大型水轮发电机定子铁心故障模拟、检测与处理

Fault Simulation,Detection and Treatment of Stator Core in Large-scale Hydro-turbine Generators

在大型水轮发电机组真机上进行大规模的故障模拟、检测和处理在国际国内不多见,本次真机试验的结果表明:额定环流法与ELCID法均能反映铁心绝缘状况,但在故障较轻的情况下,ELCID法反映更为灵敏,有助于提前发现定子铁心故障、进行处理消除隐患。因此建议常规大修时对定子铁芯进行ELCID法铁心试验;对于因为定子接地故障导致的铁心大面积或者深度熔化的铁心故障,会严重危害机组安全稳定运行,可以根据铁心故障的实际情况,判定是否需要立即进行检修及检修方法;重塑定子铁心片间绝缘的方法,经过试验验证是有效可行的。

An extensive test for the fault simulation,detection and treatment of the stator core is carried out in real largescale hydro-turbine generators. The results show that the insulation condition of the stator core can be reflected by both the rated circulation method and the ELCID method. While the ELCID method is more sensitive,which is thus more suitable for less serious faults and more helpful in fault detection and treatment. Thus,the ELCID method is recommended for the stator core in the regular overhauls. For large area or deep melting faults of the stator core due to grounding failure,which may seriously threaten the safe and stable operation of the unit,the practical conditions of the faults should be examined carefully to determine whether an immediate overhaul is necessary and the appropriate overhaul scheme. The test results also show that the insulation reconstruction method for the stator core is feasible and effective.