$SF_6-N_2$ 혼합가스의 정.부극성 뇌충격전압에 대한 50% FOV와 V-t 특성

50% Flashover Voltage and V-t Characteristics for $SF_6-N_2$ Mixtures under Positive & Negative Ligtning Impulse Voltage

Sulphur-hexafluoride has extensively been used as an insulating gas of electric power equipment in substation for its high dielectric strength, non-toixity and non-flammable properties. But it is very expensive and is liquidizable under the condition of low temperature and high pressure. And it is very sensible to the locally high electric field strength. To resolve these problems, we studied 50% FOV and V-t characteristics of $SF_6-N_2$ mixtures under positive and negative lightning impulses using a 25mm rod-plane gap. 50% FOV of $SF_6-N_2$ 50% mixture was about 85% of pure $SF_6$ and it was known that $SF_6-N_2$ mixtures can be used as an economic substitution insulating gas for $SF_6$.