Study on the Effect of O2 Content on the Decomposition Characteristics of C5F10O Under Different Buffer Gases

In recent years, C5F10O has aroused a lot of notice as a potential SF6 alternative gas. As a new kind of environmentally friendly insulated gas, the research on the effect of O2 content on the decomposition characteristics of C5F10O mixed insulating gas is still insufficient. In this paper, partial discharge tests of C5F10O/N2/O2 mixed gas and C5F10O/CO2/O2 mixed gas are carried out to imitate the work condition of gas insulation equipment under the severe non-homogeneous field. The impact of O2 content in the mixed gas on its decomposition characteristics is analyzed, and the difference of decomposition characteristics under two buffer gases is compared. We found that under the condition that N2 is the background gas, when the oxygen ratio is around 4%, the overall concentration of decomposition by-products generated by mixed gas partial discharge is the lowest. In addition, the influence of two background gases on the partial discharge decomposition of C5F10O are totally different. When N2 is the background gas, there exists an obviously trend to reduce the decomposition. But when CO2 is the background gas, it even exacerbates the decomposition to a certain extent.