Theoretical Examination of Small-Signal Impedance Models of Inverter-Based Resources

Meng L., KARAAĞAÇ U., Chan K. W., Ghafouri M., Mahseredjian J.

19th IEEE International Conference on Compatibility, Power Electronics and Power Engineering, CPE-POWERENG 2025, Antalya, Turkey, 20 - 22 May 2025, (Full Text) identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/cpe-powereng63314.2025.11027190
  • City: Antalya
  • Country: Turkey
  • Keywords: Coordinate transformation, dq-impedance, impedance transformation, sequence MIMO, sequence SISO
  • Middle East Technical University Affiliated: Yes

Abstract

Various impedance modeling methods have been developed in different reference frames for the impedance-based stability assessment (IBSA) of inverter-based resources (IBRs). In practice, these impedance models are extracted by applying electromagnetic transient (EMT)-type impedance scanning techniques to manufacturer specific (black-box) models of IBRs. However, the relationships between these models require a clearer and more comprehensible explanation. This work derives and systematically explains model equivalence through linear and coordinate transformations, as well as model simplification in the sequence multi-input multi-output (MIMO) to sequence singleinput single-output (SISO) impedance transformation. To validate the theoretical analysis, EMT-type impedance scanning is performed on a full-size converter (FSC)-based wind park (WP) in a benchmark test system exhibiting weak grid issues.