Locus and pattern of electric field vector in the insulation of three-phase gas insulated switchgear

This paper deals with electric field vector characteristics in three-phase gas insulated switchgear (GIS). The electric field in a three-phase construction of a simplified GIS model was analyzed. The results show that the electric field vector varies with phase of applied voltage. While the voltage phase varies in a cycle, the electric field vector changes and rotates continuously. There is no zero electric field in three-phase GIS. The electric field vector locus in the region between conductor and the enclosure is almost linear, resembling a single-phase construction; while ones between conductors have variations: linear, elliptic, circular. The results are compared with the electric field vector in single-phase GIS.