Optimal fault location algorithm for series-compensated transmission lines based on PMU data

Abstract

A new synchrophasor-based fault location algorithm for series-compensated transmission lines is presented in this paper. Both prefault and fault voltage and current phasors associated with either ends of a given line accessible through the phasor measurement units (PMUs) are taken as input data. The proposed algorithm initially estimates the line parameters using prefault data; thereafter, these parameters are used for estimating the fault location. This method is based on the positive-sequence equivalent π models of transmission lines, and since PMU can measure prefault and fault positivesequence data in both symmetrical and unsymmetrical conditions, the method is applicable to all types of faults. The nonlinear weighted least square error (NWLSE) as a powerful method for tackling nonlinear estimation problem is used for the estimation process. Numerical case studies using MATLAB program demonstrate effectiveness of the new method.