Thermoelectric Coupling Characteristics of 1100kV GIS/GIL Basin Insulators Under AC and DC Voltage

The basin insulator is key element of gas-insulated metal-enclosed switchgear (GIS) and transmission lines (GIL), the material properties and geometry directly affects the electric field distribution in the apparatus, further affecting its insulating properties. The insulator in operation is affected by the heating of the conductor and the external environment, and has a large temperature gradient. The dielectric constant and conductivity of the insulating material are different at different temperatures, which affects the electric field distribution. In this paper, the dielectric constant and electrical conductivity of insulating materials are measured as a function of temperature, and the factors such as the transport and diffusion of charged particles in the gas space under DC voltage and the accumulation of surface charges on insulators are considered. A temperature-coupled AC / DC electric field simulation model was established to analyze the distribution characteristics of the electric field of the basin insulator under extreme temperature conditions. This study provides a theoretical basis for the optimization and design of the insulation characteristics of GIS / GIL equipment.