雾霾环境下微细导电颗粒诱发复合绝缘子沿面放电特征

Surface Discharge Characteristics Induced by Fine Conductive Particles on Polymer Insulator in Fog-haze Environment

针对当前雾霾大气环境对输变电设备外绝缘运行可靠性的影响,在实验室条件下采用微米级铁粉模拟雾霾中微细导电颗粒,研究交流电压下铁粉颗粒直径、含量以及位置对复合绝缘子沿面放电特征的影响,运用高速摄像机观察分析沿面闪络过程中导电颗粒物动态变化及其诱发的沿面放电现象,获取电晕放电、电晕和沿面流注放电共存、沿面流注放电3个主要阶段的放电特征,建立了闪络电压、放电发光亮度与导电颗粒物粒径、含量与位置的变化规律。研究结果有助于掌握雾霾环境下绝缘子放电机理,对提高污染新形势下电力系统外绝缘可靠性具有重要意义。

The frequent occurence of fog-haze weather is becoming one of hazard conditions to affect the insulation reliability of outdoor insulator in electrical devices. In this paper,concentrating on the influence of fine conductive particles in the fog-haze environment on the insulation characteristics of outdoor insulator,the iron powders at different micro sizes are selected to simulate different sized fine conductive particles. Effects of the fine particle parameters,including particle sizes,contents and relative locations,on surface discharge characteristics of polymer insulator are investigated under AC high voltage. During the whole experimental process,both the dynamic morphology of fine particles and the induced discharge phenomena on the insulator surface are captured via a high-speed camera. It is indicated that the process of surface discharges triggered by fine conductive particles on polymer insulators is mainly divided into three stages,which are corona discharges,coexistence of corona discharges,and streamer discharges.And the relationship among surface flashover voltage,discharge light intensity and the size,content and relative location of conductive particles can be obtained. The results are beneficial to further investigation on flashover mechanism of outdoor insulator under fog-haze conditions,which can enhance the operating reliability of outdoor insulator in power system with new contaminated conditions.