Individual pitch control based on fuzzy PI used in variable speed wind turbine

With increasing of the capacity and flexibility of the wind turbine generator system (WTGS), it is more and more important to make the operation even better and to reduce the load while the wind speed is above the rated speed of WTGS. The individual pitch control can solve the above two problem efficiently. But the control of WTGS is very complicated because of the fluctuation and intermittence of wind speed and the complexity of power electronics. In classical control, the controller design needs accurate mathematical model, but this kind of model of the wind turbine generator system is very difficult to get because of the nonlinear characteristics. Using fuzzy controller, we can simplify and avoid the sophisticated mathematical model. Combining with the studied method and results of other scholars about pitch control, we put forward the individual pitch control based on fuzzy PI control and used to control the wind turbine so that it can be more stable and meanwhile its operation load can be reduced, and the fluctuation of the power is minimized. Firstly, we use oscillation acceleration of one bladed as input and PI controller to get one pitch angle; secondly, we use rotation speed as input and use fuzzy PI controller to get a pitch angle; and thirdly, we use a distributed controller to get a pitch angle; finally, combine the three pitch angles and used as the real control pitch angles of the three blades. The simulation results are given in this paper.