Short circuit between turns of the rotor winding of large turbogenerator is one of the common faults which adversely affect the safe operation of generator, the bad effects include overheating of the short circuit point, thermal bending, intensified vibration of the rotor, magnetization of the large shaft, etc. In this paper, the characteristics of inter-turn short circuit fault of rotor insulation structure are analyzed, and the optimal diagnosis method for generator running state and shutdown state is obtained with examples.
