The new method on rotor winding inter turn short-circuit fault measure of turbine generator

In this paper, the relationship between the magnetic field characteristic of the steam generator and the rotor inter turn short-circuit has been theoretically analyzed and numerically calculated. The effective magnetic field of the generator is harmed because of the occurrence of the short circuit fault, comparing the normal status, there is a trend of weakening, and the higher harmonic of the circular current and voltage in the stator side are changed accordingly. A practical method, for which the relative variety level of the exciting current before and after the fault and the higher harmonic variety of stator circular current and voltage difference are calculated and measured, is used to identify the serious level of the fault, and the fault criterion of on-line monitoring of rotor inter turn short-circuit is founded. By means of the dynamic analog experiment of the simulative experimental unit MJF-30-6 on different working conditions of the generator rotor inter turn short-circuit, the concerned theory is verified.