SF6 alternative development for high voltage switchgears

Abstract

Alternative solutions to SF6 have been researched for a long time. Up to now, no significant success has been achieved in solutions for the transmission network. This paper presents the research conducted with fluorinated compounds to qualify a new gas to be used into high voltage equipment as SF6 alternatives with properties significantly improved with respect to typical SF6/N2 mixtures or others already in use. Potential applications of SF6-free gas mixture, called g3 and based on 3M™ NovecTM 4710 Dielectric Fluid for dielectric insulation and arc switching into high voltage apparatuses are reported with the aim to be low in toxicity and to reduce the global warming potential of the new mixture to typically less than 2% of the SF6 equivalent with no or minor design modification with respect to typical SF6 design. Research in progress on arc interrupting capability of this new gas mixture has shown promising results that are not described in this publication.