倒T型布置方式能够提高绝缘子串在污秽和覆冰环境下的交直流闪络电压，但其在雷电冲击电压下的闪络特性却缺乏研究。为探究倒T型布置方式是否会影响绝缘子串的耐雷水平，本文以LXY-70玻璃绝缘子为试品，通过积污绝缘子串雷电冲击闪络试验探究不同布置方式和不同盐密下倒T型绝缘子串的雷电冲击闪络特性，并对其电场分布进行仿真计算。结果表明：倒T型绝缘子串雷电冲击闪络电压与盐密满足负幂指数函数关系；倒T型绝缘子串水平耐张段电场强度较低，电场畸变程度较小，不利于局部电弧的发展。正、负极性雷电冲击闪络电压相比悬垂布置均有提高，且在爬电距离一定时闪络电压提高百分比随着水平串长增大而增大，但增幅较小，倒T型布置方式可微弱提高绝缘子串的耐雷水平，本文结论可为倒T型布置方式在实际输电线路中的应用提供一定参考。

The inverted T-shaped arrangement of insulator strings can improve the AC and DC flashover voltage of insulator strings in polluted and icing environments, but its flashover characteristics under lightning impulse voltage lack research. In order to investigate whether the inverted T-shaped arrangement effects the lightning withstand level of insulator strings, this study used LXY-70 glass insulators as samples to explore the lightning impulse pollution flashover characteristics of the inverted T-shaped insulator strings under different arrangements and salt densities. The electric field distribution was also simulated. The results show that the lightning impulse flashover voltage of the inverted T-shaped insulator strings is inversely proportional to the salt density. The electric field strength in the horizontal tension segment is lower, with less distortion, which is not conducive to the development of local electric arcs. The flashover voltage under positive polarity and negative polarity lightning strikes is increased compared to the suspended arrangement. The percentage increase in flashover voltage with a certain creepage distance increases with the increase in horizontal string length, but the magnitude of increase is small. The inverted T-shaped arrangement can slightly enhance the lightning withstand level of insulators. These findings can provide some reference for the practical application of the inverted T-shaped arrangement in transmission lines.

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