Research on Modeling and Control Methods of Variable-speed Variable-pitch Wind Turbine Generators

In view of the high-order, nonlinear, strong coupling, multivariable and time varying character of wind energy conversion system, the fuzzy-logic control strategy is introduced in this paper. First, this thesis analyzes and establishes the mechanism model for each component element of the megawatt class variable-speed variable-pitch wind turbines as well as the wind speed model. Second, for the goal of maximum wind power extraction under rated wind and peak power output maintaining above rated speed wind, PID controllers as well as fuzzy-logic controllers are designed respectively by different wind velocity condition. The simulation results demonstrate that no matter for the following up performance or the anti-interference capability, the fuzzy controllers which are devised in the paper have a better control effect than PID controllers. The fuzzy controllers can reduce system's overshoot and regulation time more effectively, offset the negative impacts of nonlinearity, and they have better robustness too.