Imperial College London
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Professor Tim Green, FREng

Faculty of Engineering, Department of Electrical and Electronic Engineering

Academic Leader for Sustainability, Professor
 
 
 
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Contact

 

+44 (0)20 7594 6171t.green Website CV

 
 
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Location

 

1107EElectrical EngineeringSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Li:2022:10.1109/TPWRS.2022.3151851,
author = {Li, Y and Gu, Y and Green, T},
doi = {10.1109/TPWRS.2022.3151851},
journal = {IEEE Transactions on Power Systems},
pages = {4541--4554},
title = {Revisiting grid-forming and grid-following inverters: a duality theory},
url = {http://dx.doi.org/10.1109/TPWRS.2022.3151851},
volume = {37},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Power electronic converters for integrating renewable energy resources into power systems can be divided into grid-forming and grid-following inverters. They possess certain similarities, but several important differences, which means that the relationship between them is quite subtle and sometimes obscure. In this article, a new perspective based on duality is proposed to create new insights. It successfully unifies the grid interfacing and synchronization characteristics of the two inverter types in a symmetric, elegant, and technology-neutral form. Analysis shows that the grid-forming and grid-following inverters are duals of each other in several ways including a) synchronization controllers: frequency droop control and phase-locked loop (PLL); b) grid-interfacing characteristics: current-following voltage-forming and voltage-following current-forming; c) swing characteristics: current-angle swing and voltage-angle swing; d) inner-loop controllers: output impedance shaping and output admittance shaping; and e) grid strength compatibility: strong-grid instability and weak-grid instability. The swing equations are also derived in dual form, which reveal the dynamic interaction between the grid strength, the synchronization controllers, and the inner-loop controllers. Insights are generated into cases of poor stability in both small-signal and transient/large-signal. The theoretical analysis and simulation results are used to illustrate cases for single-inverter systems, two-inverter systems, and multi-inverter networks.
AU  - Li,Y
AU  - Gu,Y
AU  - Green,T
DO  - 10.1109/TPWRS.2022.3151851
EP  - 4554
PY  - 2022///
SN  - 0885-8950
SP  - 4541
TI  - Revisiting grid-forming and grid-following inverters: a duality theory
T2  - IEEE Transactions on Power Systems
UR  - http://dx.doi.org/10.1109/TPWRS.2022.3151851
UR  - https://ieeexplore.ieee.org/document/9714816
UR  - http://hdl.handle.net/10044/1/95111
VL  - 37
ER  -
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