KR20190114091A - Termination box of power cable - Google Patents

Abstract

The present invention relates to a termination connection box of a power cable which increases assembling features of a cover member mounted on an upper end of a termination connection box and increases waterproof performance while a mounting state of the cover member is stably maintained. According to the present invention, the termination connection box of a power cable comprises: a conductor drawing rod; a sleeve member in which a power cable connected to the conductor drawing rod is closely placed to the inside of the sleeve member; and a cover member surrounding the conductor drawing rod and a connection part of a conductor unit of the power cable and formed of a flexible resin material.

Description

Termination box of power cable {TERMINATION BOX OF POWER CABLE}

The present invention relates to the termination of a power cable. More specifically, the present invention relates to the termination of the power cable is improved assembly performance of the cover member mounted on the upper end of the termination box, the mounting state of the cover member is stably maintained to improve the waterproof performance.

In general, a power cable is used to supply power to a desired place through the ground, the ground or the sea floor by using a conductor that supplies the power. Such a power cable is very important to insulate the conductor. For this purpose, the insulating layer for insulating the conductor is made of XLPE (cross-linked polyethylene) or the like, or wound with insulating paper to form an insulating layer. I use it.

The power cables are connected by joint boxes at intervals of several hundred meters or several kilometers, and the ends of the power cables are connected to overhead lines or breakers by termination connection boxes. .

The air termination box (EB-A) to be connected to the overhead line is provided with a conductor withdrawing rod inside the aerial termination box (EB-A) for connecting the conductor portion of the overhead line and the power cable. The conductor portion of the power cable and the conductor drawing rod may be connected inside the termination box, and the conductor drawing rod may be drawn out to the upper end of the termination box and connected to the overhead line.

For reference, the termination box of the power cable is the air termination box (EB-A), the breaker is the gas termination box (EB-G), and the transformer is the oil termination connection. Each of them may be divided into an EB-O.

In particular, the air termination box (EB-A) can be used to interconnect the overhead line and the power cable in the outdoor substation for connection with overhead line, and the structure that uses the magnetic insulation for the external insulation is widely used.

Since the conventional air termination box (EB-A) is disposed perpendicular to the outdoors, in the case of rain or the like, a structure for preventing the internal flooding of the termination box is required.

Conventional air termination junction box (EB-A) is an oil-filled upper tube and O-ring structure, and a fixing structure and a fastening member for fixing the bracket are used, watertightness is not a problem, but the structure is complicated and many The part was taken.

Recently, an air termination box (EB-A) of a dry method has been introduced. Dry air termination box (EB-A) has the advantage that the structure is simple because it has a structure that does not receive the fluid for insulation therein. The part connected to the overhead line may also be used to mount the tape or cap.

However, stretching may occur in the conductor portion of the power cable according to the size of the power supplied through the termination box, and the stress or stress applied by the expansion may cause the conductor drawing rod lead-out portion of the termination box, that is, the cap mounting portion. Or there is a need to solve the problem because it inhibits the watertightness of the taping site.

The present invention is to solve the problem that the assembly of the cover member to be mounted on the upper end of the termination box is improved, the mounting state of the cover member is maintained stable to provide a terminal box of the power cable with improved waterproof performance.

In order to solve the above problems, the present invention is a conductor drawing rod; A sleeve member in which a power cable having a conductor portion connected to the conductor drawing rod is mounted to be in close contact with an inside thereof; And a cover member surrounding the connection portion of the conductor drawing rod and the power cable of the power cable, the cover member made of a flexible resin material, wherein the conductor drawing rod and the sleeve member are fixed to the cover member, respectively. It can provide a terminating box of.

In addition, the cover member is a threaded fastening member is inserted into the insert, the conductor withdrawal rod is formed with a screw thread for screwing the fastening member of the cover member, the cover member is screwed to the conductor withdrawing rod can be solidified have.

The conductor drawing rod may include a lead portion drawn out to be connected to a processing wire, a mount portion provided below the lead portion, and a mounting portion on which the cover member is mounted, and a connection portion inserted into and connected to the conductor portion of the power cable to the lower portion of the mount portion. The screw thread may be formed on an outer circumferential surface of the mounting part.

In addition, the cover member is formed in the shape of an inverted cup, the opening is formed so that the conductor withdrawing rod of the power cable is exposed upward, the upper end of the sleeve member may be inserted below the cover member. .

Then, an adhesive may be fixed between the lower portion of the cover member and the upper end of the inserted sleeve member.

Here, the adhesive may be a silicon bond.

