国内外导线张力设计方法的差异  

Differences of Design Methods for Domestic and Overseas Conductor Tension

作　　者：朱映洁[1] 林方新[1] 

机构地区：[1]中国能源建设集团广东省电力设计研究院有限公司,广东广州510663

出　　处：《广东电力》2016年第1期124-130,共7页Guangdong Electric Power

摘　　要：我国输电线路设计规范在计算导线张力时未考虑自然风脉动的影响,因而采用较大的安全系数来抵抗风速脉动峰值引起的过载;而国外标准采用极限张力设计方法,计算导线张力时充分考虑自然风脉动的影响,因而采用较小的安全系数使允许的最大使用张力接近塑性变形临界值。这是造成我国导线计算张力与国外计算值相差较大的主要原因,也是国内输电线路设计体系与国外标准极限张力设计方法的一个显著区别。以实例计算的方式剖析了这两种不同的方法给铁塔设计带来的影响。计算结果表明,随着代表档距的增加,按国外标准计算的大风工况张力的上升坡度明显大于我国标准。在年平工况作为控制工况的前提下,极限张力设计法不会引起导线弧垂差异,并且按照极限张力设计法设计的耐张塔可承受更大的全相不平衡张力。Influence of natural wind fluctuation is not considered for calculating conductor tension in design specifications on power transmission line in China, thereby, large safety factor is used to resist overload caused by peak value of wind speed fluctuation. While in foreign standard, ultimate tension design method fully considering influence of natural wind fluctuation is used to calculate conductor tension, thus small safety factor is adopted to make allowed maximum working strength close to critical value of plastic deformation. Above circumstances are main reasons for causing large differences between calculated values of conductor tension in domestic and overseas, as well as design methods for design system of power transmission line in China and foreign standard ultimate tension. Example calculation is used for analyzing influences on design for steel tower by using these two different methods and results indicate that with increase of ruling span, rising slope of tension under ex- treme wind condition calculated according to foreign standard is obviously larger than that according to domestic standard. On the premise of taking yearly average working condition as the controlling working condition, ultimate tension design method will not cause difference of conductor sag and tension support tower designed based on ultimate tension design meth- od can bear greater whole-phase imbalance tension.

关 键 词：极限张力设计法 自然风脉动 风振系数 单位长度风荷载 不平衡张力 

分 类 号：TM756.2[电气工程—电力系统及自动化]