基于双轴同步电机视角的构网型与跟网型变流器互联小信号同步稳定性分析

With the integration of large-scale renewable energy sources into the power grid, the interconnection between Grid-Forming (GFM) Voltage Source Converters (VSCs) and Grid-Following (GFL) VSCs has become a prominent trend in the power system. However, significant differences in the synchronization mechanisms between GFM VSCs and GFL VSCs have led to unclear small-signal synchronization stability characteristics in interconnected systems. To address the gap, this paper employs the concept of a synchronous generator that simultaneously controls the dq internal potential components for a better physical understanding, constructing an equivalent structure capable of unifying GFM-VSC and GFL-VSC. Mathematically, a synchronization stability analysis model for interconnected systems based on current sources is established. Furthermore, a quantitative indicator for the small-signal synchronization stability margin in interconnected systems is introduced based on the generalized Nyquist criterion, and a concise analysis is presented regarding the impact of control parameters on small-signal synchronization stability. In addition, an optimization method for GFM-VSCs parameters and configuration based on participation factor iteration is proposed. Finally, simulation examples are built in MATLAB/Simulink to verify the rationality of the theoretical analysis.