低气压下绝缘子雷电冲击的污闪特性

Insulator Pollution Flashover Characteristic Under Low Air Pressure Caused by Lightning Surge

运行经验表明,运行中绝缘子也会因雷击发生污闪,且随着海拔高度的升高或者气压的降低,绝缘子的雷电冲击污闪电压还将下降,故研究低气压下污秽绝缘子的雷电冲击特性具有较高的学术价值和一定的工程实际意义。为此,在大型多功能人工气候室模拟不同海拔条件下,清洁及染污4片串XP-160绝缘子和FXBW3-35/100在雷电冲击下的污闪特性,得出了盐密、气压对污秽绝缘子50%雷电冲击闪络电压影响的关系式,确定了两者的影响特征指数,并对两者的特征指数进行了比较和分析。研究结果表明,染污绝缘子的污闪电压相对清洁绝缘子干闪和雾闪有明显降低,因此,在工程实际中也应该考虑染污绝缘子的雷电冲击放电特性。

The lightning surge pollution flashover characteristics of four units XP-160 and FXBW3-35/100 insulators were experimentally studied in the large multi-function artificial climate chamber,thereby,the expression of salt deposit density,air pressure with lightning surge flashover voltage were obtained and the exponents characterizing the influence of these factors were also determined.These two exponents characterizing the influence of different insulators were also compared and analyzed.Research results show that,compared with dry flashover voltage,the fog flashover voltage of clean insulator,the pollution flashover voltage of polluted insulator under lightning surge remarkably decrease,thus the lightning surge discharge characteristics of polluted insulator should be considered in the practical engineering.