KR102776988B1 - Connecting Structure of Power Cable Conductor And Connecting Box Of Power Cable Using The Same - Google Patents

Abstract

The present invention relates to a conductor connection structure of a power cable, which omits a corona shield in an intermediate connection box of a power cable, secures a sufficient thickness of a sleeve member connected to a conductor with a rupture bolt, thereby sufficiently securing a connection force between a sleeve member and a conductor of a power cable, while also preventing shrinkage of an insulation layer of the power cable and improving the workability of an intermediate connection work of the power cable.

Description

{Connecting Structure of Power Cable Conductor And Connecting Box Of Power Cable Using The Same}

The present invention relates to a conductor connection structure of a power cable. More specifically, the present invention relates to a conductor connection structure of a power cable, which omits a corona shield in an intermediate connection box of a power cable, secures a sufficient thickness of a sleeve member connected to a conductor by a rupture bolt, thereby sufficiently securing a connection force between the sleeve member and a conductor of a power cable, while also preventing shrinkage of an insulation layer of the power cable and improving the workability of an intermediate connection work of the power cable.

Power cables can be connected at predetermined length intervals to build a long-distance power grid, and power can be supplied to power demand points after substation or distribution through terminal connections.

When connecting these power cables, the conductors of both power cables to be connected can be connected by methods such as crimping or welding using a sleeve material.

The conductor of a power cable is usually a copper (Cu) conductor or aluminum (Al) metal material, and a composite conductor made of multiple wires may be used for bending characteristics, etc.

In the case of a conventional conductor assembly composed of copper (CU) material wires, the insulation layer of each wire constituting the conductor assembly is removed, they are assembled again, inserted into a sleeve member, and connected using a crimping method. In the case of a conductor assembly composed of aluminum (AL) wires, all of the multiple aluminum (Al) material wire strands constituting the conductor assembly are separated, the watertight paper tape or compound between them is removed, and then the conductor is connected using a welding method.

All conductor connection methods, such as crimping or welding using sleeves, have the problem that potential quality risks increase due to the scattering of conductive materials during the process of removing the insulation layer of the wires that make up the conductor, and that the work time is long and the cost is high.

Recently, a method has been introduced in which a sleeve member is used to connect a conductor of a power cable, but instead of crimping or welding the conductor of the power cable, a fastening hole is formed in the sleeve member and the conductor of the power cable is fastened using a rupture bolt, etc.

The rupture bolt is connected to the sleeve member, and a conductor assembly composed of a single wire is plastically deformed so that a current-carrying path composed of the conductor, the rupture bolt, and the sleeve member can be formed.

In the case of conductor connection using a rupture bolt and sleeve member, the pressing/welding process is omitted, but in order to secure sufficient fastening force between the conductor and sleeve member, the thickness of the sleeve member configured in the shape of a pipe must be sufficiently secured.

However, in order to connect a power cable having an XLPE insulation layer, an intermediate joint box using a sleeve member uses a corona shield that wraps the conductor connection structure between the sleeve member constituting the conductor connection structure and the high-voltage electrode constituting the joint sleeve (PMJ, pre-molded joint). Therefore, when the thickness of the corona shield, etc. is taken into consideration, the thickness of the sleeve member accommodated therein is not sufficiently secured, and even when a structure omitting the corona shield is considered, a separate method is required to prevent insulation layer shrinkage (shierink back).

The present invention aims to provide a conductor connection structure for a power cable, which omits a corona shield in an intermediate connection box of a power cable, secures a sufficient thickness of a sleeve member connected to a conductor with a rupture bolt, thereby sufficiently securing a connection force between the sleeve member and a conductor of a power cable, while also preventing shrinkage of the insulation layer of the power cable and improving the workability of the intermediate connection work of the power cable.

In order to solve the above problem, the present invention provides a conductor connection structure of a power cable for connecting a conductor portion of a power cable having a conductor, an inner semiconductive layer, an insulating layer made of cross-linked polyethylene material, and an outer semiconductive layer, the conductor connection structure including: a pipe-shaped sleeve member having a pair of conductors stripped off from a pair of power cables and a plurality of fastening holes provided at both ends in the longitudinal direction, into which a pair of conductors of the power cables are inserted; and a fixing bolt fastened to the fastening holes of the sleeve member to fix the conductors each inserted into the connecting portion of the sleeve member; and a cover member mounted to close a boundary area between the sleeve member and the insulating layer.

