High-voltage cable connection method

Abstract

The present invention relates to a method for connecting high-voltage cables. The connection part of the conductor cores is fixed and electrically connects the left conductor core and the right conductor core; the heat-shrinkable semi-conductor inner tube is fixedly and hermetically connected to the left semi-conductor layer A and the right semi-conductor layer A, and the heat-shrinkable semi-conductor outer tube is fixedly and hermetically connected to the left semi-conductor layer B and the right semi-conductor layer B; insulating tape is used to insulate and isolate the heat-shrinkable semi-conductor inner tube and the heat-shrinkable semi-conductor outer tube; the tensile-resistant device is fixedly connected to the left copper tape shielding layer and the right copper tape shielding layer. The method of the present invention can improve the waterproof effect of the connection part of the high-voltage cable.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage cable connection, and specifically relates to a high-voltage cable connection method. Background Art

[0002] A high-voltage cable is a type of power cable, which refers to a power cable used for transmitting electricity between 1 kV and 1000 kV, and is mostly applied to power transmission and distribution. Figure 1 The cross-sectional schematic diagram of a high-voltage cable is shown. In the figure, 11 is the conductor core, 12 is the semiconductor layer, 13 is the insulating layer, 14 is the semiconductor layer, 15 is the copper tape shielding layer, 16 is the inner plastic layer, 17 is the armor layer, and 18 is the outer plastic layer.

[0003] Cable joints can be divided into indoor type and outdoor type according to the installation site. According to the production and installation materials, they can be divided into heat-shrinkable type, dry-pack type, epoxy resin casting type, and cold-shrinkable type. According to the core material, they can be divided into copper-core power cable joints and aluminum-core power cable joints. According to the joint material, they can be divided into plastic cable joints and metal cable joints. Metal cable joints are further divided into porous metal cable waterproof joints, anti-bending metal cable joints, double-lock metal cable waterproof joints, plastic hose cable joints, metal hose cable joints, etc.

[0004] The main reasons for moisture to enter the cable intermediate joint include two aspects: one is to enter the inside of the intermediate joint from the insulation shield fracture; the other is to penetrate from the inside of the core to the surface of the insulating layer at the connection pipe, and finally develop into surface dendritic tracking. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-voltage cable connection method to improve the waterproof effect of the high-voltage cable connection part.

[0006] The technical solution of the present invention is as follows:

[0007] A high-voltage cable connection method includes the following steps:

[0008] Process the left cable end and the right cable end so that the copper tape shielding layer, semiconductor layer B, insulating layer, semiconductor layer A, and conductor core of the left cable end and the right cable end form an annular step, mold the conductor cores of the left cable end and the right cable end, and sleeve the heat-shrinkable semi-conductor inner tube and the heat-shrinkable semi-conductor outer tube on the left cable;

[0009] Insert the conductor cores of the left cable end and the right cable end into the connection pipe, and crimp and connect the connection pipe and the conductor core of the left cable end, and crimp and connect the connection pipe and the conductor core of the right cable end;

[0010] Apply conductive grease on the conductor cores of the left cable end, the connection pipe, and the conductor cores of the right cable end. Move the heat-shrinkable semi-conductive inner tube so that the left end of the heat-shrinkable semi-conductive inner tube coincides with the semi-conductor layer A of the left cable end, and the right end of the heat-shrinkable semi-conductive inner tube coincides with the semi-conductor layer A of the right cable end. Heat the heat-shrinkable semi-conductive inner tube so that the left end of the heat-shrinkable semi-conductive inner tube is hermetically connected to the right end of the semi-conductor layer A of the left cable end, and the right end of the heat-shrinkable semi-conductive inner tube is hermetically connected to the left end of the semi-conductor layer A of the right cable end;

[0011] Wind insulating tape around the outside of the heat-shrinkable semi-conductive inner tube so that the left end of the insulating tape is fixedly connected to the semi-conductor layer A of the left cable end, and the right end of the insulating tape is fixedly connected to the semi-conductor layer A of the right cable end;

[0012] Move the heat-shrinkable semi-conductive outer tube so that the left end of the heat-shrinkable semi-conductive outer tube coincides with the semi-conductor layer B of the left cable end, and the right end of the heat-shrinkable semi-conductive outer tube coincides with the semi-conductor layer B of the right cable end. Heat the heat-shrinkable semi-conductive outer tube so that the left end of the heat-shrinkable semi-conductive outer tube is hermetically connected to the right end of the semi-conductor layer B of the left cable end, and the right end of the heat-shrinkable semi-conductive outer tube is hermetically connected to the left end of the semi-conductor layer B of the right cable end;

[0013] Use a tensile resistance device to fixedly connect the left copper tape shielding layer and the right copper tape shielding layer.

