Abstract

Armature reaction is considered as one of the challenging problems in on-load permanent magnet (PM) motors. Reducing the undesirable impacts of the armature reaction is necessary to improve the PM motors performance. The ironless stator PM motor is known as an appropriate choice for low armature reaction. Although in these motors, disturbing high-order harmonics of armature reaction are removed, improper winding distribution still causes asynchronous field harmonics. Choosing the number of poles and slots leads to various structures with different armature windings for ironless stator PM motors. Impacts of armature reaction upon the performance of the motors with different structures are addressed in this article. This is done using precisely and quickly by a combined analytical model. This model can model the PMs magnetic fields, the air gap magnets field, and the armature reaction field. The finite element modeling (FEM) results confirm the accuracy of the proposed analytical model. Then, the analytical method and FEM are used to predict the performance of the ironless stator PM motors with the different numbers of poles and slots. This makes it possible to suggest an appropriate number of poles and slots for lower armature reaction, lower disturbed voltage harmonics, lower torque ripple, higher output power, and higher winding distribution factor.

摘要

电枢反应被认为是有载永磁 (PM) 电机中具有挑战性的问题之一。减少电枢反应的不良影响对于提高 PM 电机性能是必要的。无铁心定子永磁电机被认为是低电枢反应的合适选择。尽管在这些电机中，电枢反应的干扰性高次谐波被消除，但不正确的绕组分布仍然会导致异步场谐波。选择极数和槽数会导致无铁心定子永磁电机具有不同电枢绕组的各种结构。本文讨论了电枢反应对不同结构电机性能的影响。这是通过组合分析模型准确快速地完成的。该模型可以模拟 PM 磁场，气隙磁场和电枢反应场。有限元建模 (FEM) 结果证实了所提出的分析模型的准确性。然后，利用解析法和有限元法对具有不同极数和槽数的无铁心定子永磁电机的性能进行了预测。这使得可以建议适当数量的极和槽，以降低电枢反应、降低受干扰的电压谐波、降低转矩纹波、提高输出功率和提高绕组分配系数。