Here, the cover member is made of a rubber material, the diameter of the opening of the cover member may be configured to be smaller than the diameter of the conductor withdrawing rod through.

In addition, the sleeve member is made of a rubber material or a silicone material, a plurality of wrinkles or protrusions are formed on the outer peripheral surface, an electric field relaxation cone for alleviating electric field concentration can be inserted.

According to the termination of the power cable according to the present invention, the assembly of the cover member mounted on the upper end of the power cable is improved, the mounting state of the cover member can be stably maintained, and the waterproof performance can be improved.

According to the termination of the power cable according to the present invention, the cover member is made of a flexible material such as rubber and is fixed to the conductor drawing rod and the sleeve member constituting the termination box, respectively, so that the cover member absorbs it even if the power cable is thermally stretched. It is possible to ensure the sealing performance of the upper area of the termination box.

1 shows a side view of one embodiment of a termination box of a power cable according to the invention.
2 shows a cross-sectional view of one embodiment of a power cable of the present invention.
3 shows a cross-sectional view of the power cable terminator shown in FIG. 1.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art. Like numbers refer to like elements throughout.

1 shows a side view of one embodiment of a termination box 1000 of a power cable according to the present invention, and FIG. 2 shows a cross-sectional view of one embodiment of the power cable of the present invention.

1 illustrates an example of a termination box 1000 provided with a power cable and a conductor connecting device. Hereinafter, a description will be given based on the structure of a dry air (EB-A) terminating box.

The terminal junction box 1000 of FIG. 1 accommodates a power cable 100 provided with a conductor drawing rod 200 connected to a overhead line and a conductor portion 10 connected to the conductor drawing rod 200 and forms an outer wall. And a cover member 300 surrounding the conductor drawing rod 200 and the connection portion 250 of the conductor portion 10 of the power cable.

In addition, the cover member 300 constituting the terminal box 1000 of the power cable of the present invention is inserted into the fastening member 320 is formed with a screw thread, the conductor drawing rod 200 is the cover member 300 A screw thread is formed in the fastening part, and the cover member 300 is screwed to the conductor drawing bar 200, which will be described later.

The power cable 100 introduced into the sleeve member 400 is connected to the conductor drawing rod 200 inside the sleeve member 400.

The lower end of the conductor drawing bar 200 is connected to the power cable in the sleeve member 400 and the upper end of the conductor drawing bar 200 passes through the cover member 300 mounted to the upper end of the sleeve member 400. Withdrawn.

In the case of dry air termination (EB-A) termination box, it is not a structure that attaches the bracket to the upper part of the hard magnetic pipe and the upper pipe used in the conventional termination box, and is made of flexible material such as silicone or rubber. In addition, there is an advantage that the configuration can be simplified by close contact with the cable without empty space inside, and the structure such as the bracket on the upper part is omitted.

However, the terminal junction box 1000 of the power cable is installed perpendicular to the substation outdoors for connection of overhead lines, etc., so that moisture infiltration through the upper portion of the sleeve member 400 should be prevented. Therefore, the cover member 300 mounted on the sleeve member 400 in the state in which the conductor drawing rod 200 is penetrated should be configured to provide watertightness. In addition, the terminal box 1000 of the power cable according to the present invention is the cover member 300 mounted on the sleeve member 400 in the state that the conductor drawing rod 200 is penetrated is made of a rubber material Flexibility can be prevented from breaking easily and airtightness can be improved.

Detailed description of the cover member 300 will be deferred.

The sleeve member 400 serves to insulate the power cable 100. Therefore, the sleeve member 400 needs an electrical insulation strength sufficient, and for this purpose, a plurality of wrinkles or protrusions 410 are provided on the circumferential surface of the sleeve member 400. Increasing the insulation distance by the pleats or protrusions 410 improves the dielectric strength. The sleeve member 400 is preferably made of a flexible resin material such as silicone or rubber to have a dielectric strength and at the same time ensure a moderate level of flexibility and water repellency.

As shown in FIG. 2, the power cable 100 that can be connected by the conductor connection structure according to the present invention includes a conductor portion 10, an inner semiconducting layer 20 surrounding the conductor portion 10, and the inside thereof. An insulating layer 30 surrounding the semiconducting layer 20, an outer semiconducting layer 40 surrounding the insulating layer 30, and an outer semiconducting layer 40, which are made of a metal sheath or a neutral wire, and are electrically shielded and return to a short circuit current. For the shielding layer 50, it may include a shell 60 surrounding the shielding layer (50).

