Aanalysis of the impact of grid-forming doubly-fed induction generator parameter on transient stability and small-signal stability

The Grid-Forming Doubly-Fed Induction Generator (GFM-DFIG) has attracted considerable attention due to its capabilities in voltage self-regulation and inertia support, although stability concerns persist. Transient stability is mainly governed by grid-forming control, whereas small-signal stability is more affected by both the grid-forming control and the current control loop. This paper offers a thorough investigation into how short-circuit ratio (SCR) and system parameters affect the stability of GFM-DFIG, combining transient stability and small-signal stability analyses. First, a full-order model of the GFM-DFIG is established, followed by a reduced-order transient model. Using the transient model, the transient stability limit voltage (TSLV) under permanent fault conditions is calculated, providing a key benchmark for evaluating the generator’s transient stability. A detailed quantitative analysis is then conducted to explore the effects of SCR and parameter variations on the transient stability boundary. Next, small-signal stability is assessed through eigenvalue trajectories and damping ratios, revealing the impact of various parameters. The findings show that optimizing parameter settings can enhance both transient stability and small-signal stability. Finally, simulations are performed to validate the accuracy of the theoretical analyses.