中文摘要：

线路运行过程中导线受到老化和积污影响,表面状态发生改变,产生电晕会对线路电磁环境产生不利影响。因此在小型电晕笼内,对广东省南部地区线龄24年的交流LGJ-400/50型及同型号新导线进行电晕实验;同时采用电子显微镜和白光干涉形貌仪对导线样品表面形貌以及表层成分进行了理化分析。根据实验结果对比了运行多年导线和同型号新导线的电晕起始电压、可听噪声和无线电干扰水平;由电晕起始电压计算得到了对应粗糙系数m,并与Peek公式计算值进行对比。结果表明：粤南地区长期运行后导线表面污秽成分中除原有的铝和氧元素外增加了大量的碳、硫、硅、铁、钙、钠、钾等元素;老化导线粗糙程度（轮廓算数平均偏差和轮廓算数均方根偏差）较新导线增大近20倍;长期运行后导线的电磁环境有明显恶化,电晕起始电压下降13.3%,粗糙度（Peek公式计算值）由原0.85下降至0.73;可听噪声和无线电干扰水平有所增加。

英文摘要：

During operation, conductors on transmission lines will be aged and polluted, and their surface condition will change and generate corona which impairs the electromagnetic environment （EME） around transmission lines. Hence, we used a small corona cage to test some single LGJ400/50 aged conductors, of which some had been operated for 24 years in the south of Guangdong Province and the others were new. The surface conditions of the tested conductors were de- tected by using scanning electron microscope （SEM） and phase shift MicroXAM-3D. On the basis of the test results, we compared the two groups of conductors in aspects of corona inception voltage （ICV）, audible noise, and radio interference level. We also calculated the roughness coefficient m using the ICV and compared the results to its counterpart obtained from Peek equations. The experimental results show that, besides A1 and O which are the only main elements on the sur- face of new conductors, the aged conductors have a considerable amount of additional elements, such as C, S, Si, Fe, Ca, Na, and K, on their surfaces. The surface roughness （profile arithmetic average deviation and profile arithmetic root mean square deviation） of the aged conductors is about 20 times more than that of the new conductors. The aged conductors also have worse EME than the new ones, namely lower ICV （about 13.3%）, and higher levels of audible noise and radio interference, and their roughness coefficient （calculated using Peek equation） decreases from 0.85 to 0.73.