Novel Active Damping Design Based on a Biquad Filter for an LLCL Grid-Tied Inverter

Bin Wang, Qiangsong Zhao (), Gong Zhang, Hongwei Zhang, Kaiyue Liu and Xuebin Yue
Additional contact information
Bin Wang: School of Electronic and Information, Zhongyuan University of Technology, Zhengzhou 450007, China
Qiangsong Zhao: School of Electronic and Information, Zhongyuan University of Technology, Zhengzhou 450007, China
Gong Zhang: School of Electronic and Information, Zhongyuan University of Technology, Zhengzhou 450007, China
Hongwei Zhang: School of Electronic and Information, Zhongyuan University of Technology, Zhengzhou 450007, China
Kaiyue Liu: School of Electronic and Information, Zhongyuan University of Technology, Zhengzhou 450007, China
Xuebin Yue: Department of Electronic and Computer Engineering, Ritsumeikan University, Kusatsu 525-8577, Shiga, Japan

Energies, 2023, vol. 16, issue 3, 1-15

Abstract: LLCL filters for grid-tied inverters have been adopted to get better performance for the harmonics near the switching frequency than commonly used LCL filters. However, the resonant peak caused by a pair of unstable resonance poles of the LLCL filters is introduced and makes the system become unstable. In this paper, a biquad filter composed of a notch filter and a resonator is introduced to restrain the resonant peak. In this method, the resonance point and the notch point of the biquad filter are placed at the appointed frequency, and the resonant peak is transferred to the stable area by phase transformation, so that the system does not cross −180° at the resonant peak. This method makes the system have higher control bandwidth and stronger robustness even in a weak power grid. Meanwhile, a proportional-integral multiresonant repetitive controller is used to restrain low-frequency current harmonics and improve the steady-state and dynamic performance of the control system. Furthermore, based on the active damping of the biquad filter, the stability criterion of the control system under a weak power grid is given. Finally, the accuracy of the analysis and the effectiveness of the method is verified by simulations.

Keywords: LLCL filter; grid-tied inverter; biquad filter; weak grids (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/16/3/1093/pdf (application/pdf)
https://www.mdpi.com/1996-1073/16/3/1093/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:16:y:2023:i:3:p:1093-:d:1040674

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().