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Grid-forming control for power converters based on matching of synchronous machines

Arghir, Catalin ; Jouini, Taouba LU and Dörfler, Florian (2018) In Automatica 95. p.273-282
Abstract

We consider the problem of grid-forming control of power converters in low-inertia power systems. Starting from an average-switch three-phase power converter model, we draw parallels to a synchronous machine (SM) model and propose a novel converter control strategy which dwells upon the main characteristic of a SM: the presence of an internal rotating magnetic field. In particular, we augment the converter system with a virtual oscillator whose frequency is driven by the DC-side voltage measurement and which sets the converter pulse-width-modulation signal, thereby achieving exact matching between the converter in closed-loop and the SM dynamics. We then provide a sufficient condition asserting existence, uniqueness, and global... (More)

We consider the problem of grid-forming control of power converters in low-inertia power systems. Starting from an average-switch three-phase power converter model, we draw parallels to a synchronous machine (SM) model and propose a novel converter control strategy which dwells upon the main characteristic of a SM: the presence of an internal rotating magnetic field. In particular, we augment the converter system with a virtual oscillator whose frequency is driven by the DC-side voltage measurement and which sets the converter pulse-width-modulation signal, thereby achieving exact matching between the converter in closed-loop and the SM dynamics. We then provide a sufficient condition asserting existence, uniqueness, and global asymptotic stability of a shifted equilibrium, all in a rotating coordinate frame attached to the virtual oscillator angle. By actuating the DC-side input of the converter we are able to enforce this condition and provide additional inertia and damping. In this framework, we illustrate strict incremental passivity, droop, and power-sharing properties which are compatible with conventional power system operation requirements. We subsequently adopt disturbance-decoupling and droop techniques to design additional control loops that regulate the DC-side voltage, as well as AC-side frequency and amplitude, while in the end evaluating them with numerical experiments.

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published
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in
Automatica
volume
95
pages
10 pages
publisher
Pergamon
external identifiers
  • scopus:85047901736
ISSN
0005-1098
DOI
10.1016/j.automatica.2018.05.037
language
English
LU publication?
no
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8232d426-e91e-4240-afcd-be9a5f7ef9eb
date added to LUP
2019-08-02 13:49:26
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2020-10-07 06:39:14
@article{8232d426-e91e-4240-afcd-be9a5f7ef9eb,
  abstract     = {<p>We consider the problem of grid-forming control of power converters in low-inertia power systems. Starting from an average-switch three-phase power converter model, we draw parallels to a synchronous machine (SM) model and propose a novel converter control strategy which dwells upon the main characteristic of a SM: the presence of an internal rotating magnetic field. In particular, we augment the converter system with a virtual oscillator whose frequency is driven by the DC-side voltage measurement and which sets the converter pulse-width-modulation signal, thereby achieving exact matching between the converter in closed-loop and the SM dynamics. We then provide a sufficient condition asserting existence, uniqueness, and global asymptotic stability of a shifted equilibrium, all in a rotating coordinate frame attached to the virtual oscillator angle. By actuating the DC-side input of the converter we are able to enforce this condition and provide additional inertia and damping. In this framework, we illustrate strict incremental passivity, droop, and power-sharing properties which are compatible with conventional power system operation requirements. We subsequently adopt disturbance-decoupling and droop techniques to design additional control loops that regulate the DC-side voltage, as well as AC-side frequency and amplitude, while in the end evaluating them with numerical experiments.</p>},
  author       = {Arghir, Catalin and Jouini, Taouba and Dörfler, Florian},
  issn         = {0005-1098},
  language     = {eng},
  month        = {09},
  pages        = {273--282},
  publisher    = {Pergamon},
  series       = {Automatica},
  title        = {Grid-forming control for power converters based on matching of synchronous machines},
  url          = {http://dx.doi.org/10.1016/j.automatica.2018.05.037},
  doi          = {10.1016/j.automatica.2018.05.037},
  volume       = {95},
  year         = {2018},
}