d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations

The modular multilevel converter (MMC) is a keystone of modern energy transmission systems. Consequently, there is an ongoing pursue for mathematical models to represent it under different configurations and control approaches. In short, this paper introduces an analytical Thévenin-equivalent model...

Full description

Bibliographic Details
Main Authors: Cleiton M. Freitas, Edson H. Watanabe, Luís F. C. Monteiro
Format: Article
Language:English
Published: MDPI AG 2023-02-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/16/5/2195
_version_ 1797615476986085376
author Cleiton M. Freitas
Edson H. Watanabe
Luís F. C. Monteiro
author_facet Cleiton M. Freitas
Edson H. Watanabe
Luís F. C. Monteiro
author_sort Cleiton M. Freitas
collection DOAJ
description The modular multilevel converter (MMC) is a keystone of modern energy transmission systems. Consequently, there is an ongoing pursue for mathematical models to represent it under different configurations and control approaches. In short, this paper introduces an analytical Thévenin-equivalent model for representing the MMC when it is controlled with inner current- and an outer voltage-loop altogether. The model is based on a linearized representation of the converter and conveys the dynamics of passive components, such as submodule capacitors and arm reactors, as well as both control loops. Besides that, the proposed model is divided into a close-loop transfer matrix and the equivalent impedance matrix, both of which represent the relationships between the ac-side dq voltages and currents. We also propose a framework for implementing electromagnetic–transient simulations using the impedance model of this power electronic converter. The framework reduces a multi-bus power grid to a multi-input multi-output (MIMO) feedback system where impedance/admittance matrices of the MMC and other grid elements compose its loops. For validation purposes, it is considered a three-bus power grid comprising one MMC and another two grid-connected VSC. The proposed model was validated by comparing its results with a switching-level PSCAD model of the system.
first_indexed 2024-03-11T07:26:54Z
format Article
id doaj.art-d438504ad4cb43168b626476e0defd8b
institution Directory Open Access Journal
issn 1996-1073
language English
last_indexed 2024-03-11T07:26:54Z
publishDate 2023-02-01
publisher MDPI AG
record_format Article
series Energies
spelling doaj.art-d438504ad4cb43168b626476e0defd8b2023-11-17T07:35:27ZengMDPI AGEnergies1996-10732023-02-01165219510.3390/en16052195d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient SimulationsCleiton M. Freitas0Edson H. Watanabe1Luís F. C. Monteiro2Electrical Engineering Department, Rio de Janeiro State University, 524 São Francisco Xavier, Rio de Janeiro 20550-900, BrazilElectrical Engineering Program, COPPE/Federal University of Rio de Janeiro, 149 Athos da Silveira Ramos Ave, Rio de Janeiro 21941-909, BrazilElectronic Engineering Graduate Program, Rio de Janeiro State University, 524 São Francisco Xavier, Rio de Janeiro 20550-900, BrazilThe modular multilevel converter (MMC) is a keystone of modern energy transmission systems. Consequently, there is an ongoing pursue for mathematical models to represent it under different configurations and control approaches. In short, this paper introduces an analytical Thévenin-equivalent model for representing the MMC when it is controlled with inner current- and an outer voltage-loop altogether. The model is based on a linearized representation of the converter and conveys the dynamics of passive components, such as submodule capacitors and arm reactors, as well as both control loops. Besides that, the proposed model is divided into a close-loop transfer matrix and the equivalent impedance matrix, both of which represent the relationships between the ac-side dq voltages and currents. We also propose a framework for implementing electromagnetic–transient simulations using the impedance model of this power electronic converter. The framework reduces a multi-bus power grid to a multi-input multi-output (MIMO) feedback system where impedance/admittance matrices of the MMC and other grid elements compose its loops. For validation purposes, it is considered a three-bus power grid comprising one MMC and another two grid-connected VSC. The proposed model was validated by comparing its results with a switching-level PSCAD model of the system.https://www.mdpi.com/1996-1073/16/5/2195MMC modelimpedance modelingMMC transfer functiongrid-forminginverter-based power grid
spellingShingle Cleiton M. Freitas
Edson H. Watanabe
Luís F. C. Monteiro
d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations
Energies
MMC model
impedance modeling
MMC transfer function
grid-forming
inverter-based power grid
title d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations
title_full d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations
title_fullStr d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations
title_full_unstemmed d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations
title_short d-q Small-Signal Model for Grid-Forming MMC and Its Application in Electromagnetic-Transient Simulations
title_sort d q small signal model for grid forming mmc and its application in electromagnetic transient simulations
topic MMC model
impedance modeling
MMC transfer function
grid-forming
inverter-based power grid
url https://www.mdpi.com/1996-1073/16/5/2195
work_keys_str_mv AT cleitonmfreitas dqsmallsignalmodelforgridformingmmcanditsapplicationinelectromagnetictransientsimulations
AT edsonhwatanabe dqsmallsignalmodelforgridformingmmcanditsapplicationinelectromagnetictransientsimulations
AT luisfcmonteiro dqsmallsignalmodelforgridformingmmcanditsapplicationinelectromagnetictransientsimulations