风突变效应对风力机振动特性影响研究

摘要

A wind turbine suffers from complex environmental conditions and wind is the most important and direct factor that can affect its aerodynamic and structural characteristics.Abrupt wind speed change may lead to higher aerodynamic loads.In order to analyze the structural dynamic characteristics of a wind turbine operating under the action of a strong turbulent wind,simulations were performed with a NREL WindPACT 1 .5 MW land-based wind turbine model to study dynamic responses of the wind turbine's blades and tower.The results slowed that before and after adding a coherent structure,fractal dimensions of wind speed at hub point are both around 1 .5;adding a coherent structure into a turbulent flow can cause a higher wind speed change and a stronger turbulent intensity,compared with the basic turbulent wind;when the wind achieves an ultimate speed,the wind turbine's blades have both in-plane and out-plane vibrations;turbulent wind with a coherent structure can make vibration accelerations of blades and tower foldincrease.%风是影响风力机气动特性和结构特性的最直接的因素，风速突变将诱发风力机更强的气动载荷。为分析风力机在高突变湍流风作用下结构动力学振动特性，以 NREL 实测数据为湍流风数据源，并添加拟序结构刻画风速突变，以 NREL Wind PACT 1．5 MW 桩柱式风力机为样机，分别研究了风力机叶片和塔架的动力学响应。结果表明：添加拟序结构前后，轮毂点处风速分形维数均在1．5左右；拟序结构的添加使得基础湍流风具有更大的风突变以及更高的湍流强度；切出风速工况，风力机叶尖位移同时为挥舞和摆振；拟序结构的添加使得叶片和塔架振动加速度成倍增加。