The new diagnosis method of rotor winding inter-turn short circuit fault and imbalance fault based on stator and rotor vibration characteristics

Stator and rotor vibration characteristics of generator are analyzed when the rotor winding inter-turn short circuit fault and the imbalance fault occur. The rotor vibration of fundamental frequency increases and the stator vibration of second frequency decreases when the rotor winding inter-turn short circuit fault occurs. But when the imbalance fault occurs, the rotor vibration of fundamental frequency increases and the stator vibration of second frequency increases too, so the stator vibration characteristics are different from that of the rotor winding inter-turn short circuit fault. Considering the differences of the stator vibration, a new diagnosis method of rotor fault, based on stator and rotor vibration characteristics, is developed. Comparing to the traditional method that only considering the rotor vibration signals, the rotor winding inter-turn short circuit fault and imbalance fault can be effectively diagnosed. Finally, the vibration data of a type of SDF-9 generator are measured in the laboratory to verify the theoretical analysis presented above.