Journal of Power Electronics

  • 제22권5호
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  • Pages.727-738
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  • 2022
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  • 1598-2092(pISSN)
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  • 2093-4718(eISSN)
전력전자학회 (The Korean Institute of Power Electronics)
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DOI QR코드

DOI QR Code

Phase lag compensation for improving the stability of LCL-type converters under weak grid condition

  • Wang, Jianfeng (Department of Transportation, Zhejiang Industry Polytechnic College) ;
  • Pan, Guobing (College of Mechanical Engineering, Zhejiang University of Technology) ;
  • Ouyang, Jing (College of Mechanical Engineering, Zhejiang University of Technology) ;
  • Liu, Chengyao (Department of Transportation, Zhejiang Industry Polytechnic College) ;
  • Zhou, Yinghao (College of Mechanical Engineering, Zhejiang University of Technology) ;
  • Fei, Gong (College of Mechanical Engineering, Zhejiang University of Technology)
  • 투고 : 2021.09.06
  • 심사 : 2022.01.28
  • 발행 : 2022.05.20
⟨ 이전 논문 다음 논문 ⟩

초록

LCL-type converters are widely used in the sustainable energy generation system due to their flexible current control strategies and high efficiency. The LCL filter has a resonance peak, which needs to be handled appropriately; otherwise, it causes system instability. Single-loop feedback control strategy is very popular at present; it does not require additional sensors to measure the state variables for active damping. Under weak grid condition, the resonance peak of LCL filter shifts to the left evidently and greatly reduces the stability margin; thus, maintaining the stability of single-loop control is a challenging task. This paper presents an improved grid current feedback (GCF) single-loop control strategy, which is designed to raise the stability margin of system to adapt weak grid condition. Low pass filter controller is used for phase lag compensation. A phase margin design method is proposed to ensure system stability, and the corresponding discrete method in z-domain has been proposed in detail. Experiments performed on a three-phase converter platform are finally presented to verify the effectiveness of the proposed phase lag compensation for GCF control strategy.

키워드

과제정보

This research is supported by the Scientific Research Project of Zhejiang Provincial Education Department (Grant number Y201941495), Basic Public Welfare Research Program of Zhejiang Province (Grant number LGF21E070001).

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