A brief analysis of the classification, types and uses of submarine cables

Submarine cable classification:

1.
Impregnate the paper-wrapped cable

Suitable for lines
not more than 45kV AC and not more than 400kV DC.
At present, it can only be installed in waters
with a depth of up to 500m.

2.
Self-capacitant oil-filled cable

Suitable for DC or AC lines
up to 750kV.
Since the cable is oil-filled, it can be laid in waters up to 500 m without
difficulty.

3.
Extruded insulated (XLPE insulated, EPDM insulated) cable

Suitable for voltages
up to 200kV AC.
Compared with polyethylene, EPDM can prevent tree branches and local power leakage, so that submarine cables can function
more effectively.

4.
"Hydraulic pressure" pipe cable

It is only suitable for several kilometers of cable systems, as there are great mechanical limitations
in pulling extremely long cables into the pipes.

5.
Inflatable (pressure assisted) cable

Inflatable cables using impregnated paper wraps are more suitable for longer submarine cable networks than oil-filled cables, but due to the need to use high air pressure operation under deep water, it increases the difficulty of designing cables and their accessories, which are generally limited to water depths of less than 300m
.

Types of submarine cables:

Submarine communication cable and submarine power cable
.
Submarine communication cables are mainly used for communication business, which is expensive but has a high
degree of confidentiality.
Submarine power cables are mainly used for underwater transmission of high-power electric energy, which is equivalent to the role of underground power cables, but the application occasions and laying methods are different
.
Because the submarine cable project is recognized by the world as a complex and difficult large-scale project, from environmental exploration, marine physical survey, and cable design, manufacture and installation, are the application of complex technology, so submarine cable manufacturers in the world is one of the few, mainly Norway, Denmark, Japan, Canada, the United States, Britain, France, Italy and other countries, these countries in addition to manufacturing also provide laying technology
.
At present, the submarine power cables applied in China still need to be imported
.

Submarine cable use:

Submarine communication cables are mainly used in long-distance communication networks, usually used in long-distance islands, cross-sea military facilities and other important occasions
.
The laying distance of submarine cables is much shorter than that of communication cables, and is mainly used for connecting land islands, crossing rivers or harbors, connecting drilling platforms from land or interconnection between drilling platforms
.
In general, the application of submarine cables to transmit electrical energy is undoubtedly more expensive than overhead cables of the same length, but it is often more economical than using small and isolated power stations for regional power generation, and its application in offshore areas is more
beneficial.
In countries with more islands and rivers, this cable is more
widely used.