Abstract
The investigations on dc tracking resistance should be enhanced due to the increasing of organic insulating materials being used with dc power. This paper describes the influence of gamma-rays irradiation on dc tracking failure of organic insulating materials by use of the IEC Publ. 112 method. Epoxy resin, polyethylene terephthalate and modified polycarbonate which were irradiated in air until 1×105 Gy and 1×106 Gy with dose rate of 104 Gy/h using a 60Co gamma-source have been used as the test samples. The total dose effects on the number of drops to tracking failure (or erosion depth), and scintillation discharge energy have been studied. The effects of gamma-rays irradiation on do tracking failure are due to radiation-induced degradation or cross-linking of organic insulating materials. A wavelet analysis using gaussian wavelet is applied to show the scintillation discharge energy.
