110kV高压电缆金属护层接地电流过大分析

Analysis of Excessive Grounding Current in the Metal Sheath of a 110 kV High Voltage Cable

介绍了一起典型的110 kV高压电缆金属护套接地电流过大的缺陷。通过对电缆线路接地系统的原理分析和现场实际连接方式的对比分析,确认缺陷原因为:该线路经过一次迁改,金属护层接地方式有所变更,施工时接地方式安装错误导致两侧金属护层直接接地,形成环流致使接地电流过大。同时,提供了针对性的消缺方案设计和缺陷消除过程,最后提出了类似缺陷的预防措施及建议。

This article introduces a typical defect of excessive grounding current of 110 kV high voltage cable metal sheath.Through the principle analysis of the cable line grounding system and the comparative analysis of the actual on-site connection patterns,it is confirmed that the causes of defect are the relocation of line,the change of grounding pattern of the metal sheath,and that grounding installation error during the construction results in direct grounding of metal protection sheath on both sides,and excessive grounding current due to the presence of circulating current.Meanwhile,this article provides the design of targeted defect elimination programs and the process of defect elimination,and finally proposes similar measures and suggestions for preventing similar defects.