Equivalent Modeling of DFIG-Based Wind Farms Considering Auxiliary Frequency Regulation Service

The frequency regulation pressure of power systems with high renewable power penetration can be effectively relieved by wind power participating in auxiliary frequency regulation service. This paper presented an equivalent method for doubly fed induction generator (DFIG) -based wind farms considering auxiliary frequency service. Firstly, the characteristics of different frequency regulation methods were analyzed and compared, and a single machine infinite grid model based on integrated frequency regulation strategy was built. Secondly, the differences in transient active power responses of a DFIG working on various wind speeds were qualitatively and quantitatively analyzed, respectively, and a two-step clustering method based on the active power response is proposed. Finally, the electromechanical transient model of wind farm was simulated on MATLAB/Simulink platform and the results were compared to that of the traditional equivalent model and detailed model. Simulation results showed that the proposed model can more accurately fit the power characteristics of the wind farm.