Relays installed to protect transmission lines have current inputs, which take phase currents via CTs. Almost all modern numerical relays are equipped with “Fault Recording” function to record the phase currents and/or voltages in the event of a power system fault. Recorded samples have valuable data about the fault location. This paper presents a novel fault location algorithm, which utilizes only current samples recorded by the relay in the one terminal. Recorded samples will be compared with the waveforms, which are generated by simulation of various conditions of the fault. Various conditions include different fault locations, fault resistances and equivalent models of the source. Using PSO algorithm, the best configuration that has the highest matching between sampled data and simulated waveforms is specified as the fault condition. As a result, the fault location is determined with nearly no computational error. Extensive simulations carried out in SimPowerSystem toolbox of MATALB software confirm capability and accuracy of proposed method.

Keywords