Patent ID: 7286963

Claim:
A method for locating a fault in a network including a three terminal power line, having three line sections located in front of or behind a tap point and a fault locating unit arranged at a first of the three terminals in a first of the three sections, wherein the fault occurs in at least one of the three sections, the method comprising: measuring three phase currents and voltages at the first terminal in the first section; measuring, before the fault occurs, amplitudes of load currents in a second section and a third section of the three sections; storing the measured amplitudes of load currents in the fault locating unit; calculating pre-fault phasors of currents in the second section and the third section from the measured amplitudes of load currents; determining impedance data of the network; and determining a location of the fault by determining a distance to the fault based upon the measured three phase currents and voltages, the pre-fault phasors of currents and the impedance data of the network using a symmetrical components approach.