190 / 2024-04-15 21:33:04

Breakdown Characteristics of N2-O2 Mixtures at High Pressures in Alternating Non-uniform Electric Fields

"gas insulation",N2⁃O2 mixture,breakdown voltage,breakdown criterion,non-uniform electric field,high gas pressure

Nitrogen-oxygen(N₂-O₂) mixtures have good insulating properties and economic benefits, and are widely used in the insulation of electric power equipment. The effective ionization coefficient of the N₂-O₂ mixture is related to the O₂ component ratio. Therefore, the breakdown voltage of N₂-O₂ mixture is also related to the O₂ component ratio. In this paper, the breakdown voltages and breakdown field strengths of N₂-O₂ mixtures at high pressures in non-uniform electric fields are investigated. The effect of the O₂ component ratio on the breakdown characteristics at high pressures is analyzed. The breakdown voltage increases as the decrease of the O₂ component ratio in non-uniform electric fields. The breakdown voltage fluctuation is related to the O₂ component ratio. The applicability of Paschen’s law in the N₂-O₂ mixtures insulation under non-uniform electric fields is analyzed. And the empirical formulas for the breakdown voltages of N₂-O₂ mixtures are presented. The empirical formulas for the breakdown field strengths of N₂-O₂ mixtures in different electrode structures are presented. The ionization coefficients and attachment coefficients of N₂-O₂ mixtures with different O₂ component ratios are calculated. And the optimum O₂ component ratio of N₂-O₂ mixture in the non-uniform electric field is proposed base on the calculated ionization coefficients and attachment coefficients.