ON-LINE OPTICAL DETECTION OF PARTIAL DISCHARGES IN AN OIL FILLED HIGH VOLTAGE TRANSFORMER

摘要

Partial discharges (PDs) are a major source of insulation deterioration which caused by cumulative effect of the mechanical, chemical, thermal and electrical stresses inside the insulation in the high voltage (HV) apparatus of the power system. The deterioration of the insulation system in the HV power apparatus can lead to catastrophic failure of the entire power system without continuous monitoring of such small discharges. There are several commercially available diagnostic techniques which are used to detect and monitor for the partial discharges in the HV power equipment. The commercially available diagnostic technique not only has some advantages but also has lots of limitations. To overcome these limitations of the detection of the PDs inside the power apparatus, in this work the online detection of partial discharges are carried out by optical technique in a dielectric test cell which is considered to be a laboratory model of a transformer. In this work, a He-Ne laser, a cross polarizer, a fiber cable, a detector amplifier, a digital storage oscilloscope and a laptop computer is used for online monitoring of PDs activity and the collected data are further analyzed with the above said facilities.