避雷器改善35kV配电线路耐雷水平的效果分析

Analysis on Effect of Improving Lightning Withstand Level of 35kV Transmission Line by MOAs as Line Surge Arrester

应用电磁暂态计算程序(electromagnetictransientprogram,EMTP)对安装金属氧化物避雷器的35kV配电线路的耐雷水平进行了分析计算。具体比较了雷击有、无避雷线的线路,采取不同避雷器安装方案时的耐雷水平;分析了杆塔冲击接地电阻、绕击导线位置对耐雷水平的影响。仿真计算结果表明,安装线路避雷器﹑减小杆塔的接地电阻可有效提高35kV配电线路的耐雷水平。对于35kV有避雷线配电线路,加装线路避雷器后可显著降低其发生绕击闪络的概率。

The lightning withstand level （LWL） of 35kV transmission line, in which the MOAs are installed, is analyzed by electromagnetic transient program （EMTP）. The LWLs of 35kV lines with and without lightning shield lines, in which various installation ways of MOAs used as line surge arresters are adopted, are compared; the influences of impulse grounding resistances of towers and the locations where the shielding failures occur on LWLs are analyzed. Simulation results show that the measures, such as installing line surge arresters and reducing grounding resistances of towers, can effectively improve the LWL of 35kV transmission lines. For 35kV transmission lines with lightning shield lines, the flashover probability caused by shielding failures can be evidently reduced while MOAs are installed as line surge arresters.