JP2004072922A - Mounting structure of cable terminating connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a terminating connector of a branch cable to be connected to an existing overhead wire without conducting large-scale steel tower repairing work. <P>SOLUTION: The terminating connector 7 is obtained by insulating the terminating end of the branch cable 9 from the overhead wire, and a conductor 7a of a distal end is connected to the overhead wire. The connector 7 is mounted horizontally at a body 3 of the steel tower, and a necessary insulating distance R can be surely secured between the conductor 7a of a voltage applying side and arms 5 of an installing side. In this case, since a sufficient distance is secured to secure a necessary insulating distance R between the arms 5, the connector can be mounted by simple work, and the large-scale work such as a partial repair or the like of the tower is thereby eliminated. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure for attaching a terminal connection portion of a cable connected to an overhead line, which is insulated by an insulator tube, to an existing steel tower, and a steel tower having this mounting structure.
[0002]
[Prior art]
As shown in FIG. 8, when a customer such as a factory or a substation is newly installed near a high-voltage transmission line, a cable 35 is branched from an existing transmission line (overhead line) 33 to these facilities 31 and transmitted. There is a need. If there is an obstacle such as a road 37 between the overhead line 33 and the facility 31, an underground cable is used as the branch cable 35. In this case, the terminal connection part 39 of the underground cable 35 connected to the overhead wire 33 is attached to the steel tower 41, but in this case, the location of the terminal connection part 39 becomes a problem.
[0003]
Conventionally, as shown in FIG. 9A, the terminal connection portion 39 of the cable 35 is vertically attached upward (or downward) to an arm 45 projecting from a tower main body 43 of a steel tower 41.
[0004]
[Problems to be solved by the invention]
However, when the cable terminal connection portion 39 is vertically attached to the arm 45 in this manner, the required insulation distance R ′ between the conductor 39a (power application side) at the tip of the terminal connection portion 39 and the arm 45 (ground side). (Indicated by a broken-line circle in the figure) cannot be secured in many cases. For this reason, when attaching the terminal connection portion 39, the upper structure of the existing steel tower is replaced with one having a large arm interval L so that a sufficient insulating distance can be secured between the conductor 39a and the arm 45.
[0005]
In this case, large-scale renovation work of the tower is required. That is, at the time of this repair work, in order to continue power transmission, it is necessary to construct a temporary tower near the repair tower, transfer the existing overhead line to the temporary tower, and replace the upper structure of the existing tower. Therefore, there are problems such as a longer construction period and a rise in construction costs, and there is also a problem that it is difficult to secure a temporary tower site under severe land conditions.
[0006]
In order to solve the above problem, as shown in FIG. 9 (b), it has been considered to attach the cable terminal connecting portion 39 to the arm 45 diagonally. However, a tower capable of securing a necessary insulation distance is limited, and is always effective. This is not a simple solution.
[0007]
In view of the above, an object of the present invention is to provide a cable terminal end mounting structure capable of connecting a terminal connecting portion of a branch cable to an existing overhead line without performing large-scale tower repair work.
[0008]
[Means for Solving the Problems]
All of the above-described conventional mounting structures are based on the premise that the terminal connection portion of the cable is mounted on the arm of the tower. Since the arm is designed to support the overhead wire and its accessories, it is a natural idea to attach the terminal connection to the arm, and this idea has been followed in the past.
[0009]
On the other hand, the present inventors have studied various mounting structures without being limited to the existing structure of mounting the terminal connection portion to the arm. As a result, they came up with a new technical idea of mounting the terminal connection not on the tower arm but on the tower body and horizontally.
[0010]
That is, the present invention provides a structure for attaching a terminal connection portion of a cable (including an underground cable and an overhead cable) connected to an overhead line, which is insulated by an insulator tube, to an existing steel tower, The part is mounted horizontally on the tower body of the tower.
[0011]
In order to secure the required insulation distance between the upper and lower overhead lines, an interval of at least twice the required insulation distance R 'is usually provided between the arms of the existing tower. Therefore, if the terminal connection is mounted horizontally on the tower main body, it is possible to ensure the required insulation distance between the conductor at the end of the terminal connection and the adjacent arm. In this case, the installation of the terminal connection portion can be performed by a simple operation without performing a large-scale repair work such as partially replacing an existing steel tower.
[0012]
Specifically, the terminal connection portion can be attached by erection of a mounting member between upper and lower horizontal members of the tower main body, and mounting a seat portion of the terminal connection portion to the mounting member.
