Multi-loop model and simulation research of turbine generator with inter-turn short circuits fault of field windings

The inter-turn short circuits fault of field windings is one common fault in generators. It will cause serious damages if such faults are not handled properly in time?For this reason, according to the multi-loop method of AC machines this paper proposes multi-loop mathematical model of turbine generators with inter-turn short circuits fault of field windings. The inductance parameters are calculated by air-gap permeance method and the calculated wave-form of inductance parameters shows reasonable. Combining with the actual structure of a 300MW turbine generator, the normal rated load operation and the short circuits fault operation of generator have been simulated based on the model. The normal stator winding currents and the fault currents difference in stator winding parallel branches of same phase were obtained. The currents of normal and fault field winding are calculated. The model considers the different structure and the harmonics in air gap magnetic field, which provides the basis for further fault analysis for turbine generator with inter-turn short circuits of field winding.