Application of an environmentally friendly SF6 free medium voltage switchgear technology in a pilot setup

Abstract:
Current gas insulated switchgear technologies use SF6 or other mixtures of synthetic gases as an insulation medium and often also as a breaking medium. Despite its beneficial insulation properties, SF6 is the most hazardous greenhouse gas humanity knows. Recent studies prove that reported amounts of SF6 emissions can only explain 20% of actual emissions. Moreover, increased environmental and regulatory concerns as well as the costs of gas handling and maintenance are commonly cited as disadvantages of SF6 based switchgear. An effort has been made in a pilot setup to test a new technology of gas insulated electrical switchgear using dry compressed air as an insulation medium for medium voltage applications up to 36 kV. The goal of the pilot is to prove practical feasibility of using compressed dry air as an insulation medium for gas insulated switchgear applications. Applicability of such technology is benchmarked with reference to SF6 switchgear technology. Moreover, the effort in terms of gas handling, cost and time involved in commissioning and maintenance is assessed.