This paper conducts a comprehensive investigation into both small-disturbance and large-disturbance stability of the GFM-DFIG system
focusing on the influence of short-circuit ratio (SCR) and key system parameters. Firstly
a full-order small-signal model of the GFM-DFIG is developed
and root locus analysis is employed to reveal the impacts of the grid-forming link
current control link
and SCR on the system’s small-disturbance stability. Based on this full-order model
a reduced second-order model is then derived to analyze large-disturbance stability. The equal-area criterion is used to rapidly determine the critical clearing conditions and evaluate how variations in SCR and system parameters affect the large-disturbance stability margin. Finally
simulation studies are conducted to validate the theoretical analysis. The results confirm that the identified stability characteristics provide valuable insights for parameter tuning and optimal design of GFM-DFIG systems.
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