Experimental Study on the Extinction Characteristics of Secondary Arc Under Different Secondary Arc Currents Near Outdoor Insulator

On the transmission lines, the secondary arc is the arc that remains at the fault point after the short-circuit current is interrupted, which may pose a threat to the stable operation of the power system. In this article, the extinction characteristics of secondary arc near an outdoor insulator under different secondary arc currents are studied experimentally. The secondary arc has different extinction characteristics under different secondary arc currents of 10, 30, and 50 A. The arcing time, length, morphology, diameter, and breakdown voltage of secondary arc are discussed. Experimental results show that, with the increase in the secondary arc current, the arcing time also increases. The development of the secondary arc has stage characteristics. The length of the secondary arc increases steadily in the first stage and fluctuates greatly in the second stage. In addition, during the single discharge in the second stage, the morphology of the secondary arc will change significantly. The breakdown voltage of the upper electrode in the negative polarity is higher than that in the positive polarity, and it is found that this polarity effect is related to the motion of the secondary arc in space. The research results could provide some reference for investigating the physical characteristics and suppression measures of secondary arc.