Additionally, the cover member may be configured in a pipe shape with a length smaller than the inner diameter.

In this case, the cover member may be configured to be divided into a first cover and a second cover.

Additionally, the first cover and the second cover can be fastened with a fastening member in an assembled state.

Here, the inner surface of both ends of the cover member, the insulating layer of the power cable, and the outer surface of the end of the sleeve member may be provided with a fixing means that is fitted and fixed.

In addition, the fixing means may be a projection formed on the inner surface of both ends of the cover member and a groove formed on the outer surface of the insulating layer of the power cable and the end of the sleeve member.

In addition, the fixing projections formed on the inner surface of both ends of the cover member and the fixing grooves formed on the outer surface of the insulating layer of the power cable and the end of the sleeve member can be formed continuously in the circumferential direction.

In addition, the outer diameters of the insulating layer, the cover member, and the sleeve member constituting the conductor connection structure of the power cable may be the same.

In this case, a partition wall is provided in the inner central region of the sleeve member, and a plurality of fastening holes into which a plurality of fixing bolts are fastened can be formed distributed in a region other than the central region.

In addition, the above-mentioned fixing bolt may be a breakable bolt whose head breaks and separates when a torque greater than a predetermined size is applied.

Here, the sleeve member may be made of copper, copper alloy, tin-plated copper or tin-plated copper alloy material.

Additionally, the fixing bolt may be made of brass or a brass alloy.

In addition, in order to solve the above problem, the present invention can provide an intermediate connection box for a power cable, including the above-described power cable conductor connection structure; a high-voltage electrode contacting a sleeve member constituting the conductor connection structure of the power cable, a pair of shielding electrodes contacting an outer semiconducting layer of the power cable, and a joint sleeve including a sleeve insulation layer wrapping the high-voltage electrode, an insulation layer of the power cable, and the shielding electrode; and a housing wrapping the pair of power cables and the joint sleeve.

According to the conductor connection structure of the power cable according to the present invention, since the conductor of the power cable and the sleeve member are connected by a rupture bolt, the insulation removal process of the insulated wire can be omitted, so the workability of the conductor connection work can be improved.

In addition, according to the conductor connection structure of the power cable according to the present invention, since it is not necessary to apply a corona shield constituting the conductor connection structure of the power cable, the thickness of the sleeve member is sufficiently secured so that the power cable and the sleeve member can be sufficiently fastened by the fixing bolt.

In addition, according to the conductor connection structure of the power cable according to the present invention, even if the corona shield constituting the conductor connection structure of the power cable is omitted, the boundary area between the insulation layer of the power cable and the sleeve member is finished, and a cover member that hooks and fixes the insulation layer of the power cable and the sleeve member is applied, thereby improving the workability when mounting the joint sleeve and preventing or alleviating the phenomenon of shrinkage of the insulation layer that occurs when the conductor of the power cable is energized.

Figure 1 illustrates a multi-stage stripped perspective view of the power cable of the present invention.
FIG. 2 illustrates one embodiment of a sleeve member provided in a conductor connection structure of a power cable according to the present invention, and FIG. 3 illustrates a cross-sectional view of the sleeve member illustrated in FIG. 2.
Figures 4 and 5 illustrate side views and cross-sectional views of the conductor connection structure of a power cable according to the present invention.
Figures 6 to 11 illustrate the assembly process of the conductor connection structure of the power cable according to the present invention.
Figure 12 illustrates a cross-sectional view of an intermediate connection box having a conductor connection structure of a power cable according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents can be thorough and complete, and so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Like reference numerals represent like elements throughout the specification.

Figure 1 illustrates a multi-stage stripped perspective view of the power cable of the present invention.

Referring to FIG. 1, a power cable (100) includes a conductor (11), an inner semiconductive layer (12), a cable insulation layer (14), and an outer semiconductive layer (16), and has a cable core portion (10) that transmits power only in the cable length direction along the conductor (11) and prevents current from leaking in the cable radius direction.

The conductor (11) above acts as a passage through which current flows to transmit power, and may be made of a material, such as copper or aluminum, that has excellent conductivity and strength and flexibility suitable for cable manufacturing and use to minimize power loss.

