异步电动机滚动轴承外滚道故障诊断新方法

Diagnosis method of rolling bearing outer raceway fault in induction motors

目前基于电机电流信号分析(MCSA)的诊断方法无法诊断滚动轴承外滚道轻微故障,在电机空载或轻载运行条件下存在诊断失效的问题,为此提出一种基于定子电流信号中转频多调制分量的异步电动机滚动轴承外滚道故障诊断方法。首先根据转频确定多个转频调制分量;然后在每个转频调制分量附近对定子电流信号做连续细化傅里叶变换分析;并根据正常和故障情况下的多个转频调制分量的幅值确定故障指数;最后根据故障指数判断是否发生故障。相对于其他基于MCSA的诊断方法,该方法聚焦在故障对转频调制分量的影响,不但可以诊断出轻微的外滚道故障,而且在异步电动机空载或轻载运行条件下仍然奏效。

Aiming at the problem that the published diagnosis methods based on motor current signal analysis(MCSA) is not able to diagnose the mild fault of rolling bearing outer raceway, or is no longer effective while the motor operates with no load or slight load, a diagnosis method of rolling bearing outer raceway fault based on the rotating frequency multi-modulated components in stator current signal is proposed. At first, several rotating frequency multi-modulated components were identified according to the rotating frequency, and investigated by using continuous subdivision Fourier transform analysis on stator current signal. And then, the corresponding fault index was worked out according to the amplitudes of those components under healthy and faulty conditions. Finally, the diagnosis whether the fault occurs or not was reached. Compared with other MCSA-based methods published before, this method focuses on the influence of the fault on the rotating frequency multi-modulated components. And thus, it can diagnose effectively the mild fault of rolling bearing outer raceway, even when the motor is operating with no or light load.