基于定子振动特征的转子绕组短路故障识别

分析了汽轮发电机转子绕组匝间短路故障和转子不平衡故障时定、转子径向振动特征。当转子绕组匝间短路故障发生时,转子基频振动增加,定子二倍频振动减小;当转子不平衡故障发生时,转子基频振动增加,定子二倍频振动增加,不同于转子绕组匝间短路故障时的定子振动特征。在此基础上提出了基于定子振动信号的转子绕组匝间短路故障识别方法,与传统的单纯利用转子振动信号的诊断模型相比,可有效识别转子绕组匝间短路故障和转子不平衡故障。最后实测了SDF-9型故障模拟发电机定、转子径向振动信号,与理论分析结果基本吻合。

The diagnosis method of generator rotor winding inter-turn short circuit fault based on stator vibration characteristic

The generator vibration characteristics caused by rotor winding interturn short circuit fault and imbalance fault are analyzed respectively.For the first case,the rotor radial vibration of fundamental frequency will increase,and stator radial vibration of second harmonics frequency will decrease.However for the second case,the rotor vibration of fundamental frequency will increase,and meanwhile the stator vibration of second harmonics frequency will also increase,which is different from the stator vibration characteristic on first fault. A new fault diagnosis method based on stator vibration characteristic is presented.Comparing with the conventional method which is based on only rotor vibration characteristic,this new method can distinguish either the rotor winding inter-turn short circuit fault and imbalance fault.Finally,the rotor and stator vibration of a type SDF-9 generator is measured in laboratory to verify the theoretical analysis presented above.