山脉地形条件下输电线路风偏响应特性研究

Study on Wind-induced Swing Response Characteristics of Transmission Lines Under Mountain Terrain

研究了典型孤立山脉地形因素(山脉长度、山脉坡度)对输电线路风速及风偏响应特性的影响.采用CFD数值模拟得到山脉中输电线路沿线各点横向和竖向平均风速,分析了山脉长度、山脉坡度对输电线路各点平均风速的影响.再根据风向的不同建立了两跨和三跨输电线路有限元模型,分别利用数值模拟风速和规范设计风速计算了线路各点位移,得到风偏角增大百分比.研究结果表明:数值模拟结果普遍大于规范设计值.当风向为顺山脉时,山脉入口处线路风速最大,竖向风速可以忽略不计.山脉越长风偏角增大百分比越小,且随着坡度的减小先增大后减小.当风向为垂直山脉时,竖向风速不宜忽略,山脉越长,山体底部直径越大风偏角增大百分比越大.竖向风速在底部直径大于600m时可以忽略.因此当山脉长度和坡度在某一范围内,按规范来进行输电线路的风偏设计是偏于不安全的.本文的研究结果可为实际山脉地形条件下的输电线路风偏设计提供有价值的参考.

The influence of typical isolated mountain topographic factors(mountain length, mountain slope) on the wind speed and wind-induced swing response characteristics of the transmission line was studied.The horizontal and vertical average wind speeds at various points along the transmission line in the mountain range were obtained with CFD numerical simulation, and the influence of mountain length and mountain slope on the average wind speed at each point of the transmission line was analyzed.Based on the different wind directions, the finite element models of two-span and three-span transmission lines were established.The displacements of each point of the line and the wind-induced swing angle increase percentage were calculated by numerical simulation of wind speed and standard design wind speed.The results show that the numerical simulation values are generally greater than those of the standard designation.When the wind direction is along with the mountain range, the wind speed at the entrance of the mountain range is the largest, and the vertical wind speed can be ignored.The longer the mountain range is, the smaller the percentage of swing angel is.As the slope decreases, the wind angel increases first and then decreases.When the wind direction is vertical to the mountain range, the vertical wind speed should not be ignored.The longer the mountain range is, the larger the bottom diameter and the larger the percentage of swing angel are.The vertical wind speed can be ignored when the bottom diameter is greater than 600 m.Therefore, when the length and slope of the mountain range are within a certain range, designing the wind-induced swing of the transmission line according to the standard is tend to be unsafe.The research results of this paper can provide a valuable reference for the design of transmission line wind-induced swing under actual mountain terrain conditions.