非平稳工况下感应电机匝间短路与高阻连接诊断

Diagnosis of ITSC and HRC for induction motors under non-stationary conditions

摘要:

匝间短路（ITSC）和高阻连接（HRC）是常见的定子故障，及时检测出故障可防止更严重的电机损伤，提高工业设施的可靠性和安全性。然而，这两种故障特征相似容易造成误判，在非平稳工况下检测指标波动较大，且故障相位识别需同步采集多类型信号增加了检测成本。为解决上述问题，本文提出一种仅采用电压信号实现非平稳工况下ITSC、HRC检测与相位识别的方法。首先，建立故障模型并开展机理分析，提取能够有效区分ITSC和HRC的故障特征。其次，基于VMD算法估计信号瞬时频率脊线，构建零序电压因子（ZVF）、负序电压因子（NVF），减小工况波动对检测指标的影响。最后，利用电压信号相位构建相位识别指标。通过感应电机故障模拟实验台验证所提方法的有效性。结果表明，所提方法在非平稳工况下可有效检测ITSC、HRC故障并识别相位，且不需借助转速计和电流传感器。

Abstract:

Inter-turn short circuits (ITSC) and high-resistance connections (HRC) are common faults in stators. Detecting these faults on time can prevent severe motor damage and improve the reliability and safety of industrial facilities. However, these two fault characteristics are similar, which easily leads to misjudgment. Additionally, the detection indicators fluctuate under non-stationary conditions, and identifying faulty phases requires the synchronous acquisition of multiple types of signals, increasing the cost of detection. To address these problems, this study proposes a method that only uses voltage signals to detect and identify ITSC and HRC faults under non-stationary conditions. First, fault models are established, and mechanism analysis is conducted to extract fault features that effectively differentiate between ITSC and HRC. Second, the VMD algorithm is used to estimate the instantaneous frequency ridge of the signal. Then, the zero-sequence voltage factor (ZVF) and negative-sequence voltage factor (NVF) are constructed to reduce the influence of non-stationary conditions. Finally, the phase identification indicator is constructed using the phase of voltage signals. The effectiveness of the proposed method is verified through an induction motor experimental platform. The results demonstrate that the proposed method can effectively detect ITSC and HRC faults and identify the phase under non-stationary conditions without requiring a tachometer or current sensor.