This paper presents the impacts of manufacturing tolerances on a 1 MW slotless permanent magnet synchronous motor used in an aircraft propulsion system. The motor was designed using multiphysics analysis of electromagnetics, mechanical structure and thermal analysis to obtain a high torque density. It has several governing characteristics, including a Halbach permanent magnet arrangement, slotless stator windings, an outer rotor, lower reactance and a high current density. Since the current density of this design is high, the existence of circulating currents should be considered for safe operation under different levels of manufacturing tolerances. In particular, the low reactance of the motor and the slotless structure greatly contribute to increase the circulating current. Therefore, this paper analyzes various factors affecting the circulating current such as eccentricity and imbalanced windings. Finally, an analytical model is used to calculate magnetic and electric loading, and non-linear finite element analysis are applied and compared to obtain the machine performance.

中文翻译：

---

制造公差对低电抗无槽永磁同步电机的影响

本文介绍了制造公差对飞机推进系统中使用的 1 MW 无槽永磁同步电机的影响。电机的设计采用电磁学、机械结构和热分析的多物理场分析，以获得高扭矩密度。它具有多项控制特性，包括 Halbach 永磁体布置、无槽定子绕组、外转子、低电抗和高电流密度。由于这种设计的电流密度很高，因此在不同的制造公差水平下，为了安全运行，应考虑环流的存在。特别是电机的低电抗和无槽结构大大有助于增加循环电流。所以，本文分析了影响环流的各种因素，如偏心距和绕组不平衡。最后，利用解析模型计算磁力和电负荷，并应用非线性有限元分析并进行比较，以获得机器性能。