Analysis of secondary arc extinction characteristics on UHV line

This paper presents the mechanism theory of secondary arc current generated in ultra-high-voltage (UHV) power transmission system and main suppressing method. The mathematic representations of recovery voltage and secondary arc current can be drawn by circuit principle. Utilizing MATLAB to write the program, the values of recovery voltage and secondary arc current can be obtained. It can simulate the whole circuit by SIMULINK and gets the waveforms of them. The effect of secondary arc suppression at the time when the high speed grounding switch (HSGS) is adopted is studied. The mechanism of secondary arc restriction by HSGS is analyzed. The magnitudes of the secondary arc current and recovery voltage in arc path are obviously reduced after installing HSGS on line. That in turn reduces the extinction time of the secondary arc and assures successful single-phase auto-reclosing.