Research on a novel suppressing methodology for secondary arc extinction based on an impedance paralleled to line circuit breaker

Abstract

A novel scheme is proposed for secondary arc extinction, preferably applicable to extra high voltage (EHV) and ultra high voltage (UHV) transmission lines. The topology and the operational principle of the scheme are elucidated in details. Mathematical expressions for topology parameters design and optimization under different conditions have been established based on equivalent circuit transform and are verified by simulations. Results suggest that the proposed methodology can largely reduce the forced component of the secondary arc current, one part of the complete response of a circuit under excitation. The recovery voltage is not affected by fault location, transmission power and the shunt inductors. The decay factor and oscillation frequency of the free components of the secondary arc current and the recovery voltage are also computed based on the equivalent impedance network and Laplace Transform. In addition to causing possible resonant overvoltage, the proposed theme may prolong the arcing time due to cancelling zero-crossing of the secondary arc current while shunt inductors are installed at the transmission line terminals. Simplified formula for calculating the critical compensation point are given as to be used as a reference for the re-optimization of the novel theme. The proposed methodology presents an alternative to suppress the secondary arcs for EHV and UHV transmission lines. Copyright © 2013 John Wiley & Sons, Ltd.