A comprehensive analysis of wind farm's capability to participate in frequency regulation of power grids

Due to doubly-fed induction generation (DFIG) cannot respond to changes in load because its active power is decoupled. It becomes increasingly evident that wind power's non-participation in frequency regulation negatively affects power grids as wind power penetration grows. This paper aims to analyze how DFIG participates in frequency regulation. This study examines the relationship between wind power penetration, the ratio of an adjustable wind turbine, the adjusting coefficient of frequency, and the wind energy utilization factor. A description of the control strategies for adjustable wind turbines with additional virtual inertia for frequency regulation follows. This paper analyzes the impact of wind power on the grid frequency under different conditions, such as penetration ratios at different wind speeds, steady-state operation, and sudden load changes, using the DFIG model developed for the MATLAB/Simulink simulation platform. It is also verified that DFIG is legitimately participating in frequency regulation. To ensure frequency stability of the power grid under varying penetration ratios and the ability to adjust the frequency at different wind speeds, wind turbine models participating in frequency regulation are connected to the 4-machine 2-area model; presented are the minor ratio of an adjustable wind turbine to ensure frequency stability of the power grid under different penetration ratios. According to simulation results, wind farms should ensure that wind turbines working at rated wind speeds participate in priority frequency regulation.