500kV顺江乙线老化线路电晕起始电压变化特性

Corona Initial Voltage Change Feature for Aged Conductor of 500 kV Shunjiang-Jiangmen

输电线路因电晕放电引起的电子环境问题时有发生,是影响特高压建设的难题之一。电晕起始电压是研究输电线路电晕特性的重要参数,随着线路运行年限和运行环境的改变,输电线路电晕起始电压可能发生变化。笔者针对广东南部地区顺江乙线运行年限16年的LGJ400/50老化后导线的电晕起始电压变化,利用小型电晕笼这一有效、方便的实验平台展开研究。文中通过紫外成像仪记录单根LGJ400/50老化导线和同型号新导线在相同施加工频电压下的光子计数率,并以此计算两者电晕起始电压。结果表明老化后LGJ400/50导线电晕起始电压由新导线的129.1kV下降至115.8kV。将此结果与Peek公式计算得到的光滑导体结果进行对比,从粗糙系数m的角度来讲,老化后多年导线粗糙系数从原0.85下降至0.77。实验结果表明,多年运行后的老化导线电晕起始电压有明显下降,这一结论为相关部门提供设计、维护建议。

The electromagnetic environment problem, which caused by corona discharge in transmission lines is one of UHV construction difficulty. The corona inception voltage（ICV） is an important index of the corona discharge characteristics, the 1CV would be changed with the operation time is go on and the atmospheric environment very. This LGJ400/50 conductor of Shunde-Jiangming, which had been used in South Guangdong Province over 16 years, was sit as the test simple with a effective and convenience corona cage in this paper to research the ICV feature. An ultraviolet imager was used to detect the photon count number caused by corona discharge of the single new and aged LGJ400/50 then the ICV value was calculated. The experiment results showed that ICV value of the aged LGJ400/50 was 115.8 kV while the new ones was 129.1 kV. Then the results were compared with the value which calculated by Peek low with the model of smooth cylinder conductor, the roughness coefficient m of the new and aged LGJ400/50 were gained, the value drop from 0.85 to 0.77, respectively for new and aged ones. The results demonstrated that the ICV of aged conductor dropped obvious, the conclusion will provide design and maintain suggestions for related department.