Motion Characteristics of Metal Powder Particles in AC GIL and Its Trap Design

In view of the threat of metal particles to the insulation performance of AC GIL (Gas insulated transmission line), this paper uses aluminum powder to simulate the metal particles which are closer to the engineering practice, A scaled-down model similar to the actual GIL structure was built to study the movement characteristics of aluminum powder in GIL. The discharge, movement and distribution characteristics of aluminum powder was recorded in experiment. The research shows that the particles from spacer to the part below the shielding should be prevented. The particles with particle size of about 150 mesh move more violently. At the same time, the movement of powder particle in GIL is affected by Van der Waals force. According to the characteristics of particle motion distribution, grid-shaped trap and strip-shaped trap were designed and compared in this paper, and the trap capture coefficient was proposed. Finally, the suggestion of particle trap arrangement is put forward, that is, grid-shaped trap can be set near the spacer, and strip-shaped trap can be selected for the rest of the GIL.