Rapid admittance measurement of power converters using double-PLL grid-following inverters

Weihua Zhou, Mohammad Hasan Ravanji, Nabil Mohammed, Behrooz Bahrani

Research output: Contribution to journalArticleResearchpeer-review


The increasing use of inverter-based resources (IBRs) in power systems highlights the need for a deep understanding of their stability and dynamics. Traditional analytical models, limited by the black-box nature of IBRs, underscore the importance of frequency-domain methods through measured admittance. Facing challenges in real-world admittance measurement, such as the absence of ideal voltage or current sources, the use of measurement inverters as perturbation sources has emerged as a promising approach, despite drawbacks like reduced system stability and increased measurement time. This article introduces a novel control strategy for measurement inverters, elucidating the impact of abc/dq and dq/abc transformations on admittance measurement. The key advancements are an analysis of the admittance contributions from these transformations and the implementation of double phase-locked loops in the measurement inverters, aimed at improving stability and decreasing measurement duration.

Original languageEnglish
Pages (from-to)1407-1419
Number of pages13
JournalIEEE Transactions on Power Delivery
Issue number3
Publication statusPublished - Jun 2024


  • Admittance
  • Admittance measurement
  • dynamics
  • grid-following inverter
  • Impedance
  • Impedance measurement
  • Perturbation methods
  • Phase locked loops
  • phase-locked loop
  • Power system stability
  • stability

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