500 kV线路避雷器保护失效分析及改进措施研究

线路避雷器是防止输电线路雷击跳闸的有效手段，随着高电压等级线路避雷器的使用，出现了因安装方式导致的线路避雷器保护失效问题。针对某500 kV输电线路发生的线路避雷器在大幅值雷电流反击下对绝缘子串保护失效的问题，采用电磁暂态分析软件ATP-EMTP建立了仿真分析模型，分别对雷电流绕击和反击情况下绝缘子串和线路避雷器两端承受的电压进行了量化，得出了导致反击情况下线路避雷器保护失效的原因；提出了对现有500 kV线路避雷器安装方式的改进方案，并对改进方案下反击雷电流导致的绝缘子串和线路避雷器两端电压波形进行了比较，验证了改进措施的有效性。所研究成果对于500 kV及以上电压等级线路避雷器的使用具有重要参考价值。

Analysis on Protection Failure and Research on Improvement Measures of 500 kV Line Arrester

The line arrester is an effective means to prevent the transmission line from lightning trip-out. With the use of line arresters with higher voltage class, the protection failure of line arrester caused by the installation mode appears. Taking the failure of line arrester in a 500 kV transmission line under the counterattack of large lightning current as a research case, the simulation model is established by using the electromagnetic transient analysis software ATP EMTP, the voltage of insulator string and line arrester under shielding failure and counterattack is respectively qualified, and the reasons for protection failure of line arrester under the condition of counterattack is obtained. An improvement plan for the installation mode of 500 kV line arrester is proposed, and the voltage waveforms of insulator string and line arrester caused by lightning current under thei mprovement plan are compared, which verifies the effectiveness of the proposed improvement plan. The research results have an important reference value for the use of line arresters with 500 kV and higher voltage class.