乾式架橋方式60kV級撤去CVケーブルの絶縁破壊前駆遮断による絶縁性能の経年低下特性と低下要因の把握

抄録

60kV class XLPE cable has been widely applied for power grids since 1964. In its early stage, its production technologies had been developed drastically including dry-curing method for cross linking process of cable insulation layer to avoid water-tree degradation. The developed XLPE cable has widely introduced into power grids in 1980's and 1990's and some of them are still under operation.

In order to clarify the electrical insulation performance of such highly aged XLPE cable body, this paper reports some results of the pre-breakdown discharge detection test for 60kV class decommissioned XLPE cables. The experimental investigation revealed that the electrical insulation performance in some specimen degraded to around 10% of their initial electrical insulation performance and some of them kept high performance as high as their initial condition. It is also depicted that the degradation cause was water trees even for the dry-cured XLPE cable.