Comparison of Dielectric Recovery After Arc Burning in SF 6 Gas and Its Potential Alternatives

ABSTRACT Although sulphur hexafluoride (SF 6 ) exhibits exceptional insulating properties, it is a potent greenhouse gas. Therefore, studying alternatives to SF 6 is critical for developing environmentally friendly high‐voltage electrical equipment. A review of previous studies highlights a lack of comprehensive research on the dielectric strength recovery characteristics of various alternative gas mixtures, particularly post‐arc recovery. To address this gap, we designed an experimental platform to measure the post‐arc dielectric strength recovery of these gases. The experimental results indicate that for traditional SF 6 gas mixtures, recovery characteristics tend to saturate once gas pressure and mixing ratios exceed a certain threshold. For C 4 F 7 N/CO 2 mixtures, an optimal component ratio exists. Under a liquefaction temperature constraint of 253 K, the gas mixture with the best post‐arc insulation performance is 20% C 3 F 6 and 80% CO 2 . Compared to N 2 , CO 2 is a more effective buffer gas, significantly enhancing the dielectric strength recovery rate.