【摘要】 目前,多条-800 kV直流输电线路出现大面积V串瓷绝缘子铁帽电腐蚀现象,给输电线路安全运行造成重大隐患。搭建了V串瓷绝缘子铁帽加速电腐蚀试验平台,提出了一种采用滴水法模拟现场瓷绝缘子铁帽电腐蚀情况的试验方法,并采用该方法对特高压线路瓷绝缘子铁帽进行了加速电腐蚀试验。试验结果表明,采用该方法获得的铁帽电腐蚀区域的参数与现场电腐蚀情况差别在10%之内,具有良好的等效性;在长期的液体环境下,运行线路负极性侧瓷绝缘子铁帽发生严重的电腐蚀,当损失电荷量为80 000 C时,铁帽电腐蚀深度达12.2 mm;绝缘子铁帽加装保护锌环可以改变铁帽电腐蚀的起始点和方向,并且锌环首先发生电腐蚀,因此,锌环对铁帽电腐蚀问题具有明显的抑制作用。更多还原

【Abstract】 At present,the phenomena of electrolytic corrosion of metal caps of V-shaped porcelain insulator strings for ?800 kV UHVDC transmission lines widely appear and bring great hidden danger to safe operation of UHVDC transmission lines.A test platform for accelerated electrolytic corrosion of metal caps of V-shaped porcelain insulator strings is constructed,and a test method to simulate the on-site electrolytic corrosion of metal caps by water-dripping is proposed.Test results show that the difference between the parameters of corroded region on metal cap of insulator obtained by the proposed method and those from on-site corrosion situations is less than 10%,so the proposed method is of satisfied equivalence to field conditions.Under long-term liquid environment,serious electrolytic corrosion of metal cap of insulator strings occurs at negative polarity side of the being operated transmission line,and when the lost quantity of electric charge reaches to 8 0000 C,the depth of electrolytic corrosion of metal cap is 12.2 mm;adding protective zinc ring to metal cap of insulator can change both initial point and direction where the electrolytic corrosion occurs,and the zinc ring is the first to be electrolytically corroded,thus the zinc ring can evidently suppress the phenomena of electrolytic corrosion of metal insulator caps.更多还原