Modified Empirical Mode Decomposition and Teager–Kaiser Energy Operator-Based Phasor Estimation in Presence of DC Offset for Digital Relaying Application
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Conventional discrete Fourier transform algorithm which is commonly used for phasor estimation in digital protective relays exhibits large estimation error and long convergence time in presence of exponentially decreasing DC components. This paper presents an efficient algorithm for phasor estimation using a modified empirical mode decomposition and Teager–Kaiser energy operator. The knot-based empirical mode decomposition efficiently separates the decreasing DC component from the signal and the Teager–Kaiser energy operator estimates the amplitude with minimum delay. The performance is evaluated using an ideal signal with double decreasing dc component generated in MATLAB and fault signals from a 66 kV transmission line model created in Simulink. Simulation results show promising results in terms of estimation accuracy and convergence time as compared to the Fourier transform-based method. Because of low-computational complexity, higher accuracy and satisfactory convergence time, this method is practicable and proficient for fast digital relaying applications.
KeywordsPhasor estimation Empirical mode decomposition Knot-based empirical mode decomposition Teager–Kaiser energy operator Hilbert transform
- 7.Huang, N.E., Shen, Z., Long, S.R., Wu, M.C., Shih, H.H., Zheng, Q., Yen, N.-C., Tung, C.C., Liu, H.H.: The empirical mode decomposition and thehilbert spectrum for nonlinear and non-stationary time series analysis. Proc. R. Soc. Lond. A: Math. Phys. Eng. Sci. 454(1971), 903–995 (1998)MathSciNetzbMATHCrossRefGoogle Scholar
- 10.Kaiser, J.F.: On a simple algorithm to calculate the ‘energy’ of a signal. In: International Conference on Acoustics, Speech, and Signal Processing, vol. 1, pp. 381–338 (1990)Google Scholar
- 12.Horowitz, S.H., Phadke, A.G.: Power System Relaying, p. 56. Research Studies Press, Taunton, UK (1992)Google Scholar