Alternative insulation gas for medium-voltage switchgear

Abstract

Although the contribution of SF6 (sulfur hexafluoride) emissions from gas insulated medium-voltage switchgear to man-made global warming is very small, an eco-efficient insulation gas will contribute to a reduction in the carbon footprint of the electricity grid. Based on fluoroketone molecules an alternative to SF6 gas insulation has been developed for medium-voltage switchgear applications. The alternative fluoroketone/air gas mixture combines good electrical performance with a very low global warming potential GWP < 1. Compared to the global warming potential of 22.800 from SF6, a reduction of nearly 100% can be achieved using the alternative gas. This paper presents main conclusions of the development of a medium-voltage Gas-Insulated Switchgear (GIS) using the new alternative insulation gas, including a comparison of alternative gas technologies and applying experiences from pilot projects for switchgear applications.