JPH11122799A - Terminal connecting section of power cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a terminal connecting section of a conductor connecting section in various forms, by providing a first corona shield and a second corona shield thereon to surround the entire part of a fixed terminal and a connection terminal. SOLUTION: A circular first corona shield 10 having the same size as that for surrounding the connecting section when a connecting terminal 7 is not provided is installed to the area surrounding the connecting section consisting of a fixed terminal 6 and a connection terminal 7. A second corona shield 11 having the length sufficient for covering the entire part of both terminals on the non-contact basis is arranged through the upper opening part of the first corona shield 10 at the internal side thereof. The first corona shield 10 and the second corona shield 11 are fixed to a conductive fixing metal tool 2 via a corona shield fixing metal tool 12 and is then electrically connected with a cable conductor. As a result, the manufacturing cost of the terminal connecting part for the conductor connecting portion of various forms can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal connection part of a power cable, and more particularly to a terminal connection part directly connected to equipment.

[0002]

2. Description of the Related Art Conventionally, as a method of connecting a cable end to various devices, a method of directly connecting a terminal in oil installed directly connected to a transformer or an SF ₆ gas insulated sealed type device has been used. There is known a method of using a terminal connection in a gas.

FIG. 3 is a schematic sectional view showing an example of a conventional terminal connection part in oil. In FIG. 3, a conductor fixing bracket 2 is fixed to the epoxy insulator tube 9 of the insulator via a lock nut 3 via an upper bracket 1. Further, the conductor extraction rod 4 is extracted from the insulator tube 9 by a predetermined length, and is fixed by the conductor fixing bracket 2. By connecting the fixed terminal 6 fitted to the tip of the lead wire 8 on the device side to the conductor pull-out bar 4, the conductor on the insulator tube side and the lead wire 8 are electrically connected. The connecting portion made of the above-described member on the upper portion of the epoxy insulator 9 as described above is surrounded by a corona shield 5 having a cylindrical shape having an open upper portion and electrically connected to a conductor. The electric field is prevented from being concentrated on the portion. The corona shield 5 is fixed to the conductor fixing metal 2 by a corona shield fixing metal 12.

In the above-mentioned connection portion, the corona shield 5 is a portion of the upper part of the epoxy insulator tube 9 which has a form in which uneven discharge or the like is likely to occur, that is, the upper fitting 1.
Therefore, the corona shield 5 is manufactured and used at a height corresponding to the connecting portion composed of the above-described members since the object can be achieved if it can surround from the terminal to the fixed terminal 6.

However, in the above-mentioned cable terminal portion, a connection terminal having the same form as the above-mentioned fixed terminal is fitted to the tip of the equipment-side lead wire, and this is connected to the fixed terminal fitted to the conductor lead rod. In some cases, they are connected to form a conductor connection part of a terminal connection part. A schematic cross-sectional view of such a termination connection is shown in FIG. In the terminal connection portion in FIG. 4, the connection terminal 7 is fitted to the tip of the lead wire 8 on the device side,
This is fixed to a fixed terminal 6 fitted to the conductor lead rod 4 on the insulator tube side.
, Electrical connection between the conductor on the insulator tube side and the lead wire 8 is obtained.

In the terminal connecting portion having such a structure,
Although the length of the portion to be surrounded by the corona shield is longer than that shown in FIG. 3, conventionally, as shown in FIG. 4, the length of the corona shield 5 has been increased.

However, due to such a difference in the configuration of the conductor connection portion, individually designing and producing corresponding corona shields having different lengths lowers the production efficiency of the corona shield and increases the manufacturing cost. In addition, when the corona shield is made longer and larger as described above, it may be necessary to change the design of the case for accommodating the terminal connection portion, including the case.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to easily cope with an increase in the length of the conductor connection portion, thus increasing the manufacturing cost. It is an object of the present invention to provide a structure of a corona shield which does not cause the influence and influences the design of the case of the terminal connection.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a fixed terminal fitted to a leading end of a conductor lead rod pulled out from an upper part of an insulator, and a fixed terminal fitted to a leading end of a device side lead wire. In the terminal connection portion of the power cable connected to the connection terminal, the first corona shield and the second corona shield provided on the upper portion, so as to surround the entirety of the fixed terminal and the connection terminal. The present invention is to provide a power cable terminal connection portion provided with a corona shield.

In one embodiment of the above-described terminal connection portion of the power cable according to the present invention, insulating oil-impregnated paper is wound around the outer periphery of the second corona shield.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The terminal connection portion of the power cable according to the present invention has a plurality of corona shields, that is, a first corona shield and a second corona shield provided on the upper portion thereof so as to surround the whole of the fixed terminal and the connection terminal. A corona shield comprising two corona shields is provided. That is, when the length of the conductor connecting portion is increased, the necessary portion around the conductor connecting portion is surrounded by a plurality of corona shields, instead of responding by changing the size, shape, and the like of one corona shield. So that one standard corona shield can be used regardless of the length of the conductor connection, so that if a required part cannot be surrounded, another simpler corona shield is additionally used It encloses all the parts. As a result, it is not necessary to design and manufacture a corona shield for each of the shapes of the conductor connection parts, thereby avoiding an increase in cost. Impact can be minimized.

One embodiment of the terminal connection portion of the cable according to the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing an example of a terminal connection portion of a power cable according to the present invention, and shows a device direct connection type oil terminal connection portion when connecting to a device such as a transformer.

FIG. 4 shows a structure other than the corona shield.
The conductor fixing bracket 2 is fixed to the upper portion of the epoxy insulator tube 9 of the insulator via the upper bracket 1 by the lock nut 3. The conductor extraction rod 4 is extracted from the insulator tube 9 by a predetermined length, and is fixed by the conductor fixing bracket 2. A connection terminal 7 is fitted to the tip end of a lead wire 8 on the device side, and this is connected to a fixed terminal 6 fitted on a conductor extraction rod 4 on the insulator tube side, whereby the conductor on the insulator tube side and the lead wire 8 are connected. Have an electrical connection.

