Avaliação de algoritmos numéricos de proteção para linhas com compensação série

Abstract

This work is focused on the analysis of numerical protection algorithms applied to transmission lines with series compensation. Particularly, the analysis tries to evaluate the behavior of distance and line differential protection relay algorithms. Initially, the work describes the main topics related to the numerical algorithms for the protection of transmission lines, with some initial historical background revision of the main papers developed in this area of knowledge. After that, the work describes in a special way the line protection with series capacitors, presenting typical arrangements of such installations, the protection of the series capacitors and the challenges of such elements for the line protection relays. Following we have simulations and evaluations of some of these algorithms in the presence of series capacitors for transmission lines. For such analysis, computational routines were developed in Matlab/Simulink, which allow either electromagnetic transient simulations as well as to evaluate the behavior of protection algorithms for different types of faults. The simulation of the distance algorithm routines is based on two different techniques: the Discrete Fourier Filter for one cycle and the filter based on the differential equation model. For the simulation of the line differential algorithm two different approaches were considered as well: line differential algorithm in the Cartesian plan and line differential algorithm in the alpha plan. These algorithms, for comparison reasons, were initially evaluated for transmission lines without series capacitors installed, and after evaluated with the addition of the series capacitors to the same power system model used for the initial simulations. In the end, future developments subjects are mentioned, as well as suggestions for other types of analysis that can contribute for the better understanding of the techniques here presented.