Impedance Modeling and Stability Analysis of Single-Phase LCL-type Grid-Connected VSC Based on Harmonic Linearization

This paper presents a simple time-domain input impedance modeling method based on harmonic linearization for single-phase LCL-type grid-connected voltage-source converter (VSC). The physical meaning of this method is clear, and the series resistance of the LCL filter is considered in the modeling process, which is more realistic. In addition, the generalized Nyquist criterion is used to analyze the impact of the grid impedance on the stability of the single-phase VSC-grid system. Finally, simulations are conducted to verify the effectiveness of the proposed method and the correctness of theoretical analysis.