JPH038018Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a jumper device for overhead power transmission lines.
In particular, the present invention relates to a jumper device in which a dummy rod for improving corona discharge characteristics is arranged in parallel with a jumper rod for electrically connecting main lines.

[Prior art and its problems]

FIG. 6 shows a conventional example of a jumper device for overhead power transmission lines. A rigid jumper rod 6 is suspended by a hanging member 5, and both ends of the jumper rod 6 are electrically connected to the main line 3 via a connecting conductor 7.

Jumper devices with this type of structure have been applied to large jumper devices, such as the recent million-volt class power transmission lines (hereinafter referred to as UHV power transmitters), where the length of the tensile insulator chain is over 10 meters. In some cases, it is considered to be advantageous in terms of workability and formability.

On the other hand, jumper devices in UHV transmission lines are
It is necessary to satisfy the corona discharge characteristics that cause audible noise (hereinafter referred to as AN) and radio noise (hereinafter referred to as RI) not only in dry conditions but especially in rainy days. In the case of the device, the potential gradient was large in the region of the jumper rod 6, and therefore corona discharge, which is the cause of AN and RI, was likely to occur.

To solve this problem, the present applicant lowered the potential gradient by placing a dummy rod 8 at the same potential in parallel with the jumper rod 6, as shown in FIG.
Therefore, a jumper device (Utility Application No. 135279, 1983) was proposed to suppress corona. Although this jumper device has significantly improved the corona discharge characteristics, there is a problem in that the ends of the plurality of connecting conductors 7 are close to each other and crowded together at the connection portion between the jumper rod 6 and the connecting conductor 7. Due to this, the potential gradient becomes large, and therefore, problems regarding corona discharge characteristics remain in such portions.

[Purpose of invention]

This invention is of course in the jazz parody part,
In particular, it is an object of the present invention to suppress the occurrence of corona in the vicinity of the connecting portion between the jumper rod and the connecting conductor, and thereby to obtain a jumper device of a complete corona suppressing type.

[Structure of the idea]

In the present invention, in order to solve the above problem, a dummy rod that is longer than the jumper rod is connected in parallel to the jumper rod at the same potential so that both ends reach the lower position of the connecting conductor, and both ends of the dummy rod are connected to the same potential. It has a configuration with a shield ring attached.

[Effect]

Due to the presence of the dummy rod, the electric field of the jumper rod is relaxed, the potential gradient of the jumper rod portion is lowered, and the corona discharge characteristics are improved.

In addition, near both ends of the jumper rod, the ends of the plurality of connecting conductors tend to be crowded together and the potential gradient tends to increase. Since a shield ring is attached to the end of the dummy rod, the surface potential gradient is reduced even near the end of the connecting conductor, and corona discharge characteristics are improved.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

As shown in Figure 2, the eight elementary conductors 3a to 3h are positive 8
The main line 3, which is distributed at each vertex of the rectangle and constitutes an 8-conductor power transmission line, is tension-supported on the tower arm 1 through tension-resistant insulators 2 and metal fittings 4 such as yokes, as shown in Fig. 1. The hanging material 5 attached to the left and right metal fittings 4 allows, for example, two aluminum pipes to be
A main jumper rod 6 is suspended horizontally and parallel to each other below the tower arm 1, and the ends of the main wire 3 and the jumper rod 6 are connected to a plurality of connecting conductors 7.
are electrically connected to each other via.

The above configuration is basically the same as the conventional one shown in FIG. 6, but in the present invention, as shown in FIGS. 1 to 4, a conductive dummy rod 8 is attached to a metal spacer 9. Therefore, it is arranged below and parallel to the jumper rod 6. In particular, the length of the dummy rod 6 is longer than that of the jumper rod 6, and both ends of the rod reach a position below the plurality of connection conductors 7, and a shield ring 11 is attached to each of the ends. The dummy rod 8 is electrically conductive at least on its outer peripheral surface, and can be formed of, for example, a metal tube or a synthetic resin tube coated with a conductive material.

FIG. 5 shows a second embodiment of the present invention, which differs from the first embodiment in that the shield ring 11 is attached horizontally to the end of the dummy rod 88.
The other configurations are the same as in the first embodiment.

In each of the illustrated embodiments, there are two jumper rods 6, but there may be one or three or more dummy rods. Similarly, the number of dummy rods 8 is not limited to one, but can be multiple as necessary. . In this case, it is preferable that the jumper rod and the dummy rod are arranged in a substantially regular polygonal shape. Further, the dummy rod 8 may be placed above the jumper rod. Furthermore, it goes without saying that the present invention can be applied to multi-conductor power transmission lines other than the eight-conductor power transmission line of the illustrated embodiment.

[Effect of idea]

According to the present invention, since the dummy rod 8 is arranged in parallel to the jumper rod 6 at the same potential, the potential gradient at the jumper rod portion is reduced and the corona discharge characteristics are improved.

In particular, the length of the dummy rod 8 is longer than the length of the jumper rod 6, and both ends of the dummy rod reach the lower part of the connecting conductor 7 that connects the main line 3 and the jumper rod 6, and the shield ring 11 is attached to the end. Because of the presence of the shield ring 11 having the same potential as the connecting conductor 7, the jumper rod 6 of the connecting conductor 7 is The potential gradient in the vicinity of the connection portion is reduced, and it is therefore possible to obtain a corona-suppressing jumper device suitable for use in UHV power transmission lines and the like.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, and FIG. 1 is a side view of the entire jumper device;
Figure 2 is an enlarged cross-sectional view along the - line in Figure 1;
Figure 3 is an enlarged cross-sectional view of the - line in Figure 1;
Figure 4 is an enlarged side view of the main parts in Figure 1;
The figure is a side view showing essential parts of a jumper device according to a second embodiment of the present invention, FIG. 6 is a side view showing a conventional jumper device, and FIG. 7 is a side view showing another conventional jumper device. 1... Steel tower arm, 2... Tensile insulator, 3...
Main line, 4... Metal fitting, 5... Hanging material, 6... Jumper rod, 7... Connection conductor, 8... Dummy rod, 10... Connection device, 11... Shield ring.

Claims (1)

[Scope of utility model registration request] Main line 3 consisting of tensile insulator chain 2 and multiple elementary conductors
A hanging material 5 is attached to the metal fitting 4 between the
Both ends of the jumper rod 6 placed below the tower arm 1 are suspended by the hanging member 5, and both ends of the jumper rod 6 and the main line 3 are electrically connected via a plurality of connecting conductors 7. In a jumper device connected to the jumper rod 6, a dummy rod 8, which is longer than the jumper rod 6 and whose both ends reach the lower position of the connecting conductor 7, is connected in parallel to the jumper rod 6 at the same potential. A jumper device for an overhead power transmission line, characterized in that a shield ring 11 is attached.