Compensação dinâmica dos transitórios de baixa frequência de transformadores de potencial de capacitivos para otimização da proteção de linhas de transmissão.

Abstract

A new method of numerical correction of the low frequency transients of capacitive potential transformers is presented. The proposed method is based on a simple digital filter that recovers the primary signal shape, whose frequencies are between 10 and 60 Hz, from secondary voltage samples. Unlike the techniques reported in the literature, the method does not depend directly on the transformer topology or operating characteristics of the protected system, since only the frequency response of the capacitive potential transformer is used as input data. The technique is evaluated by digital simulations using real data from the National Interconnected System. Compensation analyzes in the time-frequency domains of four capacitive potential transformers with different voltage levels are presented. The simulations prove that the proposed method is efficient in the dynamic correction of low frequency disturbances, improving the speed, reliability and safety of the numerical distance relay actuation.