Adss optical cable and Opgw optical cable selection guide
Adss optical cable and opgw optical cable are power optical cables. They make full use of the unique resources of the power system and are built closely together with the power grid structure. They are economical, reliable, fast and safe.
The special power optical cable is less likely to be damaged by external force and has high reliability. Although its own cost is relatively high, its construction cost is relatively low.
Adss optical cable and opgw optical cable are installed on various power pole towers with different voltage levels. Compared with ordinary optical cables, they have special requirements on their mechanical characteristics, optical fiber characteristics and electrical characteristics.
Adss optical cable is mainly used in the information transformation of built lines, and is mostly used in transmission lines with voltage grades of 220kV, 110kV and 35kV.
It is mainly to meet the requirements of large SAG and large span of power transmission lines. ADSS optical cable is characterized by: 1.
Adss optical cable is small in diameter and light in weight, which can reduce the influence of ice and wind on the optical cable, and its influence on the strength of the tower is also very small; 2.
Adss adopts new materials and smooth shape design, which makes it have superior aerodynamic characteristics; 3.
Electric erosion resistant adss optical cable can reduce the electric corrosion of optical cable caused by high voltage induced electric field; 4.
The expansion rate of adss can remain unchanged within a large range of temperature difference, and it has stable optical characteristics at the limit temperature; 5. The theoretical value of fiber tension in adss is zero; 6.
Adss optical cable is fully insulated and can work live during installation and line maintenance, thus greatly reducing power failure losses.
Adss optical cable works on high-voltage transmission lines, and there is a strong electric field around it. Electric corrosion often causes damage or even damage to the optical cable. The current solutions are: 1.
The space potential of the suspension point of the control cable shall not exceed 15kV for 110kV and 20kV for 220kV. 2.
The electric Mark resistant jacket is preferred for lines with different voltage levels, and the electric Mark resistant material must be selected for lines with 110kV and above. 3.
For 110kV and above lines, anti-Corona coils can be considered to effectively reduce the electric field on the surface of fittings and optical cables and reduce leakage current. 4.
220kV and above lines and strong towers in hanging Point Field, the creepage electric corrosion of shock hammer on the outer skin of optical cable is much safer than that of shock-proof whip.
Opgw optical cables are mostly applied to new lines due to power failure, safety and other factors.
It is mainly used on 500kV, 220kV and 110kV voltage grade lines. opgw optical cable is characterized by integrating overhead ground wire and communication optical cable on high voltage transmission lines into one cable, the transmission line technology and optical cable technology are combined with each other to become a multifunctional overhead ground wire, which is not only an overhead optical cable, but also a lightning protection line and a shielded line. While completing the construction of communication lines, the construction of high-voltage transmission lines has also been completed, which is very suitable for newly-built transmission lines.
There are three main types of common OPGW structures, namely, steel pipe type, aluminum pipe type and aluminum skeleton type.
The characteristics and applicable environment of opgw optical cable are: 1.
Opgw optical cable is metal armored, which has no effect on corrosion and degradation of high voltage marks; 2.
Opgw optical cable must work without live electricity during construction, and the power failure loss is relatively large. Therefore, OPGW optical cable should be used in newly-built high-voltage lines above 110kV; 3.
For lines with high voltage exceeding 110kV, the span is large (Generally above 250 M); 4.
It is easy to maintain, easy to solve the problem of line crossing, and its mechanical characteristics can meet the requirements of line crossing.
The main fault in opgw optical cable application is the broken stock caused by lightning strike. The current solutions mainly include: 1. Develop new materials for the outer layer of lightning resistance.
The outer material of the high-resistance OPGW developed in Finland in 2001 is composed of a high-grade galvanized steel wire and an aluminum tube protecting optical fibers. High-grade galvanized steel needs more energy to melt under lightning strike. 2.
Try to use aluminum-clad steel wire in the outer strand, and thicken the aluminum-clad thickness of aluminum-clad steel wire. 3.
Try to increase the design air gap between the outer and inner strands to avoid internal heat transfer. 4.
Under the same material, a larger outer strand diameter is adopted.
After the material and structure of opgw optical cable are determined, its Leech resistance is also determined.