Fast adaptive reclosing in double-circuit transmission lines for improving power system stability based on harmonic analysis scheme

Abstract

An appropriate method is proposed for identifying permanent faults from transient faults in double-circuittransmission lines. This method could be used in adaptive single phase auto-reclosures in order to diagnose betweenpermanent and transient faults, determine extinguishing time of the secondary arc, and calculate issuing time of reclosingcommands during the occurrence of transient single phase to ground faults. The proposed method is based on harmonicanalysis of the adjacent healthy circuit and could be an effective solution for blocking permanent disconnection of thepower flow, improving stability, and maintaining the power network synchronism. In this paper, transient and permanentfaults are simulated on a typical power system, and then current harmonics of the healthy circuit terminal are extractedand finally the proposed index for identifying the fault type is applied. In the case of transient faults, this methoddetermines the minimum time needed for a fast successful adaptive reclosing in the network and thus prevents instabilityand nonsynchronism in both sides of the transmission line. Results of the various simulations run in EMTP-RV verifiesaccurate performance of the proposed approach.