A Robust Synchrophasor-Based Method for Determining Three-Phase Line Impedance

A new method is developed for synchrophasor-based determination of three-phase transmission line impedance parameters, applicable for both fully transposed and untransposed transmission lines. The method is based on accurate time-synchronised measurements of the voltage and current phasors at both ends of the transmission line. The method estimates the line impedance values using a robust estimator with the desirable property of automatic bad-data rejection as an alternative to ordinary least square estimation. The performance of the estimator has been evaluated using a laboratory setup simulating real power system conditions. The necessary conditions for algorithm convergence as well as requirements for measurement accuracy have been studied as well.