湍流风况下叶片覆冰对风电机组动力学特性的影响研究

Research on the Influence of Ice Accretion on the Dynamic Characteristics of Wind Turbine Under Turbulent Wind Conditions

在湍流风模型下,使用气弹软件对不同覆冰状态的风电机组进行了建模和动力学仿真,并分析了冰层密度对叶片、塔筒变形和机舱轴向加速度、叶片加速度频谱特性的影响。仿真结果表明,当风速较低时,覆冰会增大叶尖的挥舞变形,且变形增加量随冰层密度的增大而增大;叶片覆冰会在一定程度上加剧塔顶的振动幅值;相较于正常工况,叶片覆冰后的固有频率更低,其一阶挥舞频率和机组3P频率的重合范围相对增大,加剧了共振发生的风险,在叶片设计时须引起重视。研究成果可为覆冰诊断和除冰提供参考。

Under turbulent wind cases,the aeroelastic software is employed to model and simulate the dynamics of wind turbine with various icing conditions.The influence of ice density on the deflection of blade and tower,the axial acceleration of nacelle and the spectral characteristics of blade acceleration are analyzed.The simulation results show that ice accretion will enlarge the flapping deflection of the blade tip under low wind speed.Meanwhile,the increment of deflection rises with the increase of ice density.In addition,the vibration amplitude at the top of the tower will be aggravated to some extent by icing blades.Compared with the normal cases,the ice accretion reduces the natural frequency of the blade.In the meantime,the coincidence range of blade first-order flapping frequency and the wind turbine 3P frequency is relatively increased,which intensifies the risk of resonance.This phenomenon should be paid attention to in blade design.The research results can provide a reference for icing diagnosis and deicing.