Discharge Characteristics of Liquid $SF_6$ & $N_2$ at Very Low Temperature

극저온화에 따른 액화 $SF_6$ 및 액체질소의 방전특성

This paper describes the discharge characteristics of liquid $SF_6$ (-41$[^{\circ}]$, 1.7[atm]) and $LN_2$ for plane to plane, needle to plane, plane to needle and sphere to plane electrode with gap variations from 1[mm] to 12[mm]. From this result, the breakdown voltage was increased with increasing gap length. Especially, the formation of bubbles by evaporation was observed in spite of non-applying voltage source. A corona is created of the applying voltage from the bubbles on the electrodes applied voltage. We consider it equal mechanism of corona as void exists in solid insulator. The results of liquid $SF_6$ and $LN_2$ discharge characteristics were caused by bubble formed evaporation and applied electric field voltage. Corona was happened to weak bubble and was proceed to new bubble breakdown.