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.