500kV输电线路覆冰闪络故障原因分析及防范措施

Ice Flashover Fault Analysis and Preventive Measures for 500kV Transmission Line

大兴安岭地区某500 kV输电线路发生了覆冰闪络故障。分析认为由于该输电线路所处区域为垭口地形,每年换季时节多出现雨雪天气,极易形成雨凇覆冰桥接复合绝缘子闪裙,引发覆冰闪络故障。并提出了在微地形微气象区,500 kV输电线路宜采用大伞隔断的防冰复合绝缘子或插花串,尽可能采用V形串或倒V形串防止冰凌桥接形成闪络通道,以及配置输电线路融冰装置,防止导地线覆冰断线等提高输电线路抗冰能力的防范措施。

An ice flashover fault occurred on a 500 kV transmission line in Xinganlingarea. The analysis showed that the transmission line was located in the area of the damterrain, and the rain and snow weather often occured in the changing seasons of each year,which was easy to form a composite insulator flashover skirt with ice-covered bridge andlead to ice flashover fault. And put forward the trade measures that in micro-meteorologicalarea, 500 kV transmission lines should adopt composite insulators or flower arrangementstrings with large umbrellas, using V-string or inverted V-string as far as possible toprevent the formation of flashover channel by icing bridge connection, and configurate thetransmission line ice melting devices to prevent ground conductor from icing and breaking.