Impact of inverter-based resources on negative sequence quantities-based protection elements

Aboutaleb Haddadi, Mingxuan Zhao, Ilhan Kocar, Ulas Karaagac, Ka Wing Chan, Evangelos Farantatos

Research output: Journal article publicationJournal articleAcademic researchpeer-review

33 Citations (Scopus)


Inverter-Based Resources (IBRs), including Wind turbine generators (WTGs), exhibit substantially different negative-sequence fault current characteristics compared to synchronous generators (SGs). These differences may cause misoperation of customary negative-sequence-based protective elements set under the assumption of a conventional SG dominated power system. The amplitude of the negative-sequence fault current of a WTG is smaller than that of an SG. This may lead to misoperation of the negative-sequence overcurrent elements 50Q/51Q. Moreover, the angular relation of the negative-sequence current and voltage is different under WTGs, which may result in the misoperation of directional negative-sequence overcurrent element 67Q. This paper first studies the key differences between the WTGs and SG by comparing their equivalent negative-sequence impedances with SG's. Then, simulation case studies are presented showing the misoperation of 50Q and 67Q due to wind generation and the corresponding impact on communication-assisted protection and fault identification scheme (FID). The impact on directional element is also experimentally validated in a hardware-in-the-loop real-time simulation set up using a physical relay. Finally, the paper studies the impact of various factors such as WTG type (Type-III/Type-IV) and Type-IV WTG control scheme (coupled/decoupled sequence) to determine the key features that need to be considered in practical protection studies. The objective is to show potential protection misoperation issues, identify the cause, and propose potential solutions.

Original languageEnglish
Article number9022918
Pages (from-to)289-298
Number of pages10
JournalIEEE Transactions on Power Delivery
Issue number1
Publication statusPublished - Feb 2021


  • directional negative-sequence overcurrent
  • doubly-fed induction generator
  • full-size converter
  • inverter-based resource
  • negative sequence component
  • negative-sequence overcurrent protection
  • power system modeling
  • Power system protection
  • wind farms

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


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