JPH0667095B2 - Overhead power line - Google Patents

Description

TECHNICAL FIELD The present invention relates to an overhead power transmission line which is excellent in low noise, snow-hardening, galloping prevention effect and corona noise prevention effect.

[Prior Art and Problems] A low wind noise electric wire or a snow-hardening electric wire in which a spiral element wire 2 is wound around the electric wire 1 as shown in FIG. 5 is known.

However, if this spiral wire 2 is wound only in the same direction, the aerodynamic characteristics are not stable against vibration, and in order to avoid this, as shown in FIG. The wire 2z and the S-wound spiral element wire 2s are mixed and wound to stabilize the vibration. The same can be said for the effect of preventing snow from adhering, and in order to improve the snow cutting property on the electric wire, the mixed winding as shown in Fig. 6 is also made.

On the other hand, in the case of a multi-conductor transmission line, if the winding direction is the same between adjacent conductors, the noise reduction effect is small, and as shown in Fig. 7, the spiral strands are formed between the adjacent conductors 1 and 1 '. It has also been found that the noise prevention effect is remarkably improved by configuring one of them as the Z winding 2z and the other as the S winding 2s.

However, when winding a spiral wire around an electric wire in this way, always prepare two kinds of wires, S winding and Z winding, and also in winding this, pay close attention to these two kinds of wires. It is very troublesome to select and wind the material because it is extremely complicated in terms of manufacturing, construction and management.

Moreover, when the wire is wound around the outer circumference of the electric wire as described above,
When it rains, rainwater is collected by these spiral strands to form large water droplets on the convex portions of the strands, resulting in a high potential gradient and so-called corona audible noise (AN).
There is also a possibility of deteriorating the characteristics.

[Object of the Invention] The present invention has been made in view of the above situation, and the wire to be attached to the electric wire may be one type of molded body, and the molded body may have the S and Z mixed windings. The present invention aims to provide an overhead power transmission line in which a new element wire is attached, which can exhibit the same effect as the above and can also improve the AN characteristic.

[Summary of the Invention] That is, the gist of the present invention is to form a molded body in which the tops and valleys are sequentially repeated with the same strand, and the molded body can be closely fitted to the outer circumference of the wire. As a bent structure, this is attached to the electric wire, and after attachment,
There is an overhead power transmission line configured such that the top portion or the valley portion of the molded body is located at the same position as the lower surface of the electric wire or above the lower surface of the electric wire. , The same effect as that of the Z mixed winding or better than that can be expected.

[Examples] The present invention will be described below based on Examples.

FIG. 1 is a plan view showing a state in which a molded element wire 3 according to the present invention is attached to an electric wire 1, and FIG. 2 is a front view thereof.

First, the forming wire 3 is formed in a meandering shape having a predetermined top portion 3a and a predetermined valley portion 3b. Then, the strand thus formed is formed into a curved surface whose entire meandering plane can be tightly fitted to the outer peripheral surface of the electric wire 1, and the wire is fitted from the upper part to the lower part of the electric wire. .

FIG. 2 shows a state in which the molded wire 3 is bonded to the electric wire 1 in this way, and in FIG. 2 seen from the front side, only the valleys 3b, 3b are visible (the tops 3a, 3a). Is on the back side of the electric wire 1), but the lowest point of the valley 3b is
The feature of the present invention resides in that the wires are attached so that they are located at the same position on the lower surface of the electric wire 1 or above the electric wire 1. (This is the same on the side of the top portion 3a.) According to the overhead power transmission line of the present invention configured as described above, it is only necessary to prepare one type of the molded wire 3, and as in the conventional example. Two kinds of wires, S winding and Z winding, are always prepared, and the complexity of winding while selecting this can be eliminated at once. That is, the top 3a or the valley 3
One side of the wire forming b has the same effect as the S winding, and the opposite side has the same effect as the Z winding, that is, S winding and Z winding coexist in the same wire. In addition to the effect of the S / Z mixed winding in the conventional example, especially the aerodynamic effect can be remarkably stabilized, and a remarkable effect in preventing galloping, especially vibration, can be exerted.

