Characteristics of C 4 F 7 N/Epoxy Resin Insulation System Affected by Long-Term Electro-Thermal Accelerated Aging.

The research on characteristics of C 4 F 7 N and epoxy resin insulation system affected by long-term electro-thermal accelerated aging can provide the reference for the application of C 4 F 7 N/CO 2 gas mixtures. In this paper, a long-term electro-thermal accelerated aging experimental platform of gas-solid insulation system is established, and more than 3000 hours of experiments are carried out. The results show that there is not a significant change in leakage current in the system, at the same time, none of the gas decomposition products are detected in the C 4 F 7 N/CO 2 gas mixtures during the aging experiment. With the increase of aging experiment time, the number of tiny holes on the epoxy resin surface increases significantly. The surface of the epoxy resin sample near the high voltage electrode is most obviously damaged. The surface of epoxy resin shows slightly fluorinated, and the color of it has changed from white to yellow on account of the adsorption of C 4 F 7 N gas by the holes on the sample surface. Flashover voltage of epoxy resin is basically consistent before and after aging by the power frequency or negative lightning impulse applied. It proves that the gas-solid insulation system of C 4 F 7 N and epoxy resin can keep the insulation performance basically consistent, affected by longterm electro-thermal accelerated aging. [ABSTRACT FROM AUTHOR]