交流老化导线温升特性改变对载流量的影响

发布时间：2018-12-15 02:57

【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。
[Abstract]:There are few reports on the influence of long-running wire aging on the carrier current in our country, which is often checked according to the design standards of foreign countries, and the actual measurement data are lacking. In view of the above situation, the current temperature rise experiment is carried out to measure the actual carrier current change characteristics after the aging of the lines, and the resistance per unit length of the sample is measured by using a number of AC aging conductors running for many years in our country as a sample. The results show that the temperature of the wire after aging is faster than that of the new conductor, and the temperature is higher after stabilization, and the resistance per unit length of the wire after aging does not exceed the limit of national standard, but it increases by 4% compared with the measured value of the new wire of the same type. According to the heat balance equation and the experimental results, the carrier current is calculated, and the surface radiation coefficient of the conductor is deduced. The difference between the surface radiation coefficient and the reference value is great. Based on this, the carrier current will be reduced by about 6 percent. It is considered that the surface state of the conductor changes after long term aging, and the formation of a certain thickness of dirt layer will ultimately affect the heat dissipation effect and the change of resistance per unit length of the conductor.
【作者单位】：清华大学电机工程与应用电子技术系;清华大学深圳研究生院;
【基金】：国家重点基础研究发展计划(973计划)(2009CB724503) 国家自然科学基金(50777033;50977048)~~
【分类号】：TM75

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