金属微粒和臭氧处理对GIS用盆式绝缘子闪络电压的影响

Effects of Metallic Particle and Ozone Treatment on Flashover Voltage of Basin Insulator for GIS

在SF6气氛中研究金属微粒和臭氧处理对110 kV气体绝缘金属封闭开关(GIS)盆式绝缘子闪络电压的影响。结果表明:绝缘子沿着附着在其表面上的金属微粒发生闪络,闪络痕迹明显。绝缘子未经处理时,闪络电压随金属微粒长度的增加而迅速下降。金属微粒长度增加到8 mm时,闪络电压下降趋势变缓。金属微粒靠近中心导体时,其对绝缘子闪络电压的影响较大。距中心导体0 mm时,闪络电压最小。臭氧处理后的绝缘子与未处理的绝缘子呈现出相似的闪络特性,但处理后的绝缘子闪络电压提高了约18.5%。臭氧处理可以改善绝缘子表面的陷阱特性,加快绝缘子表面电荷消散速率,提高绝缘子的闪络电压。550 k V正极性雷电冲击波无法检测出微小金属微粒的存在,也无法检测出靠近中心导体或稍远区域金属微粒的存在。

The effects of metallic particle and ozone treatment on the flashover voltage of basin insulator for 110 kV gas insulated metal-enclosed switchgear(GIS)were studied in the atmosphere of SF6.The results show that flashover occurs along the metallic particles which are attached on basin insulator surface,and there is obvious burning trace.Before ozone treatment,the flashover voltage of insulator decreases rapidly with the increase of metallic particle length.When the metallic particle length increases to 8 mm,the flashover voltage decreases slowly.When the metallic particle is close to the center conductor of insulator,it has great influence on the flashover voltage,and the flashover voltage is low when the metallic particle is 0 mm away from the center conductor.The flashover characteristic of the insulator after ozone treatment is similar to the untreated insulator,while the flashover voltage increases by 18.5%after treatment.The ozone treatment can improve the surface trap characteristics of insulator and accelerate the dissipation of surface charge,so the flashover voltage of insulator increases.Tiny metallic particles and metallic particles close to or far away from the center conductor are undetectable under 550 k V standard lightning impulse(SLI).