AC breakdown and decomposition characteristics of environmental friendly gas C5F10O/Air and C5F10O/N2

C5F10O (C5 perfluorinatedketone) has received extensive attention due to its great insulation and eco-friendly performance, which has the potential to replace SF6 usage in power industries. In this paper, the power–frequency breakdown properties and discharge decomposition characteristics of C5F10O/Air and C5F10O/N2 gas mixtures are explored. It is found that the AC breakdown voltage of the C5F10O gas mixtures increases gradually with both the gas pressure and the content of C5F10O. As the partial pressure of C5F10O increases, the relative insulation strength increasing trend of the C5F10O gas mixtures becomes less obvious with the increase in the gas pressure. The AC breakdown voltage of the C5F10O/Air gas mixture is higher than that of the C5F10O/N2 gas mixture. In addition, the decomposition products of the C5F10O gas mixtures are mainly CF4, C2F6, C3F8, C4F10, and C3F7H. Under the same condition, the content of the CF4 in C5F10O/Air gas mixture is higher than that of the C5F10O/N2 gas mixture. The decomposition of the C5F10O/Air gas mixture after breakdown did not produce C2F4 and C3F6. CF2O and CO2 are not detected in the C5F10O/N2 gas mixture. Moreover, the carbon precipitation on the electrodes’ surface can be found for the C5F10O/N2 gas mixture after 60 breakdown tests.