A PLL-Based Multirate Structure for Time-Varying Power Systems Harmonic/Interharmonic Estimation

• Published in: IEEE transactions on power delivery Vol. 24; no. 4; pp. 1789 - 1800
• Main Authors: de Carvalho, J.R., Duque, C.A., Ribeiro, M.V., Cerqueira, A.S., Baldwin, T.L., Ribeiro, P.F.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-10-2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplitude estimation; Applied sciences; Band pass filters; Capacitors. Resistors. Filters; Computation; Convergence; Disturbances. Regulation. Protection; Electrical engineering. Electrical power engineering; Electrical power engineering; Estimators; Exact sciences and technology; Filter bank; Filter banks; Filtering; Frequency estimation; Harmonic analysis; Harmonics; Interharmonics; Multirate signal processing; Phase estimation; Phase locked loops; phase-locked loop (PLL); Power harmonic filters; Power networks and lines; Power system harmonics; Strategy; Time varying systems; time-varying harmonic/interharmonic estimation; Various equipment and components; time-varying harmonic/interharmonic estimation; Input signal; Power system harmonics; Power system stability; Multirate system; Algorithm; Computational complexity; Time variation; phase-locked loop (PLL); Phase locked loop; Time varying system; Signal processing; Band pass filter; Multirate signal processing; Filter bank; Frequency filtering
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2009.2027474

This paper describes a phase-locked-loop (PLL)-based power systems harmonic estimation algorithm, which uses an analysis filter bank and multirate processing. The filter bank is composed of bandpass filters. The initial center frequency of each filter is purposely chosen to be equal to harmonic frequencies. However, an adaptation strategy makes it possible to track time-varying frequencies as well as interharmonic components. A downsampler device follows the filtering stage, reducing the computational burden, especially because undersampling operations are performed. Finally, the last stage is composed of a PLL estimator which provides estimates for amplitude, phase, and frequency of the input signal. The proposed method improves the accuracy, computational effort, and convergence time of the previous harmonic estimator based on cascade PLL configuration.