Electric Field Characteristics Inside Three-phase Gas Insulated Switchgear in the Presence of Foreign Metallic Particle

Abstract

Abstract Three-phase equipment differs from single-phase equipment in two aspects: configuration and applied voltage. In this paper the effects of these differences on electric field in the presence of foreign metallic particle in three-phase GIS are reported. The electric field characteristic in three-phase GIS is different from that in single-phase one. There are periodic changes in the electric field magnitude and direction produced by three-phase voltage at any point. While the voltage phase varies, the electric field vector changes and rotates continuously. The rotating characteristics of the electric field vector in three-phase power apparatus depended on the position inside the insulation of the tank. The electric field vector locus is circular, elliptic, or linear. The elliptical nature of rotating electric field is expressed as electric field ratio. The presence of foreign metallic particle increases significantly the maximum electric field on the particle tip, but its effect on minimum electric field is not significant. The electric field ratio in the presence of particle is lower than one without particle.