DocumentCode :
759652
Title :
A new half-cycle phasor estimation algorithm
Author :
Sidhu, Tarlochan S. ; Zhang, Xudong ; Balamourougan, Vinayagam
Author_Institution :
Univ. of Western Ontario, London, Ont., Canada
Volume :
20
Issue :
2
fYear :
2005
fDate :
4/1/2005 12:00:00 AM
Firstpage :
1299
Lastpage :
1305
Abstract :
Phasor estimation algorithms for protective relaying are required to filter out unwanted components from the input signals and retain only the components of interest. The components to be removed include harmonics and the decaying-exponential transient (dc offset) component. They affect the accuracy and the speed of convergence of the phasor estimation algorithms to a great extent. This paper presents a new technique, which effectively removes the harmonics and the decaying dc component present in the input signals, within half a cycle of the power system frequency. This is achieved by means of a simple computational procedure using three off-line look-up tables. The proposed algorithm has been tested for a wide variety of signals to assess its performance. The performance is also compared with the two most popular half-cycle phasor estimation algorithms; the half-cycle least error squares algorithms and the mimic plus half-cycle Fourier algorithm. The test results show that the proposed relaying algorithm has a faster convergence and better accuracy compared to these previously proposed algorithms. The results also indicate that the proposed algorithm converges to its final value within half a cycle of the power system frequency as compared to the other two algorithms, which take more than half a cycle to converge, when a decaying dc component is present in the input.
Keywords :
convergence of numerical methods; digital filters; filtering theory; least squares approximations; phase estimation; power system faults; power system protection; relay protection; table lookup; convergence speed; decaying-exponential transient component removal; digital filters; half-cycle least error squares algorithms; half-cycle phasor estimation algorithm; harmonics removal; mimic filters; mimic plus half-cycle Fourier algorithm; off-line look-up tables; power system frequency; protective relaying; Convergence; Digital filters; Frequency; Power harmonic filters; Power system faults; Power system harmonics; Power system interconnection; Power system protection; Power system relaying; Protective relaying; DFT; digital filtering; least error squares algorithm; mimic filters;
fLanguage :
English
Journal_Title :
Power Delivery, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-8977
Type :
jour
DOI :
10.1109/TPWRD.2004.834677
Filename :
1413393
Link To Document :
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