直流盘形悬式玻璃绝缘子

DC Plate-shape Suspension Glass Insulator

直流输电具有比交流输电稳定、线损小、线路投资少、输送距离长、功率大等优点。但直流输电对绝缘子的防污秽性能要求高 ,对其金属附件 (铁帽和钢脚 )腐蚀厉害。采用大盘径和高、矮伞棱交错结构 ,以提高防污秽性能 ;铁帽口采用锌环和钢脚采用锌套 ,以提高抗腐蚀性能 ;在玻璃配方中适当增加稀有元素Li2 O的含量 ,用K2 O取代少量Na2 O ,以提高产品的体电阻 ,避免热击穿现象的发生。采用上述措施生产的 3种直流玻璃绝缘子 ,顺利地通过了型式、陡波冲击耐受电压、直流人工污秽耐受电压、直流干耐受电压、SF6气体直流耐受电压、热电破坏和离子迁移老化等试验 ,它的挂网试运行零值自破率逐年减少 ,其中 ,LXZY - 2 10绝缘子第 3年的自破率为 0 %。

Compared to AC power transmission,DC power transmission is characterized with the following advantages:stable transmission,small line loss,less investment on line,long transmission distance,arge power and so on.While DC power transmission requires high anti-fouling property for insulators and causes serious corrosion to their metal attachments (iron cap and steel foot).Application of large diameter plate and high and low alternative structure of umbrella and rhombus shape can improve the anti-fouling property.Application of zinc ring at the iron cap open and zinc sleeve on the steel foot can improve the anti-corrosion property.Proper addition of the content of rare element Li 2O and substitution of less Na 2O with K 2O in the dispensation formula of DC glass should increase the body resistance of the product and avoid heat breakover phenomena from occurrence.Three kinds of DC glass insulators produced by means of the previous measures have successfully passed through the following tests:type test,steep wave impact withstand voltage,DC artificial fouling withstand voltage,DC dry withstand voltage,DC withstand voltage of SF 6 gas,thermoelectric failure and ionic migration aging,so on.The zero self-failure on-line for test operation has been decreased year by year,of which the self-failure rate of insulator LXZY-210 is 0% at the third year.