LIMA, H. B.; http://lattes.cnpq.br/6775866140633213; LIMA, Harrison Batista de.
Resumo:
With the development of new devices in power electronics, direct current transmission
is becoming more and more common, and its use is more advantageous in certain
situations than the transmission in alternating current. Based on this importance, it is
proposed to carry out a comparative study between the methods of detecting faults in
direct current transmission lines. The selected methods for comparative study belong to
the group of methods based on the theory of traveling wave. The methods used were
those based on the discrete wavelet transform, the redundant discrete wavelet transform,
the Park transform and a method based on the energy of the signal derivative. The
performances of the methods are compared based on simulations performed via
MATLAB/Simulink of two different configurations of HVDC systems, a monopolar
and a bipolar system. In the analyses to evaluate the performance of the methods, the
fault points, fault type and fault resistance were varied in order to test the robustness of
the methods for high and low impedance faults. In all the evaluated methods, a self-
adaptive threshold for fault detection was applied. From the results it was verified that
the methods that obtained the bests results were those based on the energy of the signal
derivative and the method based on the Park transform. The method based on signal
derivative energy has simpler code, when compared to the method that makes use of the
Park transform, thus performing the detection of faults faster.