跟网型变流器中功率-电流环交互引发的高频谐振机理分析及自稳定设计

ABSTRACT As the power conversion device between new energy generation systems and the power grid, the high‐frequency resonance self‐stability of the current loop of grid‐following (GFL) converters has been widely researched. However, this paper finds that, in addition to the current loop, the power loop of GFL converters also has high‐frequency resonance self‐stability issues when adopting a closed‐loop control strategy. Therefore, this paper researches the high‐frequency resonance mechanism in the power loop first, and the research results show that the resonance in the power loop is induced by power‐current loop interaction, which results from the mismatched control parameters between the power loop and the current loop. Based on this, a self‐stability design method is proposed in this paper. This method reduces power‐current loop interaction by designing the power loop control parameters based on existing current loop constraints, thereby suppressing the high‐frequency resonance in the power loop. Finally, the experimental results validate the feasibility and effectiveness of the theoretical analysis and the proposed design method.