JPH07130222A - Overhead electric wire of low wind-whistle and low corona noise - Google Patents

Abstract

PURPOSE:To reduce a corona noise by forming two or more protrusive steaks adjacent within a semicircle on the surface of an electric wire so as to decrease a potential gradient in a protrusive part. CONSTITUTION:In an overhead electric wire having a steel twisted wire 1 in the center, A1 strands 2a partly in the outermost layer are formed into a sectional shape protruded from the other A1 strands 2b in the same layer, and two protrusive streaks 3 are constituted of the two strands 2a as a set. An angle between the protrusive streaks 3 is selected to theta1>180 deg., theta2=5 to 40 deg.. By this constitution, even a water drop adheres to a protrusive streak part, since its potential gradient is reduced, a corona is hardly generated, to reduce a corona noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead wire which can reduce both wind noise and corona noise.

[0002]

2. Description of the Related Art When wind blows on an installed electric wire, a Karman vortex is formed on the leeward side of the electric wire, and wind noise is generated. In order to reduce this wind noise, it is effective to form a spiral ridge on the outer circumference of the wire to disturb the Karman vortex.
Corona noise is more likely to be generated when a ridge is formed on the outer circumference of the wire, but in order to reduce corona noise, one ridge should be formed by two or three strands. Is also known. (JP-A-4-39817 and 4-87210
No. 4-87211, etc.).

[0003]

However, the conventional low wind noise and low corona noise overhead wire is symmetrical with respect to the center of the wire with two ridges (two wires or three wires as one wire). Since the structure is formed at various positions, the potential gradient of the ridge portion is high, and when water droplets due to rainwater adhere to the ridge portion, corona easily occurs from there, and the corona noise reduction effect is not sufficient.

[0004]

SUMMARY OF THE INVENTION The present invention provides a low wind noise and low corona noise aerial wire that solves the above problems, and has a structure in which a part of the outermost wire is In an overhead wire in which a spiral projection is formed on the outer peripheral surface by protruding from the wire or by winding another wire on the outermost layer, the projection includes one of the wires or the wire. One set of a plurality of lines is provided with two or more lines, and one of the angles between the lines is greater than 180 °.

[0005]

By doing so, since two or more ridges are arranged within a half circumference of the outer peripheral surface of the electric wire, and adjacent ridges approach each other,
The potential gradient of the ridge portion becomes low. For this reason, even if water drops adhere to the ridges, corona is less likely to occur, and corona noise is reduced.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention. This overhead wire is an ACSR having a steel stranded wire 1 in the center, and a part of the aluminum wire 2a of the outermost layer has a cross-sectional shape protruding from other aluminum wire 2b of the same layer, and has a spiral projection on the outer peripheral surface. Article 3
It is formed by two lines. Each of the two ridges 3 is composed of two strands 2a. The angles θ ₁ and θ ₂ between the ridges 3 are preferably selected so that θ ₁ is larger than 180 ° and θ ₂ is 5 ° to 40 °. ₁ = 252 ° and θ ₂ = 36 °.

FIG. 2 shows another embodiment of the present invention. This overhead wire is made of a steel strand 1 and an aluminum element wire 4 with a circular cross section on the outer circumference.
Spiral rod 5 on top of the outermost layer
Is wound around, and two spiral protrusions 3 are formed on the outer peripheral surface. Each of the two ridges 3 is formed by a set of two spiral rods 5. The angles θ ₁ and θ ₂ between the ridges 3 are such that θ ₁ is greater than 180 °,
θ ₂ is selected within the range of 5 ° to 40 °.

In the above embodiment, the case where the number of ridges is two has been described, but three or more ridges can be provided. Further, in the above-mentioned embodiment, the single ridge is formed by two strands or spiral rods (wires), but the single ridge may be formed by one strand or wire, or three strands. It is also possible to use the above strands or wires.

[0009]

As described above, according to the present invention, 2
Since the ridges more than the number of ridges are formed close to each other within the half circumference of the outer peripheral surface of the wire, the ridge portion of The potential gradient becomes low. For this reason, corona is less likely to occur even if water droplets due to rainwater adhere to the ridge portion, and corona noise can be reduced. In addition, the effect of preventing wind noise is the same as that of the conventional one because two or more ridges are provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a low wind noise and low corona noise overhead wire according to the present invention.

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

[Explanation of symbols]

 1: Steel stranded wire 2a: Part of the outermost aluminum element wire 2b: Outermost layer of other aluminum element wire 3: Protrusions 4: Aluminum element wire 5: Spiral rod (wire material)

Claims (2)

[Claims] 1. A spiral projection is formed on the outer peripheral surface by projecting a part of the wire of the outermost layer from another wire or winding another wire on the outermost layer. In the overhead wire, the ridge has one or a plurality of the above-mentioned strands or wires.
A low wind noise and low corona noise overhead wire, characterized in that two or more lines are provided as one line in a set, and one of the angles between the lines is greater than 180 °. 2. A low wind noise low audible noise overhead conductors according to claim 1, ridges is assumed to provide two rows, one of the angle theta ₁ of the angle between the ridges and the ridge is 180 ° It is larger, and the other angle θ ₂ is 5 ° to 40 °.