长期运行老化导线表面状态及电晕特性变化研究

Surface Texture and Corona Characteristics Change of Long-time Running Aging Conductors

目的研究某地区长期运行的导线的表面状态、表面成分以及电晕特性,分析老化导线的表面特性变化规律。方法采用场发射扫描电子显微镜分析导线表面物质成分及分布状态,采用紫外成像仪对施加不同电压等级下电晕放电光子数进行计数,表征其放电的强弱程度。结果导线表面物质成分中非金属元素主要是氧、碳、硫、硅和少量的磷,金属元素主要是铁、铝、钙、钠、镁、钾,且表面状态与所处环境有关;长期运行导线表面在相同放电电压下放电光子数比新导线多。结论污秽颗粒、不规则的表面结构是长期运行的导线在正常运行电压下发生电晕放电的根源,导线表面的污秽成分与所处地区有关,导线表面凹凸不平会导致其起晕电压比新导线要小。导线的运行年限对表面状态和电晕放电特性有影响。

Objective To investigate the surface texture,surface composition and corona characteristics of selected long-time running conductors of a certain region and analyze the properties change law of the aging conductors. Methods Material composition and distribution status on the surface of the conductors were analyzed using the field emission scanning electron microscope and the discharge state was represented by the corona photon number under different applied voltages using ultraviolet imager. Results Nonmetallic elements of the aging conductors were mainly O,C,S,Si and P,metallic elements were mainly Fe,Al,Ca,Na,Mg,K,and the surface status was related with the surrounding environment; the discharge photons of the aged conductors were more than the new ones under the same applied voltage. Conclusion Pollution particles and irregular surface structure were the discharge sources of the corona under normal operating voltage; the surface composition of the long-time running conductors differed among different areas; irregular surface of the conductors would lead to smaller discharge inception voltage as compared to that of the new conductors. The operated years of the conductors had some effect on the surface status and the corona characteristics.