Resumo:
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.
