In order to solve the ablation damage caused by the differences of the electrical properties between the central conductor and basin insulation material

during the operation of UHV GIS spacer

the electric field strength concentration effect at the interface of the spacer was studied in this paper. Firstly

the electric field strength at the interface was taken as the research object

and the finite element simulation was used to analyze the reason why the electric field strength at the interface of the spacer is so concentrated. The method of coating the interfacial material was used to suppress the interfacial electric field concentration effect. Then the model of the spacer coated with interfacial material was established

and the relationship between the electric field strength on both sides of the interfacial coating materials and the parameters relating to the coating material were derived. In addition

the distribution of the electric field intensity on both sides of the interface layer of different interfacial coating materials was obtained. The research results verify the validity of the model and show that

when the thickness of the interface layer is equivalent to the height of the defect

and the relative dielectric constant is greater than 100

the interface layer can better shield the defects on the surface of the conductor. This study can provide a theoretical basis for the design and selection of interfacial coating materials.