Reduced-order Model of Frequency Response Including PLL-based DFIG Wind Turbine

In the existing power system frequency response models, most of them ignore the dynamic process of inertial response of renewable energy generation equipment, which makes the new characteristics of power system frequency dynamics not described. In this paper, we take a doubly-fed induction generator (DFIG) as an example and establish its electromechanical time-scale motion equation in the frequency domain from its basic control structure, and extract the active power-frequency branch as the equivalent inertia of the DFIG, and the average frequency response model of the system was developed on this basis. Considering the inconvenience of higher order systems in the analysis, the least squares method is used to reduce the order of the frequency response model. Finally, the above model is simulated in MATLAB/Simulink and the simulation results are analyzed.