Dry Air/O2 혼합가스의 혼합비에 따른 절연파괴 및 연면방전 특성 연구

Abstract

This paper presents the discharge characteristics and economic feasibility of a Dry Air/O2 and a N2/O2 mixture gas in order to review SF6 alternative. From AC discharge experiment in an quasi-uniform field, it was found that the optimal N2/O2 mixing ratio which breakdown voltage and surface flashover voltage were the highest was 70/30 and that the pressure dependence on the breakdown voltage was higher than that of the surface flashover voltage in the Dry Air/O2 and the N2/O2 mixture gas. The mixing ratio (70/30) and the tendency of the pressure dependence were described in detail based on physical factors (impact ionization coefficient, electron attachment coefficient, secondary electron emission coefficient) involved in discharge mechanism and a electron source, respectively. In addition, the performance insulation and the economic feasibility of the Dry Air/O2 and the N2/O2 mixture gas were discussed so that Dry Air/O2 mixture gaswas more suitable than N2/O2 mixture gas to the SF6 alternative.