Study on Post-Arc Recovery Characteristic Test of SF₆ Mixed Gas

SF₆ gas is widely used in medium and high voltage electrical equipment due to its high insulation strength and strong arc extinguishing performance. However, due to its strong greenhouse effect, efforts are being made to limit its emissions. By adding an appropriate amount of buffer gas, the insulation and arc extinguishing performance of the gas can be maintained, while reducing the greenhouse effect and gas liquefaction temperature, ensuring that the equipment operates normally in cold environments and improving the reliability of the power system. However, research on the insulation strength and arc recovery characteristics of SF₆ mixed gas media is mainly focused on simulation, lacking comparative studies on the insulation strength and arc recovery characteristics under different mixing ratios and pressures. Therefore, this study aims to investigate the insulation strength and arc recovery characteristics of SF₆ mixed gases, testing the arc recovery characteristics curves of different mixed gases under different composition and pressure conditions, and conducting comparative analysis. The results show that the arc recovery speed of SF₆ mixed gases gradually increases with increasing pressure or mixing ratio, and saturates. The recovery curves of SF₆/CO₂ mixed gases with SF₆ proportions of 70% and 90% are closest to those of pure SF₆ gas. These experimental results provide supporting data for the simulation of the insulation strength and arc recovery characteristics of SF₆ mixed gas media.