水布垭电厂发电机磁极绕组匝间短路故障分析与处理

Analysis and Treatment of the Inter-turn Short Circuit Fault of Generator Pole Windings in Shuibuya Hydropower Plant

在水布垭电厂1号发电机C修期间,对吊出机坑的2台磁极进行交流阻抗试验时,发现其中1台磁极阻抗值明显偏小。通过直流电阻测量不同电流下的交流阻抗值与历史数据及其他磁极对比,确认该磁极存在匝间短路故障,经更换故障磁极,试验判断合格。同时也说明,使用交流阻抗试验判断设备故障仍具有很大的局限性,尤其是轻微的匝间短路故障。

During the C class maintenance of the No.1 generator in Shuibuya Hydropower Plant,the impedance value of one magnetic pole of the unit in the AC impedance test is abnormally small.The DC resistance value and the AC impedance values under different currents of the pole are measured and compared with the historical data and the results of other poles.It is confirmed that the magnetic pole is of inter-turn short circuit fault.The fault pole is then replaced and the fault is successfully eliminated.The results also show that the AC impedance test is of great limitation in the determination of inter-turn short circuit fault of magnetic poles,especially for slight faults.