Supplementary Impedance-Based Fault-Location Algorithm for Series-Compensated Lines

This paper presents a new impedance-based supplementary fault-location algorithm for series capacitor-compensated transmission lines (SCCTLs), which improves the accuracy of the existing fault-location algorithms. The proposed algorithm utilizes the fact that the metal-oxide varistor (MOV) may become bypassed in faulted or all phases before the interruption of fault for certain fault scenarios. The removal of the nonlinear element, that is, MOV from the fault loop enables the proposed algorithm to provide more accurate fault-location results compared to the most advanced impedance-based technique. Another major advantage of the proposed algorithm is that the dedicated subroutines are not required for the location of a fault in a particular section of the transmission line. The proposed fault-location algorithm is rigorously tested for various fault scenarios in the 500-kV SCCTL simulated in PSCAD. The performance of the proposed algorithm is compared to a well-known existing impedance-based fault-location algorithm for SCCTLs to illustrate higher accuracy and improved sensitivity of the proposed technique.