JP2629972B2 - Low corona noise type low wind noise electric wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention can greatly reduce wind noise generated by overhead power transmission lines, and at the same time, audible noise (corresponding to corona generated from ultra-high voltage transmission lines). The present invention relates to a new wind noise countermeasure type electric wire of a wind noise AN prevention coordination type capable of minimizing noise (hereinafter referred to as AN).

[Background Art] An overhead power transmission line is usually formed of a steel core aluminum stranded wire having a circular cross section in which an aluminum wire is twisted around the outer periphery of a steel core.

When wind pressure is applied to a transmission line having such a uniform cross-sectional configuration, a steady turbulence of air is generated on the leeward side of the wire, and the air is separated from the outer surface of the wire in this turbulent flow area. Air vibration in the frequency band of
This causes wind noise having a peak in the frequency band.

Therefore, in order to prevent the above-mentioned steady state of the turbulent flow region and prevent the concentration of air vibration of a specific frequency, the applicant has proposed to wind a spiral rod around the outer periphery of the electric wire from an early stage, and the effect has been widely confirmed. As a result, the results have already been accumulated in many areas.

On the other hand, steel core aluminum stranded wires used as ultra-high voltage overhead power transmission lines use lubricating oil in the wire expansion and contraction process and stranded wire process. For example, lubricating oil is used, and the lubricating oil remains as an oil film on the electric wire surface after the overhead wire.

Therefore, at the time of rainfall, the attached raindrops form spherical waterdrops due to the water repellency of the oil film, and continue to adhere to the electric wire surface for a long time without falling. When this water droplet is formed in the ultra-high voltage power transmission line, the potential gradient at the tip of the water droplet increases, causing a corona discharge. Such corona discharge not only causes noise to be mixed into a nearby radio wave facility, but also generates hum and random sounds, that is, the above-mentioned AN, which is regarded as a problem.

For this reason, attempts have been made to reduce this AN by artificially forming fine irregularities on the outer surface of the electric wire and applying a so-called aging treatment, or by applying a surfactant to the surface of the electric wire.

However, recently, it has been gradually found that the spiral rod wound around to prevent the generation of such an AN may help the generation of the wind noise.

That is, FIG. 3 is a conventional spiral rod 2 to the wire 1 to have a 180 ° offset ^-, 2 ^- and shows the state in which turning opposite winding, FIG. (A) is its description front view, (B)
FIG. 3 is a sectional view taken along line BB of FIG.

If there is rain on the low wind noise electric wire with such a configuration,
Water droplets 10 of the rain spiral rod 2 as shown in Figure ^- adhering a major granular position became lower, in which the large water droplets 10 is AN source.

FIGS. 4 (a) and 4 (b) specifically illustrate the situation, wherein FIG. 4 (a) is a front view thereof, and FIG. 4 (b) is a cross-sectional view taken along line CC of FIG. 4 (a).

Raindrops attached to the upper surface of the wire 1 10 ^- the wire 1a of the electric wire, but flows down as in the figure along 1a of Yomizo arrow, the spiral rod 2 in the course of its flowing down ^- because of the presence of, wire 1a, 1
raindrops 10 which has flowed down along the a of Yomizo ^- dammed by, that way dam was raindrops 10 ^{- -} the spiral rod 2 is spiral rod 2 ^- flows downward along, so to speak it will form raindrop is collected by the spiral rod 2 ^- large water droplets 10 as shown in Figure the lower part of the
Is formed. As such one after another in raindrop 10 ^- supply is carried out, water droplets 10 are spiral rod 2 in a state of strong growth ^- results in the continue adhering to the bottom, the large water droplets 10 is to cause the generation of AN .

In view of the circumstances, such as in the invention is an object Solved] above, applicants spiral rod 2 above ^- without turning winding alone one article as shown in FIG. 3 a, as shown in FIG. 5 spiral rod 2 ^- 2 ^- 2
It was suggested that the article be wound closely. That is, FIG. 5A is an explanatory front view showing such a two-contact closely wound state, and FIG. 5B is a sectional view taken along the line DD of FIG. .

Spiral rod 2, as described above ^-, 2 ^- if the two Article adhesion winding state, so the formation of water droplets from capillary action or surface tension relationship between the spiral rod falls early and pelletized, the AN Occurrence will be considerably reduced. However, if the amount of rain is still large and the supply of raindrops is intense, the waterdrops 10 must be reduced to small droplets, grow into large droplets, and there is not much difference from the case of winding a single spiral rod .

Therefore, each of the examples described above spiral rod 2 ^- whereas the wound in the entire outer periphery of the electric wire 1, Applicant separately, and their description front view Figure 6 (a) and, (b ), It is proposed to provide a preformed zigzag element wire 2 ″ almost at the upper half circumference of the electric wire 1 as shown in the EE cross-sectional view.

If the zigzag wires 2 ″ are attached in this manner, there is no danger that the raindrops collected by the wires will grow as large water droplets on the lower surface of the electric wire, and the water droplets will fall in small particles. However, also in this case, when the amount of rainfall is large, the expected effect cannot be fully exerted, and the behavior is almost the same as that in the case of the double-contact winding.

In addition, there is an attempt to degrease or chemically treat the spiral rod itself to form fine irregularities on the surface, flatten the droplets of water droplets, and suppress the increase in the potential gradient of the water droplets. When the amount is large, there is not much effect, and another problem arises such that the waste liquid treatment is troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to greatly improve the AN characteristics while reliably exhibiting the conventional wind noise prevention effect. It is intended to provide.

