Fault location method using measurements of differential relays for parallel transmission lines with series capacitor compensation at both ends

This paper presents an accurate fault location algorithm for double-circuit transmission lines with series capacitor compensation at both ends. It has been considered that a fault locator utilizes a communication channel of differential protective relays through it phasors of currents at both line ends are exchanged. Besides the phasors of two-end currents, three-phase voltage measured at a local end and a zero-sequence current from a parallel healthy line circuit have been additionally included into the fault locator input signals. The developed fault location algorithm has been formulated for fault loops composed accordingly to the fault type. The algorithm has been tested and evaluated using signals taken from ATP-EMTP versatile simulations of faults on the test series compensated transmission line. The presented sample results of the evaluation show the validity of the presented fault location algorithm and its high accuracy.