Primary Frequency Control of Deloaded Wind Turbines Considering the Pitch Angle Dynamic Process

As large-scale wind power is integrated into the grid, the requirement for stable grid operation necessitates that wind turbines retain reserves and release these reserves when frequency events occur in the grid to support active power balance and frequency stability. Existing studies typically follow the steady-state perspective of primary frequency control (PFC) in synchronous units, where wind turbines assume part of the power deficit when the grid frequency reaches a steady state. However, they overlook the dynamic process of pitch angle changes and its influence on the effectiveness of wind turbines (the lowest point of grid frequency) participating in grid frequency regulation. To address this, this paper first analyzes the influence of different dynamic processes of pitch angle changes on the effectiveness of wind turbines participating in PFC in the grid. Then, it constructs the coupling relationship between the pitch angle and speed of the deloaded wind turbine, making the pitch angle change rate and speed change rate maintain a given proportional relationship. This ensures sufficient aerodynamic power during the initial stage of frequency regulation when the wind turbine bears the maximum imbalance power. The results show that the proposed control method for PFC of deloaded wind turbines can maintain turbine stability while further improving the grid's frequency nadir (FN) and enhancing the performance of wind turbines participating in grid frequency regulation.