同塔四回输电线路带电作业可行性分析

Feasibility Analysis of Live Working on the Four Circuit Transmission Lines on the Same Tower

带电作业是对同塔多回输电线路检修最直接、有效的手段,因此有必要对同塔多回输电线路带电作业可行性进行分析。文中以110 kV、220/110 kV和500/220 kV同塔四回输电线路为研究对象,并从带电作业典型作业位置危险率和作业人员体表场强2个方面对带电作业安全性进行了评价。计算表明,110 kV、220/110 kV同塔四回线路直线塔导线侧带电作业危险率大于1×10-5;110 kV同塔四回线路耐张塔横担处危险率大于1×10-5,均不满足规程要求;而500/220 kV同塔四回线路各典型位置均小于1×10-5,满足规程要求。利用有限元仿真软件计算得到:当作业人员不穿屏蔽服在同塔四回输电线路开展带电作业时,人体最大场强均出现在脚的位置,分别为1 080.3、1 482.2、2 138 kV/m,当选用屏蔽效率至少为37.15、39.90、42.67 d B的屏蔽服时即能保证作业人员安全。综上表明,当身穿合适的屏蔽服后,作业人员可安全地在500/220 kV同塔四回线路上开展带电作业,但在110 kV、220/110 kV同塔四回线路直线塔和110 kV同塔四回线路耐张塔上开展带电作业时,仍有较大的安全风险。

Live working is the most direct and effective means for the maintenance of the multiple circuit transmission lines on the same tower,so it is necessary to analyze the feasibility of live working on the four circuit transmission lines on the same tower. In this paper,the 110 kV,220/110 kV and 500/220 kV four circuit transmission lines on the same tower is taken as the research object,and the safety of live line work is evaluated from the risk of live working on typical position and the field strength of worker. The calculation results show that the risk rate of live working on the wire of 110 kV,220/110 kV four circuit transmission lines on the same straight-line tower is more than 1×10^（-5）,and the risk rate of live working on the cross arm of 110 kV four circuit transmission lines on the same strain tower is more than 1×10^（-5）,which do not meet the requirements of regulation. And the risk rate of live working on the wire of 500/220 kV four circuit transmission lines on the same tower is less than 1×10-5,which meets the requirements of regulation. When workers do not wear shielding clothes and live working on the four circuit transmission lines on the same tower,the largest field strength of the human body are in the position of the feet,respectively,10.803,1 482.2 and 2 138 kV/m,what＇s more,at least 37.15,39.90 and 42.67 d B shielding clothing can ensure the safety of the workers. In conclusion,when workers in right conductive clothes and can safely live working on the wire of 500/220 kV four circuit transmission lines on the same tower,but there are safety risks involved to which live line work on the wire of 110 kV,220/110 kV four circuit transmission lines on the same straight-line tower and 110 kV four circuit transmission lines on the same strain tower.