JPS6361727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite power cable in which a power overhead ground wire is combined with an optical cable.

Taking advantage of the non-inductive nature of optical cables, consideration is being given to installing them alongside ultra-high voltage cables, and various types of effectiveness have been demonstrated. However, conventional developments have been limited to underground conduits, tunnels, or cables for overhead wiring.

In the electric power industry, the basic communication circuit for power transmission system protection and control requires duplication of main lines and backup lines that match the power transmission route. In order to satisfy this requirement, it is possible to use underground and overhead or underground detour wiring networks within large cities.

On the other hand, with the increase in power demand and capacity, power generation and transformation facilities are becoming larger and the location conditions are becoming more and more difficult, and it is becoming impossible to avoid increasing the capacity and distance of overhead power transmission.

In response to this, conventional communication lines have been secured using electric power carriers, microwaves, etc., but the former has limited information capacity and cannot be handled by centralizing system protection control (computerization). Furthermore, in the latter case, it is thought that securing a line will become increasingly difficult in the future due to locational conditions and the diversification of other communication services.

In order to solve the above problems, here we provide an optical cable with the purpose of installing it along the power transmission line route. That is, in addition to power lines, overhead ground wires are attached to power transmission line routes to protect against lightning damage. The present invention attempts to secure a communication line by integrating an optical cable with this overhead ground wire.

In this case, the following problems can be cited.

(i) The spacing between installation columns is long. 1300m~800m (ii) Easily susceptible to vibrations caused by wind, etc.

(iii) There is a large difference in temperature.

(iv) Excessive tension is applied due to installation conditions.

(v) A large current flows due to lightning.

(vi) Construction work, especially connection work, needs to be carried out at high places.

The present invention has been made to solve these problems.

Embodiments of the present invention shown in the drawings will be described below.

Figure 1 shows a commonly used metal wire 1-1.
Overhead ground wire 1 and optical cable 2 configured by twisting together
The figure shows a composite cable in which the two are fixed together with lashing wires 3 or the like. In this case, it is necessary to make the optical cable 2 as thin as possible compared to the overhead ground wire 1 to reduce the influence of wind on the optical cable. For this purpose, it is desirable to embed the optical cable along the adjacent strand valleys on the surface of the overhead ground wire.

In addition, the expansion and contraction of the overhead ground wire due to temperature causes stress and compressive force on the optical fiber due to the long distance between the installed steel towers. In order to solve this problem, materials with uniform expansion coefficients should be selected, but in reality it is difficult to achieve a perfect match. In order to achieve this effect, each optical cable 2 is twisted along the outside of the overhead ground wire 1, as shown in Figures 1 and 2. can.

At the terminal of the composite cable configured as described above, if a removable optical connector (not shown) is attached to the outlet end of the optical cable and optical fiber, it is recommended that the composite cable be installed on a power transmission pole. Optical fiber line cleaning work can be easily performed, and the advantages of the composite cable of the present invention can be further enhanced.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a composite cable embodying the present invention, and FIG. 2 is a diagram illustrating a side configuration of the composite cable embodying the present invention. 1 is a power overhead ground wire, 1-1 is a metal wire, 2 is an optical cable, and 3 is a lashing wire.

Claims (1)

[Claims] 1. In a composite power cable in which an optical cable is combined with a power overhead ground wire composed of twisted metal wires, an optical cable having a diameter smaller than the diameter of the overhead ground wire is placed outside the overhead ground wire in contact with the overhead ground wire. A composite power cable characterized in that the cables are twisted together along the strands of an overhead ground wire and fixed with lashing wires.