The conductor (11) above may be configured as a conductor assembly in which a plurality of wires are each grouped and connected as shown in Fig. 1. The conductor assembly shown in Fig. 1 configures a conductor assembly having a 1+6 structure, but the conductor assembly may be configured in various combinations such as 4-segmentation, 5-segmentation, and 1+N-segmentation.

Since the conductor is formed by twisting multiple wires, its surface is not smooth, so the electric field may be uneven, and corona discharge may easily occur partially. In addition, if a gap is created between the conductor (11) surface and the cable insulation layer (14) described later, the insulation performance may deteriorate.

In order to solve the above problem, an internal semiconducting layer (12) may be formed on the outside of the conductor (11). The internal semiconducting layer (12) may have semiconductivity by adding conductive particles such as carbon black, carbon nanotubes, carbon nanoplates, and graphite to an insulating material.

The above inner semiconducting layer (12) prevents a sudden change in electric field between the conductor (11) and the cable insulation layer (14) described below, thereby stabilizing the insulation performance. In addition, it suppresses the uneven charge distribution on the surface of the conductor (11), thereby making the electric field uniform, and prevents the formation of a gap between the conductor (11) and the cable insulation layer (14), thereby suppressing corona discharge, insulation breakdown, etc.

The above cable insulation layer (14) is provided on the outside of the inner semiconducting layer (12) to electrically insulate the current flowing along the conductor (11) from the outside so that it does not leak to the outside.

The above insulating layer (14) is composed of an insulating composition that has a high breakdown voltage, an insulating performance that can be stably maintained for a long period of time, a low dielectric loss, and heat resistance, and the insulating composition may be a polyolefin resin such as polyethylene and polypropylene, preferably a resin based on polyethylene resin, and in particular, cross-linked polyethylene (XLPE) may be used.

In addition, the insulating composition may include inorganic nanoparticles or organic polar substances. The inorganic nanoparticles or organic polar substances trap space charges formed by by-products that are injected from the conductor (11) into the insulating layer (14) when the power cable is energized or by cross-linking of the insulating layer (14), thereby increasing the electric field intensity near the conductor due to the space charges, thereby suppressing a decrease in the superimposed impulse breakdown strength of the insulating layer.

In addition, the insulating composition may further include other additives such as a crosslinking agent, an antioxidant, and a scorch inhibitor in addition to the inorganic nanoparticles. The crosslinking agent may vary depending on the crosslinking method of the insulating composition, and may include, for example, an organic peroxide such as dicumyl peroxide in the case of chemical crosslinking. The antioxidant performs a function of suppressing deterioration due to oxidation of an insulating layer formed from the insulating composition, and may include, for example, an antioxidant such as a phenol type, a quinone type, or an amine type. The scorch inhibitor performs a function of further securing crosslinking characteristics during crosslinking of the insulating composition and suppressing scorch due to long-term extrusion.

The above insulating layer (14) can be formed by extruding the insulating composition, and by extruding together with the inner semiconducting layer and the outer semiconducting layer (16) described below, it is possible to prevent the occurrence of a gap or the intrusion of foreign substances at the interface between the insulating layer and the inner or outer semiconducting layer (16).

An external semiconductive layer (16) may be provided on the outside of the cable insulation layer (14). The external semiconductive layer (16) is formed of a semiconductive material by adding conductive particles, such as carbon black, carbon nanotubes, carbon nanoplates, and graphite, to an insulating material like the internal semiconductive layer, thereby suppressing uneven charge distribution between the cable insulation layer (14) and a metal sheath (22) described below, thereby stabilizing insulation performance. In addition, the external semiconductive layer (16) may perform the function of smoothing the surface of the cable insulation layer (14) in the cable, alleviating electric field concentration, preventing corona discharge, and physically protecting the cable insulation layer (14).

A cable protection section (20) is provided on the outside of the cable core section (10), and a power cable (100) laid on the seabed may additionally be provided with a cable outer section (30). The cable protection section and cable outer section protect the core section from various environmental factors such as moisture penetration, mechanical trauma, and corrosion that may affect the power transmission performance of the cable.

