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Journal of the Korean Institute of Illuminating and Electrical Installation Engineers

ISO Journal TitleJ Korean Inst. IIIum. Electr. Install. Eng.
Title A Study on Characteristics of Insulation Breakdown and Surface Discharge by the Mixing Ratio of Dry Air/O2 gas mixtures
Authors Jeong-Hoo Seok ; Jong-Hyun Beak ; Dong-Young Lim ; Sungwoo Bae ; Ki-Chai Kim ; Won-Zoo Park
DOI http://dx.doi.org/10.5207/JIEIE.2015.29.6.049
Page pp.49-57
ISSN 1225-1135
Keywords Breakdown Voltage ; Dry Air/O2 Mixture Gas ; SF6 ; Surface Flashover Voltage
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.