直驱永磁同步风电机组在全风速范围内的控制策略研究

Research on control strategy of direct-drive permanent magnet synchronous wind turbine in full wind speed range

为实现直驱式永磁同步风电机组在全风速范围内的高效、稳定运行,提出了一种基于最优转速给定的最大功率点跟踪控制策略与一种变桨距控制策略。当风速波动时,发电机转子转速的参考值将根据风电机组运行状态的不同选择不同的计算方式,使得风力机功率系数最大或稳定在额定转速不超速。而桨距角的大小将根据发电机的输出功率变化,当输出功率小于额定值时保持为0,大于额定值时增大使得输出功率稳定在额定值附近。最大功率点跟踪控制系统及桨距角控制系统都以发电机的输出功率大小作为控制方式的切换条件,无需复杂的切换规则。在Matlab/Simulink仿真平台上全风速范围内的风电机组的运行结果验证了所提出的控制策略的正确性与有效性。

In order to realize the efficient and stable operation of direct-drive permanent magnet synchronous wind turbines in the full wind speed range,a maximum power point tracking control strategy based on optimal speed reference and a pitch control strategy are proposed.When the wind speed fluctuates,the reference value of the generator rotor speed will be selected according to the different operating modes of the wind turbine,so that the wind turbine power coefficient is maximal or the rotor speed is stable at the rated speed without over speed.The pitch angle will vary according to the output power of the generator:when the output power is less than the rated value,it will remain at 0;when it is greater than the rated value,it will increase to reduce the power coefficient of the wind turbine so that the output power is stable at the rated value.Both the maximum power point tracking control system and the pitch angle control system use the output power of the generator as the switching condition of the control mode,which does not require complicated switching rules.The operating results of the wind turbine generator in the full wind speed range on the Matlab/Simulink platform verify the correctness and effectiveness of the proposed control strategy.