A Neuro-Fuzzy Approach for the Fault Location Estimation of Unsynchronized Two-Terminal Transmission Lines

Overheadtransmission lineis an element ofelectricalpower systemsthatare most frequentlyexperiencedshort circuitfaultscompared to otherpowersystem elements.Shortcircuitfaultsonoverheadtransmissionline cause a relatively largecurrentandthereforecan damagemechanicallythe electrical equipmentconnected to the system. Theprotection systemis essentially needed in this situation. In addition, it takes apiece ofequipment that can detectthe location offaultin order to expedite the repair process, especially ifthefaultis permanentstate.In this paper, aneuro-fuzzy aprroachfor short circuit fault location estimationwhich uses data from both ends of overhead transmission line is described. Theapproachutilizes theadvantages of digital relaying which are available today.The unsynchronizeddataoffaultvoltagesandcurrentsat two-endofoverheadtransmissionlineis applied in thistechnique.The accuratefault locationestimation technique has irrespective of source impedances, fault resistances, fault types, and loadcurrents.Simulation of short circuitfault of transmission line has done by using EDSA software. Shortcircuit currents and voltagesfromboth ends of overhead transmission linehave used to input data ofneuro-fuzzy method in Matlabprogram.Simulation results demonstrate the accuracy of the method.Theresults shows thatthelowestestimation error for single phase to ground fault with thevariation of faultresistances of0 ohms, 10 ohms, 50 ohms, and 100 ohms, respectively,is0.0027%,whilethehighestestimation erroris0.2962%