Ahead of Print article · Journal article
Block Diagonal Dominance-based Model Reduction Method Applied to MMC Asymmetric Stability Analysis
Shanghai Jiao Tong University1
Center for Electric Power and Energy, Centers, Technical University of Denmark2
Smart Electric Components, Center for Electric Power and Energy, Centers, Technical University of Denmark3
Department of Electrical Engineering, Technical University of Denmark4
Norwegian University of Science and Technology5
Frequency-domain model reduction is a crucial concern in applying the prevailing impedance method for the stability analysis of complex systems, e.g., the modular multilevel converter (MMC). Recently, it has been shown that under symmetric conditions, a 2×2 matrix-based impedance model characterizing the two coupled frequencies of MMC are sufficient for its stability analysis.
However, when the asymmetry occurs, principally, a much higher number of frequency couplings will appear in the MMC and thereby leads to a significant rise in the model dimension. Enlighted by this issue, there is an urgent need of finding a suitable frequency-domain method that can serve as a general criterion for model reduction.
To this end, this paper proposes a block diagonal dominance (BDD)-based model reduction method and applied it to the asymmetric MMC. Basically, the BDD can decompose an N-dimensional task to N one-dimensional tasks, via which a significant reduction in model dimension can be realized. It is shown that by properly shifting the impedance model from one domain to another (e.g., α-β domain to $d-q$ domain), the BDD property can be achieved for most asymmetric scenarios.
Finally, various case studies considering different asymmetry degrees are conducted to validate the effectiveness of the proposed method.
Language: | English |
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Publisher: | IEEE |
Year: | 2021 |
Pages: | 2438-2451 |
ISSN: | 15580059 and 08858969 |
Types: | Ahead of Print article and Journal article |
DOI: | 10.1109/TEC.2021.3054925 |
ORCIDs: | 0000-0001-9939-0376 , Zhang, Chen , 0000-0002-1817-7926 , 0000-0002-1621-2257 and 0000-0002-8791-0917 |