Asymmetric Synchronous Reference Frame-Based Frequency Coupling Suppression Control for Single-Phase Grid-Tied Converters

For single-phase grid-tied voltage-source converters (VSCs), frequency coupling suppression control (FCSC) emerges as a promising technique, streamlining controller design and stability analysis. However, its performance significantly degrades in the presence of grid frequency variations. This article presents an asymmetric synchronous reference frame (ASRF)-based FCSC for single-phase gridtied converters. Leveraging the inverse generalized Park transformation-based symmetrical phase-locked loop (IGPT-SPLL) and the ASRF structure, both grid frequency adaptivity and frequency coupling suppression are realized. Under this control, the studied system is accurately modeled as a simple single-input single-output (SISO) admittance, facilitating design-oriented analysis. The proposed control method stands out for its grid frequency adaptability and the achievement of zero steady-state current error, all accomplished with the utilization of proportional-integral (PI) controllers only. Simulations and experimental results validate the effectiveness of the proposed method.