Um novo método de estimação fasorial para uso em relés digitais de proteção.

Abstract

A phasor estimation method is proposed to be used in digital relays for power system protection. It aims to improve the characteristic of filtering out undesirable frequency components of signals, which are introduced during faults and switching events in electric power systems that may compromise the performance of the protection systems. Comparisons are made in relation to time response and frequency response for the proposed method and four phasor estimation methods. In relation to response time are used analytical signals from MATrix LABoratory (MATLAB®) and simulated signals from Alternative Transients Program (ATP). A distance relay was implemented by using the MODELS language in ATP to evaluate the performance of the relay. From some parameters used to evaluate the estimation methods, it was observed that the proposed method shows good results in terms of accuracy and convergence speed, with response time compatible with other methods. The frequency response of the proposed method appears to be more selective than those of the others methods because it presents lower lobes between the harmonics and a narrower pass band around the fundamental frequency. Another advantage of the proposed method is that it can be easily programmed, allowing users to change design parameters according to their needs.