涂覆RTV对瓷绝缘子盐密和灰密影响的对比观测

绝缘子盐密和灰密值是污区分级和外绝缘配置的基础,各地污区分级观测绝缘子往往以XP-70瓷绝缘子为观测绝缘子,涂覆室温硫化硅橡胶(RTV)涂料对绝缘子积污特性的影响是一个值得关心的问题。因而选择深圳地区54处代表性的输电杆塔进行涂覆RTV与未涂覆RTV的XP-70绝缘子不带电挂样观测对比,测量了积污期为2a的绝缘子盐密、灰密和灰密盐密比,对比了涂覆RTV与未涂覆RTV线路绝缘子上表面、下表面与单片均值积污规律的差别。结果表明:涂覆RTV的绝缘子与未涂RTV的XP-70绝缘子相比,上表面盐密值增加约1倍,下表面盐密值、单片盐密均值增加约2倍,上表面灰密值增加约2倍,下表面灰密值、单片灰密均值增加约3倍,涂覆RTV的XP-70绝缘子灰密盐密比大于未涂覆RTV绝缘子的灰密盐密比。污秽外绝缘配置时在注意到涂覆RTV对绝缘子污闪电压大幅提高的同时,也应注意到涂覆RTV对绝缘子积污特性的影响。

Contrast Observation on the Influence of ESDD and NSDD of Porcelain Insulator with RTV

Equivalent salt deposit density(ESDD) and non soluble deposit density(NSDD) are the basic data for outer-insulation coordination and pollution distribution classification.XP-70 is usually selected as an observation insulator for pollution distribution classification in China.We selected 54 transmission towers representing typical distribution of Shenzhen city as the contrast observation positions for XP-70 in the presence and absence of coated room-temperature vulcanized silicone rubber(RTV),then we measured ESDD,NSDD,and the ratio of NSDD to ESDD of XP-70 insulator with 2 years contamination time,and compared the differences of natural contamination characteristics of XP-70 insulators in the presence and absence of coated RTV.The results show that,the upper surface ESDD of XP-70 insulator in the presence of RTV is about twice that in the absence of RTV;the lower surface ESDD and the single insulator ESDD average value in the presence of RTV is about 3 times that of in the absence of RTV;the upper surface NSDD in the presence of RTV is about 3 times that in the absence of RTV;the lower surface ESDD and the single insulator average value the presence of RTV is about 4 times that in the absence of RTV;the ratio of NSDD to ESDD the presence of RTV is higher than that in the absence of RTV.It is necessary to notice that RTV not only remarkably improves the pollution flashover voltage but also markedly affects the natural contamination characteristics,which is both the basis of pollution outer insulation coordination.