Simulation analysis of cathodic ablation under the arcing action of vacuum rotary contacts

Abstract

During the breaking process of the switchgear, a rotational movement of 1-10 degrees per millisecond is added to the contacts. Allowing for more even distribution of arc energy affects the cathodic ablation process. The cathode ablation process under the action of a vacuum rotary contact arc and the effect of rotary motion on the cathode surface are studied during arc ignition in a vacuum metal vapour arc in the paper. A three-dimensional (3D) cathodic ablation transient model with contact rotation characteristics is developed by considering the effects of arc pressure and the Marangoni effect, combined with the hydrodynamic equations and heat transfer equations. Based on a 3D transient model, the action of the arc on the cathode surface is compared and analyzed for different modes of contact movement. The results show that there is a lower cathode surface temperature, a smaller melt zone and a smaller ablation volume by the contact rotation method.