Dielectric Characteristics of SF6 Gas under Fast Transient Overvoltage in a Non-uniform Electric Field

초록

This paper describes dielectric characteristics and discharge development mechanism of SF6 gas stressed by fast transient overvoltage in an inhomogeneous electric field.The V-t and V-p characteristics are experimentally investigated with the positive and negative non-oscillating and oscillating impulse voltages.A testing electrode system is coaxal cylindrical electrode geometry with a needle protrusion whose curvature radius is 0.3[mm].Also,the predischarge current is detected with a shunt of 50[Ω].As a result, the dependensce of the V-t and V-p characteristics on the polarity of applied voltage is appreciable and related to the predischarge development mechanisms.The V-p characteristics are more development on the gas pressure in the negative polarity than in the positive polarity.