A new technique, based on voltages, for fault location on three-terminal transmission lines

A new method for fault location on three-terminal transmission lines is described in this paper. Through this method, the faulty line branch is determined and the fault point located in a reliable and simple manner. For this, to reduce mathematical errors, a complete line model including the various characteristics of the network is used and a simple calculation method is applied, based on a new concept referred to as the ‘branch factor’. The method only uses the main components (50/60 Hz) of fault and prefault voltage values measured at the three terminals of the transmission line. Moreover, this method is independent of the fault and prefault current, type of fault and fault resistance, as well as the synchronization of recording devices located at the three terminals of the transmission line, and the prefault conditions. This paper also reviews the sensitivity of this method to errors in input data.