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Este trabalho apresenta uma técnica alternativa para a proteção de transformadores de potência utilizando a lógica diferencial associada ao uso de Redes Neurais Artificiais (RNAs). Este artifício é utilizado na distinção entre faltas internas e correntes de inrush, que surgem durante a energização do transformador. O programa EMTP-ATP (Electromagnetic Transients Program) foi escolhido como ferramenta computacional para a simulação do transformador de potência com o objetivo de gerar dados de treinamento e testes para as RNAs. Um programa em linguagem FORTRAN foi implementado a fim de avaliar o algoritmo completo da proteção diferencial e resultados promissores relativos ao novo método foram obtidos.

This work presents the study and development of a combined fault location scheme for three-terminal transmission lines using wavelet transforms (WTs). The methodology is based on the low- and high-frequency components of the transient signals originated from fault situations registered in the terminals of a system. By processing these signals and using the WT, it is possible to determine the time of travelling waves of voltages and/or currents from the fault point to the terminals, as well as estimate the fundamental frequency components. A new approach presents a reliable and accurate fault location scheme combining some different solutions. The main idea is to have a decision routine in order to select which method should be used in each situation presented to the algorithm. The combined algorithm was tested for different fault conditions by simulations using the ATP (Alternative Transients Program) software. The results obtained are promising and demonstrate a highly satisfactory degree of accuracy and reliability of the proposed method.