Data acquisition in power systems and its digital processing for measurement and automation

This paper presents results of comparison of magnitude spectrum estimation of periodical signals by Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT) and special Finite Impulse Response (FIR) filters, with other methods of spectrum analysis, based on DFT/FFT and sample interpolation in time domain (resampling). All of compared methods use a preliminary accurate estimation of the actual power line frequency, so that a difference between them is determined only by intermediate sample processing, which eliminates leakage-related errors appearing because of desynchronization between signal and sample frequencies. Different aspects of real time application of the proposed method are also discussed.

[1]  A. T. Johns,et al.  A new numeric technique for high-speed evaluation of power system frequency , 1994 .

[2]  Zhongxing Geng,et al.  The algorithm of interpolating windowed FFT for harmonic analysis of electric power system , 2001 .

[3]  Chih-Wen Liu,et al.  A precise calculation of power system frequency and phasor , 2000 .

[4]  T. Grandke.  Interpolation Algorithms for Discrete Fourier Transforms of Weighted Signals , 1983, IEEE Transactions on Instrumentation and Measurement.

[5]  L. Asnin,et al.  A new numeric technique of accurate frequency and harmonics estimation for power system protection and power quality applications , 2002, 10th International Conference on Harmonics and Quality of Power. Proceedings (Cat. No.02EX630).

[6]  D. Kottick,et al.  Comparison of Methods and Algorithms for Accurate Frequency Trend Estimation Following Emergency Transients in Power Systems , 1993, Proceedings. Joint International Power Conference Athens Power Tech,.

[7]  V. Backmutsky,et al.  Simple weight-integrating A/D converters with high noise rejection , 1994 .

[8]  L. Asnin,et al.  DSP methods for dynamic estimation of frequency and magnitude parameters in power system transients , 2001, 2001 IEEE Porto Power Tech Proceedings (Cat. No.01EX502).

[9]  Tarlochan S. Sidhu,et al.  Accurate measurement of power system frequency using a digital signal processing technique , 1999, IEEE Trans. Instrum. Meas..

[10]  V. Backmutsky,et al.  A new DSP method for precise dynamic measurement of the actual power-line frequency and its data acquisition applications , 1996 .

[11]  V. Backmutsky,et al.  New DSP method for investigating dynamic behavior of Power Systems , 1999 .