A moisture absorbing portion (21) that can be provided on the outside of the outer semiconductive layer (16) may be additionally provided. The moisture absorbing portion may be formed between the stranded wires of the conductor (11) and/or on the outside of the conductor (11), and is configured in the form of a powder, tape, coating layer, or film, etc., including a super absorbent polymer (SAP) that absorbs moisture that has penetrated into the cable at a high speed and has an excellent ability to maintain an absorbed state, and serves to prevent moisture from penetrating in the length direction of the cable. In addition, the moisture absorbing portion may have semiconductivity in order to prevent a rapid electric field change.

The above cable protection member (20) includes a metal sheath (22) and a polymer sheath (24) on the outside of the moisture absorption member (21), thereby protecting the cable from fault current, external force, and other external environmental factors.

The above metal sheath (22) can be formed to surround the core part (10). In particular, when the power cable (100) is laid in an environment such as the seabed, the cable core part (10) can be formed to seal the cable core part (10) in order to prevent foreign substances such as moisture from penetrating the cable core part (10), and the cable core part (10) can be formed to have a seamless and continuous outer surface by extruding molten metal to provide excellent water-proofing performance. Lead or aluminum is used as the metal, and in the case of a power cable (100) laid in the seabed, it is preferable to use lead that has excellent corrosion resistance against seawater, and it is more preferable to use a lead alloy to which a metal element is added to improve mechanical properties.

In addition, the metal sheath (22) is grounded at the end of the power cable (100) and acts as a passage for the accident current to flow in the event of an accident such as a ground fault or short circuit, and can protect the cable from external impact and prevent the electric field from being discharged to the outside of the cable.

In addition, the metal sheath (22) may be coated with a corrosion-preventing compound, such as blown asphalt, on the surface to further improve the corrosion resistance and water resistance of the cable and to improve the adhesion with the polymer sheath (24).

In addition, a copper wire tape or moisture-absorbing layer (21) may be additionally provided between the metal sheath (22) and the cable core portion (10). The copper wire tape is composed of copper wire and a non-woven tape, etc., and functions to facilitate electrical contact between the outer semiconducting layer (16) and the metal sheath (22), and the moisture-absorbing layer (21) is composed in the form of a powder, tape, coating layer, or film containing a super absorbent polymer (SAP) that absorbs moisture that has penetrated into the cable quickly and has an excellent ability to maintain an absorbed state, and functions to prevent moisture from penetrating in the cable length direction. In addition, the copper wire tape and the moisture-absorbing layer (21) preferably have semiconductivity in order to prevent rapid electric field changes, and may be configured by including copper in the moisture-absorbing layer so that both current-conducting and moisture-absorbing functions can be performed.

The above polymer sheath (24) is formed on the outside of the above metal sheath (22) to improve the corrosion resistance and water resistance of the cable and to protect the cable from mechanical trauma and other external environmental factors such as heat and ultraviolet rays. The above polymer sheath (24) can be formed of a resin such as polyvinyl chloride (PVC), polyethylene, etc. In the case of a power cable (100) laid on the seabed, it is preferable to use a polyethylene resin with excellent water resistance, and in an environment where flame retardancy is required, it is preferable to use a polyvinyl chloride resin.

The above power cable (100) is provided with a metal sheath layer (26) made of a zinc-plated steel tape, etc., on the outer side of the polymer sheath (24), so as to prevent the metal sheath (22) from expanding due to the expansion of the insulating oil. In addition, a bedding layer (not shown) made of a semiconductive non-woven tape, etc., to buffer external force applied to the power cable (100) may be provided on the upper and/or lower side of the metal sheath layer (26), and an outer sheath (28) made of a resin, such as polyvinyl chloride or polyethylene, may be further provided to further improve the corrosion resistance, water-proofing properties, etc. of the power cable (100), and to additionally protect the cable from mechanical trauma and other external environmental factors, such as heat and ultraviolet rays.

In addition, submarine power cables laid on the seabed are easily damaged by ship anchors, etc., and can also be damaged by bending force due to ocean currents or waves, friction with the seabed, etc., so to prevent this, a cable outer sheath (not shown) may be additionally provided on the outside of the cable protection section.

Power cables of this type are manufactured in units of a certain length, wound on bobbins, etc., and provided to the installation site, where intermediate connections are made through intermediate connection boxes, or terminal connections are made through terminal connection boxes, thereby constructing a power grid.

Below, the conductor structure of the power cable in the intermediate connection box and terminal connection box is described in detail.

FIG. 2 illustrates one embodiment of a sleeve member (200) provided in a conductor connection structure of a power cable according to the present invention, and FIG. 3 illustrates a cross-sectional view of the sleeve member (200) illustrated in FIG. 2.

