SF6와 SF6/CO2 혼합기체 중에서의 뇌임펄스 전구방전의 특성

초록

This paper describes the experimental results of the pre-breakdown phenomena in SF6/CO2 mixtures under non-uniform electric fields caused by positive and negative lightning impulse voltages. SF6/CO2 mixtures have an advantage of an environmental aspect and cost reduction, and safety aspects. In order to analyze the pre-breakdown processes in SF6/CO2 mixtures stressed by impulse voltages, pre-breakdown current and luminous signals were measured by a shunt and a photo-multiplier tube, respectively. Dielectric strengthes of SF6/CO2 mixtures were investigated. Additionally, characteristics of discharge channels were observed by high speed cameras and the physical properties were discussed. The pre-breakdown propagates with a stepwise process. The time to breakdown from the corona onset point in positive polarity was shorter than that in negative polarity. The time intervals of positive leaders are shorter than those of negative leaders, and the path of positive leader channel is zigzag