Page 42 - Analysis Report of Global Market in the Submarine Cable Field (2017)

Wire and Cable

As the amount of seawater infiltrated and depth of infiltration changes change in dielectric strength. Characteristic of material which is in the
according to the time, the field distribution of the insulation layer is use of water pressure environment is also a key indicator. Insulation
constantly changing with the infiltration of seawater. As the infiltration material before and after seepage performance, please see Table.2 and
of seawater result in the insulation layer electrical field distortion, the Table.3.
insulation life have an impact. Figure3: the rate of water absorption of insulating materials

1.1 Research on the performance of submarine optical fiber cable
insulation material
The selection and design of the submarine optical fiber cable insulation
layershould also consider about the electrical performance and changes
of water pressure infiltrate the common submarine optical fiber cable
insulation material is in the following table.
Table 1The main insulating material of submarine optical fiber cable

Table2: Conductivity change after seepage
The intuitive parameter of the polyethylene materials insulating are
electrical conductivity (the reciprocal of insulation resistance) and the AC
high voltage breakdown field, it is easy to test the electrical conductivity
and the AC high voltage breakdown field under the normal temperature
and pressure. The submarine optical fiber cable system is different,
it must be add water in the application environment, performance
parameters under pressure conditions can be as an input condition for
submarine optical fiber cable insulating design. In this paper, the research Table3: other dielectric properties of insulation materials
on submarine optical fiber cable insulating technology is as follow table
2, it put material into a pressure vessel containing seawater and test its
water absorption rule, carry out the change characteristics of the strength
and conductivity of the material under different load temperature and
field, and then put test results as input conditions to calculate the electric
field distribution.
Figure2: the research route of relay submarine optical fiber cable
insulation technology 1.2 The simulation design of submarine optical fiber cable in
insulation structure
In order to verify the dielectric performance change after insulating
material permeate different concentration of seawater and the influence
on electric field distribution,we use the software of finite element
analysis to build model and calculate the change of insulating layer's
electric field distribution according to the obtained result of experiment
in different retting to material direct current conductivity,disruptive
strength and space charge characteristic.Based on the structure of deep
submarine composite cable(Table4),we build models.System voltage is
–10kv,the internal electric field is zero under the direct current because
of the stainless steel optical fiber unit and wire armor are both in the
Under high pressure conditions of the deep sea, moisture will infiltrate equipotential plane of copper conductor.The simulation result of electric
to insulation materials gradually. First, we need to test the law of water field distribution before water seepage is showed in figure 4 left and the
absorption of different materials. It is proved that moisture can infiltrate right is after water seepage.
to insulation materials for polyethylene through experiments, but
moisture content of the material has a saturation, the change in water Table 4 structural parameters of the deep submarine composite cable
absorption of different materials is shown in Figure.3. Different types of
materials have different intermolecular crystal arrangements, the water
saturation is about 1-3‰.

By making statistics of the Weibull distribution of the breakdown
strength of different types of insulating materials, we set up the
histogram of their different characteristic breakdown strength. The Figure 4 The distribution of submarine optical fiber cable insulating electric field
breakdown strength of polyethylene insulation material decreases
with increasing infiltration of sea water, higher density of polyethylene
crystallinity and dense molecular chain arrangement make water
molecules penetrate the insulating material difficultly. Due to less water
absorption, the breakdown strength and conductivity did not change
obviously. The water infiltration characteristic is determined by the
crystallization characteristics of the material itself, causing the regular
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