Space charge characteristics of multiple reigniting secondary arc in atmospheric air

In order to investigate the electrical characteristics and the morphologic development of secondary arc in atmospheric air, a simulative experimental platform of secondary arc for UHV transmission lines was built and the corresponding experimental procedure was introduced in this paper. The discharge waveforms were categorized into three stages: the short-circuit arc period, the transition period of short-circuit arc and the secondary arc, as well as the secondary arc period. And the electrical characteristics of each stage were analyzed, involved with discharge power and discharge energy. By observing the arc discharge images, the forming process and the multiple reignition phenomenon of secondary arc were displayed and analyzed in associated with the corresponding discharge waveforms. A short-cutting event of the plasma column may happen when suddenly a new, shorter current path forms and the former arc path gradually disappears because of larger arc resistance. It was also found that the arc length and the arc diameter in the experiment were consistent to the computational values. The research results present analytical basis and theoretical reference for explanation and suppression of secondary arc on UHV transmission lines.