Electric Field Simulation of a Voltage Graded Type Insulator for DC GIL

Electric charge will accumulate on the GIL (gasinsulated metal-enclosed transmission line) insulator under DC voltage, which will distort the electric field distribution at the solid-gas interface and cause the flashover voltage to drop. It is the main reason that hinders the application of DC GIL. A study on the optimization of insulator structure in DC GIL was carried out and a voltage graded type insulator is proposed. The insulator is similar to a bushing core, which uses multiple layers of electrodes to clamp the potential in the insulator, and regulates the electric field distribution on the insulator surface. The electric field simulation analysis proves that the insulator meets the design requirements.