Wind farm model with DFIG for small signal stability study

Appropriate models of wind farm are necessary for the power system stability study with large scale wind farm penetration. In this paper, an aggregated wind farm model with doubly fed induction generator (DFIG) based wind turbine for small signal stability study is proposed to deal with the situation that the wind turbines operate receiving different incoming wind speeds. The different control strategies of wind turbines are considered for modelling wind farms. It is demonstrated that the wind turbines with the identical dynamic parameters and control strategies can be aggregated as one equivalent wind turbine, even though the operating condition for each wind turbine is not the same. Through the calculation of eigenvalues and participation factors, the aggregated wind farm model is verified by comparing with the full wind farm model. From the simulations, it comes to the conclusion that the improved aggregated model considering the different control strategies and wind speed can effectively track the changes of the dominant oscillation mode.