Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection
The voltage source converters (VSCs) are used to interface and control the renewable energy resources that are integrated into the power grids. However, a weak grid connection raises a stability problem for grid synchronization of the grid-feeding current-controlled VSCs (CCVSCs). This paper handles...
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| Format: | Article |
| Language: | English |
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IEEE
2022-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/9970332/ |
| _version_ | 1811297285896667136 |
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| author | Mohsen Eskandari Andrey V. Savkin Hassan Haes Alhelou Frede Blaabjerg |
| author_facet | Mohsen Eskandari Andrey V. Savkin Hassan Haes Alhelou Frede Blaabjerg |
| author_sort | Mohsen Eskandari |
| collection | DOAJ |
| description | The voltage source converters (VSCs) are used to interface and control the renewable energy resources that are integrated into the power grids. However, a weak grid connection raises a stability problem for grid synchronization of the grid-feeding current-controlled VSCs (CCVSCs). This paper handles modeling and controller design for stabilizing the weak grid connection of CCVSCs. The impedance modeling/shaping of the VSC has been recognized as an effective tool to analyze and design the dynamics of the VSC. But an explicit and accurate impedance model of the CCVSC is required. Particularly, modeling the impact of the phase-locked loop (PLL) synchronization unit on the impedance model of the CCVSC is complex. Therefore, at first, an efficient impedance model of the CCVSC is developed while the impact of the PLL is rigorously considered through a complex procedure that results in an explicit/accurate impedance model. The developed impedance model is used to conduct passivity/weak grid connection stability analysis to clarify the underlying causes of instability problems. Then, a novel PLL, with an in-loop low-pass filter (LPF) to account for harmonics/asymmetries, is proposed with enhanced characteristics using the state feedback control. The impedance shaping method (with the aid of the impedance model) is utilized to design the state feedback gains. The state feedback loops provide degrees of freedom for bandwidth design of the PLL considering the current/power control loops and stabilize the system under weak grid connection/distorted conditions. Simulation results prove the accuracy and effectiveness of the models. |
| first_indexed | 2024-04-13T06:01:57Z |
| format | Article |
| id | doaj.art-f901756dd79c4c4c8572d5eb03043690 |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-04-13T06:01:57Z |
| publishDate | 2022-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-f901756dd79c4c4c8572d5eb030436902022-12-22T02:59:24ZengIEEEIEEE Access2169-35362022-01-011012887412888910.1109/ACCESS.2022.32268189970332Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid ConnectionMohsen Eskandari0https://orcid.org/0000-0003-1185-9585Andrey V. Savkin1https://orcid.org/0000-0001-9390-6634Hassan Haes Alhelou2https://orcid.org/0000-0002-7427-2848Frede Blaabjerg3https://orcid.org/0000-0001-8311-7412School of Electrical Engineering and Telecommunication, University of New South Wales, Sydney, NSW, AustraliaSchool of Electrical Engineering and Telecommunication, University of New South Wales, Sydney, NSW, AustraliaDepartment of Electrical and Computer Systems Engineering, Monash University, Clayton, VIC, AustraliaDepartment of Energy Technology, Aalborg University, Aalborg, DenmarkThe voltage source converters (VSCs) are used to interface and control the renewable energy resources that are integrated into the power grids. However, a weak grid connection raises a stability problem for grid synchronization of the grid-feeding current-controlled VSCs (CCVSCs). This paper handles modeling and controller design for stabilizing the weak grid connection of CCVSCs. The impedance modeling/shaping of the VSC has been recognized as an effective tool to analyze and design the dynamics of the VSC. But an explicit and accurate impedance model of the CCVSC is required. Particularly, modeling the impact of the phase-locked loop (PLL) synchronization unit on the impedance model of the CCVSC is complex. Therefore, at first, an efficient impedance model of the CCVSC is developed while the impact of the PLL is rigorously considered through a complex procedure that results in an explicit/accurate impedance model. The developed impedance model is used to conduct passivity/weak grid connection stability analysis to clarify the underlying causes of instability problems. Then, a novel PLL, with an in-loop low-pass filter (LPF) to account for harmonics/asymmetries, is proposed with enhanced characteristics using the state feedback control. The impedance shaping method (with the aid of the impedance model) is utilized to design the state feedback gains. The state feedback loops provide degrees of freedom for bandwidth design of the PLL considering the current/power control loops and stabilize the system under weak grid connection/distorted conditions. Simulation results prove the accuracy and effectiveness of the models.https://ieeexplore.ieee.org/document/9970332/Dynamic stabilitygrid integrationimpedance shapingphase-locked loop (PLL)renewable energy resources (RESs)voltage source converters (VSC) |
| spellingShingle | Mohsen Eskandari Andrey V. Savkin Hassan Haes Alhelou Frede Blaabjerg Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection IEEE Access Dynamic stability grid integration impedance shaping phase-locked loop (PLL) renewable energy resources (RESs) voltage source converters (VSC) |
| title | Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection |
| title_full | Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection |
| title_fullStr | Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection |
| title_full_unstemmed | Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection |
| title_short | Explicit Impedance Modeling and Shaping of Grid-Connected Converters via an Enhanced PLL for Stabilizing the Weak Grid Connection |
| title_sort | explicit impedance modeling and shaping of grid connected converters via an enhanced pll for stabilizing the weak grid connection |
| topic | Dynamic stability grid integration impedance shaping phase-locked loop (PLL) renewable energy resources (RESs) voltage source converters (VSC) |
| url | https://ieeexplore.ieee.org/document/9970332/ |
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