Directional motion behavior of metallic conductive particles in GIS

Abstract

Currently, metallic conductive particles constitute a significant risk to GIS insulation, and the motion of the particle is the direct cause of GIS insulation failure. The motion characteristic of particles is the key to conducting the study about the mechanism of particle-induced GIS insulation failure and the technology of particle suppression. However, current research lacks an analysis of the axial motion of particles, which should not be ignored. In this paper, the intensity and direction of the axial Coulomb force in the vicinity of the basin insulator are analyzed. Based on this, the relationship between the polarity of the charge on particles and the axial Coulomb force with time under AC voltage is analyzed. The research results show that the axial Coulomb forces on the outwardly and inwardly curved surfaces of the basin insulator have opposite directions so that they can propel the particles in the direction of the outwardly curved surface. Finally, the verification experiment conducted on the 252 kV GIS can also prove that particles indeed have the trend of directional motion under AC voltage, and multiple particles will eventually gather on the outwardly curved surface side. The research provides theoretical support for the motion of metallic particles and the particle suppression technology in GIS.