Impedance based fault location method for single phase to earth faults in transmission systems

This paper presents a new impedance based fault location method in the case of single phase to earth faults. This method utilized the measured impedance by distance relay and super imposed current factor, which is the ratio of postfault current to super imposed current, to discriminate the fault position on the line. This method is robust against the fault resistance. The presented method only uses the measured impedance by distance relay, the super imposed current factor and few data which could be achieved through the SCADA based databases.