Experimental Study on Insulation Coordination of Arcing Horns on HVDC Electrode Lines

In this paper, the insulation coordination of arcing horns on the electrode lines of a 5000 MW, ±800 kV HVDC system have been analysed. Experiments have been carried out to study the arc extinction characteristic of arcing horns. The discharge gap length of the arcing horns is from 400 mm to 1500 mm. A pulse-wave generator is chosen as the power supply. The maximum output pulse width is 70 ms, and the peak current is 2500 A. In order to investigate the fault clearing efficiency of the arcing horns, dynamic U-I characteristic method is introduced. The influences of line parameters and arc elongation are analysed in detail as well. The results indicate that the arcing horns have limited fault clearing efficiency, especially on long distance and high capacity HVDC electrode lines. The fault…