山区特高压线路大悬垂角解决方案的研究

Suggestions to the Solution of Large Vertical Angle for UHV Power Transmission Lines across Mountain Area

架空输电线路常穿越高山大岭和跨越江河等艰难的地理环境,高差大、大小档距等会引起直线塔悬垂线夹的悬垂角过大,从而引起线夹出口处导线对单回路铁塔塔窗、双回路铁塔层间横担等的间隙距离不足的问题。通常特高压线路规划杆塔的水平、垂直档距等条件大于常规交流线路杆塔,因此大垂直档距出现的几率增多,大悬垂角问题更为严重。本文以1000kV浙福线工程的山区段线路设计方案为例,提出采用悬垂串偏挂来解决山区特高压线路大悬垂角问题的新方法,并给出挂点角钢多种组合及布置的新方式;对比解决大悬垂角问题的各种常规方法,本文进行了杆塔综合利用率和经济性能的比选,论证了悬垂串偏挂法在解决山区、大跨越等悬垂角问题方面具有节省工程造价和设计工作量的明显优势。

Overhead power transmission lines often cross mountains and rivers. Height difference and size spans may lead to increasing vertical angle ,which cause the shortage of safety clearance between wire in clamp and single-circuit tower window or double-circuit cross arm. The designed tower level and vertical spans of UHV power transmission lines are larger than conventional power transmission lines,thus there may be the probability of increasing large vetrical spans or the problem of large vertical angle. This paper,taking ＂1000kV ZheFu power transmission line crossing mountain areas＂ as an example,puts forward a new method to solute large vertical angle in mountain areas by using suspension string＇s deviated position. And the arrangement and layout of suspension angle steel bars are also proposed. Compared with some conventional methods about large vertical angle,the choice of utilization rate and economic performance are considered,and advantages of deviated suspension methods in mountains are highlighted both in saving engineering cost and in design work.