[0013]
The terminal connection part is connected to a jumper line connecting the overhead wires. In this case, the jumper line is attached to the arm of the tower, and is supported via a support member having a displacement portion displaced upward, and the terminal connection portion is connected to the jumper line, so that the support member can move in the horizontal direction. Projection width can be suppressed.
[0014]
When the terminal connection portions are arranged horizontally as described above, the terminal connection portions are cantilever-shaped, and a large load is applied to the mounting portion. Since the weight is reduced, the load applied to the mounting portion can be reduced.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0016]
FIG. 1 illustrates a power transmission tower 1 to which an attachment structure for a terminal connection according to the present invention is applied. As shown in the figure, the tower 1 includes a tower body 3 that rises in a vertical direction, and an arm 5 (arm) that projects horizontally from the tower body 3. The arm 5 supports one or more transmission lines (overhead lines) via insulators 25 (see FIG. 6). In the tower 1 illustrated in FIG. 1, the arms 5 are provided on both sides of the tower main body 3 and are provided in a plurality of stages (for example, six stages) in a vertical direction.
[0017]
It should be noted that the steel tower 1 referred to here is not particularly limited in its electric wire supporting type (suspended type or tension-resistant type), and its constituent materials (angle steel tower, steel pipe steel tower, concrete filled steel pipe steel tower, etc.) are not particularly limited.
[0018]
As shown in FIG. 2, a cable extending from a customer or a substation, for example, a terminal connection portion 7 (also referred to as a cable head) of an underground cable 9 is horizontally attached to the tower body 3. The terminal connection portion 7 is attached between the vertically adjacent arms 5 so as to secure a required insulation distance R (for example, 760 mm in air if the operating voltage is 77 kV) indicated by a broken-line circle. The terminating connection part 7 is obtained by covering a terminating part of the branch cable 9 with an insulator tube for external insulation, and the conductor 7 a at the tip is electrically connected to the branch cable 9.
[0019]
The terminal connection 7 can be attached to the tower body 3 by, for example, the following means. That is, as shown in FIGS. 2 and 3, steel materials such as L-shaped steel as the base member 11 are horizontally separated from each other on the upper and lower horizontal members 3 a of the tower body 3 installed at the base end of the arm 5. On one surface of the base member 11, two steel materials such as U-shaped steel as the attachment member 13 are vertically provided between the upper and lower horizontal members 3a. By attaching the seat portion 7b of the terminal connection portion 7 to the mounting member 13 with a bolt or the like, the terminal connection portion 7 is mounted on the tower body 3, and the load is supported by the tower body 3.
[0020]
The above mounting can be performed only by newly attaching the base member 11 and the mounting member 13 to the tower main body 3, and therefore, it is possible to perform a very simple operation without partially replacing the tower main body as in the related art. The terminal connection 7 can be attached to the tower body 3. Note that the above mounting structure is merely an example, and other mounting structures may be employed as long as the terminal connection portion 7 can be securely fixed to the tower body 3. In addition, the terminal connection portion 7 can be installed at only one location of the tower main body 3 or can be installed at a plurality of locations of the tower main body 3 (see FIG. 1).
[0021]
When the terminal connection part 7 is mounted in a horizontal direction, the terminal connection part 7 becomes a cantilever shape, and it is expected that a large stress is applied to the mounting part. Therefore, in order to reduce this load, it is desirable to use a lightweight polymer type as the terminal connection part 7. The polymer-type terminal connection portion 7 uses an insulator tube in which a cap made of rubber or resin is provided in a cylinder made of reinforced resin such as FRP. In the polymer type terminal connection portion 7, silicone oil or the like is generally sealed as an internal insulating material, but a gas such as SF ₆ is sealed as an internal insulating material to further reduce the weight and prevent internal flashing. It is desirable to do.
[0022]
As shown in FIG. 4, the conductor 7a at the end of the terminating connection portion 7 is connected via a lead wire 15 to a jumper wire 19a of a jumper device 19 for connecting the overhead wires 17 to each other.
[0023]
By the way, if an accident occurs on the branch cable 9 side, it is necessary to disconnect the branch cable 9 side from the overhead line 17 in order to restore the power transmission of the overhead line 17 (this operation is performed, for example, when the operator disconnects the lead wire 15). Done by). When the jumper wire 19a is located at a broken line position A immediately below the tip of the arm 5, as shown in FIG. 5, for example, as shown in FIG. The required insulation distance R (indicated by a broken-line circle) cannot be secured between the (ground side) and the jumper wire 19a (power application side).
