Patent ID: 7472026

Claim:
A fault position detection system for a power transmission line having at least two terminals and at least one line segment, the system comprising: a tap common to each of the at least two line segments wherein residual voltage and current values are determined; first means for representing three phase voltages and currents by composite current and voltage signals at each of the at least two terminals; second means for determining which of the line segments of the power transmission line is a faulted line segment containing a fault, using composite voltage and current phasor measurements of the composite current and voltage signals and the residual voltage and current signals at the node; third means for determining a fractional fault location from one terminal of the at least two terminals on the faulted line segment using the composite voltage and current phasor signals and the residual voltage and current values for each line segment at the node; fourth means for determining the position of the fault on the faulted line segment using the fractional fault location and length of the faulted line segment on which the fault is located.