DIELECTRIC DETERIORATION DIAGNOSTIC METHOD FOR POWER MACHINE

PURPOSE:To allow highly accurate diagnosis of dielectric deterioration by observ ing both the state in time region and the distribution in frequency region of electromagnetic signal radiated following partial discharge. CONSTITUTION:When partial discharge 7 takes place due to dielectric deterioration in a power machine 1, electromagnetic signal produced through the partial discharge 7 is received by means of an antenna 2 installed in the vicinity thereof. The signal thus received is the amplified through an amplifier 3 and observed by means of an oscilloscope 4 and a spectrum analyzer 5. The signals are taken into a computor 6 where the waveform pattern and frequency distribution of the signals are inspected. In other words, generating state of electromagnetic wave radiated following partial discharge is evaluated at the time of occurrence of dielectric deterioration. In this case, both of the state (frequency of occurrence, magnitude) in time region and frequency distribution (spectral distribution) are observed and the extent of dielectric detradation is classified into several ranks.