Surface flashover characteristics of epoxy resin under different atmospheres enhanced by 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane

Epoxy resin (EP) is widely used in gas-insulated switchgear (GIS) due to its excellent mechanical and insulation properties. However, surface flashover on epoxy caused by charge accumulation at the gas-solid interface under DC electric field significantly threatens the reliability of GIS. In this study, a series of epoxy composites were prepared using 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (6FAP) as a filler. The surface flashover characteristics were investigated under both air and SF6 conditions. Experimental results show that, under air condition with the increase in 6FAP content, the flashover voltage decreases at first and then increases. Similar phenomena occur in the surface conductivity and charge dissipation rate of 6FAP/EP composite in air. When the content increases from 0 to 2 wt%, deep trap density increases. When the content further increases, deep trap density decreases and the fluorine atoms in 6FAP has strong electron affinity which increase the flashover voltage. Under SF6 condition the flashover voltage increases with 6FAP content. This work lays a foundation not only for the improvement of flashover voltage of epoxy composite but also for the reliability of GIS application.