<abstract xmlns="http://www.w3.org/1999/xhtml">

Capacitor-Current Feedback Active Damping (CCFAD) is widely employed in LCL grid-tied inverters. However, the delay introduced by digital control can alter the traditional active damping characteristics, with the equivalent virtual resistance having a positive/negative crossover frequency of <italic>f</italic>s/6. The LCL filter’s resonant frequency may change due to the extensive variation in grid impedance under weak grid conditions. When the resonant frequency of the LCL filter exceeds <italic>f</italic>s/6, the stability of the system is severely compromised. A better approach is to add a lead compensation element to the current feedback branch of traditional CCFAD in response to these issues. This compensates for the phase lag caused by control delay, effectively extending the active damping region to (0, <italic>f</italic>R), <italic>f</italic>R ∈ (<italic>f</italic>s/3, <italic>f</italic>s/2), thereby enhancing system stability and robustness. The proposed method’s effectiveness has been confirmed by theoretical analysis and simulation on the MATLAB/Simulink platform, which utilizes a single-phase LCL grid-tied inverter model.
</abstract>

Capacitor-Current Feedback Active Damping (CCFAD) is widely employed in LCL grid-tied inverters. However, the delay introduced by digital control can alter the traditional active damping characteristics, with the equivalent virtual resistance having a positive/negative crossover frequency of fs/6. The LCL filter’s resonant frequency may change due to the extensive variation in grid impedance under weak grid conditions. When the resonant frequency of the LCL filter exceeds fs/6, the stability of the system is severely compromised. A better approach is to add a lead compensation element to the current feedback branch of traditional CCFAD in response to these issues. This compensates for the phase lag caused by control delay, effectively extending the active damping region to (0, fR), fR ∈ (fs/3, fs/2), thereby enhancing system stability and robustness. The proposed method’s effectiveness has been confirmed by theoretical analysis and simulation on the MATLAB/Simulink platform, which utilizes a single-phase LCL grid-tied inverter model.

An Active Damping Method With Improved Capacitor Current Feedback

Applied Mathematics and Nonlinear Sciences

This work is licensed under the Creative Commons Attribution 4.0 International License.

{"article-title":"An Active Damping Method With Improved Capacitor Current Feedback"}

Capacitor-Current Feedback Active Damping (CCFAD) is widely employed in LCL grid-tied inverters. However, the delay introduced by digital control can alter the...

An Active Damping Method With Improved Capacitor Current Feedback

Published Online: May 15, 2024

Page range: -

Received: Feb 18, 2024

Accepted: Apr 20, 2024

DOI: https://doi.org/10.2478/amns-2024-1069

Keywords
LCL-type Grid-connected Inverter, Active damping, Control delays, Resonance shift, Weak grid, Robustness

© 2024 Youjie Ma et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

An Active Damping Method With Improved Capacitor Current Feedback

Published Online: May 15, 2024

Page range: -

Received: Feb 18, 2024

Accepted: Apr 20, 2024

DOI: https://doi.org/10.2478/amns-2024-1069

KeywordsLCL-type Grid-connected Inverter, Active damping, Control delays, Resonance shift, Weak grid, Robustness

© 2024 Youjie Ma et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
LCL-type Grid-connected Inverter, Active damping, Control delays, Resonance shift, Weak grid, Robustness