基于增量谐波平衡法的覆冰输电线舞动分析

覆冰输电线的舞动是一种非线性振动。应用增量谐波平衡法推导了覆冰输电线的有限元分析模型及运动平衡方程,并对舞动方程进行了求解。该方程具有非线性平方及立方刚度项、平方及立方粘滞阻尼项。把振动过程分解成为瞬态的持续增量振动过程,迭代求出舞动频率及振幅,求得方程解的表达式。结合实例分析了输电线舞动的极限环现象和谐波项数的取值问题,与时程积分方法分析结果比较表明吻合较好。对风速增量进行了参数分析推导,算例表明不同风速下覆冰输电线舞动频率与振幅是不同的,在某个临界风速处会发生舞动分岔。

Galloping analysis of iced transmission lines based on incrementalharmonic balance method

The galloping of iced transmission lines is a kind of strongly nonlinear vibration.The incremental harmonic balance method is employed to establish the finite element model and balanced equations of iced conductor vibration.Then,vibration balanced equations were solved,which include the square and cubic stiffness items,square and cubic viscous damping items.Wave frequency and amplitude are obtained,and then the analytical expressions of equations are solved by iteration of a transient incremental continuous vibration process,which is decomposited from the vibration process.Taking an example,the limit cycle phenomena of galloping of the iced power line and the harmonic wave number are discussed.The results show that there is good agreement with time history methods.The parameters analysis equation of the wind increments are derived,which show that iced transmission line has different galloping frequency and amplitude on different wind speeds,that galloping bifurcation occurs on a critical velocity.