交流输电线路导线表面状态的实验研究

Experimental Investigation on Surface Conditions of Conductors in AC Power Transmission Lines

导线表面状态是影响其电晕特性的重要因素,研究实际运行后导线的表面状态对输电线路的设计、运行都有着重要的理论意义。为此,选取了华北、华中和华南典型地区的500kV交流输电线路导线及新导线样本进行了表面状态的研究。场发射环境扫描电子显微镜的实验结果表明:实际运行后导线的表面物质成分比新导线大大增加,表面形貌更加凹凸不平;非金属元素主要含有碳、氧、硅、硫,金属元素主要含有铝、铁、钙、钾、钠、镁。表面形貌仪的实验结果表明:与新导线相比,运行后导线的粗糙度增加,同一地区的导线表面粗糙度相差不大,随着运行时间的增加,导线表面粗糙程度有所提高。

The influence of conductor surface conditions on corona discharge is of great value to the design and operation of power transmission lines in power system.Six strands of the aged conductors acquired from 500 kV AC transmission lines in northern,central,southern China respectively and two strands of the new conductors China were used.The results of scanning electron microscopy（SEM） and energy-dispersive X-ray analysis（EDX） showed that the morphologies of the aged strands were greatly different from the new ones.The aged strands had been corrupted in the ambient atmospheric conditions during their long-term operating in power grid;many substances in the neighborhood of the conductors were also adhered to the surfaces as a result of the strong electric field and gravitational force.Therefore,the surfaces of the aged strands are much coarser and more uneven than the new ones.For the new strands,aluminum is the main component,there are few impurities.However,in the surface layer of the aged strands,there are many other elements,such as oxygen,carbon,silicon,sulfur,chlorine,kalium,calcium,zincum,natrium,iron,magnesium etc.Two basic roughness parameters Ra and Rq were introduced to express the roughness degree of the strands.Ra and Rq of the aged strands was much more than the new ones.The roughness degree of the strands was similar in the same area,and it increased as the operating time became longer.