In order to connect a power cable, the end of the power cable is stripped so that the conductor and insulator are exposed, and a sleeve member (200) is provided for inserting and connecting the stripped conductor.

There are two methods for connecting conductors of a power cable: a method using a sleeve member (200) and a method of welding two conductors. However, considering workability, etc., a conductor connection structure can be formed by inserting and mounting a pair of conductors (10a, 10b) of a power cable into a sleeve member (200) and compressing the sleeve member (200) to which the conductors are mounted.

The sleeve member (200) may be configured in a pipe shape, and is provided with a connecting portion (210) at both ends that allows conductor insertion in opposite directions. In addition, a partition wall (250) may be provided at the inner center of the sleeve member (200) to determine a conductor insertion position or limit, and the partition wall (250) may be configured to make electrical contact with the cross sections of both conductors to secure a sufficient current conduction path.

The above sleeve member (200) may be composed of copper, copper alloy, tin-plated copper, or tin-plated material having good electrical conductivity.

In addition, the sleeve member (200) constituting the conductor connection structure according to the present invention may be provided with a plurality of fastening holes (230) for fastening a plurality of fixing bolts (330).

The above-described partition wall (250) may be provided in the inner central region of the sleeve member (200), and a plurality of fastening holes (230) into which a plurality of fixing bolts (330) are fastened may be formed dispersedly in a region other than the central region. In addition, the fastening holes (230) formed in the sleeve member (200) may have screw threads formed on the inner surface for fastening the fixing bolts (330).

And, the outer surface of the end of the sleeve member (200) may be provided with a fixing means to which the cover member (50) described later is fitted and fixed, and the fixing means may be a fixing projection formed on the inner surface of both ends of the cover member (50) described later and a fixing groove (215) formed on the outer surface of both ends of the sleeve member (200), and further, as illustrated in FIGS. 2 and 3, the fixing groove (215) as the fixing means may be configured to be continuously formed in the circumferential direction.

Figures 4 and 5 illustrate side views and cross-sectional views of a conductor connection structure (1) according to the present invention.

The present invention provides a conductor connection structure (1) of a power cable for connecting a conductor portion of a power cable having a conductor, an inner semiconductive layer, an insulation layer made of cross-linked polyethylene (XLPE) material, and an outer semiconductive layer, wherein the conductor connection structure (1) of the power cable may include: a pair of conductors (10a, 10b) stripped from a pair of power cables and exposed; a pipe-shaped sleeve member (200) provided with a connection portion (210) into which a pair of conductors (10a, 10b) of the power cables are inserted and a plurality of fastening holes (230) at both ends in the longitudinal direction; a fixing bolt (330) fastened to the fastening holes (230) of the sleeve member (200) to fix the conductors each inserted into the connection portion (210) of the sleeve member (200); and a cover member (50) mounted to close a boundary area between the sleeve member (200) and the insulation layer.

When the conductor connection structure (1) of the power cable according to the present invention is installed in an intermediate connection box, the corona shield installed between the joint sleeve and the conductor connection structure (1) can be omitted.

In a conventional conductor connection structure, a corona shield is mounted to surround the sleeve member (200), and the corona shield is connected to the sleeve member (200) by a metal wire or the like to form an equipotential, and the joint sleeve is mounted to the conductor connection structure (1) so that the corona shield comes into contact with the high-voltage electrode (430) of the joint sleeve.

Accordingly, the finish of the conductor connection structure (1) of the power cable is configured with a corona shield, and the outer diameter of the corona shield and the outer diameter of the insulation layer of the power cable are configured to be the same.

The present invention is a method of connecting a conductor and a sleeve member (200), in which a fixing bolt (330) in the form of a rupture bolt, rather than a compression bolt, is used to plastically deform the conductor and fasten the sleeve member (200), and in order to fasten the fixing bolt (330) and the sleeve member (200) with sufficient fastening force, it is preferable that the thickness of the sleeve member (200) be sufficiently secured. However, in order to mount the corona shield described above, the thickness of the sleeve member (200) needs to be reduced by the thickness of the corona shield having the same outer diameter as the outer diameter of the insulating layer, and therefore, the thickness of the sleeve member (200) fastened to the conductor using a rupture bolt or the like may be insufficient.

