Improving the accuracy of synchrophasor-based overhead line impedance measurement

Knowledge of real-time impedance parameters of overhead lines can significantly enhance power system monitoring and control applications such as dynamic line rating and fault location. To ensure high accuracy of the determined parameters, methods for error detection and correction are required. In this paper the impact and correction of systematic errors in the voltage phasors are considered and corrected using an optimization procedure. The effectiveness of the proposed method was demonstrated in a case study involving a laboratory-based overhead line model. In contrast to a least squares-based estimator, a significant improvement in the impedance parameter accuracy was achieved, even when only phasor measurements from similar loading conditions were used.