风、浪对海上风电机组振动特性的影响及控制策略

建立了波浪模型,分析了风力机气动载荷和气动转矩中与水动频率相关的脉动分量产生的原因,并基于GH Bladed平台仿真验证了这种脉动的存在性。为减小这种脉动以及风切变和塔影效应对风力机产生的影响,将积分后的塔顶振动加速度信号与统一变桨距参考信号叠加,减小统一变桨距信号,结合风力机输出功率的3倍频风轮旋转频率(3P)脉动分量以及每支叶片的方位角将其转换为该叶片的桨距角调节信号,实现变桨距控制。仿真结果表明,所提变桨距控制策略不仅能有效平缓风、浪引起的海上风力机叶根挥舞载荷的脉动,还能明显减小其气动转矩以及输出功率的波动,在减小风轮疲劳载荷的同时提高了海上风力机的输出电能质量。

Effect of wind and wave on vibration characteristics of offshore wind turbines and control strategy

A wave model is established, and the causes of the fluctuation components related to the hydrodynamic frequency in the aerodynamic loads and torque of offshore wind turbines are analyzed. The existence of the fluctuation is verified by simulation on GH Bladed platform. In order to reduce the fluctuation, wind shear and tower shadow effect on wind turbine, the integrated vibration acceleration signal of the top tower is superimposed with the reference signal of uniform variable pitch control, and converted into the variable pitch control signal of each blade combined with the 3P fluctuation components of output power and its azimuth. The simulative results show that the proposed variable pitch control strategy can not only effectively smooth the fluctuation of blade root flap-wise load caused by wind and wave, but also significantly reduce the fluctuation of aerodynamic torque and output power, which improves the output power quality of offshore wind turbines while reducing the fatigue loads.