Modelling of the DFIG based wind farms for small signal stability analysis of weak power grids

This work proposes a model of the doubly fed induction generator (DFIG) based wind farm for small signal stability analysis (SSSA) of weak power grids. As indicated in the paper, dynamics of the phase locked loop (PLL) and DFIG rotor current loop of the proposed model are crucial for the accurate SSSA of the wind power integrated power system, especially in the weak power system situation where the wind park is linked into the grid with long transmission lines. Compared with the full-scale and other well-known models, the proposed reduced-order model presents high precision and satisfactory simplification for SSSA and transient simulations. The results are verified by modal analysis and nonlinear time domain simulation.