A method for internal and external fault discrimination for protection of series compensated double-circuit line

This paper presents a new method designated for determination whether detected fault is placed on a protected double-circuit line or outside the line. It suits for protection of parallel uncompensated or series-compensated lines and uses one-end phase currents measurements only. The developed algorithm has been tested and evaluated using signals taken from ATP-EMTP versatile simulations. A detailed model of considered transmission line including the SCs&MOVs banks as well as the measurement channels has been developed. Using this model, the reliable fault data on a double-circuit uncompensated/series-compensated transmission line as well as for faults outside the line have been generated under variety of fault conditions. The sample results of this evaluation are presented and discussed.