Fault location estimator for series compensated transmission line under power oscillation conditions

Abstract

This study proposed a novel fault-location algorithm for a series capacitor (SC) compensated transmission lines under power oscillation conditions. Synchronous voltage and current phasors from both terminals of the transmission line are employed to estimate the fault location while considering the distributed parameter line model. An iterative method is proposed to obtain the voltage across the SC under power oscillation conditions. The fault-location algorithm includes three stages. Firstly, the distributed parameters of the transmission line are estimated by the dynamic parameters estimate method. Secondly, the voltage of the SC can be solved by the iterative method based on the phasor measurements and the transmission line parameters. Finally, the fault location can be attained via Newton iteration method. A 300 km/500 kV transmission compensated by SC simulated in PSCAD/EMTDC has been employed to evaluate the performance of the proposed algorithm under various power oscillation situations. The simulations have demonstrated that the proposed method independent of fault types, fault resistance and fault distances under power oscillation conditions. The accuracy of the proposed algorithm is far higher than that of the conventional fault location algorithms in most cases.