Método analítico para localização de faltas monofásicas em sistemas de distribuição

Abstract

Electric power distribution systems have become increasingly larger and more complex due to the continued growth of demand in rural and urban centers. Thus, good practices of operation and maintenance are necessary to improve energy quality. Among these activities, those related to the detection, location and elimination of faults in the distribution systems are of great importance. Faults are frequent disturbances in the systems and result in losses and dissatisfaction from consumers and fines for utilities. To contribute to these activities, we highlight the studies of efficient methodologies for fault location, which seek to assist engineers and technicians to perform fault location more quickly and more accurately. In view of the importance of the theme, the present work aims to develop a method that aims to locate high impedance faults (HIFs) in distribution systems. The method is based on the use of the zero sequence component of the current circulating in the medium voltage feeders of the system, which are obtained from phasorial meters positioned along the feeder. For the simulations, the software PSCAD® was used and three systems were simulated, including the IEEE 34 bus system, which was modified so that specific characteristics of real distribution networks could be simulated and the method verified. In this system, load variation, mutual inductances between feeder cables, unbalanced loads, capacitor banks and voltage regulators were included. A focus on single-phase faults was given, considering that this is the most recurrent type of short-circuit in these networks. The results show high precision and robustness of the method.