低风速风力机最大风能追踪的互补滑模控制

Complementary sliding mode control for maximum wind energy tracking of low wind turbines

针对风力机系统在最大功率点跟踪(MPPT)阶段易受风速等不确定因素的影响,为了进一步提高风力机的风能捕获效率,本文在滑模控制的基础上提出了一种互补滑模控制方法.首先,建立了含有干扰项的风力机系统的线性化模型,采用广义滑模面与互补滑模面相结合的方法设计了互补滑模控制器,并在理论上证明了此控制方法能够有效保证风力机转速跟踪误差的收敛性,且能提高转速跟踪精度.其次,采用风力机专业仿真软件FAST对美国可再生能源实验室(NREL)的600 kW风力机进行了仿真实验,结果表明本文所提出的控制方法不但能提高风力机的风能捕获效率,而且能有效减小转速跟踪误差.最后,将本文所提方法与现有常见的几种控制方法相比较发现:风力机系统在互补滑模控制策略下,具有更高的风能捕获效率和更小的转速跟踪误差.

In the maximum power point tracking(MPPT)stage,the wind turbine system is susceptible to wind speed and other uncertainties,in order to improve the MPPT efficiency of wind turbines,a complementary sliding mode control method based on sliding mode control is proposed in this paper.Firstly,the linearized model of wind turbines with disturbance is established.A complementary sliding mode controller is designed by combining generalized sliding surface and complementary sliding surface.It is proved theoretically that this control method can effectively guarantee the convergence of the rotor speed tracking error of wind turbines and improve the tracking accuracy of rotor speed.Secondly,the 600 kW wind turbine of the renewable energy laboratory(NREL)of the United States is used to simulation by the professional simulation software FAST.The simulation results show that the proposed control method can not only improve the MPPT efficiency of wind turbines,but also reduce the rotor speed track error.Finally,the method proposed in this paper is compared with several common control methods,it is found that the higher MPPT efficiency and smaller rotor speed tracking error can be achieved under the complementary sliding mode control strategy.