[0014] Preferably, after applying conductive grease on the conductor cores of the left cable end, the connection pipe, and the conductor cores of the right cable end, wind the connection pipe with a conductive plate, and make the left end of the conductive plate electrically connected to the undeformed section of the conductor core of the left cable end, and the right end of the conductive plate electrically connected to the undeformed section of the conductor core of the right cable end. Constrain the movable end of the conductive plate, and then fixedly connect the heat-shrinkable semi-conductive inner tube, the semi-conductor layer A of the left cable end, and the semi-conductor layer A of the right cable end.

[0015] Preferably, tensile resistance ribs are arranged on the side of the cable. Use one fixed clamp to fixedly connect the tensile resistance ribs and the left copper tape shielding layer, and use another fixed clamp to fixedly connect the tensile resistance ribs and the right copper tape shielding layer.

[0016] More preferably, there are at least three tensile resistance ribs, and at least three tensile resistance ribs are evenly distributed on the side of the cable.

[0017] More preferably, the tensile resistance ribs are tubular ribs.

[0018] The beneficial effects of the present invention are:

[0019] 1. The wire core connection part is fixed and electrically connects the left wire core and the right wire core, which can achieve the electrical connection between the left wire core and the right wire core, and avoid electric sparks caused by the loosening of the left wire core and the connection part, or electric sparks caused by the loosening of the right wire core and the connection part; the heat-shrinkable semi-conductor inner tube is fixedly and hermetically connected to the left semi-conductor layer A and the right semi-conductor layer A, so that moisture at the wire core can be isolated from entering the insulating layer through the connection, and the heat-shrinkable semi-conductor outer tube is fixedly and hermetically connected to the left semi-conductor layer B and the right semi-conductor layer B, so that moisture outside the cable can be isolated from entering the insulating layer through the connection, and the waterproof effect is good; the insulating layer insulates the heat-shrinkable semi-conductor inner tube and the heat-shrinkable semi-conductor outer tube, which can improve the safety of the cable. In addition to the insulating effect, the insulating tape also has an adhesive effect; the tensile resistance device is fixedly connected to the left copper tape shielding layer and the right copper tape shielding layer, which can improve the tensile resistance of the cable joint. In summary, the connection quality of the waterproof connection part of the high-voltage cable of the present invention is high and the waterproof performance is good. The insulating tape for high-voltage cables is a special tape. When in use, it is not spirally wound on the surface of the conductor, but wound and pasted on the surface of the conductor.

[0020] 2. When crimping and connecting the connecting pipe, the left wire core and the right wire core, the outer diameter at the wire connection changes, affecting the resistance at the connection. After the conductive plate is coated and connected to the left wire core, the connecting pipe and the right wire core, due to the skin effect of alternating current, the conductive plate acts as a conductor, and the resistance at its connection is smaller than that at the wire core, and the heat generation is small. After the conductive grease fills the gaps between the conductive pipe, the left wire core, the connecting pipe and the right wire core, the conductive pipe, the left wire core, the connecting pipe and the right wire core form an integral conductive body, avoiding the accumulation of moisture in the wire core in the gap. Description of the Drawings

[0021] Figure 1 It is a cross-sectional schematic diagram of a high-voltage cable in the prior art.

[0022] Figure 2 It is a longitudinal sectional view of the waterproof connection part of the high-voltage cable of the present invention.

[0023] Description of the reference numerals: 11 - wire core, 12 - semi-conductor layer A, 13 - insulating layer, 14 - semi-conductor layer B, 15 - copper tape shielding layer, 16 - inner plastic layer, 17 - armor layer, 18 - outer plastic layer, 21 - left wire core, 22 - left semi-conductor layer A, 23 - left insulating layer, 24 - left semi-conductor layer B, 25 - left copper tape shielding layer, 31 - right wire core, 32 - right semi-conductor layer A, 33 - right insulating layer, 34 - right semi-conductor layer B, 35 - right copper tape shielding layer, 41 - connecting pipe, 42 - conductive grease, 43 - conductive pipe, 44 - heat-shrinkable semi-conductor inner tube, 45 - fixing ring, 46 - insulating layer, 47 - heat-shrinkable semi-conductor outer tube, 48 - heat-shrinkable tube, 49 - tensile resistance rib, 50 - fixing clamping ring. Detailed Embodiments

[0024] The present invention will be described below in the form of embodiments with reference to the accompanying drawings to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise specified, the following embodiments and the technical terms therein should be understood without departing from the technical knowledge background of the technical field.

