35kV输电线路玻璃绝缘子串中残锤的危害分析

Hazard Analysis of Residual Section in Glass Insulator Strings of 35 kV Transmission Lines

针对35 kV输电线路玻璃绝缘子零值自爆后的残锤,分析残锤的外绝缘、内绝缘特性,并结合两个实例分析在大风大雨作用下35 kV输电线路玻璃绝缘子串中残锤的危害,还针对残锤的危害提出了反措。结果表明:雨水可通过残锤的外绝缘渗浸内绝缘;运行中若未能及时发现和更换残锤,大风大雨将有可能引发存在残锤的35 kV输电线路玻璃绝缘子串发生单相接地闪络故障。其中,在残锤的内绝缘没有被雨水渗浸前,其内绝缘水平高于外绝缘水平,闪络电弧从残锤的外绝缘直接拉弧导通,将有可能导致单相接地闪络故障延时跳闸的35 kV输电线路发生烧断导线故障;在残锤的内绝缘被雨水渗浸后,其内绝缘水平低于外绝缘水平,闪络电弧从被雨水渗浸的残锤内绝缘导通,将有可能发生35 kV输电线路掉串故障。

Aiming at the residual section of 35 kV transmission line glass insulator after zero value self-explosion,the extermal insulation and interal insulation characteristics of the residual section are analyzed.Combined with two examples,the damage of the residual section in the glass insulator string of 35 kV transmission line under the action of strong wind and heavy rain is analyzed,and the countermeasures are put forward for the damage of the residual section.The results show that rainwater can be infiltrated into the internal insulation through the external insulation of the residual section;If the residual section is not found and replaced in time during operation,heavy wind and rain may cause single-phase ground flashover fault of 35 kV transmission line glass insulator string with residual section.Among them,before the intermal insulation of the residual section is not infilrated by rainwater,the intermal insulation level is higher than the external insulation level,and the flashover are is directly pulled from the external insulation of the residual section,which may cause the 35 kV transmission line with single-phase grounding flashover fault and delayed tripping to burn out the wire fault;Afer the intermal insulation of the residual section is soaked by rainwater,the internal insulation level is lower than the external insulation level,and the flashover arc is conducted from the internal insulation of the residual section soaked by rainwater,which may cause the 35 kV transmission line drop string fault.