Analysis and modeling of wind turbine generators considering frequency controls

A rapid increase in wind power installed capacities in many countries can potentially have an effect on their power grid dynamics, in particularly, on the system frequency stability. This is due to the fact that some basic wind turbine generator technologies such as doubly fed induction generator (DFIG), which is most commonly and widely used at present time, do not originally contribute to frequency response in a similar manner to conventional synchronous generators. Therefore, the frequency response feature of the DFIG-based wind turbine needs to be developed. In this paper, the frequency control for the DFIG-based wind turbine has been modeled using synthetic inertia and rotor speed control schemes, in which both controls are implemented according to the mathematic calculation. Then, the frequency response characteristics of the DFIG-based wind turbine associated with the individual control schemes and combined control schemes have been analyzed using MATLAB/Simulink. The simulation results indicate that the frequency response performance of the DFIG-based wind turbine can be enhanced by using the combined control schemes.