不同独立变桨控制策略对风电机组部件载荷及变桨轴承寿命的影响研究

STUDY ON INFLUENCE OF DIFFERENT IPC STRATEGIES ON LOAD OF WIND TURBINE COMPONENTS AND LIFE OF PITCH BEARINGS

独立变桨控制(IPC)策略能够有效降低风轮的不平衡载荷,不同的IPC策略会直接影响风电机组的载荷及变桨轴承寿命。以降低风电机组运行过程中的不平衡载荷和成本,提升其竞争力为目的,基于叶根载荷测量方法设计了IPC策略控制器,以某兆瓦级风电机组为例,设计了不同开启条件的IPC策略,对不同IPC策略在风电机组运行过程中的降载效果进行了分析,研究了其对风电机组整机部件载荷及变桨轴承寿命的影响,并与统一变桨控制(CPC)策略进行对比,验证了IPC策略的可行性及实用性。研究结果表明:1) IPC策略对极端湍流风工况、极端风剪切工况下的叶根合弯矩、轮毂合弯矩有明显的降载效果。2) IPC策略对风电机组疲劳载荷有明显的降载效果,尤其对旋转轮毂坐标系下轮毂沿y轴力矩(My)的等效疲劳载荷的降载效果最为显著。3) IPC策略对变桨轴承寿命有非常明显的影响,影响程度与IPC动作的开启条件有关,越早开启IPC策略,对风电机组疲劳载荷的降载效果越明显,但越不利于变桨轴承寿命。

The independent pitch control(IPC)strategy can effectively reduce the unbalanced load of wind wheels,and different IPC strategies will directly affect the load and pitch bearing life of wind turbines.With the aim of reducing the unbalanced load and cost during the operation of wind turbines and enhancing their competitiveness,this paper designs an IPC strategy controller based on the blade root load measurement method.Taking a certain megawatt level wind turbine as an example,IPC strategies with different opening conditions are designed to analyze the load reduction effect of different IPC strategies during the operation of wind turbines.The impact of different IPC strategies on the load of wind turbine components and the life of pitch bearings is studied,and compared with the collective pitch control(CPC)strategy to verify the feasibility and practicality of the IPC strategy.The research results show that:1)The IPC strategy has a significant load reduction effect on the root resultant bending moment and hub resultant bending moment under extreme turbulent wind operating conditions and extreme wind shear operating conditions.2)The IPC strategy has a significant reduction effect on the fatigue load of wind turbines,especially on the equivalent fatigue load of the hub along the y-axis moment(My)in the rotating hub coordinate system.3)The IPC strategy has a very significant impact on the life of pitch bearings,and the degree of impact is related to the opening conditions of the IPC action.The earlier the IPC strategy is opened,the more obvious the load reduction effect on the fatigue load of wind turbines,but the less conducive it is to the life of pitch bearings.