A Model Modification Process for Grid-Connected Inverters Used in Islanded Microgrids


A method of modifying existing grid-connected inverter models for use in droop-controlled microgrids is presented. The modification involves combination with a model of a grid-forming inverter to accurately represent the coupling between complex power, bus voltage, and frequency. The combination is performed after the individual models are linearized, adding little in terms of computational complexity. The method is applicable to any three-phase inverter operating in a grid-supporting capacity and is scalable for any number of parallel inverters at the same point of connection. To examine the modification process and its effect on model performance, a generic grid-tied inverter model is derived and used as a test case. The newly derived model is modified according to the proposed method. The validity of this process is assessed through comparisons of model predictions - both from before and after modification - to results of hardware experiments. A simple design example is given to demonstrate the application of this process in the design of inverters in distributed-generation-based microgrids.


Electrical and Computer Engineering


United States. Department of Energy


This work was supported in part by the U.S. Department of Energy SunShot Initiative under Award DE0006341 (Mid-America Regional Microgrid Education and Training (MARMET) Consortium).

Keywords and Phrases

Electric Power Distribution; Grid Connected Inverters; Hardware Experiment; Individual Models; Model Modification; Model Performance; Modification Process; Supporting Capacities; Three-Phase Inverter; Electric Inverters; Distributed Power Generation; Microgrids; Power System Dynamics; Inverters; Mathematical Model; Phase Locked Loops; Voltage Control; Couplings; Computational Complexity; Invertors; Power Generation Control; Power System Simulation; Reactive Power Control

International Standard Serial Number (ISSN)

0885-8969; 1558-0059

Document Type

Article - Journal

Document Version


File Type





© 2016 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Mar 2016