Institute for Energy Engineering, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
Sensors (Basel). 2022 Apr 20;22(9):3150. doi: 10.3390/s22093150.
Induction machines (IMs) are a critical component of many industrial processes, and their failure can cause large economic losses. Condition-based maintenance systems (CBMs) that are capable of detecting their failures at an incipient stage can reduce these risks by continuously monitoring the IMs' condition. The development and reliable operations of CBMs systems require rapid modeling of the faulty IM. Due to the fault-induced IM asymmetries, these models are much more complex than those used for a healthy IM. In particular, a mixed eccentricity fault (static and dynamic), which can degenerate into rubbing and destruction of the rotor, produces a non-uniform IM air gap that is different for each rotor position, which makes its very difficult to calculate the IM's inductance matrix. In this work, a new analytical model of an eccentric IM is presented. It is based on the winding tensor approach, which allows a clear separation between the air gap and winding-related faults. Contrary to previous approaches, where complex expressions have been developed for obtaining mutual inductances between conductors and windings of an eccentric IM, a conformal transformation is proposed in this work, which allows using the simple inductance expressions of a healthy IM. This novel conformal winding tensor approach (CWFA) is theoretically explained and validated with the diagnosis of two commercial IMs with a mixed eccentricity fault.
感应电机（IM）是许多工业过程的关键组成部分，其故障会导致巨大的经济损失。能够在初始阶段检测到其故障的基于状态的维护系统（CBM）可以通过持续监测 IM 的状况来降低这些风险。CBM 系统的开发和可靠运行需要快速对有故障的 IM 进行建模。由于故障引起的 IM 不对称性，这些模型比用于健康 IM 的模型复杂得多。特别是，混合偏心故障（静态和动态），可能会演变成转子的摩擦和损坏，会产生不均匀的 IM 气隙，每个转子位置都不同，这使得计算 IM 的电感矩阵变得非常困难。在这项工作中，提出了一种新的偏心 IM 分析模型。它基于绕组张量方法，可以清楚地分离气隙和绕组相关的故障。与之前的方法不同，之前的方法针对获得偏心 IM 中导体和绕组之间的互感开发了复杂的表达式，而在这项工作中提出了保角变换，可以使用健康 IM 的简单电感表达式。这种新颖的保角绕组张量方法（CWFA）从理论上进行了解释，并通过诊断具有混合偏心故障的两台商用 IM 进行了验证。
