Frequency Regulation Method for Wind Turbines Considering Fatigue Loads Based on Model Predictive Control

To address the conflict between frequency regulation requirements and structural fatigue mitigation in wind turbines (WT), this paper proposes a Model Predictive Control (MPC)-based frequency regulation (FR) methodology. A dynamic wind turbine model encompassing aerodynamic, drive-train, and pitch control subsystems is established. This model is linearized to formulate state-space equations with rotor speed and pitch angle as state variables, and frequency regulation demand as the input. The MPC framework dynamically optimizes power references by predicting drive-train torque and tower thrust fluctuations while enforcing operational constraints. This enables simultaneous fulfillment of grid frequency regulation requirements and proactive suppression of mechanical loads. Case studies under turbulent wind conditions demonstrate that the proposed method significantly reduces fatigue damage in both drive-train torque and tower thrust loads compared to conventional control strategies, with particularly pronounced effectiveness at above-rated wind speeds. By incorporating power reserve capacity design, the approach harmonizes grid stability demands with turbine fatigue life optimization, providing an effective solution for the secure and economic operation of power systems with high wind penetration.