Research on Active Damper Siting Strategy Based on Resonance Modal Analysis

In multi-inverter parallel grid-connected systems, harmonic resonance can lead to performance degradation and even instability. Although installing active dampers (ADs) is considered an effective approach to suppress harmonic resonance, research on the optimal installation positions for ADs is still limited, and specific optimization methods require further exploration. This paper proposes an AD siting strategy based on resonance modal analysis (RMA) and node participation factor (PF) calculations. The method aims to select the installation positions for AD by identifying the nodes that significantly contribute to harmonic resonance, and the validity of this approach is confirmed through modal sensitivity analysis. To address the challenge of conducting RMA with inverter black-box models, impedance models of the inverters are obtained through frequency scanning, and the nodal admittance matrix of the system is established. Additionally, this method considers the impact of changes in grid impedance on AD siting results. Finally, both simulation and experimental results validate the effectiveness of the proposed strategy.