INFLUENCE OF AGING ON CLASSIFICATION OF PARTIAL DISCHARGES IN CAVITIES

In this work the effect of aging on discharge patterns from cavities i n polyethylene (PE) is investigated. Two aspects were taken into accou nt-aging due to discharges and the location of the cavity (dieletric o r electrode bounded). Discharge patterns were analyzed using a previou sly developed technique involving statistical parameters. This tool su ccessfully discriminated various aging stages and cavity types. No dif ference was found between discharge patterns of dieletric- and electro de-bounded cavities in the first minutes from the beginning of measure ment. Clear recognition of dieletric- and electrode-bounded cavities i n the conditioned and aged stage was achieved. For discharge patterns with asymmetry between the positive and the negative half of the volta ge cycle, the ability of statistical parameters to follow changes in t he defect location in a test object was proven.