The detection and location of eccentricity faults in a permanent magnet synchronous generator (PMSG) become increasingly essential, especially in safety-critical applications. However, the existing approaches for monitoring eccentricity subject to many limitations. In this article, a novel method for online detection and location of the eccentricity fault in a PMSG is proposed based on the external magnetic sensing. The noninvasiveness facilitates installation and maintenance work. In this article, the effect of different eccentricity faults on the external leakage flux density is analyzed theoretically with the magnetic equivalent circuit method first. Then, two indicators are proposed for detecting static eccentricity (SE) and dynamic eccentricity (DE), respectively. The amplitudes of the SE and DE indicators are proportional to the fault degree. The angle of the SE indicator proves to be the direction of SE. Meanwhile, two indicators show excellent robustness and are independent of loads and rotation speed. Moreover, these indicators can be applied in any surface-mounted PMSG with a three-multiple number of slots. Accordingly, an algorithm to diagnose the eccentricity fault is shown based on two indicators from three sensing points outside. The computation of the method is light, which leads to fast detection speed. Finally, the accurate results in multioperating conditions from simulations and experiments verify the feasibility of the proposed approach.

中文翻译：

---

外磁感应永磁同步发电机偏心故障在线检测与定位

永磁同步发电机 (PMSG) 中偏心故障的检测和定位变得越来越重要，尤其是在安全关键型应用中。然而，现有的监测偏心率的方法受到许多限制。本文提出了一种基于外磁传感的永磁同步发电机偏心故障在线检测与定位的新方法。非侵入性便于安装和维护工作。本文首先采用磁等效电路法从理论上分析了不同偏心故障对外漏磁通密度的影响。然后，提出了两个指标分别用于检测静态偏心率（SE）和动态偏心率（DE）。SE 和 DE 指标的幅值与故障程度成正比。SE 指标的角度证明是 SE 的方向。同时，两个指标显示出极好的鲁棒性，并且与负载和转速无关。此外，这些指示器可以应用于任何具有三倍数插槽的表面安装 PMSG。相应地，给出了一种基于外部三个传感点的两个指标来诊断偏心故障的算法。该方法计算量轻，检测速度快。最后，模拟和实验在多操作条件下的准确结果验证了所提出方法的可行性。这些指示器可应用于任何具有三倍数插槽的表面安装 PMSG。相应地，给出了一种基于外部三个传感点的两个指标来诊断偏心故障的算法。该方法计算量轻，检测速度快。最后，模拟和实验在多操作条件下的准确结果验证了所提出方法的可行性。这些指示器可应用于任何具有三倍数插槽的表面安装 PMSG。相应地，给出了一种基于外部三个传感点的两个指标来诊断偏心故障的算法。该方法计算量轻，检测速度快。最后，模拟和实验在多操作条件下的准确结果验证了所提出方法的可行性。