微地形下输电线路跳线的风偏分析

摘要

Finite element analysis was applied to a real transmission line and an effective model for estimating a jumper wire swing under wind actions was proposed, in order to investigate wind-induced swing characteristics of jumper wires under hilly terrain and to ensure safe operation of a transmission line.Wind tunnel tests of a typical hill were combined with numerical simulation method to derive three-dimensional fluctuating wind speeds of incoming flow.Using the obtained wind speeds and time history analysis method, wind-induced swing of the jumper wire under hilly terrain was calculated and then compared with results of the terrain category B as defined in the Chinese load code.Results show that conductor motions on both the ends of a jumper wire have significant effects on wind-induced swing of the jumper wire.Under a hilly terrain, horizontal wind speed increases significantly while the turbulence intensity decreases at the hill top where notable vertical wind speeds can also be observed.Compared to hillside, hill top has higher horizontal wind speeds but lower vertical wind speeds.Wind-induced swing of a jumper wire under hilly terrain increases more significantly relative to the terrain category B.%为了解微地形条件下跳线风偏的特性以保障输电线路的安全运行,对某条实际输电线路进行有限元分析,提出适用于跳线风偏计算的有效模型.采用微地形下风场的风洞试验结果结合数值方法模拟来流三维脉动风,以此对微地形下的跳线风偏进行时程分析并与我国荷载规范中平坦B类地貌下的结果进行比较.研究结果表明:跳线两端的导线运动对跳线风偏有影响显著.微地形下,水平风速在山顶有明显增加而湍流度则有所减少,且有不可忽略的竖向风速产生.相比山坡,山顶处的水平风速更大而竖向风速偏小.微地形下跳线风偏比平坦B类地貌有显著增加.