Pitch angle controllers design for a horizontal axis wind turbine

This paper focuses on control system design for wind turbine power regulation and the comparison of the techniques presented. A PI controller, Fuzzy controller and a combined Fuzzy-PI are applied to a 750KW fixed-speed horizontal axis wind turbine. The Fuzzy controller is proposed with two inputs, wind speed and output power error, with these inputs the controller adjusts the pitch angle of the turbine blades to regulate the output power for wind speeds above rated speed. The PI controller is designed by means of Ziegler-Nichols method and the Fuzzy-PI presents a correlation factor to combine the control actions of both controllers and assign a specific weight to each one. Simulations are presented to prove the efficiency of each control technique; the results show that the Fuzzy-PI controller gives a better behavior than the Fuzzy controller or PI controller on their own.