Simulation Analysis of DC Arc Extinguishing Characteristics of Arcing Horn

Due to Direct Current (DC) has no periodic zero crossing, the arc is difficult to extinguish by itself. To prevent grounding insulator surface flashover, a protective gap is set on the grounding insulator. The Claw arcing horns are one of the protection gap devices and produce DC arc. In this study, the simulation model of Claw arcing horns is established, based on the Magneto Hydro Dynamics (MHD) theory. The arc development characteristics are analyzed, which is of maximum temperature and the corresponding time. The simulation results show that the minimum distance of its installation gap and the material of its electrode have a great influence on the DC arc. When the gap minimum distance between the gaps of its electrodes increases, the temperature of arc changes regularly. The minimum gap distance for this model is 3.5 mm. And the Claw arcing horns are made of copper, which is conducive to arc extinguishing. This study has guiding significance for the structural design and material selection of the arc extinguishing horn in DC grounding system.