Some Insights Into Submarine Cables

On August 16 in 2017, Belgian dredging company DEME announced a contract to install a submarine cable for a modular offshore power grid in Beihai, Belgium. 

And the value of this order is about 130 million euros, awarded by the Belgian transmission system operator Elia. 

Under the terms, the contractor will supply, install and maintain three 220 kV submarine cables. 

The cable will be manufactured by the Greek company Hellenic cable. And the modular facility will connect the next four offshore wind farms to the Belgian grid, with a total capacity of 1030 megawatts.

The submarine cable plays a more and more important role for the development of the world,it provide opportunities for future development and interconnection with neighboring countries .

Submarine cable is wrapped with insulating material wire, laying in the seabed and river water for telecommunications transmission. 

Modern submarine cables are used as fiber materials, transmission telephones and Internet signals.

Submarine cables are submarine communication cables and submarine power cables. 

Submarine communication cable is mainly used for communication services, expensive, but high degree of confidentiality. 

Submarine power cable is mainly used for underwater transmission of high-power power, and plays the same role as underground power cable, but the application of the occasion and the way of lay is different.

Here is the Classification of Submarine Cable as Following:

1 Impregnated Paper Bag Cable

For more than 45kV AC and no more than 400kV DC line. 

It is currently limited to water within 500m of water depth.

2 Self-Contained Oil-Filled Cable

For up to 750kV DC or AC lines. As the cable is oil-filled, it can be difficult to lay in the water depth of 500m of the sea.

3 Extruded Insulation (XLPE Insulated, Ethylene Propylene Rubber Insulation) Cable

For up to 200kV AC voltage. 

Ethylene-propylene rubber than polyethylene to prevent the phenomenon of branches and local discharge, so that the submarine cable more effectively play a function.

4 "Hydraulic" Pipe Cable

Only for a few kilometers long cable system, because the very long cable into the pipeline, subject to great mechanical restrictions.

Inflatable (pressure-assisted) cable

Inflatable cable with impregnated paper bag is more suitable for longer submarine cable glands than oil-filled cables.

But due to the need for high pressure operation under deep water, the design cable and its accessories Of the difficulties, generally limited to water depth of 300m or less.

Submarine communication cable is mainly used for long distance communication network, usually used for long distance islands, cross-sea military facilities and other more important occasions. 

Submarine power cable laying distance is much shorter than the communication cable, mainly used for land between islands, across the river or harbor.

From the land connection drilling platform or drilling platform between the interconnection.