Degradation analysis of epoxy resin surfaces exposed to partial discharge

The purpose of this study is to investigate the degradation process of polymer insulation materials exposed to partial discharge. Active oxygen, ozone, nitrogen oxides, nitric acid, etc. are generated by partial discharge. The polymer insulation materials degrade for such chemical stress. Moreover, surface resistivity of insulation materials is reduced with humidity. Therefore, it is necessary to take the affection of humidity into consideration for partial discharge. The purpose of this study is to investigate the effects of humidity on the degradation of an epoxy resin surfaces exposed to partial discharge. Experimental conditions are air atmosphere, and relative humidity was varied to 0, 25, 50, and 75 %. The quantity of partial discharge pulses can be evaluated with number of pulses. The degradation characteristics of epoxy resin surfaces were analyzed FTIR and SEM.