Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems
LCL-filtered grid-connected converters are widely used for distributed generation systems. However, the current regulation of such converters is susceptible to weak grid conditions, e.g., grid impedance variation and background harmonics. Paralleling multiple harmonic compensators (HCs) is a commonl...
| Main Authors: | , , , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2019
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/80637 http://hdl.handle.net/10220/50070 |
| _version_ | 1826128317468639232 |
|---|---|
| author | Li, Xiaoqiang Fang, Jingyang Tang, Yi Wu, Xiaojie Geng, Yiwen |
| author2 | School of Electrical and Electronic Engineering |
| author_facet | School of Electrical and Electronic Engineering Li, Xiaoqiang Fang, Jingyang Tang, Yi Wu, Xiaojie Geng, Yiwen |
| author_sort | Li, Xiaoqiang |
| collection | NTU |
| description | LCL-filtered grid-connected converters are widely used for distributed generation systems. However, the current regulation of such converters is susceptible to weak grid conditions, e.g., grid impedance variation and background harmonics. Paralleling multiple harmonic compensators (HCs) is a commonly used method to suppress the current distortion caused by grid background harmonics, but the control bandwidth should be wide enough to ensure system stability. In order to enhance the adaptability of LCL-filtered grid-connected converters under weak grid operation, this paper proposes an improved capacitorvoltage-feedforward control with full delay compensation. When used with converter-side current feedback, the proposed control can keep system low-frequency characteristic independent of grid impedance and provide a high-harmonic rejection capability without using additional HCs. Moreover, it completely avoids the design constraints of an LCL filter, i.e., ω τ <; ω 8 /6 is required for singleloop converter-side current control. Therefore, a higher resonant frequency can be designed to achieve a wider control bandwidth and to lower the current distortion caused by the paralleled filter capacitor branch. Experimental results are finally presented to verify the proposed control, which are also in good agreement with theoretical analysis. |
| first_indexed | 2024-10-01T07:23:00Z |
| format | Journal Article |
| id | ntu-10356/80637 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:23:00Z |
| publishDate | 2019 |
| record_format | dspace |
| spelling | ntu-10356/806372020-03-07T13:57:23Z Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems Li, Xiaoqiang Fang, Jingyang Tang, Yi Wu, Xiaojie Geng, Yiwen School of Electrical and Electronic Engineering Capacitor-voltage Feedforward Control Bandwidth Engineering::Electrical and electronic engineering LCL-filtered grid-connected converters are widely used for distributed generation systems. However, the current regulation of such converters is susceptible to weak grid conditions, e.g., grid impedance variation and background harmonics. Paralleling multiple harmonic compensators (HCs) is a commonly used method to suppress the current distortion caused by grid background harmonics, but the control bandwidth should be wide enough to ensure system stability. In order to enhance the adaptability of LCL-filtered grid-connected converters under weak grid operation, this paper proposes an improved capacitorvoltage-feedforward control with full delay compensation. When used with converter-side current feedback, the proposed control can keep system low-frequency characteristic independent of grid impedance and provide a high-harmonic rejection capability without using additional HCs. Moreover, it completely avoids the design constraints of an LCL filter, i.e., ω τ <; ω 8 /6 is required for singleloop converter-side current control. Therefore, a higher resonant frequency can be designed to achieve a wider control bandwidth and to lower the current distortion caused by the paralleled filter capacitor branch. Experimental results are finally presented to verify the proposed control, which are also in good agreement with theoretical analysis. NRF (Natl Research Foundation, S’pore) Accepted version 2019-10-01T09:10:24Z 2019-12-06T13:53:39Z 2019-10-01T09:10:24Z 2019-12-06T13:53:39Z 2017 Journal Article Li, X., Fang, J., Tang, Y., Wu, X., & Geng, Y. (2018). Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems. IEEE Transactions on Power Electronics, 33(1), 749-764. doi:10.1109/TPEL.2017.2665483 0885-8993 https://hdl.handle.net/10356/80637 http://hdl.handle.net/10220/50070 10.1109/TPEL.2017.2665483 en IEEE Transactions on Power Electronics © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The published version is available at: https://doi.org/10.1109/TPEL.2017.2665483. 16 p. application/pdf |
| spellingShingle | Capacitor-voltage Feedforward Control Bandwidth Engineering::Electrical and electronic engineering Li, Xiaoqiang Fang, Jingyang Tang, Yi Wu, Xiaojie Geng, Yiwen Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems |
| title | Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems |
| title_full | Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems |
| title_fullStr | Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems |
| title_full_unstemmed | Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems |
| title_short | Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems |
| title_sort | capacitor voltage feedforward with full delay compensation to improve weak grids adaptability of lcl filtered grid connected converters for distributed generation systems |
| topic | Capacitor-voltage Feedforward Control Bandwidth Engineering::Electrical and electronic engineering |
| url | https://hdl.handle.net/10356/80637 http://hdl.handle.net/10220/50070 |
| work_keys_str_mv | AT lixiaoqiang capacitorvoltagefeedforwardwithfulldelaycompensationtoimproveweakgridsadaptabilityoflclfilteredgridconnectedconvertersfordistributedgenerationsystems AT fangjingyang capacitorvoltagefeedforwardwithfulldelaycompensationtoimproveweakgridsadaptabilityoflclfilteredgridconnectedconvertersfordistributedgenerationsystems AT tangyi capacitorvoltagefeedforwardwithfulldelaycompensationtoimproveweakgridsadaptabilityoflclfilteredgridconnectedconvertersfordistributedgenerationsystems AT wuxiaojie capacitorvoltagefeedforwardwithfulldelaycompensationtoimproveweakgridsadaptabilityoflclfilteredgridconnectedconvertersfordistributedgenerationsystems AT gengyiwen capacitorvoltagefeedforwardwithfulldelaycompensationtoimproveweakgridsadaptabilityoflclfilteredgridconnectedconvertersfordistributedgenerationsystems |