高海拔地区750kV输电线路绝缘子选型研究

在2种盐密、4种海拔高度下对8种典型的大吨位电瓷和玻璃绝缘子进行了人工污秽试验,得出了各种绝缘子污闪电压随海拔高度的变化规律。通过比较,三层伞型电瓷绝缘子的耐污闪性能最好,双层伞型电瓷绝缘子的耐污闪性能也较好,而且随海拔升高其污闪电压降低幅度较小,所以推荐使用三层伞或双层伞电瓷绝缘子。采用工程设计中广泛采用的爬电比距法,给出了4种污秽等级、4种海拔高度下750kV线路悬式绝缘子的片数,并用污闪试验结果对选择结果进行了验证。

Study on selection of 750 kV transmission line insulators in high altitude area

For four different types of porcelain insulators with 210 kN,300 kN and four different types of 210 kN,300 kN glass insulators,the artificial contamination tests were carried out in four pressure cases corresponding to the altitude from 0 m to 3 000 m and in two typical kinds of equivalent salt deposit density(ESDD).The tests show that the flashover voltage of polluted insulators regularly decreases with the increasing of the altitude.And the flashover performance of No.4 and No.2 porcelain insulators' is better than other insulators,so No.4 or No.2 porcelain insulator is recommend in this paper.At last,the pieces of No.4 and No.2 insulators for 750 kV transmission line at different altitude are given and are proved in this paper.