A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme

Abstract The high penetration of renewable energy sources (RES) results in a low‐inertia, weak power grid. To mitigate this and restore system inertia, it has been widely proposed to operate the inverters of RES units to mimic synchronous generators; this technology is known as a virtual synchronous...

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Main Authors: Daniel Angelo Kisinga, Peter Makolo, Paul Trodden
Format: Article
Language:English
Published: Wiley 2024-10-01
Series:IET Renewable Power Generation
Subjects:
Online Access:https://doi.org/10.1049/rpg2.13118
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author Daniel Angelo Kisinga
Peter Makolo
Paul Trodden
author_facet Daniel Angelo Kisinga
Peter Makolo
Paul Trodden
author_sort Daniel Angelo Kisinga
collection DOAJ
description Abstract The high penetration of renewable energy sources (RES) results in a low‐inertia, weak power grid. To mitigate this and restore system inertia, it has been widely proposed to operate the inverters of RES units to mimic synchronous generators; this technology is known as a virtual synchronous generator (VSG). In weak grids there is, however, strong coupling between active power (P) and reactive power (Q), and any VSG technique therefore requires PQ decoupling in order to operate effectively. This article proposes a new PQ decoupling technique based on the transformation of the PQ power circle of a VSG connected to a weak grid: first, the power circle is translated from its designed position to that of a conventional synchronous generator (SG) connected to a strong grid, achieving partial PQ decoupling. Then, to achieve full PQ decoupling, the authors propose further to modulate the radius of the translated PQ power circle; this is achieved using a series resistance‐capacitance–inductance (RCL) circuit which is virtually implemented in the VSG controller. The efficacy of the proposed scheme is validated using a modified synchronverter connected to the weak grid in representative loading scenarios. It is demonstrated that the technique achieves a decoupled PQ control for the synchronverter connected in a weak grid. Moreover, the modified synchronverter is capable of supporting frequency and voltage regulation in the grid without inducing large transient grid currents during mild frequency and voltage variations.
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spelling doaj-art-07a718c4ac3746419b723b48f96a55202025-01-10T17:41:03ZengWileyIET Renewable Power Generation1752-14161752-14242024-10-0118142723273610.1049/rpg2.13118A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling schemeDaniel Angelo Kisinga0Peter Makolo1Paul Trodden2Department of Automatic Control & Systems Engineering University of Sheffield Sheffield UKDepartment of Electrical Engineering University of Dar es Salaam Dar es Salaam TanzaniaDepartment of Automatic Control & Systems Engineering University of Sheffield Sheffield UKAbstract The high penetration of renewable energy sources (RES) results in a low‐inertia, weak power grid. To mitigate this and restore system inertia, it has been widely proposed to operate the inverters of RES units to mimic synchronous generators; this technology is known as a virtual synchronous generator (VSG). In weak grids there is, however, strong coupling between active power (P) and reactive power (Q), and any VSG technique therefore requires PQ decoupling in order to operate effectively. This article proposes a new PQ decoupling technique based on the transformation of the PQ power circle of a VSG connected to a weak grid: first, the power circle is translated from its designed position to that of a conventional synchronous generator (SG) connected to a strong grid, achieving partial PQ decoupling. Then, to achieve full PQ decoupling, the authors propose further to modulate the radius of the translated PQ power circle; this is achieved using a series resistance‐capacitance–inductance (RCL) circuit which is virtually implemented in the VSG controller. The efficacy of the proposed scheme is validated using a modified synchronverter connected to the weak grid in representative loading scenarios. It is demonstrated that the technique achieves a decoupled PQ control for the synchronverter connected in a weak grid. Moreover, the modified synchronverter is capable of supporting frequency and voltage regulation in the grid without inducing large transient grid currents during mild frequency and voltage variations.https://doi.org/10.1049/rpg2.13118AC‐DC power convertorslow‐pass filterspower convertorspassive filterspower system transient stabilityRenewable Energy Power Conversion
spellingShingle Daniel Angelo Kisinga
Peter Makolo
Paul Trodden
A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme
IET Renewable Power Generation
AC‐DC power convertors
low‐pass filters
power convertors
passive filters
power system transient stability
Renewable Energy Power Conversion
title A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme
title_full A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme
title_fullStr A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme
title_full_unstemmed A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme
title_short A modified synchronverter for a weak grid with virtual power circles‐based PQ decoupling scheme
title_sort modified synchronverter for a weak grid with virtual power circles based pq decoupling scheme
topic AC‐DC power convertors
low‐pass filters
power convertors
passive filters
power system transient stability
Renewable Energy Power Conversion
url https://doi.org/10.1049/rpg2.13118
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