Circular degradation patterns on XLPE surfaced electrodes

A study has been carried out to characterize the degradation patterns observed on XLPE surfaces exposed to partial discharges in air, O2 and N2 atmospheres, using circular electrode systems. FT-IR analyses indicated that the resulting circular degradation patterns were composed of different chemical products. The results suggested that, under different experimental conditions of applied voltage, ambient gas composition and gas flow rates, the ring patterns were formed due to temporally separated interactions of different discharge intensities and ion activities with the XLPE and the dicumylperoxide decomposition products in the respective degradation regions