Effect of phase-locked loop on dynamic performance of Grid Forming inverter

Ziqian Zhang, Robert Schürhuber, Lothar Fickert, Katrin Friedl, Guochu Chen, Yongming Zhang, Feng Wang

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


The main control loop of the synchronizer of the Grid Forming inverter can be synchronized with the voltage of the grid without using a phase-locked loop. However, in order to enable the inverter to realize the frequency regulation function accurately, a phase-locked loop is still required to obtain the grid`s frequency information. Since the time constants of the phase-locked loop and P-f loop of grid forming control are at the same order of magnitude, the introduction of the phase-locked loop will affect the original dynamic performance of P-f loop. In this paper, small-signal modelling is performed on the P-f loop of the grid forming with considering phase-locked loop to obtain the transfer function of the system. The influence of the cutoff frequency of phase-locked loop on the system dynamics is mainly related to the expected damping of the P-f loop. When the P-f loop of the system is designed to be underdamped, decreasing the cutoff frequency of the phase-locked loop can increase the system damping, which increases the adjustment time and reduces the overshoot. The paper uses controller hardware-in-the-loop to verify the analysis results.
Original languageEnglish
Title of host publicationWind Integration Workshop 2020
EditorsUta Betancourt, Thomas Ackermann
Place of PublicationDarmstadt
PublisherEnergynautics GmbH
ISBN (Electronic)978-3-9820080-8-0
Publication statusPublished - 11 Nov 2020
EventWind Integration Workshop 2020: 19th International Workshop on Large-scale Integration of Wind Power into Power Systems as well as on Transmission Networks for Offshore Wind Power Plants - Virtuell
Duration: 11 Nov 202012 Nov 2020


ConferenceWind Integration Workshop 2020
Internet address


  • grid-connected inverters
  • phase-locked loop
  • grid forming
  • virtual synchronous generator

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