Analysis Of Generator Rotor Widing Inter-turn Short Circuit Fault Based On Shaft Voltage

As all generators have eccentricity more or less, shaft voltage always exists in machines. When rotor winding inter-turn short circuit fault has happened, rotor dynamic eccentricity aguments at the same time under the effect of unbalanced magnetic pull and rotor heat bending.It makes air-gap more uneven,and consequently there is more high value of shaft voltage in the rotor.This paper will give a better comprehension of shaft voltage mechanism produced by homopolar effect and air-gap eccentricity. The fault characteristic spectrums of shaft voltage is analyzed through air-gap flux density. Finally, Shaft Voltage Diagnosis System on rotor inter-turn short circuit fault(SVDS) is developed with Viusal C++. It has realized on-line sepectrum analysis and report successfully,and also analyzes shaft voltage off-line for operation staff finding new fault characteristic spectrums about inter-turn short circuit fault.