特高压直流输电线路不停用再启动功能情况下的带电作业安全性分析

Safety Analysis of Live Working on UHVDC Transmission Lines with Restart Function

摘要:

在开展特高压直流线路带电作业时，一般要求停用直流线路再启动功能，然而过多的停用该功能会降低系统 安全运行水平，因此有必要分析在不停用直流线路再启动功能情况下开展特高压带电作业的安全性。首先分析了停 用直流线路再启动功能的作用; 然后考虑在不停用该功能的情况下，结合特高压直流输电线路最大操作过电压水平， 校核分析了带电作业安全距离; 最后结合典型直流线路带电作业项目，分析了不停用直流线路再启动功能时进行带 电作业的可行性。分析结果表明，特高压直流线路塔头空气间隙尺寸一般均满足带电作业最小安全距离的要求。在 各类带电作业操作项目中，若极地或极间采用绝缘承力工具，应停用直流线路再启动保护功能，其他情况可不停用。

Abstract:

Restart function is generally required to be withdrawn during live working on UHVDC transmission lines，but extra withdrawal may reduce the safety operation level of power system． Thus，safety analysis about live working on UHVDC transmission lines with restart function is necessary． Firstly，the effects of withdrawing restart function is analyzed． And then，in consideration of using restart function and according to the maximum switching overvoltage level of UHVDC transmission lines， the safety distance for live working is calculated． Finally，combined with the typical live working projects on DC transmission lines，the feasibility of live working with restart function is analyzed． The results show that tower head air gaps of UHVDC transmission lines can meet the requirement of minimum safety distance for live working． In all kinds of live working projects， restart function should be withdrawn once phase － ground or phase － phase insulated bearing tools are used，and otherwise it can be used．