Use of Fuzzy logic in calculation of short-circuit for locating faults in distribution networks

Traditional methodologies for calculating short-circuit are strongly influenced by the influential parameters of the calculation, among them: Short-circuit power; Resistance and reactance of cables; Fault impedance. The vagueness of these parameters may compromise the setting protection and lead even to a complete lack of protection in some situations. This paper presents a methodology of calculation of the short-circuit electrical currents in primary feeders which is based on the treatment of uncertainties of these parameters by Fuzzy Logic. This methodology was implemented in software whose main application is a fault location module that uses information from the electrical waveform records of events in distribution substations and topology data of primary feeders and their physical parameters.