Fuzzy-PI Control, PI Control and Fuzzy Logic Control Comparison Applied to a Fixed Speed Horizontal Axis 1.5 MW Wind Turbine

This paper presents a comparison between three types of control algorithms for a 1.5 MW horizontal axis fixed speed wind turbine. It presents a fuzzy logic proportional integral control (Fuzzy P1), a fuzzy logic control (FLC) and a classical proportional integral (PI) control. Design of the proposed Fuzzy PI control algorithm was achieved via tuning with the Ziegler-Nichols approach at low and nominal wind speeds, using the same methodology for the PI controller tuning with the difference of incorporating a fuzzy logic section. The fuzzy logic section selects the desired PI gains according to wind speed with a smooth control transition. Fuzzy logic control was designed to obtain maximum power extraction at low wind speeds and to limit power extraction at 1.5 MW nominal power set point. Aerodynamic characteristics of the wind turbine were studied in order to gain a basic understanding of the system dynamics. A 1.5 MW horizontal axis wind turbine model with a squirrel cage induction generator model was designed for tuning as well as simulation performance studies. Simulation of the wind turbine was performed for two wind profiles, low wind speed and near nominal with fast wind speeds to test the controller's response. Results demonstrate the effectiveness all techniques; appropriate responses were obtained for both simulation scenarios, achieving a controlled power extraction near the nominal value for the three controllers and maximum power extraction in low wind speeds for the Fuzzy PI and FLC control algorithms. A robustness test was performed by adding a normally distributed noise effect to wind speed input to the controllers, achieving good results for the Fuzzy PI control algorithm.