Predictive Control For Performance Optimal For Large-scale Wind Turbines

With the constant depletion of un-renewable global energy and the increasingly idea of environment protection, to develop and exploit the renewable energy effectively is more and more important for Human civilization. However, there are many new problems need to be solved for exploitation more efficient of new energy. Only for the utilize of wind energy, we usually want to build more bigger wind field and make more larger-scale wind turbines. There are more uncertainty and more bad condition with more larger wind farm, more nonlinear and effect from uncertainty with more larger-scale wind turbines. We need to improve the performance of wind turbine system to overcome the disadvantageous result from the certainty, to capture the wind energy as much as possible, to transform to power more stable. At the same time, to ensure the mechanical behavior and life of wind turbine.A PID controller with variance speed variance pitch is designed based on study to operation performance of wind turbines in this thesis. A DAC controller to restrain disturbance by step signal is designed against the effect from random disturbance. A LQR controller for optimize performance is designed against loads in power control. To ensure performance of close-loop system with PID at different operation points, a control strategy is presented by PI gain-schedule for variance speed variance pitch system. This strategy get better track performance of the system response by regulation of PI coefficients. Taking into account the adverse effects from the mechanical loads because of wind turbulence, KALMAN filter provide the optimal estimation wind speed for feed-forward, control strategy is presented combined disturbance feed-forward and predictive feedback for wind turbine to reduce loads on the basis of the above controllers. To restrain the wind disturbance timely, reduce the load efficiently, improve the power quality.