Dynamic physical characteristics of DC arc on arcing horn for HVDC grounding electrode line

The dynamic physical characteristics of a DC arc on an arcing horn for a high voltage direct current (HVDC) grounding electrode line are significantly different from those of the switching device arc, secondary arc, AC fault arc and pantograph-catenary arc. In this work, an experimental platform for the DC arc on the arcing horn was built, and mechanisms of the arc column short circuit and arc root movement were studied. This work further analyzes the characteristics and mechanisms of the arc motion when wind speed and direction, magnetic field and the expansion angle of the electrode are varied. Arc root movement is more likely to occur at the upper electrode. There is a competitive relationship between arc expansion and the transferring effect. The effect of wind on the arc column is greater than the effect on the arc root. The magnetic field has a significant driving effect on both the arc column and the arc root. The research results provide a comprehensive experimental basis for further probing the method of DC arc suppression, and the improvement of the arcing horn.