Dielectric Characteristics of SF6 Gas Stressed by VFTO in Inhomogeneous Field

초록

THis paper describes the dielectric characteristics of SF6 gas in a non-uniform electric field under non-oscillating and oscillating impulse voltages.The V-t and V-p characteristics are investigated within a gas pressure range extending from 0.1 to 0.5 [MPa] for the plane electrode system with a needle-shaped protrusion.The curvature radius of the needle protrusion is 0.5 mm.Also, the growth process of the predischarge are ovserved.The dielectic characteristics of SF6 in this work are strongly associated with the predischarge propagation progress.The minimum breakdown voltage of the oscillating impulse voltage in the positive polarity is slightly lower than that of the non-oscillating impulse voltages.The time lag to breakdown at the V-t curve is longer under the oscillating impulse voltages than under the non-oscillating impulse voltages