一起220kV架空线路地线金具发热分析及对策探讨

Analysis and Countermeasure Discussion on Heating of Fittings on Grounding Wire of 220kV Overhead Transmission Line

针对佛山地区一起220 kV架空线路地线挂点金具出现的异常发热现象,通过建立等效模型,计算分析并发现地线感应电压和地线金具连接处接触电阻综合作用对金具温度升高具有较大的影响,结合发热处金具的具体情况,探究出其异常发热的主要原因为:架空地线、大地、两相邻铁塔和各自的挂点金具可能形成一个能够导通的电流回路;导地线间距离小和接触电阻大等。最后提出了可行的解决方案及预防控制措施。

To a phenomenon of abnormal heating of fittings on suspension points of 220 kV overhead grounding wire in Foshan area,this paper discovers that induction voltages of the grounding wire and effects of the contact resistance at the joint of fittings on the grounding wire have great influence on temperature rises of fittings by establishing an equivalent model for calculation and analysis.It also finds out that main reasons for abnormal heating by combining particular cases of heating fittings are a probable conductive current circuit formed by the overhead grounding wire,the earth,adjacent towers and their fittings,large induction voltage caused by short distance between the grounding wires,large contact resistance,and so on.Finally,the paper proposes feasible solution and pre-control measures.