Control of Variable Speed Wind Turbines: Comparing ۱DoF Closed-Loop, PID, and Modified PID Controllers

Effective control strategies are necessary for enhancing wind turbine efficiency and lifespan. The purpose of this paper is to control the rotational speed of a wind turbine by adjusting the pitch angle of the blades. Initially, a one-degree-of-freedom closed-loop controller is designed based on the complementary sensitivity function, followed by a PID and a modified PID controller. Finally, their performance in tracking the desired rotational speed of the wind turbine, which includes step and sinusoidal signals, is compared. The ۱DOF controller introduced oscillation, while the PID controller eliminated oscillation but exhibited steady-state error. To preserve the advantages of the PID controller and eliminate steady-state error, an integrator term (۱/s) has been added to the controller. Consequently, the modified PID controller has been designed. The results of the modified PID controller show no steady-state error or peak overshoot percentage for step inputs. While, the PID and the one-degree-of-freedom closed-loop controller in tracking the step reference input result in steady-state errors of ۱.۴۶۴% and ۰.۴۹۷% and peak overshoot percentages of ۲۳.۶۸۸% and ۸۴.۳۸۹%, respectively. During the implementation of the one-degree-of-freedom closed-loop controller, significant oscillations occur while tracking the desired input. The oscillations occurring in the rotor speed can lead to increased fatigue in various wind turbine components, which is an undesirable outcome. However, no oscillations are observed in rotor speed with the PID and modified PID controllers. Finally, according to the obtained results, the modified PID controller demonstrates superior performance compared to the other controllers in tracking the desired rotor speed

کلیدواژه ها:

Wind Turbine ، Rotational Speed ، Step Tracking ، Modified PID Controller ، Wind Turbine ، Rotational Speed ، Step Tracking ، Modified PID Controller