[0025] The material of the semiconductor tube can be made from polyethylene copolymer resin, acetylene carbon black, and peroxide.

[0026] Embodiment 1: A method for connecting high-voltage cables, comprising the following steps:

[0027] Process the left cable end and the right cable end so that the left copper tape shielding layer 25, left semiconductor layer B24, insulating layer 23, left semiconductor layer A22, and left wire core 21 of the left cable end form an annular step, and the right copper tape shielding layer 35, right semiconductor layer B34, insulating layer 33, right semiconductor layer A32, and right wire core 31 of the right cable end form an annular step, and mold the ends of the left wire core 21 and the right wire core 31;

[0028] Sheath the heat-shrinkable semi-conductor inner tube 44 and the heat-shrinkable semi-conductor outer tube 46 on the left cable; in other embodiments, the heat-shrinkable semi-conductor inner tube 44 and the heat-shrinkable semi-conductor outer tube 46 can also be sheathed on the right cable; or, one is sheathed on the left cable and the other is sheathed on the right cable.

[0029] Insert the left wire core 21 and the right wire core 31 into the connecting tube 41, press-connect the connecting tube 41 and the left wire core 21, and press-connect the connecting tube 41 and the right wire core 31;

[0030] Apply conductive grease 42 on the left wire core 21, connecting tube 41, and right wire core 31, move the heat-shrinkable semi-conductor inner tube 44 so that the left end of the heat-shrinkable semi-conductor inner tube 44 coincides with the left semiconductor layer A22, the right end of the heat-shrinkable semi-conductor inner tube 44 coincides with the right semiconductor layer A32, heat the heat-shrinkable semi-conductor inner tube 44 so that the left end of the heat-shrinkable semi-conductor inner tube 44 is hermetically connected to the right end of the left semiconductor layer A22, and the right end of the heat-shrinkable semi-conductor inner tube 44 is hermetically connected to the left end of the right semiconductor layer A32;

[0031] Wind insulating tape around the heat-shrinkable semi-conductor inner tube 44 so that the left end of the insulating tape is fixedly connected to the left semiconductor layer A22, and the right end of the insulating tape is fixedly connected to the right semiconductor layer A32;

[0032] Move the heat-shrinkable semi-conductor outer tube 47 so that the left end of the heat-shrinkable semi-conductor outer tube 47 coincides with the left semiconductor layer B24, the right end of the heat-shrinkable semi-conductor outer tube 47 coincides with the right semiconductor layer B34, heat the heat-shrinkable semi-conductor outer tube 47 so that the left end of the heat-shrinkable semi-conductor outer tube 47 is hermetically connected to the right end of the left semiconductor layer B24, and the right end of the heat-shrinkable semi-conductor outer tube 47 is hermetically connected to the left end of the right semiconductor layer B34;

[0033] Use a tensile-resistant device to fixedly connect the left copper tape shielding layer 25 and the right copper tape shielding layer 35.

[0034] In this embodiment, after applying conductive grease 42 on the left wire core 21, the connecting pipe 41, and the right wire core 31, use a conductive plate to wind around the connecting pipe 41, and electrically connect the left end of the conductive plate to the undeformed section of the left wire core 21, and the right end of the conductive plate to the undeformed section of the right wire core 31. Restrain the movable end of the conductive plate, and then fixedly connect the heat-shrinkable semi-conductive inner tube 44, the left semi-conductive layer A22, and the right semi-conductive layer A32. The ways to restrain the movable end of the conductive plate include bonding, tying, etc.

[0035] In this embodiment, a tensile-resistant rib 49 is provided on the side of the cable. Use a fixing clamp 50 to fixedly connect the tensile-resistant rib 49 and the left copper tape shielding layer 25, and use another fixing clamp 50 to fixedly connect the tensile-resistant rib 49 and the right copper tape shielding layer 35. In this embodiment, the tensile-resistant rib 49 is a tubular rib. In other embodiments, there are at least three tensile-resistant ribs 49, and at least three tensile-resistant ribs 49 are evenly distributed on the side of the cable.

