JPH04308609A - overhead power lines - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to overhead power transmission lines.

0002

[Prior Art] Electric wires used for overhead power transmission lines include:
Hard copper stranded wire, steel core aluminum stranded wire, aluminum alloy stranded wire, etc. are known. Among them, steel core aluminum stranded wire (ACS
R) is widely used in high-voltage power transmission lines because it is lightweight.

[0003] Steel core aluminum stranded wire is generally an electric wire in which a galvanized steel wire is twisted in the center and a hard aluminum wire is twisted on the outside. The conductivity of aluminum wire used as a conductor is about 60% that of copper wire, but the weight is about one-third that of copper, so even if the cross-sectional area is increased to flow the same current as copper wire, It can be lighter than using copper wire. Furthermore, since a reinforcing member such as a galvanized steel wire is placed in the center, the tensile strength is high.

0004

[Problem to be solved by the invention] Such a conventional AC
In SR, when a large current flows, Joule heat is generated, which causes the wire to thermally expand, increasing its slack and reducing the insulation distance from the ground. Therefore, the current capacity of the conventional ACSR was also determined by such slackness. One possible way to suppress the increase in sag is to combine it with carbon fiber, which is a material with a low coefficient of thermal expansion. Unexamined Japanese Patent Publication 1986-
Publication No. 86606 relates to conductor strands for indoor wiring, etc., and discloses a technique of reinforcing copper or aluminum by dispersing carbon fibers therein.

However, when such a technique is applied to conductor strands of overhead power transmission lines, the interface between the carbon fiber and aluminum or aluminum alloy tends to corrode, resulting in a significant decrease in corrosion resistance.

[0006]Also, in order to obtain a larger current capacity, it is sufficient to use a wire with a larger diameter, but using a wire with a larger diameter increases the weight and puts a greater burden on the steel tower.

[0007] An object of the present invention is to provide an overhead power transmission line that has corrosion resistance, is lightweight, has small sag, and is capable of increasing current capacity.

[0008]

[Means for Solving the Problems] The overhead power transmission line of the present invention is characterized in that it is constructed by assembling a plurality of conductor wires formed by coating an aggregate of carbon fibers with aluminum or an aluminum alloy. There is.

[0009] In this invention, the carbon fiber aggregate is
It is preferable to collect them using aluminum or an aluminum alloy. For example, an aluminum film can be deposited around the carbon fibers and compressed and/or heated, etc., into an aggregated state. The volume percentage of carbon fiber in the conductor wire is preferably in the range of 1 to 50%.

0010

[Operation] The overhead power transmission line of the present invention is characterized in that it is constructed by assembling a plurality of conductor strands formed by coating an aggregate of carbon fibers with aluminum or an aluminum alloy. Since carbon fiber has high strength, it is possible to increase overhead wire tension and reduce sag. Furthermore, since it has a low coefficient of thermal expansion, there is little increase in sag when energized. Furthermore, since carbon fiber is lightweight, it can reduce the burden on the steel tower when it is erected, and it is possible to run wires with larger diameters on the same tower.

Further, in the overhead power transmission line of the present invention, since the aggregate of carbon fibers is coated with aluminum or aluminum alloy, there are few interfaces with the carbon fibers.
Corrosion resistance does not decrease.

[0012] Furthermore, since carbon fiber has excellent high-temperature strength and heat resistance, it can withstand heat and can increase current capacity.

In this invention, carbon fibers are used as an aggregate because industrially obtained carbon fibers have a size of several μm to 10 μm.
It is approximately μm in size, and must be made into an aggregate in order to obtain sufficient strength.

[0014] In the present invention, an aggregate of carbon fibers is coated with aluminum or an aluminum alloy. This coating additionally aggregates the carbon fibers. In addition, as a coating provided around the carbon fiber aggregate,
The coating itself must be a conductor, and generally aluminum or an aluminum alloy is used, but a coating of aluminum or an aluminum alloy is preferable from the standpoint of ensuring the corrosion resistance of these coatings. Furthermore, by using aluminum or an aluminum alloy, the weight can be reduced.

[0015] In this invention, carbon fibers are used as an aggregate, and in order to form an aggregate, the surface of each carbon fiber is coated with aluminum or aluminum alloy by vapor deposition or the like, and pressure and/or heat is applied to this. Alternatively, the carbon fibers may be immersed in an aluminum or aluminum alloy solution.

In the present invention, the volume percentage of carbon fiber in the conductor element wire is preferably 1 to 50% as described above. If the volume ratio is less than 1%, it will not be possible to obtain sufficiently high strength and it will be difficult to obtain a low coefficient of thermal expansion. Moreover, if the volume ratio exceeds 50%, electrical conductivity cannot be ensured.

[0017]

[Example] PAN-based high-strength carbon fiber (tensile strength 450k
gf/mm2) were bundled, and aluminum was vapor-deposited on the surface to form an aggregate. Al-0.2 around the aggregate
It was covered with 7% Zr alloy tape and the seams were welded in the longitudinal direction. This was diced to obtain a conductor wire with a wire diameter of 3.0 mm.

FIG. 1 is a cross-sectional view showing the conductor wire thus obtained. Referring to FIG. 1, an aluminum alloy layer 2 is formed around a carbon fiber aggregate 1, and constitutes a conductor strand 3. Table 1 shows the specific gravity, tensile strength, and coefficient of thermal expansion of the single conductor wire.

[0019] The conductor strands were twisted together in the arrangement shown in FIG. 2 to produce an overhead power transmission line. Referring to FIG. 2, an overhead power transmission line 4 is formed by twisting a plurality of conductor strands 3 together. Table 1 shows the tensile strength (
The composite tensile strength) and the coefficient of thermal expansion from room temperature to 300°C (composite thermal expansion coefficient) when used as an overhead power transmission line are shown. In addition, for comparison, the conventional ACSR value using a steel core is also shown.

[0020] In Table 1, the sag is a value obtained by relative evaluation of the sag when the overhead power transmission lines were installed on a trial basis at intervals of 20 m, with the sag of the conventional ACSR being set to 1. In addition, the increase in sag is caused by the Joule heating caused by the transmission of large amounts of electricity to overhead power lines.
This value is a relative evaluation of the increase in sag when the temperature reaches 0°C, with that of the conventional ACSR set as 1. Conventional ACSR has two types: ACSR A, which has a large proportion of steel wire and has high strength and low thermal expansion, but low conductivity (ACSR A), and ACSR A, which has a small proportion of steel wire and has low strength and high thermal expansion compared to ACSR A. However, the conductivity was high (ACSR B).

[0021]

[Table 1]

The overhead power transmission line according to the invention is superior to ACSR B when the amount of carbon fiber is low, and superior to ACSR A when the amount of carbon fiber is high.

[0023]

As described above, according to the overhead power transmission line of the present invention, it is possible to obtain an overhead power transmission line that is lightweight, has small sag, and can increase current capacity.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conductor strand according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

1 Carbon fiber aggregate 2 Aluminum alloy layer 3　Conductor strand 4 Overhead power transmission lines

Claims (3)

[Claims] 1. An overhead power transmission line constructed by assembling a plurality of conductor strands formed by coating an aggregate of carbon fibers with aluminum or an aluminum alloy. 2. Claim 1, wherein the carbon fiber aggregate is made of aluminum or an aluminum alloy.
Overhead power lines as described in . 3. The overhead power transmission line according to claim 1, wherein the proportion of carbon fiber in the wire rod of the conductor element wire is 1 to 50%.