Influence of Temperature on the AC Breakdown Voltage of SF6in Slightly Inhomogeneous Field

摘要

Obtaining the influence of temperature on the dielectric strength of SF6is important for GIS or GIL equipment operating in various temperatures. Previous researches only considered a smaller temperature range higher than the liquefaction temperature of SF6 gas and couldn't reflect the situation in extremely low ambient temperature. In this paper, the AC breakdown voltages of SF6 gas at different temperatures from −50°C to 20°C are obtained with rod-plate electrodes. The results show that the breakdown voltage of SF6decreases nonlinearly with the decrease of temperature. The phenomena can be explained by the liquefying of SF6gas. The liquefying temperature of SF6gas is firstly obtained by breakdown experiment. This study can provide a reference for ensuring the safe operation of GIS and GIL in low temperature areas.