Means for Solving the Problems According to the present invention, a spiral rod is used as a core member on the outer periphery of a transmission line so that a small gap is formed between the core member and the outer periphery of the spiral member. It is formed by winding a composite spiral rod pre-wound with a spiral wound element wire having a small outer diameter, and the outer diameter of the spiral wound element wire is d ₁ , and the outer diameter of a rod serving as a core member is d ₂ . When you do, 2d ₁
≦ d ₂ .

[Operation] If the spiral wound wire is wound around the spiral rod so as to have a small gap, even if raindrops are collected by the spiral rod, drainage is large due to the presence of the spiral wound wire. The width is improved, and the water drops fall without growing into large grains, so that the AN characteristics can be remarkably improved.

[Example] Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is an explanatory front view of an embodiment according to the present invention,
FIG. 2 is a sectional view taken along line AA of FIG.

As shown in the figure, in the present invention, there is no difference in winding the spiral rod around the electric wire 1, but there is a difference in winding the composite spiral rod 2 as the spiral rod to be wound. There is.

Composite spiral rod 2 according to the present invention, the spiral rod 2 shown in the conventional example of earlier ^- whereas is constituted by a single striatum, the conventional spiral rod 2 ^-
Is configured to be the core member 2a. Then, the outer periphery of the center member 2a, so as to form a small gap, than the outer diameter d ₂ of hearts member 2a put previously winding a spiral Makimotosen 3 made with small streak of outside diameter d ₁ The composite spiral rod 2 is wound around the electric wire 1 as shown in FIG.

If the spiral rod is wound wire 1 wound is long is configured in such composite spiral rod 2, 4th raindrop as described with FIG. 10 above ^- is 1a, it flows down along 1a of Yomizo However, even if the raindrops are collected by the composite spiral rod 2, the collected raindrops flow down the spiral wire 3 and flow down.

Since the spiral wire 3 has a small wire diameter and a small gap 4 formed between the spiral wire 3 and the core member 2a, the capillary phenomenon is hindered, the surface tension of water droplets is weak, and the water drainage property is improved. The water droplets 10 are easily fragmented, and the water droplets 10 are collected at the lower part of the electric wire and do not grow into large particles as in the conventional example, but fall quickly in the state of fine particles.

Therefore, in order to further promote the drainage effect and the fine-graining effect of the spiral wound wire 3 and to make water droplets fall earlier, the outer diameter d ₁ of the spiral wound wire 3 with respect to the core member 2a must be made somewhat thinner. It is necessary to perform the core member 2a according to various experiments.
It was also found that is possible to configure the such that half or less i.e. 2d ₁ ≦ d ² of the outer diameter d ₂ is more suitable.

FIG. 7 is a line showing the result of performing an artificial rainfall experiment on each of the conventional example shown in FIG. 5, the conventional example shown in FIG. 6, and the embodiment according to the present invention, and measuring the reduction state of AN. FIG.

FIG. 7 is a sectional view showing the arrangement of each spiral rod of the test wire on the outer periphery of the wire.

As is clear from FIG. 7, in the embodiment of the present invention, the AN reduction amount has already reached −10 dB after one minute, and the water droplet flowing down along the wire strands is small between the core members. This clearly indicates that the presence of the spirally wound wire wire with a gap greatly improves the water drainage property, and that the wire is dropped and left early in a fine-grained state. Looking at the subsequent time-dependent changes, the AN reduction characteristics of the examples of the present invention are significantly superior to those of the conventional examples, especially the double-wound windings, which have been relatively effective. It can be said that this experimental result clearly shows this.

[Effects of the Invention] As described above, according to the electric wire in which the spiral rod according to the present invention is wound, the AN characteristics can be further improved, and the conventional wind noise prevention effect is maintained as it is. The significance of the present invention is extremely significant in that the transmission voltage of overhead transmission lines, such as UHV transmission, is going to be dramatically increased to an extremely high voltage in the future.

[Brief description of the drawings]

FIG. 1 is an explanatory front view of an embodiment according to the present invention, FIG. 2 is an AA sectional view of FIG. 1, and FIG. 3 is an explanatory view showing a configuration of a conventional low wind noise electric wire. (A) is an explanatory front view, (b) is a cross-sectional view taken along the line BB of FIG. (A), and FIG. 4 is a diagram showing a state of influence of a conventional spiral rod on water droplet formation. (A) is an explanatory front view thereof, (b) is a cross-sectional view taken along the line CC of FIG. (A), and FIG.
This figure shows a case where the strips are closely wound, wherein FIG. 7A is an explanatory front view thereof, FIG.
FIG. 1 shows still another conventional example, in which FIG. 1 (a) is an explanatory front view, FIG. 2 (b) is a sectional view taken along line EE of FIG. 1 (a), and FIG. FIG. 4 is a diagram plotting the relationship between the elapsed time and the amount of AN reduction by performing an artificial rainfall experiment using. 1: electric wire, 2: composite spiral rod, 2a: core member, 3: spiral wound wire, 4: small gap, 10: water droplet.

Continued on the front page (72) Inventor Katsuyoshi Unto 3550 Kida Yomachi, Tsuchiura-shi, Ibaraki Hitachi Metals, Ltd. Metal Research Laboratory (72) Inventor Kenji Yamamoto 1500 Kawajiri-cho, Hitachi-shi, Ibaraki Hitachi Cable Toyoura Plant (56) References Japanese Utility Model, Sho 64-20025 (JP, U)

Claims (1)

(57) [Claims] A spiral wound wire having an outer diameter smaller than that of the spiral rod so as to form a small gap between the outer circumference of the transmission line and the core member. A low corona noise type low wind noise electric wire formed by winding a composite spiral rod wound in advance, wherein the outer diameter of the spiral wound wire is d ₁ , and the outer diameter of the rod serving as the core member is d ₂ . A low corona noise type low wind noise electric wire configured so that 2d ₁ ≦ d ₂ when performed.