融冰期绝缘子伞间电场动态特性仿真研究

Simulation of Dynamic Characteristics of Insulator Umbrella Skirt Gap Electric Field During Ice Melting Period

现有试验研究表明,融冰期绝缘子的放电与局部电场强度增大密切相关,而融冰期的水滴动态形变对局部电场的影响尚未研究。为了得到在融冰水滴的动态形变影响下,绝缘子伞间电场随时间和空间变化的动态特性,以复合绝缘子伞裙单元为对象,通过建立流体电场耦合仿真模型,从水滴的形变长度、破碎以及不同融冰滴水位置等3个方面对伞间电场的影响进行了分析。结果表明:大伞冰棱尖端水滴的形变长度增加将使得伞间电场强度值增加;水滴破碎行为将使得伞间电场强度最大值显著上升,改变间隙电场强度的空间分布,使得最大电场强度的位置发生转移,在间隙距离较小时,可能诱发局部电弧产生;而由于高电导率水膜的屏蔽作用,中小伞裙冰棱尖端发生融冰滴水对间隙电场强度的影响较小。

The existing experimental studies show that the discharge of insulators in the ice melting period is closely related to the increase of local electric field,while the influence of dynamic changes of water droplets in the ice melting period on local electric field has not been studied.In order to get the dynamic characteristics of the electric field of umbrella skirt clearance with time and space under the influence of dynamic deformation of melting water droplets,this paper takes composite insulator umbrella skirt unit as an object and establishes a fluid-electric field coupling simulation model to analyze the influence of droplet deformation length,broken and different melting drop location on the electric field of umbrella skirt clearance.The results show that the gap electric field intensity increases with the increase of deformation length of water droplets at the tip of the icicle.The water droplet breakage behavior will significantly increase the maximum value of the gap electric field intensity,change the spatial distribution and make the location of the maximum electric field intensity shift.When the gap distance is small,the water droplet breakage may induce local arc generation.However,due to the shielding effect of high conductivity water film,the melting water drop at the tip of small and medium-sized umbrella skirt has little influence on the gap electric field strengt.