The Comparison of Arc-Extinguishing Capability of Sulfur Hexafluoride (SF6) with Alternative Gases in High-Voltage Circuit-Breakers

Abstract

This paper describes the influence of the switchgear geometry, the priming pressure of the SF6 switchgear and the magnitude of the short-circuit current on the dielectric recovery of the arc gap, using the example of a high-voltage circuit-breaker for a 145 kV network. The results of other tests document the influence of the arc-quenching gases nitrogen (N2), carbon dioxide (C02) and a nitrogen/SF6 mixture on the arc gap recovery in comparison with SF 6' The results show that the arc control capability of these gases is very limited compared with SF6. Consequently, it will not be possible totally to replace the SF6 in high- voltage switchgear in the short to medium-term.