膨胀土地区玻璃绝缘子积污原因分析及防范措施

Cause Analysis and Preventive Measures of Glass Insulator Fouling in Expansive Soil Area

架空输电线路绝缘子常年暴露在自然界中,由于受多种环境因素的影响,绝缘子表面积污在所难免,积污特征决定于其所处的地理位置和周围环境的作用情况,在线路设计和运行中会将绝缘子污秽层度进行等级划分,按照轻污区、中污区、重污区进行分级,而膨胀土地区的输电线路设计时往往按轻污区考虑,但随着线路周围环境的变化,膨胀土地区绝缘子积污速度也越来越高。笔者根据多年线路运行维护经验,发现近年来膨胀土地区的绝缘子污秽层度较为严重,以广西百色地区膨胀土区域内的500 kV天平双回线路为列,位于该区域内的玻璃绝缘子污垢黏附性极强,在线路维护时人工清污难度极大,甚至无法将污垢清除干净。为了弄清污垢成分,通过对绝缘子污秽物进行提取化验分析,得知导致膨胀土区域内的玻璃绝缘子积污速率高,难以清污的原因是膨胀土中的矿物质成份蒙脱石的细微颗粒长期在风力作用下附着于玻璃绝缘子伞裙内部所致。

Overhead transmission line insulators are exposed to nature all year round.Due to the influence of various environmental factors,insulator surface pollution is inevitable.The special name of accumulated pollution depends on its geographical location and the role of the surrounding environment.In line design and operation,the degree of pollution layer will be classified according to light pollution area,medium pollution area and heavy pollution area,The transmission line design in the expansive soil area is often considered as the light pollution area,but with the change of the surrounding environment,the pollution accumulation speed of insulators in the expansive soil area is becoming higher and higher.Based on many years of line operation and maintenance experience,the author found that the insulator pollution layer in the expansive soil area is relatively serious in recent years.Taking the 500 kV balance double line in the expansive soil area in Baise,Guangxi as the column,the dirt adhesion of glass insulators in this area is very strong.It is very difficult to remove the dirt manually during on-line road maintenance,and even can not remove the dirt.In order to clarify the dirt composition,through the extraction,test and analysis of insulator dirt,the author knows that the reason for the high fouling rate of glass insulator in the expansive soil area and the difficulty in cleaning is that the fine particles of montmorillonite,the mineral composition in the expansive soil,are attached to the inside of the umbrella skirt of glass insulator under the action of wind for a long time.