运行复合绝缘子护套与芯棒界面蚀损问题探讨

Discussion of the Erosion on the Interface between Housing and Core of Composite Insulators

针对南方电网500 k V某线复合绝缘子芯棒脆断和上海供电公司500 k V徐杨5123线,发现25号、38号、42号的复合绝缘子运行温度超标的情况,对其复合绝缘子进行了外观、憎水性、材料和机械等试验。试验结果表明,复合绝缘子憎水性良好,硅橡胶材料未见老化,但是护套出现破损或者外突,未出现破损的护套和芯棒之间的界面出现大面积蚀损,出现明显的吸红现象(品红溶液),而且该现象由高压向中间延伸。认为界面蚀损的起因之一是由于脱模剂渗出引起的界面缝隙,进而导致局部放电,生产中芯棒吸入的水分参与了电化学反应所致。

According to the core fracture of composite insulator on the 500 kV power line of CSPG and the temperature abnormal rise of composite insulators which the numbers are 25, 38, and 42 on No. 5123 tower Xuyang power line of Shanghai power company of SGCC, these composite insulators have been done test about appearance inspection, hydrophobicity, material check and mechanical strength and etc. The results of test show that the hydrophobicity is well and the material of silicon shed isn＇t aging. But there are some humps on the surface of housing and erosion on the interface between whole housing and core of composite insulators. The penetrant （1%fushine） appear on the interface between housing and core. The erosion had extended from high voltage to the middle part of composite insulator. One of the reasons about erosion on the interface between housing and core of composite insulators is mold releasing agent seeping from core. The crack between housing and core has been made by the mold releasing agent and the partial discharge has appeared. The water which are absorbed on the production of core has taken part in electrochemical reaction leading to erosion.