The conductor part 10 may be formed of a stranded wire in which a single wire or a plurality of conductor wires made of copper, aluminum, and preferably copper are associated with each other, and the diameter of the conductor part 10 and the stranded wire 11 constituting the stranded wire. The standard including the diameter may be different depending on the transmission voltage, the use, etc. of the power cable 100 including the same, and may be appropriately selected by the designer. When the conductor part 10 is provided with a plurality of element wires 11 and each element wire 11 is provided in an insulated state, the amount of power transmission can be maximized by reducing the conductor resistance due to the skin effect.

The internal semiconducting layer 20 constituting the power cable 100 is disposed between the conductor portion 10 and the insulating layer 30 to lift the interlayers of the conductor portion 10 and the insulating layer 30. It removes the air layer that causes it, and alleviates local electric field concentration.

On the other hand, the outer semiconducting layer 40 performs a function of applying an even electric field to the insulating layer 30, localized electric field concentration relaxation and the function of protecting the insulating layer from the outside.

The inner semiconducting layer 20 and the outer semiconducting layer 40 have conductive particles such as carbon black, carbon nanotubes, carbon nanoplates, graphite, and the like dispersed in a base resin, and further include a crosslinking agent, an antioxidant, a scorch inhibitor, and the like. It is formed by extrusion of the added semiconducting composition.

Here, the base resin is of a similar type to that of the base resin of the insulating composition for forming the insulating layer 30 for the interlayer adhesion between the inner semiconducting layer 20 and the outer semiconducting layer 40 and the insulating layer 30. Olefin resins can be used.

In addition, the insulating layer 30 may be, for example, a polyolefin resin such as polyethylene or polypropylene as a base resin, and preferably, may be formed by extrusion of an insulating composition having a polyethylene resin as a base resin.

The polyethylene resin may be applied to ultra low density polyethylene (ULDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE) and the like, in the case of a high-pressure cable Cables are quickly being replaced by crosslinked polyethylene (XLPE) insulated cables.

The outer shell 60 provided at the outermost portion of the power cable 100 may be made of any one material of polyethylene, polyvinyl chloride, and polyurethane.

3 shows a cross-sectional view of the power cable terminator 1000 shown in FIG. 1.

In the power cable introduced below the sleeve member 400, the outer shell 60, the shielding layer (not shown), the outer semiconducting layer 40, and the like are sequentially removed, and the insulating layer 30 is formed inside the sleeve member 400. ) Is disposed in close contact with the inner surface of the sleeve member 400 in an exposed state.

In addition, when the power cable 100 having a portion of the outer semiconducting layer 40 removed to expose the insulating layer 30 is introduced into the sleeve member 400, a voltage is generated between the inner semiconducting layer. When applied, an electric field may be concentrated at the end of the outer semiconducting layer 40. This may cause breakage of the outer semiconducting layer 40 and the insulating layer 30. Therefore, the electric field relaxation cone 600 for alleviating the electric field concentration of the power cable 100 may be injected and inserted into the sleeve member 400.

In the end region of the sleeve member 400, the conductor portion 10 of the power cable is exposed to connect with the conductor drawing rod 200.

The conductor drawing bar 200 is provided at the lead portion 210 which is drawn out to be connected to the processing wire, the lower portion 210 and the mounting portion 230 and the mounting portion 230 to which the cover member 300 is mounted. The power cable may be partitioned into a connection part 250 which is inserted into and connected to the lower part, and the connection part 250 of the conductor drawing rod 200 and the conductor part of the power cable near the upper end of the sleeve member 400. (10) is connected.

The connection part 250 of the conductor drawing rod 200 has a connection space in which the conductor part 10 of the power cable 100 is inserted and connected to the lower part. The connection part 250 of the conductor drawing rod 200 into which the conductor part 10 of the power cable is inserted may be fixed to the conductor part 10 of the power cable by crimping or the like.

A mounting portion 230 on which the cover member 300 is mounted is provided at an upper portion of the connection portion 250 of the conductor drawing rod 200. The mounting portion 230 is a portion in which the cover member 300 is mounted.

The cover member 300 according to the present invention may be made of a flexible resin material, for example, rubber, to correspond to the stretching of the power cable conductor part 10 or the conductor drawing rod 200.

However, since the cover member 300 must seal the sleeve member 400 in a state where the lead portion 210 connected to the processing wire is penetrated in addition to the flexibility, the cover member 300 is blocked and sealed from the upper portion of the sleeve member 400. It must be stable.

To this end, the conductor drawing rod 200 is preferably fixed to the cover member 300 and the sleeve member 400, respectively.

