关于农网35kV线路防雷措施探讨  

Discussion about the Measures Taken against Thunder Strike on Rural 35 kV Distribution Line

作　　者：李志娟[1] 李景禄[1] 宋珂 李鹏鸣 

机构地区：[1]长沙理工大学电气与信息工程学院,长沙410076 [2]河南省许昌供电公司,河南许昌461000 [3]河南省开封供电公司调通中心,河南开封475000

出　　处：《电瓷避雷器》2007年第5期39-42,共4页Insulators and Surge Arresters

摘　　要：雷击是导致农网35kV线路故障的重要原因之一。衡量线路防雷性能优劣的重要指标有两个:一是线路雷击跳闸率;二是线路耐雷水平。分析了35kV线路防雷现状,认为线路绝缘水平低,绝缘子老化严重,导线老化和线径过小,极易造成雷击闪络时绝缘子损坏和导线断线。提出了在现有防雷措施的基础上,安装线路型避雷器,降低杆塔接地电阻,在单相接地电流大于10A的35kV电网采用中性点经消弧线圈接地的运行方式,可降低线路的雷击跳闸率。Lightning strike is one of the important reasons which causes the rural 35 kV distribution lines faults. There are two indexes to evaluate the power line performance on preventing lightning strikes： the one is the lightning trip-out rate, the other is the lightning withstand level of the power line. The author analyzed the present situation of lightning protection of 35 kV line. It is considered that line has low insulation level, severe insulator aging, wire aging and too small diameter of wires, which leading to the insulator damage and wire breakage when lightning flashover happens. The author proposes to install the line surge arrester on the lines and reducing the ground resistance of the pole tower based on the current measures of the lightning-prevention, and to decrease the pole ground resistance. Meanwhile, the author also suggests that the neutral point should be grounded through arcsuppression coil in the 35 kV electrical network if the earthing current of single-phase exceed 10 A. In this way, the tripping ratio due to lightning strikes on the power line can be reduced.

关 键 词：农网35kV线路 耐雷水平 雷击跳闸率 接地电阻 线路避雷器 

分 类 号：TM863[电气工程—高电压与绝缘技术]