风力发电塔系统整体建模与模态分析研究

Research on Inherent Characteristics of Wind Turbine Tower

为了判断风力发电塔系统是否能避开共振,需对其进行模态分析。提出了考虑"桨叶—轮毂—机舱—塔筒"耦合的整体建模的方法,可用于风力发电塔系统模态的计算。分别进行了停机阶段、运行阶段和切出阶段的模态分析,对比其频率和固有振型。对比结果表明:三个阶段的频率基本相同,只须验算停机状态下的频率满足规范即可;塔筒的振动形式主要为侧向弯曲振动、前后弯曲振动和扭转振动;桨叶在前十阶的振动形式主要为挥舞振动和摆振,且三桨叶振动存在一定的规律;相对于停机阶段,运行阶段时振型基本相同,切出阶段时振型有较大差异。

Modal analysis must be carried out in order to judge whether the wind turbine tower system can avoid resonance. A coupling method of the overall model of blade, hub, nacelle and tower is put forward and is used for the modal computation of wind turbine tower system. The modal analyses are carried out respectively in outage state, running state and feathering state, and the frequencies and modes of running state and feathering state are compared with the test results in outage state. The results show that the frequencies in the three stages are basically the same, and the frequency in outage state need only to satisfy the design requirements of Germanischer Lloyd guideline; the main vibration styles of the wind turbine tower appear lateral bending vibration, forth-and-back bending vibration and torsion vibration ; the main vibration styles of the blades in the previous ten phrases appear out-of-plane vibration and in-plane vibration, and the three blade vibration has certain rule. Through comparison with the modes in outage state, the modes in running state are consistent basically on the whole and the modes in feathering state have remarkable differences.