Passivity-based Design of Capacitor-Current-Feedback Active Damping for LCL-Filtered Inverter Considering Computation Delay Reduction

Capacitor-current-feedback active damping (CCF AD) is widely applied to damp the LCL resonance peak. However, it suffers from the wide-range variation of grid impedance. To address this issue, a passivity-based CCF AD scheme is proposed in this paper, where the optimal CCF coefficient is analytically derived, avoiding the time-consuming interactions, and the computation delay elimination helps the inverter immune to filter parameters fluctuation. The superiority of the proposed design is confirmed by the experimental results.