Types of power special optical cables and field optical fibers
With the acceleration of the trend of optical fiberization of communication networks, the transition process from the trunk line to the access network to the optical fiber has basically been completed in many areas of the power-specific communication network. Therefore, it is necessary to understand the types of power special optical cables and field optical fibers. The following is a detailed understanding of the types of power special optical cables and field optical fibers.
Types of power special optical cables and field optical fibers
Power special optical cable generally refers to OPGW (optical fiber composite ground wire), OPPC (optical fiber composite phase wire), MASS (metal self-supporting optical cable), ADSS (all-dielectric self-supporting optical cable), ADL (phase/ground bundled optical cable) and GWWOP (phase/ground bundled optical cable) / ground wire winding optical cable) and so on. At present, the most widely used power special optical cables in my country are ADSS and OPGW.
Special optical cable
1. Optical fiber composite ground wire - OPGW (Optical Ground Wire) OPGW, also known as ground wire composite optical cable, optical fiber overhead ground wire, etc., is an optical fiber unit for communication in the ground wire of the power transmission line. It has two functions: one is to act as a lightning protection wire for the transmission line, providing shielding protection for the transmission wire against lightning discharge; the other is to transmit information through the optical fiber compounded in the ground wire. OPGW is a composite of overhead ground wire and optical cable, but it is not a simple addition between them.
OPGW optical cable is mainly used on 500KV, 220KV, 110KV voltage level lines, and is mostly used on new lines due to line power failure, safety and other factors.
The applicable features of OPGW are:
(1) Lines with high voltage exceeding 110kv have a large span (generally above 250M);
(2) It is easy to maintain, easy to solve the problem of line crossing, and its mechanical characteristics can meet the large crossing of the line;
(3) The outer layer of OPGW is metal armor, which has no effect on high-voltage electrical corrosion and degradation;
(4) OPGW must be powered off during construction, and the power outage loss is relatively large, so OPGW should be used in new high-voltage lines above 110kv; (5) In the performance indicators of OPGW, the greater the short-circuit current, the more it is necessary to use good conductors for armoring, Then the tensile strength is correspondingly reduced, and in the case of a certain tensile strength, to increase the short-circuit current capacity, the only way to increase the metal cross-sectional area is to increase the cable diameter and cable weight, which poses a safety issue for the strength of the line tower. .
There are three main types of common OPGW structures, namely aluminum tube type, aluminum frame type and (stainless) steel tube type.
2. Optical Phase Conductor - OPPC (Optical Phase Conductor)
In the power grid, some lines may not have overhead ground wires, but phase wires are essential. In order to meet the requirements of optical fiber networking, similar to OPGW technology, optical fiber is added in a suitable method to the traditional phase line structure, which becomes an optical fiber composite phase line (OPPC). Although their structures are similar, OPPC and OPGW differ in principle from design to installation and operation.
3. Metal Aerial Self Supporting Cable - MASS (Metal Aerial Self Supporting)
From the structural point of view, MASS is consistent with the OPGW of the central tube single-layer stranded wire. If there is no special requirement, the metal stranded wire is usually made of galvanized steel wire, so the structure is simple and the price is low. MASS is a product between OPGW and ADSS. When MASS is used as a self-supporting optical cable, the main consideration is the strength and sag, as well as the safety distance from the adjacent conductor/ground wire and the ground.
It does not need to consider short-circuit current and heat capacity like OPGW, nor does it need to consider insulation, current carrying capacity and impedance like OPPC, nor does it need to consider the field strength of the installation point like ADSS, and its outer metal stranded wire is only used to accommodate and Protect the fiber. When the breaking force is similar, although MASS is heavier than ADSS, its outer diameter is about 1/4 smaller than that of central tube ADSS, and about 1/3 smaller than that of layer twist ADSS. In the case of similar diameters, the breaking force and allowable tension of ADSS are much smaller than those of MASS.
4. All-dielectric self-supporting optical cable - ADSS (All Dielectric Self Supporting)
ADSS optical cable is widely used on 220KV, 110KV, 35KV voltage level transmission lines, especially on existing lines. It can meet the requirements of large span and sag of power transmission lines. Standard ADSS designs are available up to 144 cores.
Its characteristics are:
(1) The theoretical value of fiber tension in ADSS is zero;
(2) ADSS optical cable is a fully insulated structure, which can be operated live during installation and line maintenance, which can greatly reduce power failure losses;
(3) The stretching ratio of ADSS can remain unchanged in the range of large temperature difference, and it has stable optical properties under extreme temperature;
(4) The galvanic corrosion-resistant ADSS optical cable can reduce the electrical corrosion of the high-voltage induced electric field to the optical cable; (5) The 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 small; ( 6) ADSS adopts new material and smooth shape design, which makes it have superior aerodynamic characteristics.
ADSS cable is mainly composed of cable core, reinforced aramid yarn (or other suitable material) and outer sheath. A variety of ADSS optical cable structures can be classified into two main types: central tube type and layer twist type.
5. Additional optical cable - OPAC
Metal-free bundled aerial optical cable (AD-Lash) and metal-free wrapping optical fiber cable GWWOP (Ground Wire Wrapped Optical Fiber Cable) Optical cables are sometimes collectively referred to as additional optical cables - OPAC, which is an existing method for building optical fiber communication networks on power lines. Economical and fast way.
Special optical cable technology is constantly developing and improving, and new optical cable structures are constantly appearing in front of us. At this time, people's demand for special optical cables is also increasing. ZR Cable focuses on the R&D and sales of optical fiber products. If you have requirements for optical fiber-related products, you can learn about the ZR Cable optical fiber brand.