Dual-Stage Active Power Control for Wind Turbines via Coordinated Pitch and Torque Adjustments

Although the traditional pitch angle control (PAC) method has a wide regulation wind speed range for tracking active power commands, the pitch servo system’s slow response speed hampers the wind turbine’s ability to track power commands accurately and increases the mechanical loads on the pitch system. To deal with this issue, this paper proposes a novel dual-stage active power control strategy based on coordinated pitch and torque adjustments, considering the difference in response speed of different actuators of the wind turbine. In this design, the pitch angle control loop is defined as a slow actuator control loop, while the torque control loop is regarded as a fast actuator control loop. On this basis, we study the integration of three dual-stage control structures and the PAC method, namely parallel PAC (P-PAC), master-slave PAC (MS-PAC), and decoupled PAC (D-PAC). Finally, comparison studies are conducted using the OpenFast platform, demonstrating that the P-PAC method has the best control performance in tracking power commands and the load optimization of the pitch system.