Study on identification methodology of instantaneous and permanent fault for high-voltage overhead transmission line

Identification of instantaneous and permanent faults for transmission line is a problem that needs to be solved urgently for the power system. This paper presents an identification methodology which can recognize instantaneous and permanent faults occurring on overhead transmission lines effectively. This methodology regards the transient voltage and current resulting from faults as signal sources, makes the transient voltage and current decomposed into a series of harmonics and constructs criterion function depending on transient voltage and current. The proposed identification methodology can avoid the reclosure operation caused by permanent faults, and it is of benefit to security, stability and economic operation of power system.