损耗。因此，在本文中，对具有轴向分段环形磁体的逆变器供电的两极无槽永磁电机中产生的谐波损耗进行了原始分析。使用基于碳化硅的三相逆变器和带有各种磁体段厚度（3-12.6 mm）的转子，开发的三维省时数值模型在高速空载运行下得到了成功验证。该模型在较宽的频率范围（8-120 kHz）内实现了谐波损耗预测能力（包括损耗分离），精度为 15%，这是一项独特的贡献。灵敏度分析主要强调考虑轴向分段的重要性，其次强调转子轴磁弹性效应对于谐波损耗精确建模的重要性。进行的案例研究表明，宽带隙晶体管可以有效地消除电机驱动器中对电感滤波器的需求。