架空导线破断力的工艺提高途径

Process Ways to Improve Breaking Force of Overhead Conductor

架空导线的破断力(尤其是长时间高温下的破断力)是影响架空导线在复杂环境下敷设安全可靠性的重要因素,因此对其工艺提高途径展开了探讨。架空导线独特的绞合结构使其在受力情况下,股线所在绞层的节径比越大,股线的应变随之越大,并且在随着节径比增大的同时,应变增幅呈现逐渐变小的趋势,因此通过将铝线各层及钢线节径比控制在一定范围内,以改善各铝股线间应变的均匀性,增大铝线和钢线间的应变差,实现架空导线破断力的提高。同时,通过提高钢线的1%伸长时应力或选用高强度、特高强度的钢线,适当地改良生产工艺和调整材料的成分来提高硬铝线的断裂伸长率,以及调整铝股线的强度极差,可提高架空导线的破断力。此外,开发耐热型铝合金线,不仅可提高架空导线长时间高温下的破断力,提高电力传输的可靠性,而且还具有线路扩容的效果。

The breaking force of overhead conductors(especially the breaking force at high temperature for a long time) is an important factor affecting the safety and reliability of overhead conductors laid in complex environments. Therefore, the process ways to improve breaking force of overhead conductors are discussed. Because of the unique stranding structure of overhead conductors, in the case of stretching, the larger the lay ratio of the strand located layer is, the larger the strain of the strand is, at the same time with the increase of lay ratio, the strain increase tends to decrease gradually. Therefore, by controlling the lay ratio of each layer of aluminum wire and steel wire to a certain range, the uniformity of strain between aluminum strands can be improved, the strain difference between aluminum wires and steel wires can be increased, and the breaking force of overhead conductors can be improved. Meanwhile, the breaking force of overhead conductors can be increased by increasing the stress of 1% elongation of steel wires or choosing high-strength and ultra-high-strength steel wires, properly improving the production process and adjusting the composition of materials to improve the breaking elongation of hard aluminum wires, and adjusting the strength range of aluminum strands. In addition, the development of thermal-resistant aluminum alloy wires can not only improve the breaking force of overhead conductors under high temperature for a long time to improve the reliability of power transmission, but also have the effect of transmission line capacity expansion.