股线扭角和温度对导线综合系数取值影响的有限元仿真及应用

Finite element simulation and application on the influence of twist angle and temperature on wire synthesis coefficient

根据力学理论分析了考虑股线扭角的钢芯铝绞导线综合系数理论计算公式,通过有限元仿真研究了导线运行温度变化对绞线综合系数的影响;同时以某实际工程为例,分析综合系数理论解与有限元仿真解对导线弧垂应力计算误差的影响。研究表明:钢芯铝绞导线的轴向综合热膨胀系数不随温度变化,而综合弹性模量随温度的升高而变大;小截面导线JL/G1A-400/35在小档距400 m和大截面导线AACR/EST-500/227在大档距2 000 m,温度每升高10℃,综合弹性模量约增加2~3 GPa;考虑温度效应下综合系数的不同取值,在最高设计运行温度时,小档距小截面输电线路弧垂应力存在大于5%的计算误差,大档距大截面输电线路弧垂应力计算误差小于1%。

Based on the mechanics theory, the theoretical calculation formula of the synthesis coefficient of the steel core aluminum stranded wire considering the twist Angle was analyzed.The influence of the conductor operating temperature on the synthesis coefficient of the stranded wire was studied by finite element simulation.At the same time, taking a practical project as an example, the influence of the theoretical solution of comprehensive coefficient and the finite element simulation solution on the calculation error of sag stress of wire was analyzed.The results showed that the axial comprehensive thermal expansion coefficient of steel core aluminum stranded wire does not change with temperature, but the comprehensive elastic modulus increased with temperature.The comprehensive elastic modulus of small section conductor JL/G1A-400/35 and large section conductor AACR/EST-500/227 increased by 2 to 3 GPa for every 10 ℃ increasing in temperature at a small distance of 400 m and a large section conductor AACR/EST-500/227 at a large distance of 2 000 m.Considering the different values of the comprehensive coefficient under the temperature effect, the calculation error of the vertical stress of transmission lines with small distance and small section was more than 5%,and that of transmission lines with large distance and large section was less than 1% at the maximum design operating temperature.