代入公式:llm?1.325?[?0]?
求得该线路极限档距 llm=1364.5m
第七章
6.
通过我国典型气象区1区的某110KV线路,采用LGJ-185/30钢芯铝绞线,孤立档档距l=100m,采用XP-70单联耐张绝缘子串,共8片重438.7N。耐张绝缘子串长1582mm试分别求架线施工观测和竣工时的应力、弧垂(考虑初伸长) 解:
(1)计算基本数据
α p l h Cosb λ1=λ2 A d E 100 0 1 1.582 210.93 18.88 76000 18.9 7.184 p=34.06*10-3×210.93=7.184 [ζ0]= ζp/2.5=115.875 MPa [ζcp]=72.422 (2)气象条件数据与相应荷载
气温 风速 冰厚 绝缘子片荷载 -5 - 10 0 10 35 0 0 0 GV1 438.7 438.7 438.7 GH1 0 6.977 135.21 GJ1 438.7 438.76 459.06 438.7 架空线荷载 PH 0 - 11.13 0 P 7.184 - 13.247 7.184 最低温 最厚冰 最大风 PV 7.184 -7.184 7.184 7.184 年均温 20 0 0 438.7 0 绝缘子串垂直荷载GV1=438.7,最厚冰时GH1= ??10,0??J40.625*n1*AJ?n2*Ac?A*10*v22?0.625*8*0.0203?1*0.01421.582*210.93?3U
?33.07*10GH1??J4?10,0?A?6.977N
??35,0??J40.625*n1*AJ?n2*Ac?A*35*v22?0.625*8*0.0203?1*0.01421.582*210.93?3
?405.19*10GH1??J4?35,0??A?135.21
最大风速??35ms时,计算强度时,?c?1.0,?f?0.70,?sc?1.1
w30?0.625?2?0.625?35w30Asin??10765.625210.932?32?765.625?Pa?
?4?0,30???c?f?scd
?10?3?1.0?0.70?1.1?18.88??52.77?10?3?MPam?Ph=?4?0,30?*A?11.13N (3)计算各种情况下的线长系数 耐张串等长等重且无几种荷载 1)求最大风时K
??13.24210.93?62.803*10?3
l1?100?2*1.582?96.836
W1??l1cos??62.803*10?3*96.8361?3?6.082
????cos?2?62.803*103
12?0GJW1??A2GJ3AK??Ecos?24[l1(l1?6?0)?)*76000*12(W1?)]12*1.582*459.066.082*62.083*10?3?(62.803*10?3243[(96.836*(96.836?6*1.582)?*210.93(6.082?2*459.063*210.93)]
?138.779*102)求最低温时K ??7.184210.93?34.059*10?3 *96.836W1??l1cos??34.059*10?31?3?3.298
????cos?2?34.059*103
12?0GJW1??A2GJ3AK??Ecos?24[l1(l1?6?0)?)*76000*12(W1?)]12*1.582*459.0633.298*34.059*10?3?(34.059*10?3243[(96.836*(96.836?6*1.582)?*210.93(3.298?2*459.0633*210.93)]
?43.8706*103)年均温线长系数
年均温下参数与最低温时参数相同,即线长系数也相同