The breakdown characteristics of the liquefied SF6

In this paper the investigation of breakdown characteristics liquefied SF₆ (LSF₆) in model GIS (gas insulated switchgear) were described. The ability of LSF₆ insulation is higher than high-pressurized SF₆ gas. The breakdown characteristics of LSF₆ were produced by bubble formed evaporation of LSF₆ and bubble caused by high electric emission and corona. Also, The property of dielectric breakdown is determined by electrode form, electrode arrangement, bubble formation and movement, arc extinguishing capacity of media, difficulty in corona formation, and the distance between electrodes. The bubble formation and flow separation phenomenon were identified for LSF₆. It is considered in this paper that the results are fundamental data for electric insulation design of a high-temperature superconductor and cryogenic equipments machinery which will be studied and developed in the future.