Braitor, A.-C. orcid.org/0000-0002-7666-0457, Konstantopoulos, G. and Kadirkamanathan, V. (2020) Stability analysis and nonlinear current-limiting control design for DC micro-grids with CPLs. IET Smart Grid, 3 (3). pp. 355-366. ISSN 2515-2947
Abstract
In this study, a DC micro‐grid consisting of multiple paralleled energy resources interfaced by both bidirectional AC/DC and DC/DC boost converters and loaded by a constant power load (CPL) is investigated. By considering the generic dq transformation of the AC/DC converters' dynamics and the accurate nonlinear model of the DC/DC converters, two novel control schemes are presented for each converter‐interfaced unit to guarantee load voltage regulation, power sharing and closed‐loop system stability. This novel framework incorporates the widely adopted droop control and using input‐to‐state stability theory, it is proven that each converter guarantees a desired current limitation without the need for cascaded control and saturation blocks. Sufficient conditions to ensure closed‐loop system stability are analytically obtained and tested for different operation scenarios. The system stability is further analysed from a graphical perspective, providing valuable insights of the CPL's influence onto the system performance and stability. The proposed control performance and the theoretical analysis are first validated by simulating a three‐phase AC/DC converter in parallel with a bidirectional DC/DC boost converter feeding a CPL in comparison with the cascaded PI control technique. Finally, experimental results are also provided to demonstrate the effectiveness of the proposed control approach on a real testbed.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 IET Smart Grid published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/) |
Keywords: | cascade control; nonlinear control systems; voltage control; AC‐DC power convertors; control system synthesis; power distribution control; electric current control; closed loop systems; power generation control; distributed power generation; DC‐DC power convertors; power system stability; control design; CPL; DC microgrid architecture; multiple paralleled energy resources; constant power load; nonlinear model; control schemes; converter‐interfaced unit; load voltage regulation; power sharing; closed‐loop system stability; novel control framework; input‐to‐state stability theory; converter unit; current limitation; cascaded control; DC microgrid instability; system performance; control performance; theoretical stability analysis; traditional cascaded PI control technique; control approach; droop control expressions; C1310 Control system analysis and synthesis methods; C1320 Stability in control theory; C1340K Nonlinear control systems; C3110B Voltage control; C3110D Current control; C3340H Control of electric power systems; B8120K Distributed power generation; B8360D DC‐DC power convertors; B8360J AC‐DC power convertors (rectifiers) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Automatic Control and Systems Engineering (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S001107/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S031863/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 02 Mar 2020 14:54 |
Last Modified: | 03 Feb 2021 16:14 |
Status: | Published |
Publisher: | Institution of Engineering and Technology (IET) |
Refereed: | Yes |
Identification Number: | 10.1049/iet-stg.2019.0235 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:157775 |