Multi-loop model and simulation research of hydrogenerators with rotor winding inter-turn short circuit fault

In the power system, 1/3 of the load is by hydro-generating power supply where its reliability is important requirement. Rotor internal turn-to-turn short circuit is a common fault in hydro-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 hydro-generators with inter-turn short circuits fault of field windings. The simulation for the inter-turn short circuit of rotor winding on a six poles hydro-generator is carried out by multi-loop methods and the currents in stator winding parallel branches of same phase are calculated quantitatively, based on the analysis, the paper gives the value of the fractional harmonic circulation, which will provide the protection basis for the hydro-generators with rotor winding inter-turn short circuit fault.