Therefore, the present invention does not use a conventional corona shield, but applies a structure in which the sleeve member (200) and the high-voltage electrode of the joint sleeve described below are in direct contact, so that the thickness of the sleeve member (200) is reinforced by the thickness of the corona shield, and when the sleeve member (200) and the conductor are connected using a fixing bolt in the form of a breakable bolt, sufficient fastening force can be provided.

In addition, the above-mentioned fixing bolt (330) is made of brass or brass alloy material and can be used as a current path in a state where fastening is completed.

Since the present invention is configured such that the corona shield is omitted from the conductor connection structure (1) of the power cable and the sleeve member (200) is in direct contact with the joint sleeve described later, as shown in FIG. 4, the outer diameter of the sleeve member (200) of the conductor connection structure (1) of the power cable and the outer diameter of the insulation layer of the power cable can be configured to be the same.

As shown in FIG. 5, the fixing bolt (330) is fastened to the sleeve member (200), penetrates the conductor inside it, plastically deforms the conductor, and firmly fastens the conductor and the sleeve member (200), while forming a current path through the conductor and the sleeve member (200) without removing the wire insulation.

Accordingly, the tensile strength of the conductor connection structure according to the expansion of the conductor can be improved compared to the method of connecting the conductor and the sleeve member by a method such as compression, and the electrical connection performance through the fixing bolt (330) that is connected by digging into the conductor can also be formed, and the work of removing the insulation of the wires that constitute the conductor can also be improved, so the workability of the conductor connection work can be improved.

In this way, the fastening of the conductor and sleeve member (200) is performed through a fixing bolt (330), but it is necessary to prepare for the shrink back phenomenon of the insulation layer of the power cable that occurs when the conductor is energized.

In the case of the corona shield applied in the past, the outer side of the sleeve member of the conductor connection structure was installed and the end of the insulation layer was clamped at the same time, thereby preventing or alleviating the shrinkage phenomenon of the insulation layer. However, since the corona shield is omitted in the present invention, a cover member (50) is applied to the conductor connection structure of the power cable to compensate for this. The cover member (50) closes the boundary area between the sleeve member (200) and the insulation layer, and can be installed while fixing the sleeve member and the insulation layer. The cover member (50) is configured in a pipe shape whose length is smaller than the inner diameter, and fastens the edges of both ends of the insulation layer and the sleeve member (200) together. A detailed description of the cover member (50) will be postponed.

Figures 6 to 11 illustrate the assembly process of the conductor connection structure of the power cable according to the present invention.

As shown in FIGS. 6 and 7, in order to configure a conductor connection structure of a power cable according to the present invention, a pair of conductors (10a, 10b) of a power cable are inserted into the connection portions (210) at both ends of a pipe-shaped sleeve member (200) provided with a plurality of fastening holes (230).

The conductor (10a, 10b) of each power cable can be inserted into the partition wall (250) provided in the central area of the sleeve member (200).

When each conductor (10a, 10b) is completely inserted into the connecting portion (210) of the sleeve member (200), as illustrated in FIG. 8, fixing bolts (330) are installed in all fastening holes (230) formed in the sleeve member (200), and when each fixing bolt (330) is fastened so that the head of the fixing bolt (330) is broken as illustrated in FIG. 9, the lower region of each fixing bolt (330) digs into the conductor of the power cable, plastically deforms the conductor, and becomes integrated with the conductor, and the upper portion is fastened to the sleeve member (200).

As described above, the above-mentioned fixing bolt (330) may be a breakable bolt whose head breaks and separates when a torque greater than a predetermined size is applied.

If the thickness of the sleeve member is insufficient, the lower area of the fixing bolt may dig into the conductor and become integrated, and the upper area may not be supported by the sleeve member, which may cause the sleeve member to be distorted or damaged.

However, since the corona shield is omitted in the present invention, the thickness of the sleeve member (200) can be made relatively thick enough, thereby improving the fastening force between the sleeve member (200) and the conductor.

And, as shown in Fig. 9, when the conductor of the power cable and the sleeve member (200) are completely fastened with the fixing bolt (330), the outer diameter of the insulation layer of the power cable and the sleeve member (200) are configured to be the same, which can facilitate the installation of the joint sleeve, etc. described later.

