A Joint Active Damping Strategy Based on LCL -Type Grid-Connected Inverters for Grid Current Feedback and PCC Voltage Unit Feedforward

• Published in: Sensors (Basel, Switzerland) Vol. 24; no. 18; p. 6029
• Main Authors: Ke, Shanwen, Liang, Bo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.09.2024; MDPI
• Subjects: active damping; Alternative energy sources; Controllers; Electric inverters; Electric power systems; grid current feedback (GCF); grid impedance; joint active damping; Methods; Renewable resources; robustness; Systems stability; joint active damping; robustness; grid impedance; active damping; grid current feedback (GCF)
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s24186029

The negative high-pass filter feedback of the grid current (NFGCF) can offer active damping for the -type grid-connected inverter. Due to the control delay in digital control systems, this damping can cause the system to exhibit non-minimum phase behavior within specific frequency ranges. This study proposes a joint active damping approach that combines grid current feedback and the point of common coupling (PCC) voltage unit feedforward. The proposed method introduces a dynamic damping region that varies with grid impedance. By developing suitable damping loop control parameters, this region can span the entire frequency range, even exceeding the Nyquist frequency /2. The research results demonstrate that the proposed approach enhances robustness against variations in grid impedance and eliminates non-minimum phase behavior. Simulation and experimental outcomes validate the effectiveness of this joint active damping method.