Study on Movement and Distribution Characteristics of Metal Particle Dust in DC GIL

Abstract

Gas-insulated transmission lines (GILs) have a wide application prospect in special occasions such as cross-terrain power transmission. Metal particle contamination is an important reason for low insulation performance of GIL. To better suppress metal particle contamination, it is necessary to master the motion characteristics of metal particles. Based on that, this article took the metal particle dust (MPD), which is common in engineering, as the research object. The boundary element method (BEM) was introduced, and the boundary integral equations (BIEs) of multimedia domain Poisson equation in 3-D were given. The electric field distribution considering charged particles was obtained. Then the motion model of MPD was established. Combined with experiments, the movement and distribution characteristics of MPD in direct-current (dc) GIL were studied. The results show that the randomness of MPD movement in dc GIL is strong, and near the ground, MPD presents a “sandstorm” movement. Second, due to the influence of charged metal particles on electric field distribution, the collision between metal particles, and the randomness of the collision between metal particles and wall, the range of MPD’s motion in the axial direction of GIL chamber is wide, which increases the probability of MPD adhering to the insulator. The adhesion of MPD is more obvious on the convex surface of the insulator near the high-voltage electrode. The above research results can be used to guide the suppression of metal particle contamination in dc GIL.