Simulation and Analysis on Motion Behavior of Metal Particles in AC GIL

Metal particle contamination can seriously affect the reliability of gas-insulated metal enclose transmission line (GIL) and cause insulation failure. In this article, we investigate the metal particle motion patterns based on the entity model of GIL by using finite element simulation. Analysis of motion characteristics of metal particles at different GIL locations is presented based on the charged mechanism and dynamic equation. The impacts of particle attributes, applied voltage, and shielding electrode on motion characteristics are studied. It is found that under ac voltage, the metal particles on the concave and convex sides basically move toward the insulation components. When the metal attributes are different, the size and density of particles dominate the motion pattern under the same voltage. The research observations also indicate that a higher value of applied voltage facilitates the particle to reach the insulator surface while a higher frequency inhibits the particle movement and increases the number of collisions at the ground electrode. Furthermore, the shielding shape affects the electric field distribution, which in turn changes the motion characteristics of particles. Accordingly, the strategy of voltage withstand test and the improved scheme of particle collector are discussed and suggested. This work provides a valuable basis and reference for metal particle control and will guide the design of particle collectors in ac GIL.