Intelligent control of a class of wind energy conversion systems

This paper discusses the control problem for a class of wind energy conversion systems (WECS). It first develops a detailed model and then compares four control algorithms based on conventional and intelligent control theories. A simple PI conventional controller for the exciter loop is carried out by using a first order model. When the system operating points change, the PI controller fails to provide sufficient damping or acceptable performance. Therefore both fuzzy voltage and fuzzy power regulators are introduced. Also a conventional adaptive pitch controller is proposed to adjust the pitch angle of the rotor blades in order to maximize the energy capture and reduce the mechanical loads. As an alternative to this controller, a neural network controller is also designed. Using the existing nonlinear wind model and the different control algorithms, the dynamic behavior of the controlled (WECS) is simulated. By selecting convenient wind data, the system characteristics such as its tracking performance, its robustness and its ability to recover from large disturbances are studied and discussed.