Proteção de linhas de transmissão de corrente alternada baseada em ondas viajantes utilizando um terminal

Abstract

In this work, the traveling wave protection principles are investigated and two oneterminal transmission line protection method based on traveling waves are proposed. The first method is dependent of the first wave reflection, whereas the second one is based on modal waves detections and does not require wave reflections, however, is valid only to earth-faults. The effect of the sampling frequency on the protection is considered, what until then has not yet been investigated for one-terminal methods. In contrast to the high sampling frequencies normally adopted in one-terminal-based methods, procedures for determining the minimum sampling frequency are defined. In addition, classical problems inherent to protection based on traveling waves, such as the occurrence of faults near the line terminals and the estimation of the waves velocity, are detailed equated and solutions to such problems are presented. The methods were evaluated by means of computational simulations and the results show that they have an operation time far below the conventional methods. They also demonstrate that the method based on the wave reflections, despite the good results obtained, can present difficulties for its application, since it depends on the correct detection of the wave reflected in the fault point, since the method based on modal waves is reliable, but applicable only to earth-faults.