Comparative analysis of algorithms for elimination of exponentially decaying DC component

• Published in: 2012 19th International Conference on Systems, Signals and Image Processing (IWSSIP) pp. 362 - 367
• Main Authors: Musa, O., Aksamovic, A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.04.2012
• Subjects: Algorithm design and analysis; Approximation algorithms; DC decaying component; digital relaying; discrete Fourier transform (DFT); Discrete Fourier transforms; Estimation; fault current; Fourier algorithm; Frequency estimation; Harmonic analysis; off-nominal frequencies; phasor estimation; Power system harmonics
• ISBN: 1457721910; 9781457721915
• ISSN: 2157-8672

Digital protection systems rely on accurate phasor estimation. When a fault occurs in such systems, fault current contains non-fundamental frequency components and DC component in addition to the fundamental frequency component. A DC component has a significant impact on the performance of the Fourier filter. A lot of different algorithms have been proposed in the past in order to eliminate this component. In this paper, we present a comparative analysis of the selected algorithms. Furthermore, we propose a new algorithm which combines different approaches and exploits their advantages. A performance evaluation of these algorithms is done by using a simple power system network model. Finally, the selected algorithms are compared using following criteria: the speed of convergence of the Fourier algorithm, the impact of non-fundamental frequency components, the impact of off-nominal frequency and computation burden. Our results have shown that the proposed algorithm outperforms previously proposed algorithms under a variety of negative effects encountered in a real power system.