Controlling structural vibrations in wind turbines by constructing function V

For a variable speed large scale wind turbine, the vibration issues become a key problem that cannot be ignored in the turbine's life cycle. Wind turbine tower vibration will cause superfluous mechanical loads. To resolve the vibration issue, a method for constructing the energy function V is proposed to meet the demands of safe operation. The Lyapunov theorem has been embedded in a wind turbine control algorithm, proving the theoretical feasibility of stability control based on function V. According to an analysis of this complex nonlinear model for the wind turbine, the general method of constructing an energy function suitable for a wind turbine is presented explicitly. The feasibility of applying an energy function to wind turbine vibration control is verified experimentally using a 3.0-MW direct drive wind turbine model. The experimental results indicate that the dynamic performance of the tested wind turbine model with energy function control is significantly better than that of the uncontrolled structure in terms of the reduction of nacelle acceleration, velocity, and displacement response.