불평등전장에서 SF6 기체의 뇌임펄스 절연파괴특성

초록

Abstract - In this paper, the V-p characteristics, the V-t characteristics and the discharge luminous characteristics in inhomogeneous SF6 gas gap under the positive and negative lightning impulse voltages are presented. The test gap was composed of the plane-to-plane with a needle-shaped protrusion. The applied voltage and the prebreakdown current were measured by the electric field sensor and the shunt of 50 Ω, respectively. The light emission signals were observed by a photomultiplier tube. Also, the discharge growth paths were observed by a high-speed camera. In a consequence, the dielectric strengths and time to breakdown of SF6 gas gap under positive lightning impulse voltages were independent of the gas pressure. In the presence of the positive polarity, because the corona stabilization effect was weaker at high gas pressure, the leader could be easily generated. So, the branches of discharge channel were created and the directions of the discharge paths were random. On the other hands, the discharge paths were more thicker and brighter, in the case of the negative polarity.