Decomposition Characteristics of C 3 F 7 CN/EP With Different Partial Discharge Intensities on Surface Discharge

C 3 F 7 CN/CO 2 gas mixtures is considered to be one of the most potential SF 6 alternative gases on account of its excellent insulation and environmental-friendly performance. The research on the decomposition characteristics of C 3 F 7 CN and Epoxy resin (EP) with insulation defects can provide a reference for formulating the operation and maintenance strategy of environmental-friendly electrical equipment. In this paper, the partial discharge experimental platform of gas-solid insulation system was established, the degradation experiments of C 3 F 7 C N /EP with different discharge intensities were carried out, and the characteristics of products with test time and discharge intensity were obtained. The result showed that the types of gas decomposition products increased with the discharge time increasing. The main decomposition products of C 3 F 7 CN/EP with surface discharge were CF 4 , C 3 F 8 , C 3 F 6 , C 6 F 14 , C 4 F 6 , C 4 F 10 , C 4 F 8 , CF 3 CN, CNCN and C 12 F 7 H 17 O 2 . It can also be found that, with the increase of discharge intensity, the appearance time of some products was advanced and the rate of gas production increased, and the product CNCN appeared.