Fault location on two-terminal transmission lines based on voltages

Abstract

A new method for locating faults in two-terminal transmission lines is discussed. The procedure is based on the fundamental components of fault and prefault voltage at 50/60 Hz measured at the two ends of a transmission line. The methodology allows one to establish a direct calculation procedure that is independent of fault and prefault currents, fault type, fault resistance, synchronisation condition of register devices located on line ends, and prefault condition, either balanced or not. This is achieved by defining a new concept called ‘distance factor’. The technique developed was validated at two levels: first, from exact data obtained using a fault simulation software program, which allows the accuracy to be evaluated, and secondly, from erroneous voltage data taken at the ends of the line or from erroneous source impedances, which allows assessment of the sensitivity against incorrect data.