JPH0320973Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a grounding wire for an arrester that protects electrical equipment, particularly power transmission and distribution lines.

(Prior art and problems to be solved) Arresters are normally used to protect power transmission and distribution lines from intrusion of conductive lightning. For example, when arresters are installed on utility poles in power distribution lines, A grounding wire is required to connect the pillar to the ground. The length of this grounding wire is about 10m, and conventionally, for example, a normal polyvinyl chloride insulated wire with a conductor cross section ^{of 5.5mm2} has been used, but if a sudden surge voltage enters, its impedance becomes large. Therefore, even if the arrester operates, the intruding surge cannot be released to the ground (the inductance of the grounding wire is limited by ωL), and excessive surge voltage may be transmitted to the power distribution system, making it impossible to protect the system. , there was a demand for a low-inductance grounding wire.

It is known that it is effective to use a flat insulated wire using copper tape as the low-inductance grounding wire, but since the cross section of the utility pole is circular, it is difficult to run a wide flat wire along the pole, and If it is fastened with a wire or the like, there are problems such as damage to the insulating protective layer and exposure of the conductor, so it has not been put into practical use.

(Means for solving the problem) The present invention improves the above-mentioned flat insulated wire and provides a low-inductance grounding wire suitable for practical use. The present invention is characterized in that longitudinal projections are provided on at least the upper portions of both side edges of the above-mentioned insulating coating layer of the flat electric wire that is divided and buried within the same plane.

(Example) FIG. 1 is a cross-sectional view of a specific example of a low-inductance grounding wire according to the present invention.

In the drawing, 1a, 1b, and 1c are tape-shaped conductors divided into three parts.For example, a copper tape with an equivalent cross-sectional area of 0.15 mm thick and 40 mm wide as a conventional 5.5 mm ² conductor is divided and placed in the same plane. . Reference numeral 2 denotes an insulating coating layer made of polyethylene, crosslinked polyethylene, polyvinyl chloride, etc., and projections 21 are provided in the length direction at the upper portions of both side edges and at the center of the top surface of the insulating coating layer 2.

In this way, in the grounding wire of the present invention, by arranging the tape-shaped conductor in three parts within the same plane, the effective width is increased compared to using a single strip of tape-shaped conductor with the same cross-sectional area. Inductance can be further reduced.

In addition, since projections 21 are provided in the length direction at the top of both side edges and the center of the top surface of the insulating coating layer 2, when the grounding wire is placed along the surface of the utility pole and fastened with a binding wire or the like, the projections 21 has a shock-absorbing effect,
The main body of the insulating coating layer 2 can be protected from external damage.
The central part of the protrusions 21 may be omitted depending on the case, or the number may be increased as appropriate.

FIG. 2 is a cross-sectional view of another embodiment of the low inductance grounding wire according to the present invention.

When a flat grounding wire as shown in FIG. 1 is fastened to a utility pole with a binding wire or the like, wind may enter between the utility pole and the grounding wire, causing a flapping sound.
In order to prevent this, as shown in FIG. 2, an adhesive layer 3 is provided on the smooth surface of the insulating coating layer 2 opposite to the protrusion 21, and the adhesive layer 3 is attached to the surface of the utility pole.
This increases the strength of the grounding wire to the utility pole and prevents damage caused by wind. In the drawing, 4 is an adhesive layer protective tape, which is removed when attaching the grounding wire to the utility pole.

In Fig. 2, instead of providing an adhesive layer 3 directly on the smooth surface of the insulating coating layer 2, adhesive layers 3a and 3b are provided on both sides of a cushion layer 5 such as a foamed polyurethane sheet as shown in Fig. 3. One surface 3a of the adhesive layer of the provided sheet may be attached to the surface of the insulating coating layer 2, and the other surface 3b may be attached to a utility pole. In this case, when manufacturing the ground wire, the cushion layer 5 is simultaneously formed on the surface of the insulating coating layer 2, and the adhesive layer 3
a can also be omitted.

By providing the cushion layer 5 on the surface of the insulating coating layer 2 to be adhered to the utility pole in this way, even if the adhesive layer 3b peels off during use and the grounding wire is affected by wind, the cushion layer can be used. 5, there is no flopping sound.

(Effects of the invention) As explained above, according to the low inductance grounding wire of the invention, by dividing and arranging the tape-shaped conductor in the same plane, the inductance can be significantly reduced compared to the conventional round conductor. At the same time, it becomes easier to align it with the utility pole.

Further, since the upper part of the insulating coating layer has a longitudinal protrusion, it has a buffering effect against external forces and can protect the insulating coating layer from external damage.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of specific examples of low-inductance grounding wires according to the present invention. FIG. 3 is a cross-sectional view of an example of a cushion layer used in the ground wire of the present invention. 1a, 1b, 1c...divided tape-shaped conductor, 2...
...Insulating coating layer, 21...Protrusion, 3, 3a, 3b...
...Adhesive layer, 5...Cushion layer.

Claims (1)

[Scope of utility model registration request] A low inductance grounding wire, characterized in that a tape-shaped conductor is split in the same plane and buried within the insulation coating layer, and a projection in the length direction is provided on at least the upper part of both side edges of the insulation coating layer. .