中文摘要：

国内对于长期运行的导线老化对其载流量影响的研究鲜有报道,往往根据国外设计标准进行载流量校验,缺乏实际测量数据。针对上述情况,采用我国多条运行多年的交流老化后导线作为样本进行了通流温升实验测量到线路老化后实际载流量变化特性;同时对样本单位长度电阻进行了测量。结果表明老化后导线温升快于新导线,且稳定后温度更高;老化后导线单位长度电阻虽未超过国标限值,但与同型号新导线实测值相比增加4%～14%。根据热平衡方程和实验结果对载流量进行了计算,并反推出导线表面辐射系数,表面辐射系数与参考值相比差异较大,据此估算将使载流量下降约6%。分析认为导线长期运行老化后表面状态改变,形成一定厚度的污质层最终影响了导线的散热效果和单位长度电阻变化。

英文摘要：

Commonly, some foreign design criteria are taken for verifying aged conductors due to the lack of actual measurement data. Hence, taking several long-term operated and aged conductors in China as the samples, we conducted time-temperature experiments. Their current carrying capacity, as well as their resistivity, was measured. The result showed that the aged conductors got heated up faster than new ones and had higher stable temperature. Though the aged conductors had their resistivity within the limited range of national standards of China, the resistivity was 4%～14% higher than that measured with new conductors. Then, using heat balance equation, we calculated the samples＇ current-carrying capacity, and revealed the conductors＇ surface radiation factor. The factor of aged conductors was obviously different from its design criterion, decreasing by 6% in the conductors＇ current-carrying capacity. According to the results, it is suggested that, for conductors, long-time operation and aging will change their surface condition and form pollutant layers on them, which will eventually affect their heat dissipation and resistivity.