500kV线路绝缘地线的设计

Design on Insulated Ground Wire of 500 kV Transmission Line

合理选择绝缘子、并联间隙 ,可使绝缘地线在正常情况下减少潜供电流 ,节约能源 ,又可用于高频载波通信、电流熔冰和电容抽能 ;在雷击或接地短路故障时将并联间隙击穿使地线接地 ,起到防雷保护、降低线路零序阻抗、降低工频过电压和降低对通信设施的干扰影响等作用。文章结合广东 5 0 0kV电网 ,就合理选择地线绝缘子、布置并联间隙及整定间隙距离等方面 。

Reasonable selection of the insulators and parallel gaps can reduce the latently supplied current for the insulated ground wire under the normal operation conditions and save the energy.It can also be used for high frequency carrier wave communication,ice melt by current and capacitor energy extraction.During the lightning or ground short circuit failure the parallel gap will be broken down,which lets the ground wire is grounded to function as lightning protection,reduction of the line zero-sequence impedance,reduction of working frequency over voltage and reduction of interference on the communication facilities.The paper introduces the design experiences for reasonable selection of the insulators for the ground wire,arrangement of parallel gaps and setting of the gap distance in combination with 500 kV power network in Guangdong.