输电线路融冰初期易冰闪机理试验研究

Experimental Study on Icing-flashover Mechanism for Iced Transmission Line in Early Ice-melting Stage

冰灾及输电线路冰闪事故严重威胁电网安全,有必要研究输电线路冰闪机理并采取措施防止线路冰闪事故。笔者提出了盐析及污秽在冰层中迁移现象的观点。通过盐析及污秽在冰层中迁移试验,从机理上解释了绝缘子在融冰初期最容易发生闪络的原因。试验证明污秽程度越高,迁移过程越快;融冰水电导率为覆冰水电导率的1.5～2.5倍,且凝结时间愈长,迁移时间愈充分,融冰水电导率的变化愈明显。

Salting-out and filth migration phenomena in ice is found to be concerned with icing-flashover of transmission lines. Through the tests of salting-out and filth migration in ice, the reason why flashover more easily happens in early ice-melting stage of iced insulators is explained. The tests indicate heavier the filth, the faster the migration; The conductivity of the meltwater is 1.5~2.5 times of water; The conductivity of the meltwater changes more obviously with increasing icing time migration time.