A Study on Characteristics of Insulation Breakdown and Surface Discharge by the Mixing Ratio of Dry Air/O2 gas mixtures

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

Seok, Jeong-Hoo;Beak, Jong-Hyun;Lim, Dong-Young;Bae, Sungwoo;Kim, Ki-Chai;Park, Won-Zoo

  • Received : 2015.02.17
  • Accepted : 2015.05.13
  • Published : 2015.06.30


This paper presents the discharge characteristics and economic feasibility of a Dry $Air/O_2$ and a $N_2/O_2$ mixture gas in order to review $SF_6$ alternative. From AC discharge experiment in an quasi-uniform field, it was found that the optimal $N_2/O_2$ 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 $Air/O_2$ and the $N_2/O_2$ 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 $Air/O_2$ and the $N_2/O_2$ mixture gas were discussed so that Dry $Air/O_2$ mixture gaswas more suitable than $N_2/O_2$ mixture gas to the $SF_6$ alternative.


Breakdown Voltage;Dry $Air/O_2$ Mixture Gas;$SF_6$;Surface Flashover Voltage


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