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Aggregated Modeling and Power Hardware-in-the-Loop Emulation of Grid Impedance

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


Original languageEnglish
Title of host publicationThe 10th Annual IEEE Energy Conversion Congress and Exposition (ECCE 2018)
Subtitle of host publicationSeptember 23-27, 2018, Portland, Oregon, USA
Number of pages8
ISBN (Electronic)978-1-4799-7312-5
Publication statusPublished - 6 Dec 2018
Publication typeA4 Article in a conference publication
EventIEEE Energy Conversion Congress and Exposition - Portland, United States
Duration: 23 Sep 201827 Sep 2018

Publication series

ISSN (Electronic)2329-3748


ConferenceIEEE Energy Conversion Congress and Exposition
CountryUnited States


The rapid growth of renewable energy production increases the number of grid-connected inverters in the power system. The interface between the inverter and the grid may face stability issues, which can be assessed using impedance-based stability criterion. The frequency-dependent grid impedance is often an unknown parameter, and vastly simplified grid impedance models are widely used. Most common modeling approach is to use series-connected inductor as the grid impedance. However, measurements on real grids have shown the grid to be more complex, resonant, and time-variant. This paper introduces a grid-impedance model based on aggregation of sub-models, which drastically simplifies complex grid modeling, while still accurately captures resonances and possible time-variant behavior. Numerical sensitivity analysis is carried out for grid parameters to illustrate the significance of separate grid elements. Lastly, impedance measurements are shown for emulated full-order and aggregated impedance models in an experimental power hardware-in-the-loop setup.