A Framework to Analyze the Stochastic Harmonics and Resonance of Wind Energy Grid Interconnection

Eduard Muljadi, Youngho Cho, Choongman Lee, Kyeon Hur, Yong Kang, Sang-Ho Park, Young-Do Choy, Gi-Gab Yoon

Research output: Contribution to journalArticlepeer-review

5 Scopus Citations


This paper addresses a modeling and analysis methodology for investigating the stochastic harmonics and resonance concerns of wind power plants (WPPs). Wideband harmonics from modern wind turbines are observed to be stochastic, associated with real power production, and they may adversely interact with the grid impedance and cause unexpected harmonic resonance if not comprehensively addressed in the planning and commissioning of the WPPs. These issues should become more critical as wind penetration levels increase. We thus propose a planning study framework comprising the following functional steps: First, the best-fitted probability density functions (PDFs) of the harmonic components of interest in the frequency domain are determined. In operations planning, maximum likelihood estimations followed by a chi-square test are used once field measurements or manufacturers' data are available. Second, harmonic currents from the WPP are represented by randomly-generating harmonic components based on their PDFs (frequency spectrum) and then synthesized for time-domain simulations via inverse Fourier transform. Finally, we conduct a comprehensive assessment by including the impacts of feeder configurations, harmonic filters, and the variability of parameters. We demonstrate the efficacy of the proposed study approach for a 100-MW offshore WPP consisting of 20 units of 5-MW full-converter turbines, a realistic benchmark system adapted from a WPP under development in Korea, and discuss lessons learned through this research.
Original languageAmerican English
Number of pages16
Issue number9
StatePublished - 2016

NREL Publication Number

  • NREL/JA-5D00-67044


  • harmonics
  • resonance
  • statistical modeling
  • wind power plant
  • WPP


Dive into the research topics of 'A Framework to Analyze the Stochastic Harmonics and Resonance of Wind Energy Grid Interconnection'. Together they form a unique fingerprint.

Cite this