Liu Yingming

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.

Research and simulation of direct drive wind turbine VSCF characteristic

For the purpose of achieving VSCF control system, this paper, stemming from the aerodynamics basic theory, analyzing the principle of pursuiting most wind energy. Through constructing the wind turbine stress model. Theory Wind energy utilization modulus is inferred in this paper. The paper focuses on VSCF control theory and operation mode. Firstly, the analysis of the relationship diagram of power curve in different wind speed is represented. Secondly, an optimal power curve is found. The wind turbine which works along this curve could obtain a maximum output power, achieving the goal of VSCF.

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.