And, as shown in Fig. 10, when the connection between the conductor and the sleeve member (200) is completed, the boundary area between the sleeve member (200) and the insulation layer of the power cable can be finished with a cover member (50).

As described above, the above cover member (50) can not only simply close the boundary area, but can also provide a function of preventing shrinkage of the insulation layer, etc.

As shown in Fig. 10, the cover member (50) may be configured in a pipe shape with a length smaller than the inner diameter, and the cover member (50) may be configured to be divided into a first cover (50a) and a second cover (50b) so as to be mounted in a state where the connection between the conductor and the sleeve member (200) is completed.

In addition, as shown in Fig. 10, the first cover (50a) and the second cover (50b) can be fastened with a fastening member (53) in an assembled state to maintain the assembled state.

And, as shown in FIGS. 6 to 10, the inner surface of both ends of the cover member (50) and the insulating layer of the power cable and the outer surface of the end of the sleeve member (200) may be provided with a fixing means that is fitted and fixed, and the fixing means are a fixing projection (51) formed on the inner surface of both ends of the cover member (50) and a fixing groove (115, 215) formed on the outer surface of the end of the sleeve member (200), and the fixing projection (51) formed on the inner surface of both ends of the cover member (50) and the insulating layer (14a, 14b) of the power cable and the fixing groove (115, 215) formed on the outer surface of the end of the sleeve member (200) are continuously formed in the circumferential direction, and the cover member (50) that closes the boundary area between the sleeve member (200) and the insulating layer is formed by connecting the insulating layer and the sleeve. Since separation of the absence (200) can be prevented, shrinkage of the insulation layer can be prevented or alleviated.

In addition, when mounting the joint sleeve described later, the outer diameters of the insulating layer (14), the cover member (50), and the sleeve member (200) may be configured to be the same in order to minimize physical interference at the boundary area of the conductor connection structure, and as illustrated in FIG. 11, when the cover member (50) is mounted between the sleeve member (200) and the insulating layer of the power cable, the conductor connection structure of the power cable may be configured in a form in which the protruding or sunken area is minimized.

Figure 12 illustrates a cross-sectional view of an intermediate connection box (200) having a conductor connection structure (1) of a power cable according to the present invention.

The present invention can provide a power cable conductor connection structure (1) as described above; a high-voltage electrode (430) in contact with a sleeve member (200) constituting the conductor connection structure of the power cable, a pair of shielding electrodes (440) in contact with an outer semiconducting layer of the power cable, and a joint sleeve (400) including a sleeve insulation layer (430) that surrounds the high-voltage electrode (430), an insulation layer (14a, 14b) of the power cable, and the shielding electrode (440); and a power cable intermediate connection box (600) including a pair of power cables and a housing (200) that surrounds the joint sleeve.

The power cable connected to the conductor connection structure (1) of the power cable according to the present invention described above may have an insulation layer composed of cross-linked polyethylene (XLPE), etc., and the power cable intermediate connection box according to the present invention may include a joint sleeve (400) that surrounds the conductor connection structure of the power cable.

The above joint sleeve (400) may be composed of an elastic material that can be contracted at room temperature and wraps a pair of power cables (100A, 100B) and the conductor connection structure described above, and may be provided in the form of a pre-molded joint.

The above joint sleeve (400) may be configured to include a high-voltage electrode (430) mounted on the outside of the conductor connection structure and electrically connected to the sleeve member (200), a pair of shielding electrodes (440) in contact with the outer semiconducting layers of the pair of power cables, and a sleeve insulating layer (430) that surrounds the high-voltage electrode (430), the insulating layer of the power cable, and the shielding electrode (440).

The high voltage electrode (430) and shielding electrode (440) constituting the above joint sleeve serve to ensure that the electric field is evenly spread between them rather than being locally concentrated.

In addition, the high-voltage electrode (430) is made of a semiconducting material and is electrically connected to the conductor of the power cable through a sleeve member (200), and the shielding electrode (440) is also made of a semiconducting material and is mounted so as to be connected to the outer semiconducting layer (16a, 16b) of the power cable.

Accordingly, the electric field distribution inside the power cable intermediate connection box is distributed along the area between the high voltage electrode (430) and the shielding electrode (440). In addition, the sleeve insulation layer (430) surrounding the high voltage electrode (430), the insulation layer (14a, 14b) of the power cable, and the shielding electrode (440) is made of an insulating material and comes into contact with the insulation layers (14a, 14b) of the pair of power cables.

