基于电流频谱分析的高压电机笼条断裂在线诊断及处理

On-line Fault Diagnosis and Treatment of High Voltage Motor Rotor based on Current Spectrum Analysis

本文利用电流频谱分析技术对一起330MW发电机组高压电机进行在线检测,发现1号循泵电机电流频谱工频边带中出现明显的极通过频率峰值,且极通过频率峰值达到了工频峰值的1.41%,判定1号循泵电机存在笼条断裂故障。因机组满负荷运行,未能立即停机处理,监测运行30d后进行解体处理,发现1号循泵电机转子笼条断裂7处,并出现明显的扫膛现象,经过现场焊接处理后,循泵电机正常投入运行。该案例表明电流频谱分析技术可在不停机的状态下有效诊断异步电机转子笼条断裂等早期故障,具有较强的实用价值。

The current spectrum analysis technology was used on the fault diagnosis of a high voltage motor of a 330 MW generator set in this paper. In the current spectrum characteristics of the No.1 circulating-pump motor, a significant frequency peak was observed in the power frequency sideband, and it was up to 1.41% of the power frequency peak, which was the fault characteristics of motor rotor. Due to the full load operation of the unit, it could not be shut down immediately. After monitoring and running for 30 days, the motor was disassembled, and it was found that the rotor cage of the circulating-pump motor was broken in 7 places. After the welding treatment, the circulating-pump motor was put into normal operation. The case shows that the current spectrum analysis technology can effectively diagnose early faults such as rotor fault of asynchronous motors without power cut off, which has strong practical value.