First, when the conductor drawing rod 200 examines the fixing method of the cover member 300, the conductor drawing rod 200 and the cover member 300 constituting the power cable termination junction box 1000 according to the present invention. ) May be fixed by screwing.

Therefore, a thread is formed on the outer circumferential surface of the mounting portion 230 provided between the connection portion 250 and the lead portion 210 of the conductor drawing rod 200, and the fastening member 320 such as a nut is formed on the cover member 300. Is inserted into the cover member 300 may be configured to be screwed with the conductor drawing rod 200.

The cover member 300 is configured in the shape of an inverted cup, the opening 310 is formed so that the conductor drawing rod 200 of the power cable penetrates and is exposed upward, and fastened inside the opening 310. Member 320 may be insert injection molded. In addition, a lower portion of the cover member 300 may have a structure in which an upper end of the sleeve member 400 is inserted below and surrounds an upper end of the sleeve member 400.

Due to the structure, the conductor drawing bar 200 and the cover member 300 are screwed and fixed, so that in the case of thermal expansion and the like of the power cable conductor part 10 or the conductor drawing bar 200, the conductor drawing bar ( It is possible to prevent the relative movement of the cover member 300 of the 200.

In addition, the lower inner surface of the cover member 300 and the outer circumferential surface of the upper end of the sleeve member 400 are fixed to attach the boundary region A with an adhesive or the like in a state where insertion is completed, thereby preventing gaping and watertightness together. Can be. The adhesive may be used for the adhesive silicone or silicon bond resistant to heat and moisture.

As described above, the conductor drawing bar 200, the cover member 300, and the sleeve member 400 constituting the terminal junction box 1000 of the power cable according to the present invention are sequentially fixed through the cover member 300. When the expansion or contraction of the power cable conductor portion 10 or the conductor drawout rod 200 can be prevented, and due to the material of the cover member 300 to some extent the power cable conductor portion 10 or the conductor drawout rod ( Since the amount of expansion and contraction of 200 may be absorbed, the watertightness of the terminal junction box 1000 may be improved.

In addition, the cover member 300 is made of a material such as rubber, the diameter of the opening 310 of the cover member 300 is smaller than the diameter (d) of the conductor drawing rod through the flexible material such as rubber When the cover member 300, which is composed of, is mounted on the conductor drawing rod 200, it may be naturally mounted while being sealed.

Although the present specification has been described with reference to preferred embodiments of the invention, those skilled in the art may variously modify and change the invention without departing from the spirit and scope of the invention as set forth in the claims set forth below. Could be done. Therefore, it should be seen that all modifications included in the technical scope of the present invention are basically included in the scope of the claims of the present invention.

1000: Termination box of power cable
100: power cable
200: conductor draw bar
300: cover member
400: sleeve member

Claims (8)

Conductor drawing rod;
A sleeve member in which a power cable connected to the conductor drawing rod is closely attached to the inside of the sleeve member; And,
And a cover member surrounding the connection portion of the conductor drawing rod and the electric power cable of the power cable and made of a flexible resin material.
And the conductor drawing rod and the sleeve member are fixed to the cover member, respectively. The method of claim 1,
The cover member has a threaded fastening member is inserted, the conductor drawing rod is formed with a screw thread for screwing the fastening member of the cover member, the cover member is characterized in that the screw is fixed to the conductor withdrawal rod Termination box of power cable. The method of claim 2,
The conductor drawing rod is provided with a lead portion which is drawn out to be connected to the overhead wire, a lower portion of the lead portion, a mounting portion on which the cover member is mounted, and a connection portion in which the conductor portion of the power cable is inserted into and connected to the lower portion of the mounting portion. The terminal box of the power cable, characterized in that the thread is formed on the outer peripheral surface of the mounting portion. The method of claim 2,
The cover member is configured in the shape of an inverted cup, the opening is formed so that the conductor drawing rod of the power cable penetrates upwards, the upper end of the sleeve member is inserted below the cover member Termination box of power cable. The method of claim 4, wherein
Terminating box of the power cable, characterized in that for fixing the adhesive between the lower end of the cover member and the inserted sleeve member. The method of claim 5,
Wherein said adhesive is a silicon bond. The method of claim 1,
The cover member is made of a rubber material, the diameter of the opening of the cover member is connected to the terminal of the power cable, characterized in that configured to be smaller than the diameter of the conductor drawing rod through. The method of claim 1,
The sleeve member is made of a rubber material or silicon material, a plurality of wrinkles or protrusions are formed on the outer circumferential surface, and the electric cable relaxation cone characterized in that the electric field relaxation cone to mitigate electric field concentration is inserted.

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