华东电网500 kV线路历年污闪事故分析及外绝缘配置优化研究

对华东电网500 kV线路发生的污闪事故分析表明，爬距不足和绝缘子伞型不合理是造成线路污闪的最主要原因。根据污闪事故分析，以及为确认线路的安全运行状况，对不同串型、不同形式500 kV线路绝缘子串进行了不同污秽度下的污秽试验，得到了不同试品的污耐压曲线，试验结果为500 kV线路的污秽外绝缘配置以及正确选型提供参考依据。在此基础上，通过总结华东电网超高压线路的运行经验，并结合试验研究和实际工程应用的基础，研究了各种绝缘子积污特性和爬距有效利用系数，对华东电网500 kV线路提出了合理的外绝缘配置。

Analysis on Pollution Flashover Accidents in 500 kV Transmission Lines of East China Power Grid over the Years and Research on Optimal Configuration of External Insulation

The results of analysis on pollution flashover accidents occurred in 500kV transmission lines of East China Power Grid show that insufficient creepage distance and irrational shed profiles of insulators are the principal reasons to cause pollution flashover of transmission lines. According to the analysis on pollution flashover, in order to confirm the secure operation of transmission lines the pollution tests of insulator strings with different types and different forms for 500kV transmission lines under different pollution extents are conducted and the withstand voltage curves of different specimens under polluted conditions are obtained. The test results are available for reference to the configuration of external insulation as well as to correct selection of shape and arrangement of insulator strings for 500 kV transmission line. On this basis, by means of summarizing operational experiences of UHV transmission lines in East China Power Grid and combining with experimental investigations and practical engineering applications, the contamination accumulation characteristic and creepage distance utilization coefficients of various insulators are researched, then reasonable external insulation configuration for 500 kV transmission lines in East China Power Grid are recommended.