Characteristics of lightning impulse corona discharges under non-uniform electric fields in $SF_6$ and $SF_6/N_2$ mixtures

불평등전장에서 $SF_6$와 $SF_6/N_2$ 혼합기체의 뇌임펄스 전압에 대한 코로나 방전특성

This paper presents an experimental study on the prebreakdown characteristics in $SF_6/N_2$ mixtures under non-uniform electric fields when subjected to the positive and negative lightning impulse voltages. $SF_6/N_2$ mixtures have a merit of an environmental aspect and cost reduction, and safty aspects. In order to analyze the prebreakdown processes in $SF_6/N_2$ mixtures stressed by impulse voltages, prebreakdown current and light were observed by a shunt with high sensitivity and a photo-multiplier tube, respectively. Additionally, characteristics of luminous events in flashovers were discussed.