Fuzzy Logic Control Versus Traditional PI Control Applied to a Fixed Speed Horizontal Axis Wind Turbine

Abstract

A comparison between three types of control algorithms for a 1.5 MW horizontal axis fixed speed wind turbine is presented. A fuzzy logic proportional integral control (Fuzzy PI), a fuzzy logic control (FLC) and a classical proportional integral (PI) control are tested. A robustness test by adding noise to the wind speed signal is also performed. Design of the proposed Fuzzy PI control algorithm was achieved via tuning with the Ziegler-Nichols approach, 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 a 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 was designed for tuning as well as simulation performance studies. Results demonstrate the effectiveness of all techniques, 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.