Abstract：Internal dischargefailure of the transformer has characteristics of long latent time and weak signal, etc, and it is difficult to carry out effective detection during operation, therefore the safe operation of the transformer is threatened seriously by it. According to a fault for the excessive acetylene of the transformer oil in a 500kV substation, combined with oil chromatographic analysis, a variety of live detections include infrared temperature measurement、ultrasonic partial discharge detection are applied, and according to the infared spectrum and various modes of the discharge waveform, through expert consultation and fault pattern recognition, a conclusion is reached that imperfect earth of the magnetic shield result in the discharge to shell in the transformer. Finally, the treatment scheme and preventive measures are put forward, which have a high application value.
2014, Vol. 15 
