Relationship Between Electric Field Distribution Computation and Insulation Performance of GIS Spacer

GIS spacer is very important insulating part in GIS. In actual operation, the insulation performance of GIS spacer is closely related to the electric field distribution. This paper starts with the analysis of the accident of GIS spacer. The component analysis of the ablation products and fault gas has been done. The analysis results show that the local high electric field leads to the flash-over large current, the high temperature caused the ablation of the GIS spacer surface and SF6 gas composition. Based on this, through the theoretical analysis method, the theoretical explanation of the local high electric field strength is explained from three kinds of defects which are the metal chips, metal protrusion and air bubbles inside the insulating medium, and the local field strength enhancement factor has been got. Then the three-dimensional electric field simulation model of the GIS spacer has been built, the electric field distribution law has been got. It found that the surface field strength distribution of the spacer is not uniform. The local field intensity concentration is easy to form near the center conductor. The shielding measures should be strengthened in the GIS spacer design. The research results of this paper have certain theoretical and guiding significance for the insulation structure design of the GIS spacer and the field monitoring and maintenance of the GIS equipment.