Experiment of dielectric strength of C5F10O gas mixture and calculation of stratification

When SF₆ was designated as a green house gas to be reduced, there has been a wish to use an alternative insulating gas to replace pure SF6 gas. And a fluoroketon, C₅F₁₀O attracts great attention as a potential substitute. In this paper, the breakdown characteristics of C₅F₁₀O/CO₂ as mixtures in nonuniform electric filed and the variation of the mixing ratio with elevation were studied. The positive and negative breakdown voltages are measured in rod-plane electrode. The gap length is 25mm and the gas mixtures' partial pressure of C₅F₁₀O to be 20kPa and 40kPa, and the total pressure varying from 0.1MPa to 0.7MPa. The effects of polarity for different gas pressure in non-uniform electric filed is analysed. Results show that when the gas pressure increases, the positive voltage increases while the negative breakdown voltage approaches saturation before its decline. As for the variation of the mixing ratio with elevation. We calculated the variation with temperature and height according to a Hydrostatic equation. The calculated results indicated that, the gas stratified variation with temperature and height is not obvious.