Gain Normalized Adaptive Observer For Three-Phase System

Hafiz Ahmed, Miao Lin Pay, Mohamed Benbouzid, Yassine Amirat, Elhoussin Elbouchikhi

Research output: Contribution to journalArticle

1 Citation (Scopus)


This paper proposes the estimation of parameters and symmetrical components of unbalanced grid using adaptive observer framework. Recent adaptive observers proposed in the literature doesn’t employ any gain normalization in their frequency estimation loop. This can be problematic in the presence of large voltage dip. This paper proposes a solution to overcome this limitation using a novel gain normalized - frequency-locked loop (GN-FLL). Technical details of GN-FLL, stability analysis and tuning are provided in this paper. Comparative experimental results with adaptive Luenberger observer, second-order generalized integrator - phase-locked loop (SOGI-PLL) and enhanced PLL (EPLL) are provided to demonstrate the effectiveness the proposed technique in the single-phase case. Comparative experimental results with double SOGI-FLL (DSOGI-FLL) and adaptive notch filter (ANF) are provided to demonstrate the effectiveness the proposed technique in the three-phase case.
Original languageEnglish
Article number105821
JournalInternational Journal of Electrical Power and Energy Systems
Early online date15 Jan 2020
Publication statusE-pub ahead of print - 15 Jan 2020


Bibliographical note

NOTICE: this is the author’s version of a work that was accepted for publication in International Journal of Electrical Power and Energy Systems. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Electrical Power and Energy Systems, 118, (2020) DOI: 10.1016/j.ijepes.2020.105821

© 2020, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International


  • Frequency estimation
  • Frequency-Locked Loop (FLL)
  • Phase estimation
  • Three-phase sequence detection

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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