Dynamic secondary arc analysis and simulation research under different line model

In the extra high voltage (EHV) transmission system, the transient single-phase to ground faults are the most frequent to occur. Even after the opening of breakers in the two sides of the fault line, an induced current still exists in the arc because of the electrostatic and the electromagnetic coupling from the other two sound phases. Along with the enhancement of the voltage grade, the influence of the secondary arc becomes more and more, and may probably lead to the failure of the reclosing if the secondary arc is not extinguished promptly. In this paper, the dynamic secondary arc model (including recovery voltage and the secondary arc current) in single-phase asymmetric breaking is established based on the distribution parameters of EHV long-line. The method of twice-mode transformation is adopted to calculate the steady-state value of the secondary arc current and recovery voltage. Furthermore, the affects of different overhead line models on the secondary arc current are also analyzed through the real time digital simulation.