Development of an Innovative MV Submarine XLPE Cable Repair Joint by CLP Power

摘要

A number of outlying islands in Hong Kong are famous for their attractive scenery and heritage. Supply of electricity to these islands is provided through MV distribution submarine cables. Inevitably part of these cables are occasionally located at busy shipping channels or near marine vessel anchorage areas, and therefore these submarine cables are vulnerable to damages by ship anchors. As many of the cables were installed long time ago, they are of non-watertight design. If a submarine cable is damaged, sea water may penetrate into the interior of the cable and cause electrical failures. Such failures will adversely impact supply reliability to the concerned island. According to past experience, due to severe water ingress, there is a high chance of failure of the cable joint shortly after the repair. By conducting extensive surveys worldwide among cable joint manufacturers, it was realized that the design of conventional submarine cable joint, i.e. tape wrapping, could not effectively repair the cable. To resolve the problem, CLP Power (CLPP) has developed an innovative MV submarine XLPE cable repair joint as a solution. In this paper, the authors will share the design concepts and development of this innovative MV submarine cable repair joint, and their field experience of its application.