气动力及外部荷载下覆冰输电线共振特性分析

Aeroelasticity and resonance characteristics analysis of ice-covered transmission lines under aerodynamic and external loads

为进一步研究覆冰输电线的非线性振动问题,在考虑气动荷载和外部激励的前提下分析输电线的舞动特征,建立覆冰输电线在气动荷载及外部激励作用下的力学模型,推导模型的非线性舞动方程。基于Galerkin方法将推导的非线性舞动方程转换成常微分方程,利用多尺度法得到模型的主共振及谐波共振的幅频响应函数。数值分析结果表明:输电线产生主共振时,响应幅值随着调谐参数的变化会出现同步与失步现象,外部激励荷载或风速的增大均会使系统响应幅值增大并呈多值性及不稳定性;张力的增大使系统响应幅值减小,并减弱其非线性特性;谐波共振的响应幅值随外部激励荷载或风速的增大而增大,呈现多值性和跳跃性;共振峰向调谐参数右方向偏移,系统呈硬弹簧特性。

To further study the nonlinear vibration problem of iced power lines,this paper analyzes the dancing characteristics of power lines considering aerodynamic loads and external excitations.First,the mechanical model of the iced transmission line under aerodynamic load and external excitation is built and the nonlinear dancing equation of the model is derived.Then,based on the Galerkin method,the derived nonlinear dance equation is converted into an ordinary differential equation,and the amplitude-frequency response functions of the principal resonance and harmonic resonance of the model are obtained by using the multi-scale method.Finally,a numerical analysis is conducted.Our results show when the main resonance is generated in the transmission line,the response amplitude will be synchronized and out of step with the change of tuning parameters,and the increase of external excitation load or wind speed will increase the response amplitude of the system and show multi-value and instability.The increase of tension reduces the response amplitude of the system and weakens its nonlinear characteristics.The response amplitude of harmonic resonance increases with the rise of external excitation load or wind speed,showing multi-value and jumping,and the resonance peak shifts to the right direction of the tuning parameter,and the system exhibits the hard spring characteristics.