单回配电线路全线安装避雷器直击雷保护特性研究

Lightning Protection Characteristics of Lightning Arresters Installed on Single Circuit Distribution Lines

针对配电线路直击雷防护问题,对线路在全线避雷器配置密度情况下的保护特性进行了研究,使线路的直击雷耐雷水平有较大提高。相对于只安装绝缘子线路,当避雷器放电电流为5 kA等级时,雷击相导线耐雷水平提高了3.5倍左右,雷击杆塔的耐雷水平提高了1.4倍多。当避雷器放电电流为10 kA等级时,雷击相导线的耐雷水平提高了7.3倍,雷击杆塔的耐雷水平提高了近3.6倍。雷击杆塔时,三相避雷器分流和能量吸收比较均匀;被击杆避雷器承受最大的雷电流吸收最多的能量,往线路两侧会迅速降低。雷击上相导线时,上相避雷器流过的雷电流和吸收能量是三相避雷器里相对最大的;同样在被击点处的杆塔流过最大的雷电流,流过线路两侧远处避雷器的雷电流会迅速减小。

Aiming at the problem of direct lightning protection of distribution lines,the protection characteristics of the lines under the condition of full-line lightning arrester configuration density are studied,which greatly improves the lightning protection level of the lines.Compared with the insulator-only line,when the discharge current of the arrester is5 kA,the lightning resistance level of the lightning-struck phase conductor is increased by about 3.5 times,and the lightning resistance level of the lightning-struck tower is increased by more than1.4 times.When the discharge current of lightning arrester is 10 kA,the lightning resistance level of lightning-stricken phase conductor is increased by7.3 times and that of lightning-stricken tower is increased by 3.6 times.When lightning strikes the tower,the shunt and energy absorption of the three-phase arrester are more uniform.The lightning current absorbed by the lightning struck rod arrester is the largest and the energy absorbed by the three-phase arrester is the most,which will rapidly decrease to both sides of the line.When lightning strikes the upper-phase conductor,the lightning current and energy absorbed by the upper-phase arrester are relatively the largest in the three-phase arrester,and the tower at the hit point flows through the largest lightning current,and the lightning current flowing through the remote arrester on both sides of the line will rapidly reduce.