First, a cylindrical first corona shield 10 having the same size as that for surrounding the connection portion without the connection terminal 7 is provided around the connection portion including the fixed terminal 6 and the connection terminal 7. is set up. Furthermore, a second corona shield 11 having a length sufficient to cover the entirety of the two terminals in a non-contact manner with the above-mentioned two terminals is provided inside thereof.
The first corona shield 10 is arranged so as to penetrate an upper open portion. The first corona shield 10 and the second corona shield 11 are fixed to the conductor fixing metal 2 via the corona shield fixing metal 12, and are electrically connected to the cable conductor.

As the first corona shield 10, it is possible to use a standard product having a predetermined length used for the connection portion when the connection terminal 7 normally used for the terminal connection portion in oil is not provided. The second corona shield 11 provided above the first corona shield 10 has a length that can sufficiently surround the portion of the upper connection terminal 7 that is not surrounded by the first corona shield 10. And These two corona shields surround all non-smooth portions of the conductor connection, including the fixed terminals and the connection terminals, to be surrounded.

The shape of the first corona shield and the second corona shield is not particularly limited as long as the effect of preventing the electric field from being concentrated by the terminal projections can be obtained. Shapes are preferred. The second corona shield 11 shown in FIG. 1 has a tapered end on the lead wire side so as not to affect the design of the terminal connection case as much as possible. When it is not necessary to take into account, for example, a cylindrical form having the same diameter may be used.

Further, in the terminal connecting portion of the present invention, the object of providing the corona shield is achieved if the entire portion to be surrounded by the corona shield is surrounded by any of the first and second corona shields. Is done. For example, in the example shown in FIG. 1, since the second corona shield is mounted on the corona shield fixing bracket 12, the portion above the corona shield fixing bracket 12 and below the upper end of the first corona shield is the second corona shield. Although surrounded by both the first and second corona shields, it is not necessary that the second corona shield be present in this portion. Therefore,
For example, as shown in FIG.
Is fixed near the connection portion between the fixed terminal 6 and the connection terminal 7 by the second fixing metal fitting 13 for the corona shield and provided above the vicinity of the connection portion, and the first corona shield is provided by the second corona shield 11. It is also possible to surround the part that cannot be surrounded by 10 and reduce the length of the part that is surrounded by both the first and second corona shields.

With the above-described structure of the terminal connection portion of the cable according to the present invention, the first corona shield 10 produced at a predetermined length can be used as it is regardless of the structure of the conductor connection portion. Smaller than the corona shield of
By adding the second corona shield 11 that is lightweight and easy to manufacture, the electric field at the terminal connection can be reduced, and the manufacturing cost of the corona shield and, consequently, the manufacturing cost of the terminal connection can be reduced. Also, as shown in FIG. 4, by making the second corona shield smaller and lighter,
The effect of manufacturing cost reduction is further improved. In addition, since the second corona shield can be easily used with a smaller diameter than the first corona shield, it is possible to minimize the influence of the terminal connection on the case design.

In the terminal connection portion of the cable according to the present invention, the shapes, sizes and the like of the fixed terminals 6 and the connection terminals 7 are not limited to those shown in FIGS.
Any shape and size can be used, and the corona shield can be shaped and dimensioned accordingly.

As the material of the first and second corona shields, those generally used as corona shields can be used. For example, iron casting, aluminum,
Aluminum alloy, copper alloy and the like can be mentioned. In particular, it is particularly preferable that the second corona shield be made of a material such as aluminum, an aluminum alloy, or a copper alloy, from which the corona shield can be easily produced.

Further, in the terminal connection portion of the cable according to the present invention, insulating oil immersion paper or the like may be wound around the inner corona shield to improve the insulation performance of the terminal connection portion conductor.

Although the above embodiment has been described with reference to the case of the terminal portion in oil, the present invention can be similarly applied to the connection portion in gas.

[0023]

According to the cable terminal connecting portion of the present invention, a corona shield having a standard length can be obtained regardless of the shape of the conductor connecting portion by additionally using a corona shield having an auxiliary simple structure. Can be used, and the cost of manufacturing the terminal connection portion for various types of conductor connection portions can be reduced. In addition, a corona shield having a structure that does not require a design change of the case of the terminal connection portion can be easily formed.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a terminal connection portion of a power cable of the present invention.

FIG. 2 is a diagram showing another embodiment of the terminal connection part of the power cable of the present invention.

FIG. 3 is a diagram showing a conventional underwater connection portion of a power cable.

FIG. 4 is a view showing a conventional power cable end connection part in oil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Upper bracket 2 ... Conductor fixing bracket 4 ... Conductor lead-out bar 5 ... Corona shield 6 ... Fixed terminal 7 ... Connection terminal 8 ... Lead wire 9 ... Epoxy insulator 10 ... First corona shield 11: second corona shield 12: corona shield fixing bracket 13: second corona shield fixing bracket

Claims (2)

[Claims] 1. A terminal connecting portion of a power cable, wherein a fixed terminal fitted to a leading end portion of a conductor lead rod pulled out from an upper portion of an insulator is connected to a connecting terminal fitted to a leading end portion of a device-side lead wire. Wherein a corona shield comprising a first corona shield and a second corona shield provided thereon is provided so as to surround the whole of the fixed terminal and the connection terminal. Connection. 2. The power cable terminal connection according to claim 1, wherein an insulating oil-impregnated paper is wound around the outer periphery of the second corona shield.