An Extended SFR Model With High Penetration Wind Power Considering Operating Regions and Wind Speed Disturbance

High-penetration wind power grid access requires wind turbine generators (WTGs) to provide frequency regulation, and an accurate system frequency response (SFR) model is required for frequency stability analysis. To overcome the limitations of conventional methods, different operational regions of WTGs and wind speed disturbances are fully taken into account and a frequency response model of wind power (WPFR) participating in primary frequency control is developed by employing small signal analysis theory. Then, the WPFR model is integrated into the conventional SFR model to obtain an extended SFR model, which is given in the form of a symbolic transfer function with two input variables and single output variable, and can clearly and intuitively show the specific parameters that determine the system frequency response. Finally, the accuracy and effectiveness of the extended SFR model are verified through comparisons of the detailed model, and the impacts of initial wind speed, wind speed disturbance, and the wind power's penetration level on the system frequency response characteristics are analyzed and discussed. Such extended SFR model significantly avoids the need for modeling complex transient process while preserving the frequency response fidelity in a satisfactory level.