330MW机组励磁机振动故障分析与处理

Analysis and Treatment of Exciter Vibration Fault in 330 MW Unit

某330 MW机组启动过程中,励磁机转子在通过临界转速时振动较大,通过对振动波德图与频谱图进行分析,判断振动故障原因为质量不平衡。对励磁机转机进行现场动平衡试验,配重位置分别为发电机与励磁机对轮和励磁机风扇环,配重质量分别为360 g∠168°与340 g∠200°。现场动平衡试验后,临界转速下励磁机振动由207μm降至120μm,工作转速下励磁机振动数值由102μm降至65μm。由结果可知,现场动平衡可有效解决临界转速下振动故障,且跨内的配重效果显著优于跨外,为解决类似问题提供借鉴。

In the start-up process of a 330 MW unit,the exciter rotor vibrates greatly when it passes through the critical speed.By analyzing the Bode diagram and spectrum diagram of vibration,it is judged that the cause of vibration fault is mass imbalance.Field dynamic balance test is carried out for the exciterrotor.Add balance mass 360 g∠168°oncoupling between generator,and 340 g∠200°on exciter fan.After the field dynamic balance test,the exciter vibration at the critical speed decreasedfrom 207μm to 120μm,and the exciter vibration at the working speed decreased from 102μm to 65μm.The results show that the field dynamic balance can effectively solve the vibration fault at the critical speed,and the dynamic balance effect inside the span is significantly better than that outside the span.It provides reference for solving similar problems.