Moreover, the molded element wire 3 according to the present invention does not have a structure of being wound around the outer circumference of the electric wire 1 unlike the conventional example. In the case of a conventional wound wire, rainwater is collected at the time of rain to form and attach large water droplets, which causes deterioration of AN characteristics. However, in the case of the wire according to the present invention, since it is not wound, and the top or valley is located at the same level as or above the lower surface of the wire, capillary action works with the wire. It was also confirmed by experiments that the AN characteristics are remarkably improved without forming and adhering large-sized water droplets unlike the conventional example.
In order to further improve the AN characteristic, it is preferable to form a groove in the forming wire in the longitudinal direction, which further promotes the capillary phenomenon and increases the flattening effect of water droplets.

By the way, the top portion 3a and the valley portion 3b of the strand 3 according to the present invention do not always have to have the same height or the same pitch in a sine curve. That is, as shown in FIG. ₂ , by providing a difference between the lower surfaces of the wires, t ₁ and t ₂ , or by providing a difference in the pitch between P ₁ and P ₂ , the change is given, The turbulence of air and fluid and the cutting effect of snow can be greatly enhanced.

3 and 4 are a plan view and a front view showing another embodiment of the overhead power transmission line according to the present invention.

The present embodiment shows an example (both ends in this embodiment) in which at least one end 4 of the forming wire 3 is spirally wound by a half pitch or more, and thus the spiral winding portion 4 is formed at the end. By providing it, the molded element wire 3 can be more securely fixed to the electric wire 1, and the differences t ₁ and t ₂ from the lower surface of the electric wire shown in FIG. 2 can be made large. As a result, it is possible to further improve the AN characteristics.

However, the location of this spiral winding is not limited to the end portion, but may be the intermediate portion.

In addition, in order to emphasize a specific effect, a top portion or a valley portion is provided to extend further than the lower surface of the wire, that is, 360
It is also possible to wind it as a structure that goes beyond the bend of a degree.

[Effects of the Invention] As described above, according to the overhead power transmission line of the present invention, the following excellent effects can be achieved.

(1) Since the bottom of the molded wire is the same as or above the bottom surface of the wire, it does not increase the electric potential gradient of the wire and exhibits excellent AN characteristics.

(2) Since both the S direction and the Z direction are constituted by a single forming wire, it is aerodynamically stable and can largely prevent galloping, especially vibration.

(3) Even when applied to multiple conductors, it exhibits excellent wind noise prevention characteristics.

(4) In addition to the S and Z configurations, the bottom portion is located below, which has a great effect of preventing the rotational growth of snow, and can be expected to have excellent characteristics as a snow-difficulty electric wire.

[Brief description of drawings]

1 is a plan view of one embodiment according to the present invention, FIG. 2 is a front view thereof, FIG. 3 is a plan view of another embodiment according to the present invention, FIG. 4 is a front view thereof, and FIG. 7 to 7 are explanatory views showing specific examples of the conventional spiral wire winding method. 1 ... Electric wire, 3 ... Molded wire, 4 ... Winding part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuo Kimura 1500 Kawajiri-cho, Hitachi-shi, Ibaraki Inside Toyoura Plant, Hitachi Cable Co., Ltd. (56) Reference JP-A-58-93415 (JP, A) JP-A-51 -138873 (JP, A)

Claims (2)

[Claims] Claim: What is claimed is: 1. Forming a molded body in which the top and the valley are repeatedly formed with the same elemental wire in order, and the molded body is formed into a curved structure that can be tightly fitted to the outer periphery of the electric wire, and the curved structure is attached to the electric wire. An overhead power transmission line configured such that, after the fitting, the top or valley of the molded body is located at the same position as or above the lower surface of the electric wire. 2. The overhead power transmission line according to claim 1, wherein at least one portion of the molded body is spirally wound on the electric wire by a half pitch or more.