The intermediate connection box (600) according to the present invention may be provided with a housing made of a so-called 'coffin box' or 'metal casing' that surrounds the joint sleeve (400), and in this case, the space between the housing (200) and the joint sleeve (400) may be filled with a waterproofing material (not shown) to complete the intermediate connection box.

In this way, according to the conductor connection structure of the power cable and the intermediate connection box having the same according to the present invention, since the conductor of the power cable and the sleeve member are connected by a rupture bolt, the insulation removal process of the insulated wire can be omitted, so the workability of the conductor connection work can be improved, and since the corona shield constituting the conductor connection structure of the power cable does not need to be applied, the thickness of the sleeve member can be sufficiently secured, so that the power cable and the sleeve member can be connected with sufficient fastening force by the fixing bolt, and even if the corona shield constituting the conductor connection structure of the power cable is omitted, the boundary area between the insulation layer of the power cable and the sleeve member can be finished, and a cover member that hooks and fixes the insulation layer of the power cable and the sleeve member can be applied, so that the workability when installing the joint sleeve can be improved, and the effect of preventing or alleviating the phenomenon of shrinkage of the insulation layer that occurs when the conductor of the power cable is energized can be obtained.

Although this specification has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to modify and change the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the claims below. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

100 : Power Cable
200 : Sleeve Absence
10 : Conductor
14 : Insulator
50 : Absence of cover

Claims (13)

The insulation and conductors are stripped and exposed from a pair of power cables;
A pipe-shaped sleeve member having a connecting portion into which a pair of conductors of the power cable are inserted at both ends in the longitudinal direction and a plurality of fastening holes; and,
A fixing bolt fastened to a fastening hole of the sleeve member to fix each conductor inserted into the connecting portion of the sleeve member; and,
It comprises two cover members each arranged on both ends of the sleeve member,
One of the two cover members closes the boundary area between one end of the sleeve member and the insulation of the power cable inserted into one end of the sleeve member,
A power cable system characterized in that the other of the two cover members closes the boundary area between the other end of the sleeve member and the insulation of the power cable inserted into the other end of the sleeve member. In the first paragraph,
A power cable system characterized in that the above cover member is configured in a pipe shape whose length is smaller than its inner diameter. In the first paragraph,
A power cable system, characterized in that the above cover member is divided into a first cover and a second cover. In the third paragraph,
A power cable system characterized in that the first cover and the second cover are fastened with a fastening member in an assembled state. In the first paragraph,
A power cable system characterized in that the inner surface of both ends of the cover member, the insulating layer of the power cable, and the outer surface of the end of the sleeve member are fitted with a fixing means for hooking and fixing. In paragraph 5,
A power cable system characterized in that the above fixing means is a fixing projection formed on the inner surface of both ends of the cover member and a fixing groove formed on the outer surface of the insulating layer of the power cable and the end of the sleeve member. In Article 6,
A power cable system characterized in that the fixing projections formed on the inner surface of both ends of the cover member and the fixing grooves formed on the outer surface of the insulating layer of the power cable and the end of the sleeve member are formed continuously in the circumferential direction. In the first paragraph,
A power cable system, characterized in that the outer diameters of the insulating layer, the cover member, and the sleeve member are the same. In the first paragraph,
A power cable system characterized in that a partition wall is provided in the inner central region of the sleeve member, and a plurality of fastening holes into which a plurality of fixing bolts are fastened are formed dispersedly in an area other than the central region. In the first paragraph,
A power cable system characterized in that the above-mentioned fixing bolt is a breakable bolt whose head breaks and separates when a torque greater than a predetermined size is applied. In the first paragraph,
A power cable system, characterized in that the sleeve member comprises at least one of copper, a copper alloy, tin-plated copper or a tin-plated copper alloy. In the first paragraph,
A power cable system, characterized in that the above fixing bolt comprises at least one of brass or a brass alloy. In the first paragraph,
A joint sleeve including a high voltage electrode contacting the sleeve member, a pair of shielding electrodes contacting the outer semiconducting layer of the power cable, and a sleeve insulating layer surrounding the high voltage electrode, the insulating layer of the power cable, and the shielding electrode; and
A power cable system further comprising: a housing surrounding the pair of power cables and the joint sleeve.