Wang Xiaodong

Individual pitch control for variable speed turbine blade load mitigation

Dynamic load is a key consideration in large scale wind turbine design. It is approved that the performance of controller can distinguish impact wind turbine loads. During pitch control algorithm design, if load influence is considered, it will be benefit to lower cost of whole wind turbine and extend longevity. In this paper, an individual pitch controller is developed based on a kind of model free control strategy, to mitigate the blade root load for variable speed wind turbine. The measured blade root bending moment is taken as one of the inputs of the controller, and the three pitch demand as the controller output. The control strategy was simulated in bladed external controller based on a 3.0 MW doubly fed variable speed wind turbine model, the simulation result verified itpsilas feasible and effective. The blades root load is mitigated evidently compared to classic collective pitch control.

Coordinate control strategy based on expert decision system of wind turbine

In this thesis, the torque control, pitch control and general wind turbine coordinate control strategy of variable-speed adjustable-pitch wind turbine were researched. The control object is local SUT-1500 wind turbine based on independent design. First, the control object was modeled by the modal linearization process using Bladed software, among which the mechanical dynamic response was considered. Then the operation range of wind turbine was divided into several regions and the main control strategy of each region was researched. After the description of optimal tip speed ratio control in region 2, the PID control and Simplex Method PID parameters optimal were used in region 2psila torque control and region 3psila pitch control. In the end, the coordinate control strategy based on Expert Decision System of the general whole wind turbine was described and comparatively analyzed based on experiment results.

Multi-objective optimization torque control of wind turbine based on LQG optimal control

Considering power quality and drive train load, a kind of linear quadratic Guassian optimal control strategy based on Kalman filter is proposed in this thesis, in order to reduce gearbox fatigue load while improving output power quality of wind turbines. With this optimization strategy, system noise and measurement noise are estimated through Kalman filter, adjusting dynamic optimal gain according to the system of estimation, in order to achieve optimal control of different working point. A 3MW doubly-fed wind turbines is taken as the control object in the simulation,the results indicate that, compared with the conventional pitch control strategy, the proposed pitch controller not only reduced the fluctuation of power but also reduced the torque ripple of gearbox, the fatigue load of gearbox and other key component in drive train were mitigated.