LCL-filter Optimization Design Considering Stability of Grid-Connected Inverters in Microgrid

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CIRED 2018 Ljubljana WS - 0214 - 20690.pdf (564.21 KB)
Paper number
0214
Working Group Number
Conference name
CIRED 2018 Ljubljana Workshop
Conference date
7 - 8 June 2018
Conference location
Ljubljana, Slovenia
Peer-reviewed
Yes
Short title
Convener
Authors
Chen, Tiantian, Electric Power Research Institute of State Grid Shanghai Electric Power Company, China
Zhang, Peng, Electric Power Research Institute of State Grid Shanghai Electric Power Company, China
Luo, Ling, Electric Power Research Institute of State Grid Shanghai Electric Power Company, China
Pan, Ling, Electric Power Research Institute of State Grid Shanghai Electric Power Company, China
Abstract
As the existing optimized filter of grid-connected inverter design schemes give no consideration to the effect of grid impedances and current controllers, it will eventually cause the grid-connected LCL-filtered inverters lose stability when operating under the microgrid with small short-circuit ratio. This article thus presents a LCL-filter optimization design taking into account stability of grid-connected inverters. In the proposed approach, a multiple-objective optimal model is established, the objective functions of which are minimal damping power loss, minimal cost and optimum current tracking performance, and the constraint about stability is obtained by the impedance analysis method. PSO algorithm with compression factor is used to solve the optimization problem for its unique advantage on the convergence. Compared with conventional design methods, such as optimized design of LCL filter for minimal damping power loss, the optimization in this article has a higher standardized satisfaction value, which means it can balance well cost and filtering performance and stability margin, especially suited for LCL filter parameters design under microgrid with small short-circuit ratio. For improving practical value of the proposed method, it is further demonstrated that the damp resistance has the most remarkable affect to the optimization results, so the precise selection of damp resistance is indispensable for achieving the desired performances. Moreover, the proposed method has a strong robustness for variation of the main circuit parameters, which makes the optimization design has a better practical value. Finally, the comparative simulaton results verify the effectiveness of the proposed method.
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Publisher
AIM
Date
2018-06-07
Published in
CIRED 2018 Ljubljana Workshop on Microgrids and Local Energy Communities
Permanent link to this record
https://www.cired-repository.org/handle/20.500.12455/1239
http://dx.doi.org/10.34890/392
ISSN
2032-9628
ISBN
978-2-9602415-1-8