发电机转子绕组匝间短路引起的机组振动诊断与处理

Diagnosis and Treatment of Unit Vibration Caused by Interturn Short Circuit of Generator Rotor Winding

针对某生物质电厂发电机组运行中轴瓦振动突然增大的问题,经全方面分析原因,并通过一系列试验,最后诊断为发电机转子存在匝间短路,从而引起振动,现场抽出转子打开两侧护环,发现励侧转子端部绕组积灰严重,汽轮机侧转子绕组靠近铁心根部有两匝线棒断裂,部分绕组匝间有放电现象,绝缘层被破坏。更换新转子后,机组运行正常,振动消失,为现场诊断发电机类似故障提供了借鉴。

The Vibration of bearing bush of turbogenerator sets in a biomass power plant suddenly increased during operation.Through a series of tests,it is diagnosed finally that inter-turn short circuit occurred in the rotor of the generator caused vibration.The rotor is pulled out in order to open the guard rings on both sides.It is found that large amount of dust had accumulated at the end coil of the rotor on the excitation side.Besides,two turns of wire rod are broken near the core root of the coil on the turbine side,and some of the coils are discharged between turns that led to the damagement of insulation layer.After replacing the new rotor,the unit runs normally and the vibration disappears.The reference for onsite diagnosis of similar faults generators are provided.