Apparatus for detecting faults or damage of an electrical device or a rotating electrical machine

摘要

Abnormality detecting apparatus for high voltage electrical equipment 70 measures the frequency spectrum 52, 53 of a signal detected by a partial discharge sensor 9, and detects a partial discharge signal having a frequency component in the neighbourhood of a resonance frequency determined on the basis of the electric equipment and its measuring circuit. In a rotating electric machine, a narrow band filter circuit 23 passes a frequency component around a resonance frequency determined on the basis of the length of the stator core to detect a partial discharge signal. Discharge may be caused by the presence of impurities or insulation aging. Identification of the resonant frequency enables location of the position of a fault. IMAGE