Simulation and Analysis of Internal Arc Plasma Motion in GIL based on Magnetohydrodynamics Model

This paper aims at internal arc plasma motion in alternating current in Gas insulated transmission lines (GIL). By establishing 2D internal arc plasma simulation model based on magnetohydrodynamics (MHD), the characteristics of arc plasma motion is revealed in GIL. The arc motion process can be visually studied and analyzed by the computing the distribution of temperature field of arc plasma. Besides, the influence of different alternating current at power frequency on arc motion and shape is investigated. Furthermore, regarding the position of maximum temperature around the junction of the arc plasma with the inner conductor or outer enclosure as arc root, the speeds of arc roots are obtained. The simulation result of arc root speed is compared with the experimental data under the same condition and the model have been effectively verified. The arc plasma motion characteristics is discussed and the temperature distribution, plasma shape and speed of arc plasma motion is analyzed. The speed and temperature of arc plasma are positively correlated with the current level. The overall speed of arc plasma motion ranges from 4m/s to 9m/s and the speed of arc root on inner conductor is higher than arc root on outer enclosure. At the same current level, the arc speed is almost unchanged, the plasma become bow shape when arc plasma motion. However, the speed of arc increases and the bow shape is more difficult to be formed with the current level increases.