191 / 2022-03-14 16:31:23

Analysis of Arc Motion in a Convergent Expansion Arc-extinguishing Chamber

MHD,arc motion,arc-extinguishing chamber,convergent expansion structure

Lightning strikes on transmission lines lead to insulator flashover to form a ground fault, which endangers the stable operation of 10 kV distribution network in mountainous areas. The fault arcs of transmission lines struck by lightning can be effectively extinguished by multi-cavity arc-extinguishing gap connected in series with several arc-extinguishing chambers. It is important to optimize the structure of arc-extinguishing chamber for improving the performance of quenching arc and reducing the lightning trip-out rate. In this paper, based on the theory of magnetohydrodynamics(MHD), according to the three conservation laws and the characteristic relationship between electric field, magnetic field, arc motion and airflow state, the two-dimensional arc model is established by using the COMSOL Multiphysics simulation software, and the arc quenching process of the convergent expansion structure and the tube structure arc quenching chamber is simulated and analyzed. Simulation results show the motion of arc plasma in different chamber structures. The motion characteristics are characterized by arcing speed, and the results indicate that the convergent expansion structure improves arc plasma velocity distribution in the chamber and accelerates arc motion, then shortens the extinguishing time. It is significant to optimize the structure of the chamber.