Computation of secondary arc current on double-circuit EHV line employing single-pole switching

Successful selective-pole switching (SPS) of faulted extra high voltage (EHV) transmission lines depends on rapid secondary arc extinction. Two factors which govern the probability of secondary arc extinction are the effective value of the steady-state secondary arc current and the rate of rise of the recovery voltage. Successful application of SPS requires keeping the magnitude of the secondary arc current below a certain level. The purpose of this research is to present a method for the computation of the effective value of the secondary arc current on a double-circuit transmission line employing SPS. The model developed for the double-circuit line takes into account the mutual coupling between the two individual circuits. A typical 400 kV double-circuit line is considered and the effective value of the secondary arc current is evaluated for both transposed and untransposed configurations of the line. A comparison with the results available from simple network analysis is made