电涌放电器第8部分:1kV以上交流系统架空输配电线路用带外部串联间隙（EGLA）的金属氧化物电涌放电器

[中文适用范围]： IEC 60099 的这一部分涵盖了具有外部串联间隙的金属氧化物避雷器（外部间隙线路避雷器 (EGLA)），这些避雷器应用于架空输电和配电线路@，仅用于保护绝缘子组件免受雷击引起的闪络。本文件定义了电涌放电器，仅用于保护绝缘子组件免受雷击引起的过电压的影响。因此@并且由于金属氧化物电阻器并未永久连接到线路@，本文档不考虑以下项目： ?开关脉冲击穿电压； ？陡峭电流和开关电流脉冲时的残余电压； ？热稳定性; ？长时间的电流冲击承受能力； ？避雷器的工频电压与时间特性； ？隔离开关测试； ？通过工频电压进行老化工作。考虑到架空输配电线路的特殊设计理念和特殊应用，@引入了一些独特的要求和试验@如绝缘子耐压与EGLA防护等级配合的验证试验@续流开断试验@机械负载试验@等. 本文件不涵盖 EGLA 外部串联间隙与绝缘体并联安装的设计。 [外文原描述]： IEC 60099-8:2017 covers metal-oxide surge arresters with external series gap (externally gapped line arresters (EGLA)) that are applied on overhead transmission and distribution lines, only to protect insulator assemblies from lightning-caused flashovers. This document defines surge arresters to protect the insulator assembly from lightning-caused over-voltages only. Therefore, and since metal-oxide resistors are not permanently connected to the line, the following items are not considered for this document: - switching impulse spark-over voltage; - residual voltage at steep current and switching current impulse; - thermal stability; - long-duration current impulse withstand duty; - power-frequency voltage versus time characteristics of an arrester; - disconnector test; - aging duties by power-frequency voltage. Considering the particular design concept and the special application on overhead transmission and distribution lines, some unique requirements and tests are introduced, such as the verification test for coordination between insulator withstand and EGLA protective level, the follow current interrupting test, mechanical load tests, etc. Designs with the EGLA's external series gap installed in parallel to an insulator are not covered by this document. This second edition cancels and replaces the first edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: The Lightning discharge capability test has been completely re-written and re-named to Test to verify the repetitive charge transfer rating, Qrs with lightning discharges to reflect changes introduced in IEC 60099-4 Ed.3 (2014) regarding new methods for rating the energy and charge handling capability of metal-oxide arresters. In addition to testing to evaluate the performance of the MO resistors, procedures for evaluating the performance of the EGLA series gaps have been introduced. - Omissions from Ed. 1 of this standard have been included, notably an RIV test and a means for determining the thermal time constant of the SUV portion of the EGLA. - Definitions for new terms have been added - A number of NOTES in Ed. 1 have been converted to normative requirements Keywords: externally gapped line arresters (EGLA), lightning-caused over-voltages