侧向避雷针在35kV线路中的防雷分析

Research on Lightning Protection Effect of Sideward Rods for 35 kV Distribution Lines

采用三维EGM模型,Eriksson的雷击距公式对35 kV配电线路绕击进行了建模分析。通过计算,得到了单回35kV配电线路能实现绕击防护的侧向避雷针的有效长度。对于35 kV同塔多回线路,侧向避雷针安装部位距导线越远,对该导线的绕击防护效果越差;线路保护角越大,侧向避雷针安装于该线路时的保护效果越差。

The probability of shielding failure tripping is generally small for 35 kV distribution lines, but for some special terrains such as mountain areas, the tripping rate caused by lightning shielding failure may increase significantly. At this situation, installing sideward rod could avoid shielding failure and decrease tripping rate. Shielding failure model for 35 kV distribution lines is build and analyzed by three dimension EGM model and Eriksson＇ s lightning striking distance formula. By computing, the effective length of sideward rod which could shield the danger area of lines is 2.5 m. For 35 kV Multi - circuit with Same Tower lines, the longer dis- tance to the sideward rod, the shielding failure protection effect is worse. The bigger of line protection angle, the shielding failure protection effect of sideward rod installed on the corresponding cross arm is worse. By the running experience, the lightning protec- tion measure of installing the sideward rod has the characteristics of easy to maintain and good economic and technical benefits.