Electric Field Control and Metal Particle Suppression by Structure Optimization of DC-GIL Spacer

Metal particles are inevitably generated in gas insulated transmission lines, which are charged and tend to move towards the spacer under DC voltage, leading to partial discharges and flashover failures. The electric field plays a dominant role in the motion behavior of metal particles, which is influenced by the geometric structure of spacers. This paper proposes a geometric optimization method for DC GIL spacers, designed to control metal particles motion by regulating electric field forces, thereby repelling particles from the spacer. Results show that spacer with superior structure has excellent inhibition effect of metal particles adsorption. Compared with the initial spacer, the scope of absorption area of the optimized spacer narrows by 12.05 % and 100 % at convex and concave side, respectively. The method avoids traditional issues like field distortion, offering a workable solution for GIL insulation improvement. The geometric optimization method offers a practical solution for the treatment of metal particle contamination in HVDC GIL.