电缆交叉互联换位失败缺陷分析及应对措施

Defect Analysis and Countermeasures of Cable Cross Linking Transposition Failure

在输电电缆运检工作中,曾出现由于同一个交叉互联单元中2个交叉互联箱内铜排排列方式不同而导致的交叉互联换位失败缺陷。这种缺陷导致接地环流大幅上升,影响电缆线路的供电可靠性。在理想条件下,根据交叉互联换位失败缺陷下的交叉互联单元示意图,用相量法分析回路感应电压,研究这种缺陷导致环流超标的原因,并进一步利用ATP-EMTP软件进行仿真,直观展示非理想条件下交叉互联换位失败缺陷会造成的影响。通过改变交叉互联箱内接线柱的位置或增加绝缘挡块的方式,有效避免交叉互联换位失败。

In the operation and inspection of transmission cable,there had been cases of cross linking transposition failure defects,which were caused by the different arrangement modes of the coppers in the two cross linking protection grounding boxes of a cross linking unit.Such defects led to a significant increase in grounding loop current,affecting the power supply reliability of cable lines.The loop induced voltages were analyzed through the phasor method under ideal conditions,based on the schematic diagram of a unit with a cross linking transposition failure defect,to get the reason for the increase of the loop current.Further simulation was performed using the software of ATP-EMTP to visualize the impact that would be caused by the defect under the non-ideal condition.A cross linking transposition failure defect could be effectively avoided by changing the positions of a wiring column in cross linking protection grounding boxes or by adding an insulating block to the boxes.