电压跌落对风力机叶片振动影响分析  

Investigation of voltage sag impact on wind turbine blade vibrations

作　　者：尹尧杰 廖明夫[1] 吕品[1] 刘展翅 王四季[1] 

机构地区：[1]西北工业大学动力与能源学院,西安710029

出　　处：《振动与冲击》2016年第10期192-201,共10页Journal of Vibration and Shock

基　　金：中央高校基本科研业务专项资金资助(310201513J(Ⅱ)CG015)

摘　　要：风力机单机容量不断增大,装机容量不断增长,风力机与电网之间的耦合效应越发突出。电网的干扰以及故障会对风力机机械部件产生冲击。为了获得叶片在电网电压跌落时的动态响应,把叶片简化为悬臂梁,用3D Timoshenko梁进行离散化建模,建立了叶片运动的动力学方程,基于某1.5 MW风力机低电压穿越测试得到的转速,变桨曲线,获得叶片所受时变载荷的基础上,运用Newmark法对叶片在电压三相对称跌落与不对称跌落下的动态响应进行了计算。结果表明电压的跌落会对叶片产生冲击效应,在叶片拍打方向振动幅值比挥舞方向更大。叶片振动变化的总体特征随着风机载荷和电压跌落的幅值增大而增大的。同等工况和跌落幅度下,三相对称跌落时振动的变化要大于不对称跌落的振动变化。Recently the size and the capacity of wind turbines increase rapidly,the interactions between the wind turbines and the electric grid becomes more obvious.The disturbances from the grid and the faults of the grid will have impact on mechanical components of wind turbines.In order to obtain the dynamic responses of the blade under voltage sag,the blade was modeled as a cantilever and discretized by applying 3D Timoshenko beam element,considering the centrifugal stiffening of the rotating blade.The structural dynamic equation of the blade was established and the time-varying loads acting on the blade were calculated based on the data from a 1.5 MW wind turbine LVRT（low voltage ride through）test.The dynamic responses of the blade under the three-phase symmetrical voltage dip and three-phase asymmetry dip were calculated by applying Newmark method.The results show that,the voltage dip produces the transient loads and excites the vibrations of the blade.The amplitude of vibration in the flap wise is bigger than that in the edgewise.The vibration increases with the increase of the load of wind turbine and the magnitude of voltage drop.The dynamic responses of the blade under the three-phase symmetrical voltage dip are larger than those under three-phase asymmetry dip.

关 键 词：电压跌落 风力机 叶片 Timoshenko梁模型 动态响应 

分 类 号：TK83[动力工程及工程热物理—流体机械及工程]