JP2583300B2 - Low corona low wind noise wire - Google Patents

Description

The present invention relates to a low corona low wind noise electric wire used as an overhead transmission line.

(Prior art)

In order to prevent wind noise generated when wind is blown on a power transmission line, it is effective to form a spiral ridge on the outer periphery of the wire to disturb the flow of the wind. Conventionally, by using this principle, the outermost layer of the electric wire is constructed by twisting many thin strands and a few thick strands,
2. Description of the Related Art There is known an electric wire having a thick wire protruding from an outer peripheral surface of a wire by a wire diameter difference from that of a thin wire to have a wind noise prevention effect.

〔Task〕

However, such a low wind noise electric wire has a problem that corona is easily generated from the thick wire protruding from the outer peripheral surface of the electric wire. In other words, from the viewpoint of preventing wind noise, it is preferable that a thick strand protrudes from the outer peripheral surface of the electric wire.

[Means for solving the problem and its operation]

In order to suppress the occurrence of corona, it is effective to increase the outer diameter of the electric wire and reduce the potential gradient on the surface of the electric wire. However, simply increasing the outer diameter of the electric wire increases the weight of the electric wire and increases the cost. Therefore, it is conventionally known that, when the outer diameter of the electric wire is increased, it is better to provide a gap inside.

Therefore, it is conceivable to apply this air-gap type stranded wire structure to low wind noise electric wires, but in the case of low wind noise electric wires, the thick wires protrude on the outer peripheral surface as described above, so there is no air gap inside. If it is provided, the following problems occur during the erection. In other words, it is necessary to pass the wheel while laying the electric wire, but when a thick wire projecting from the outer peripheral surface of the wire crosses the wheel, a large pressure is locally applied to that part, so there is a gap inside. If there is, that part will sink into the inside.

The present invention provides a low wind noise electric wire having an air gap type stranded wire structure and no digging of a thick wire portion when passing through a wheel, based on the above-described examination results, and its configuration, the outer periphery of the center stranded wire. , Three or more spacer strands are twisted at intervals in the circumferential direction, and a strand of uniform thickness is densely twisted on the outer periphery in the opposite direction to the spacer strand, and a thin strand on the outer periphery And the thick strand is twisted in the same direction as the spacer strand, and the thick strand is positioned above the spacer strand.

In this way, a gap is formed inside the spacer wires, the outer diameter of the wires can be increased without increasing the weight of the wires, the occurrence of corona can be reduced, and the thick wires of the outermost layer are supported by the spacer wires. And it will not be sunk when passing through the wheel.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 to FIG. 6 each show an embodiment of a low corona low wind noise electric wire according to the present invention. In the figure, reference numeral 1 denotes a central steel stranded wire, which is usually formed by twisting steel wires having a circular cross section, but may be formed by twisting segment-type steel wires as shown in FIG. . Further, it may be constituted by a metal wire other than a steel wire or an FRP wire.

Three spacer strands 2 are twisted around the outer circumference of the steel strand 1 at equal intervals in the circumferential direction. Usually, an aluminum or aluminum alloy wire is used as the spacer wire 2. In the example of FIG. 2, the spacer strand 2 having a groove formed on the outer periphery is used for weight reduction.

An inner layer element wire 3 having a uniform thickness is densely twisted around the outer periphery of the spacer element wire 2 with the twist direction reversed.
This inner layer element wire 3 is also usually made of aluminum or aluminum alloy wire. The twisted layer of the inner element wire 3 has a cylindrical shape, and a gap G is formed therein. To prevent the cylindrical shape from being collapsed, a segment type element as shown in FIG. 4 or FIG. It is effective to use a line.

Further, on the outer circumference of the inner layer element wire 3, a thin element wire 4 and a thick element wire 5 are twisted in the same direction as the spacer element wire 2 to form an outermost layer. The thick wire 5 is twisted so as to be located on the spacer wire 2, so that even if a large pressure is applied when the thick wire 5 gets over the wheel, the portion does not sink into the inside. It has become.
The outermost element wires 4 and 5 are also usually made of aluminum or aluminum alloy wire. The thick wires 5 are twisted together as a set of two wires. This is to reduce the disturbance of the electric field due to the protrusion of the thick wires 5 and to prevent water droplets caused by rain from forming the two thick wires 5. This is to reduce the occurrence of corona due to water droplets in a timely manner.

〔The invention's effect〕

As described above, the low wind noise electric wire according to the present invention can reduce the occurrence of corona because the outer diameter is increased by providing a gap inside, and the thick outer wire of the outermost layer is placed on the spacer wire. Because it is twisted so that it is located, the ridge by the thick wire does not sink into the inside when passing the wheel,
A good wind noise prevention effect can be obtained.

[Brief description of the drawings]

FIGS. 1 to 6 are cross-sectional views of a low corona low wind noise electric wire according to an embodiment of the present invention. 1: center steel strand, 2: spacer strand, 3: inner layer strand, 4: thin strand, 5: thick strand, G: void.

Claims (1)

(57) [Claims] (1) three or more spacer strands are twisted around the outer periphery of the center strand at intervals in the circumferential direction, and a strand having a uniform thickness is densely formed on the outer periphery in a direction opposite to the spacer strand. Characterized in that a thin wire and a thick wire are twisted around the outer periphery thereof in the same direction as the spacer wire and the thick wire is positioned on the spacer wire. Low wind noise electric wire.