Adaptive Frequency Estimation in Smart Grid Applications: Exploiting Noncircularity and Widely Linear Adaptive Estimators

Accurate estimation of system frequency in real time is a prerequisite for the future smart grid, where the generation, loading, and topology will all be dynamically updated. In this article, we introduce a unified framework for the estimation of instantaneous frequency in both balanced and unbalanced conditions in a three-phase system, thus consolidating the existing approaches and providing next-generation solutions capable of joint adaptive frequency estimation and system fault identification. This is achieved by employing recent developments in the statistics of complex variables (augmented statistics) and the associated widely linear models, allowing us to benefit from a rigorous account of varying degrees of noncircularity corresponding to different sources of frequency variations. The advantages of such an approach are illustrated for both balanced and unbalanced conditions, including voltage sags, harmonics and supply-demand mismatch, all major obstacles for accurate frequency estimation in the smart grid.

[1]  Farrokh Albuyeh,et al.  Grid of the future , 2009, IEEE Power and Energy Magazine.

[2]  Danilo P. Mandic,et al.  Complex Valued Nonlinear Adaptive Filters , 2009 .

[3]  Danilo P. Mandic,et al.  The least-mean-magnitude-phase algorithm with applications to communications systems , 2011, 2011 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP).

[4]  Bernard C. Picinbono,et al.  On circularity , 1994, IEEE Trans. Signal Process..

[5]  Tianshu Bi,et al.  Measurements get together , 2009, IEEE Power and Energy Magazine.

[6]  T. Lin,et al.  A wavelet approach to real time estimation of power system frequency , 2001, SICE 2001. Proceedings of the 40th SICE Annual Conference. International Session Papers (IEEE Cat. No.01TH8603).

[7]  Louis L. Scharf,et al.  Second-order analysis of improper complex random vectors and processes , 2003, IEEE Trans. Signal Process..

[8]  M. Akke.  Frequency Estimation by Demodulation of No Complex Signals , 1997, IEEE Power Engineering Review.

[9]  P.N. Enjeti,et al.  Effect of voltage sags on adjustable speed drives-a critical evaluation and an approach to improve its performance , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[10]  Danilo P. Mandic,et al.  Performance analysis of the conventional complex LMS and augmented complex LMS algorithms , 2010, 2010 IEEE International Conference on Acoustics, Speech and Signal Processing.

[11]  Danilo P. Mandic,et al.  THE AUGMENTED COMPLEX LEAST MEAN SQUARE ALGORITHM WITH APPLICATION TO ADAPTIVE PREDICTION PROBLEMS 1 , 2008 .

[12]  Daryn Lehoux,et al.  A mighty wind , 2008, Clinical toxicology.

[13]  V. Eckhardt,et al.  Dynamic measuring of frequency and frequency oscillations in multiphase power systems , 1989 .

[14]  Math Bollen,et al.  Characteristic of voltage dips (sags) in power systems , 2000 .

[15]  Pascal Chevalier,et al.  Widely linear estimation with complex data , 1995, IEEE Trans. Signal Process..

[16]  D. Lineweber,et al.  The Cost of Power Disturbances to Industrial & Digital Economy Companies , 2001 .

[17]  Steven Kay,et al.  Fundamentals Of Statistical Signal Processing , 2001 .

[18]  B. Kroposki,et al.  Sun Also Rises: Planning for Large-Scale Solar Power , 2009 .

[19]  Ganapati Panda,et al.  Frequency estimation of distorted power system signals using extended complex Kalman filter , 1999 .

[20]  D. Mandic,et al.  Complex Valued Nonlinear Adaptive Filters: Noncircularity, Widely Linear and Neural Models , 2009 .

[21]  M. Sachdev,et al.  A Least Error Squares Technique For Determining Power System Frequency , 1985, IEEE Transactions on Power Apparatus and Systems.

[22]  Edith Clarke,et al.  Circuit analysis of A-C power systems , 1950 .

[23]  P.A. Crossley,et al.  Bridging the gap between signal and power , 2009, IEEE Signal Processing Magazine.

[24]  Davood Yazdani,et al.  Robust Adaptive Frequency Estimation of Three-Phase Power Systems , 2010, IEEE Transactions on Instrumentation and Measurement.

[25]  Seppo J. Ovaska,et al.  Digital filtering for robust 50/60 Hz zero-crossing detectors , 1995 .

[26]  Miodrag D. Kusljevic,et al.  Frequency Estimation of Three-Phase Power System Using Weighted-Least-Square Algorithm and Adaptive FIR Filtering , 2010, IEEE Transactions on Instrumentation and Measurement.

[27]  B. Widrow,et al.  The complex LMS algorithm , 1975, Proceedings of the IEEE.

[28]  K. Nam,et al.  Instantaneous phase-angle estimation algorithm under unbalanced voltage-sag conditions , 2000 .

[29]  Donald Beeman.  Industrial power systems handbook , 1955 .

[30]  Esa Ollila,et al.  On the Circularity of a Complex Random Variable , 2008, IEEE Signal Processing Letters.

[31]  Mauricio Aredes,et al.  Analysis and Software Implementation of a Robust Synchronizing PLL Circuit Based on the pq Theory , 2006, IEEE Transactions on Industrial Electronics.

[32]  T.M. Jahns,et al.  Source current harmonic analysis of adjustable speed drives under input voltage unbalance and sag conditions , 2004, IEEE Transactions on Power Delivery.

[33]  Ali H. Sayed,et al.  Least mean-phase adaptive filters with application to communications systems , 2004, IEEE Signal Processing Letters.

[34]  Robert Boorstyn,et al.  Single tone parameter estimation from discrete-time observations , 1974, IEEE Trans. Inf. Theory.

[35]  Math Bollen,et al.  Understanding Power Quality Problems: Voltage Sags and Interruptions , 1999 .

[36]  Danilo P. Mandic,et al.  An adaptive approach for the identification of improper complex signals , 2012, Signal Process..

[37]  Carl H. Hauser,et al.  Smart Generation and Transmission With Coherent, Real-Time Data , 2011, Proceedings of the IEEE.

[38]  B. Kroposki,et al.  The sun also rises , 2009, IEEE Power and Energy Magazine.

[39]  D. Boroyevich,et al.  Decoupled Double Synchronous Reference Frame PLL for Power Converters Control , 2007, IEEE Transactions on Power Electronics.

[40]  C. W. Liu,et al.  A Precise Calculation of Power System Frequency , 2001, IEEE Power Engineering Review.

[41]  A.K. Pradhan,et al.  Power system frequency estimation using least mean square technique , 2005, IEEE Transactions on Power Delivery.

[42]  Danilo P. Mandic,et al.  Widely Linear Adaptive Frequency Estimation of Unbalanced Three-Phase Power Systems , 2012, IEEE Transactions on Instrumentation and Measurement.

[43]  S. Kay.  Fundamentals of statistical signal processing: estimation theory , 1993 .

[44]  S. Grillo,et al.  Impact evaluation of plug-in electric vehicles (PEV) on electric distribution networks , 2010, Proceedings of 14th International Conference on Harmonics and Quality of Power - ICHQP 2010.

[45]  M. H. J. Bollen,et al.  Voltage Sags in Three-Phase Systems , 2001, IEEE Power Engineering Review.

[46]  Tarun Kumar Rawat,et al.  A continuous-time least mean-phase adaptive filter for power system frequency estimation , 2009 .