Efficient harmonic and phase estimator for single-phase grid-connected renewable energy systems

Ali Elrayyah, Ali Safayet, Yilmaz Sozer, Iqbal Husain, Malik Elbuluk

Research output: Contribution to journalArticle

18 Citations (Scopus)


Renewable energy sources (RESs) in any power system can participate in removing the harmonics from the line voltage, but the RESs need to estimate these harmonics first. In this paper, an efficient method to estimate grid harmonics is proposed to be used by single-phase RESs. The proposed method provides accurate estimation for the harmonics while it has lower computation complexity than the other existing methods. To make the harmonic estimation process fast and accurate, the harmonics in the sampled grid voltage is eliminated before passing it to the phase-locked-loop block used for estimating the grid phase. Another application of the proposed method is to transform single-phase voltage or current from the stationary reference frame into the dq rotating reference frame. In this application, the use of the proposed method eliminates the need of generating fictitious voltage or current waveforms orthogonal to the measured quantities. The elimination of need to generate fictitious waveforms speeds up the transformation transients and reduces the operations to less than half of those required by traditional methods. Simulation and experimental results verified that the algorithm achieves fast and accurate harmonic estimation of highly distorted grid voltage.

Original languageEnglish
Article number6531639
Pages (from-to)620-630
Number of pages11
JournalIEEE Transactions on Industry Applications
Issue number1
Publication statusPublished - 1 Jan 2014



  • Harmonic effect elimination
  • harmonic estimation
  • phase-locked loop (PLL)
  • renewable energy source (RES) control

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering

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