限功率控制下风电机组叶片疲劳损伤研究

基于叶素-动量理论计算风电机组叶片气动载荷,建立其疲劳载荷模型;将叶片简化为悬臂梁,采用雨流计数法、Goodman经验公式和Miner线性累计损伤理论计算风力机叶片疲劳损伤和等效疲劳载荷;根据2种限功率控制策略计算不同限功率水平和湍流强度下风力机叶片单位时间的疲劳损伤量,分析限功率运行工况对叶片疲劳损伤的影响。结果表明,新型限功率控制策略可减少变桨系统的动作频率和动作幅度,但其稳定运行状态对叶片的疲劳损伤量大于传统限功率控制策略。最后通过三维函数拟合得到疲劳损伤函数,可应用于限功率条件下风电场优化调度。

STUDY ON FATIGUE DAMAGE OF WIND TURBINE BLADE UNDER POWER CURTAILMENT CONTROL CONDITION

The fatigue load model of wind turbine blade is established based on the Blade Element Momentum theory,and the validity of the model is verified the results of GH-Bladed.The blade is simplified as a cantilever beam,then the fatigue damage and equivalent fatigue load are calculated by the Rain-flow counting method,Goodman empirical formula and Miner linear fatigue damage accumulation rule.In this paper,two kind of wind power curtailment control(WPCC)strategy are introduced,then the fatigue damage of wind turbine blade under different power level and turbulence intensity is calculated to analyze the influence of limiting power conditions on the fatigue damage of blades.The results showed that the novel WPCC strategy can decrease the frequency and amplitude of the pitch actor,but the fatigue damage of the blade is worse than the traditional WPCC strategy.The fitting fatigue damage function can be used to optimal power dispatch in wind farm under the condition of WPCC.