JPH047630Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a lightning-resistant type of overhead ground wire that does not melt or break due to lightning strikes when the overhead ground wire installed above the power transmission line is struck by lightning. It's about lines.

[Prior art and its problems] In general, overhead ground wires are prone to arc melting and disconnection due to lightning strikes, given their purpose.
However, recently, in the case of optical cable composite type overhead ground wire OPQW that houses optical fiber cable for signal transmission inside, the optical fiber cable is adversely affected when the overhead ground wire is damaged by arc.
There are concerns that the transmission characteristics may be impaired. Therefore, against this background, it is necessary to take measures to prevent arc damage and disconnection of overhead ground wires due to lightning strikes.

[Purpose and structure of the invention] The purpose of this invention is to provide a new overhead ground wire that takes measures to prevent arc damage caused by lightning strikes. An arc melting body formed by combining a pair of half-rings divided into two to form an annular shape as a whole is provided, and the inner diameter D of the arc melting body is set to the outer diameter d of the overhead ground wire. A gap of (D-d)/2=H is maintained between the overhead ground wire and the arc-eroded body, and the arc-eroded body 3 and the overhead ground wire are connected to a ground fault current discharge conductor This is a lightning-resistant overhead ground wire that is connected through the ground wire.

[Operation] Lightning that occurs near the railway line directly hits the arc-eroded body and causes a ground fault through the ground fault current discharge conductor.
Further, the arc melting body suppresses the movement of the arc and fixes the arc spot there, and the arc heat is consumed by melting (melting), evaporation, vaporization (sublimation), etc. of the arc melting body. The gap existing between the arc melting body and the overhead ground wire reduces as much as possible the possibility that the overhead ground wire will be adversely affected by heat.

[Example] Figures 1 and 2 show an example of this invention. An overhead ground wire 2 is installed between the supports 1 of steel towers, etc., and a wire with an inner diameter larger than the outer diameter d of the overhead ground wire 2 is installed on the outer periphery of the overhead ground wire 2 at an appropriate position in the length direction of the overhead ground wire 2. An arc erosion body 3 having a diameter D is coaxially arranged. As shown in Fig. 2, this arc-eroded body 3 is formed by combining a pair of half-rings 3A and 3B, which are divided into upper and lower (left and right) halves, so as to form an annular shape as a whole. Approximately the center of the bodies 3A, 3B connects the rib or spoke-shaped ground fault current discharge conductor 4 to the two-split overhead ground wire fastening fittings 6A, 6B which have tightening protruding seats 5A, 5B on both sides outward. Thus, between the arc erosion body 3 and the overhead ground wire 2 (D-
A gap of d)/2=H is maintained.

FIG. 3 shows another example of an arc-eroded body, in which the arc-drawing parts of two members that are generally D-shaped as a whole form half-rings 3A and 3B, and the circular arc The side portion connecting both ends of the above constitutes the ground fault current discharge conductor 4 and the overhead ground wire fastening fittings 6A, 6B, and the pair of semicircular bodies 3
The arc melting body 3 is formed by combining A and 3B so as to form an annular shape as a whole.

In addition, when implementing this idea, it is preferable to use metals or non-metals that have relatively large heat of fusion, heat of vaporization (sublimation), heat of thermal decomposition, etc. as the material constituting (forming) the arc melting body 3. Preferably,
Further, the shape of the arc-eroded body 3 may be not only an annular shape as shown in the drawing, but also a polygonal annular shape.

[Effect of the invention] According to this invention, the arc erosion body 3 is arranged around the outer periphery of the overhead ground wire 2, and the arc erosion body 3 is connected to the overhead earth wire 2 via the ground fault current discharge conductor 4. Since they are connected, lightning that occurs near the line directly hits the arc-eroded body 3 and causes a ground fault through the ground fault current discharge conductor 4. Then, the arc melting body 3 fixes the arc spot there, and melts itself (melting).
In addition to absorbing and consuming arc heat through evaporation, vaporization (sublimation), etc., this arc melting body 3 and overhead ground wire 2
The gap H existing between the two prevents the overhead ground wire 2 from being thermally damaged. Therefore, it is possible to eliminate the risk of melting or disconnection of the overhead ground wire 2 due to lightning strikes. In addition, the arc-eroded body 3 is formed by arranging a pair of semicircular bodies 3A and 3B opposite each other so as to sandwich the overhead ground wire 2, and combining and connecting these two to form a ring shape. Attachment to the ground wire 2 is extremely easy.

[Brief explanation of the drawing]

1 and 2 show an embodiment of a lightning-resistant overhead ground wire according to this invention, in which FIG. 1 is a schematic side view of the overall configuration, and FIG.
FIG. 3 is an enlarged front view of the arc melting body mounting portion seen from the arrow line, and FIG. 3 is an enlarged front view showing another example of the arc melting body mounting portion. In the figure, 1 is a pillar, 2 is an overhead ground wire, 3A,
3B is a half ring, 3 is an arc erosion body, and 4 is a ground fault current discharge conductor.

Claims (1)

[Scope of utility model registration request] Overhead ground wire 2 installed across pillars 1
A pair of semicircular bodies 3 are placed on the outer periphery at appropriate positions in the length direction.
An arc erosion body 3 formed by combining A and 3B so as to form an annular shape as a whole is provided, and an inner diameter D of the arc erosion body 3 is equal to that of the overhead ground wire 2.
A gap of (D-d)/2=H is maintained between the overhead ground wire 2 and the arc-eroded body 3, and the gap is larger than the outer diameter d of the arc-eroded body 3 and the overhead ground wire. 2 are connected to each other via a ground fault current discharge conductor 4.