架空线路雷击造成断路器断口绝缘击穿的实例分析  

Event Analysis of Insulation Breakdown of Circuit Breaker Fracture Caused by Lightning Strike of Overhead Line

作　　者：王永宁[1] 李宏博[1] 杜岳凡 WANG Yongning;LI Hongbo;DU Yuefan(Maintenance Company of State Grid Tianjin Electric Power Company,Tianjin 300232,China)

机构地区：[1]国网天津市电力公司检修公司,天津300232

出　　处：《电工技术》2020年第9期108-111,共4页Electric Engineering

摘　　要：某220kV线路发生雷电多重绕击,造成线路架空地线多处断裂及断路器分闸失败,并使220kV母线跳开。为探究断路器分闸失败的原因,通过对比雷电、继电保护动作信息,并借助电气试验、带电检测和设备拆解的方法,综合各项诊断试验的结果,判定断路器在断口绝缘强度尚未完全恢复期间再次经受过电压是造成断口绝缘击穿放电,致使断路器分闸失败的原因。基于缺陷成因并结合实际,提出了在变电站进出线入口处加装金属氧化锌避雷器等预防措施,为避免同类型故障的发生提供了技术和管理措施。Multiple lightning shielding failures occurred on a 220 kV transmission line,which resulted in broken-line fault of overhead ground wire and the failure of the breaker to open,and made the 220 kV bus trip.In order to investigate the cause of the failure,the operation process of relay protection is compared with lightning information in this paper.Then,electrical testing,live detection and disassembly methods are also used.Based on the results of various diagnostic tests,it is determined that the overvoltage experienced by the circuit breaker during the period when the insulation strength of the fracture has not been fully restored is the cause of the insulation breakdown discharge of the fracture and the opeing failure of the breaker.Based on the cause of the defect and in combination with the actual situation,preventive measures such as installing MOA at the entrance of the substation′s inlet and outlet lines are proposed,which provides technical and management measures to avoid the occurrence of similar types of failures.

关 键 词：绕击 断线 断路器 绝缘击穿 

分 类 号：TM07[电气工程—电工理论与新技术]