[0024]
In this case, as shown in the figure, a support member 21 'is horizontally attached to the arm 5, and the jumper wire 19a is supported by the support member 21' via the insulator 23 so that the jumper wire 19a has a required insulation distance. It is also possible to evacuate far beyond R. However, in this case, since the horizontal width of the support member 21 'is large, the strength of the support member 21' and, consequently, the arm 5 is reduced, and there is a possibility that the earthquake resistance and the like may be reduced. The appearance is poor and there is a problem in terms of environmental harmony.
[0025]
On the other hand, as shown in FIGS. 6 and 7, if a displacement portion 21a that displaces upward is formed at, for example, an intermediate portion of the support member 21, the position of the jumper line 19a can be changed as shown by a solid line in FIG. It can be moved to the main body 3 side. As a result, the horizontal protrusion width of the support member 21 can be suppressed by P as compared with the structure (shown by a broken line) shown in FIG. 5, and the above problem can be solved.
[0026]
6 and 7 illustrate the case where the displacement portion 21a of the support member 21 is formed in an inclined shape, but may be formed vertically as shown in FIG.
[0027]
If the horizontal projection width does not matter so much, a horizontal support member 21 '(see FIG. 5) having no displacement portion 21a can be used instead of the support member 21 having the displacement portion 21a. In this case, as shown in FIG. 1, both types of support members 21 and 21 ′ can be mixed in a common steel tower 1.
[0028]
【The invention's effect】
As described above, according to the present invention, since the terminal connection portion is horizontally attached to the tower main body, a necessary insulation distance can be reliably secured between the conductor at the end of the terminal connection portion and the adjacent arm. Attachment of the terminal connection portion can be performed by simple work without performing large-scale renovation work such as partially replacing an existing steel tower, thereby shortening the construction period and reducing the construction cost. In addition, since it is not necessary to replace the existing tower, it is not necessary to secure land for temporary towers, and branch cables can be connected regardless of the installation conditions of the tower (whether or not land can be secured). Become.
[Brief description of the drawings]
FIG. 1 is a side view of a power transmission tower to which a terminal connection portion mounting structure according to the present invention is applied.
FIG. 2 is an enlarged side view showing a mounting portion of a terminal connection portion.
FIG. 3 is a horizontal cross-sectional view showing, on an enlarged scale, a mounting portion of a terminal connection portion.
FIG. 4 is a perspective view showing a connection state between a terminal connection portion and a jumper wire.
FIG. 5 is a side view showing an example of the arrangement of jumper lines.
FIG. 6 is a perspective view showing an improved example of a connection state between a terminal connection portion and a jumper wire.
FIG. 7 is a side view showing another example of the arrangement of the jumper wires.
FIG. 8 is a perspective view schematically illustrating a relationship between a transmission line and a branch cable.
9A and 9B are side views showing a conventional attachment structure of a terminal connection portion, wherein FIG. 9A shows a case where the terminal connection is mounted upward, and FIG. 9B shows a case where the terminal connection is installed obliquely.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tower 3 Tower main body 3a Horizontal member 5 Arm 7 Terminal connection part 7a Conductor 7b Seat 9 Branch cable 11 Base member 13 Mounting member 15 Lead wire 17 Overhead wire 19 Jumper device 19a Jumper wire 21 Support member 21 'Support member 23 Insulator 25 insulator R required insulation distance

Claims (5)

A structure for attaching a terminal connection portion of a cable connected to an overhead line, which is insulated by an insulator tube, to an existing steel tower,
An installation structure for a cable terminal connection portion, wherein the terminal connection portion is horizontally mounted on a tower main body of a steel tower. 2. The jumper wire according to claim 1, wherein a jumper wire connecting the overhead wires is supported via a support member attached to the arm of the tower and having a displacement portion displaced upward, and a terminal connection portion is connected to the jumper wire. Mounting structure for cable termination connection. 3. The mounting structure according to claim 1, wherein a mounting member is provided between the upper and lower horizontal members of the tower body, and a terminal connecting portion is mounted on the mounting member. The mounting structure for a cable terminal connection according to any one of claims 1 to 3, wherein a polymer type is used as the terminal connection. A steel tower having a structure for attaching a cable terminal connection portion according to any one of claims 1 to 4.

Images