特高压八分裂导线尾流驰振研究

由于多分裂导线的子导线排列密集，尾流引起的驰振问题可能会严重危害输电系统的安全运行。为研究特高压八分裂导线的尾流驰振特征，通过风洞试验测量了八分裂导线各子导线的气动力系数随风攻角的变化情况，可以看出：由于子导线之间尾流的干扰，八根子导线的气动力系数存在较明显差异，尤其是当子导线处于上风子导线的尾流区时，作用于其上的阻力会明显下降；同时，利用 ABAQUS 有限元软件模拟研究了档距分别为308 m和405 m 的两条八分裂孤立档线路的尾流驰振过程，基于该数值模拟结果，可以分析得到：八分裂导线尾流驰振存在一个临界风速，当风速小于临界风速时，没有发生尾流驰振现象；当线路发生尾流驰振时，子导线的运动轨迹近似为椭圆；在相同风速下，大档距线路的尾流驰振幅值大于小档距线路。

Wake-induced galloping of eight bundle conductor lines

Wake-induced galloping is a high risk for a safe operation of electrical transmission system due to dense arrangement of sub-conductors in multi-bundle conductors.To investigate the wake-induced galloping characteristics of eight bundle conductors with extra-high voltage,the variation of aerodynamic forces of each sub-conductor in the eight bundle conductors changing with angle of attack was tested by wind tunnel tests.Because of the wake interaction within sub-conductors,a relatively distinguishable difference can be observed among the aerodynamic forces of the eight conductors.Especially,when a leeward sub-conductor is in the wake of windward sub-conductor,the drag exerted on the leeward conductor significantly drops.The wake-induced galloping of eight bundle conductors with two span-lengths 308 m and 405 m was numerically simulated by the ABAQUS software.Based on the simulation results,a critical wind speed has been found for the wake-induced galloping.The galloping will not take place when the wind speed is lower than the critical speed.The motion orbit of the sub-conductor is elliptical with wake-induced galloping.Given the same wind speed,the amplitude of the galloping with long span-length is greater than that with short span-length.