风力机叶片压电抑振效应与能量耗散机制研究

Piezoelectric vibration suppression effect and dissipation mechanism of energy of wind turbine blades

压电智能叶片是随着风力机向大型化发展而被提出的自适应减振概念叶片,本文探索了叶片压电抑振效应和能量耗散机制,提出了适用于变截面三维叶片的等效梁截面气弹模型设计方法,并基于同步测振测力气弹风洞试验对比研究了15 MW风力机叶片压电抑振效应;再基于二次开发的机电耦合叶片动力学模型,分析了机电气弹耦合模态的转速演变规律与能量分布形式,揭示了压电叶片的能量耗散机制。研究表明:提出的气弹风洞试验方法可有效反映压电叶片风振抑制效果;压电材料可缩小风力机叶片的敏感风向角区间,提高大幅锁频振动临界风速,延长气弹失稳的能量积累时间;压电材料导致叶片风振能量在模态空间均分转移,削弱了负阻尼模态的能量集聚,增强了正阻尼模态的能量耗散。

Intelligent piezoelectric wind turbine blade is a new conceptual blade with adaptive vibration attenuation proposed with the large-scaled development of wind turbines.This study explores the vibration attenuation effect and energy dissipation mechanism of piezoelectric blades.It could provide a theoretical reference for piezoelectric load vibration reduction design for ultra-large offshore wind turbine blades.Moreover,an aeroelastic model design method of equivalent beam section applicable to section-variable three-dimensional blades is proposed and the piezoelectric vibration attenuation effects of 15 MW wind turbine blades are com‑pared based on synchronous aeroelastic wind tunnel test of vibration and force.The evolution law of rotate speed and energy distribution form of electrical-aeroelastic coupling mode are analyzed based on the secondary developed kinetic model of electromechanical coupling blades.Meanwhile,the dissipation mechanism of energy of piezoelectric blades is disclosed.The research demonstrates that the proposed aeroelastic wind tunnel test can reflect the wind-induced vibration attenuation effect of piezoelectric blades.Piezoelectric materials can narrow the interval of sensitive wind angle of wind turbine blades,increase the critical wind speed for frequency-locked vibration significantly and prolong the energy accumulation time of aeroelastic instability.Piezoelectric materials lead to a uniform transfer of wind-induced vibration energy of blades in the modal space,weaken energy accumulation of negative damping modal,and strengthen the energy dissipation of positive damping modal.