[0036] Embodiment 2: A waterproof joint for a high-voltage cable, comprising a wire core connecting part, a heat-shrinkable semi-conductive inner tube, a heat-shrinkable semi-conductive outer tube, an insulating layer, and a tensile-resistant device.

[0037] The wire core connecting part is used to fixedly and electrically connect the left wire core and the right wire core. In this embodiment, referring to Figure 2 , the wire core connecting part includes a connecting pipe 41 and a conductive pipe 43. The connecting pipe 41 is used for crimping connection with the left wire core 21 and the right wire core 31, and the conductive pipe 43 is used for electrically connecting the left wire core 21 and the right wire core 22. Conductive grease 42 is provided between the conductive pipe 43, the left wire core 21, the connecting pipe, and the right wire core 31. In this embodiment, the conductive pipe 43 can be formed by winding a thin plate. Since when crimping and connecting the left wire core 21, the connecting pipe 41, and the right wire core 31, it will cause the left wire core 21 and the right wire core 31 to have a reduced-diameter section. Therefore, the left end of the conductive pipe 43 is electrically connected to the non-reduced-diameter section of the left wire core 21, and the right end of the conductive pipe 43 is electrically connected to the non-reduced-diameter section of the right wire core 31. In this way, when an alternating current passes through the wire core, due to the skin effect of the charge, the conductive pipe 43 forms a conductive part at the reduced-diameter section of the left wire core 21, a conductive part at the connecting pipe 41, and a conductive part at the reduced-diameter section of the right wire core 31. Its cross-section is larger than the cross-section of the left wire core and larger than the cross-section of the right wire core, so its resistance is the smallest and the heat generation is small.

[0038] The heat-shrinkable semi-conductive inner tube 44 is used to fixedly and sealingly connect the left semi-conductive layer A22 and the right semi-conductive layer A32. In this way, moisture at the wire core can be prevented from entering the insulating layer. After the heat-shrinkable semi-conductive inner tube 44 shrinks, its left end head is adhesively connected to the left semi-conductive layer A22, thus being able to fixedly and sealingly connect the joint between the heat-shrinkable semi-conductive inner tube 44 and the left semi-conductive layer A22. Its right end head is adhesively connected to the right semi-conductive layer A32, thus being able to fixedly and sealingly connect the joint between the heat-shrinkable semi-conductive inner tube 44 and the right semi-conductive layer A32.

[0039] The heat-shrinkable semi-conductive outer tube 47 is used to fixedly and sealingly connect the left semi-conductive layer B24 and the right semi-conductive layer B34. In this way, moisture outside the cable can be prevented from entering the insulating layer. After the heat-shrinkable semi-conductive outer tube 47 shrinks, its left end head is adhesively connected to the left semi-conductive layer B24, thus being able to fixedly and sealingly connect the joint between the heat-shrinkable semi-conductive outer tube 47 and the left semi-conductive layer B24. Its right end head is adhesively connected to the right semi-conductive layer B34, thus being able to fixedly and sealingly connect the joint between the heat-shrinkable semi-conductive outer tube 47 and the right semi-conductive layer B34.

[0040] The insulating layer 46 is used for insulating and isolating the heat-shrinkable semi-conductive inner tube 44 and the heat-shrinkable semi-conductive outer tube 47. In this embodiment, the insulating layer is an insulating tape wound around the heat-shrinkable semi-conductive inner tube 44. The left side of the insulating tape is adhesively connected to the left semi-conductive layer A22, and the right side of the insulating tape is adhesively connected to the right semi-conductive layer A32.

[0041] The tensile resistance device is used to fixedly connect the left copper tape shielding layer 25 and the right copper tape shielding layer 35. In this embodiment, the tensile resistance device includes a tensile resistance rib 49 and two fixing hoops 50. One of the fixing hoops 50 fixedly connects the tensile resistance rib 49 and the left copper tape shielding layer 25, and the other fixing hoop 50 fixedly connects the tensile resistance rib 49 and the right copper tape shielding layer 35.

[0042] In this embodiment, a heat-shrinkable tube 48 is further provided between the heat-shrinkable semi-conductive outer tube 47 and the tensile resistance device.

[0043] Embodiment 3: A high-voltage cable waterproof joint of the present invention forms a high-voltage cable after connecting a left cable section and a right cable section. See Figure 2, a high-voltage cable includes a left cable section, a right cable section, and the aforementioned high-voltage cable waterproof connection part. The left cable section includes a left conductor core 21, a left semiconductor layer A 22, a left insulating layer 23, a left semiconductor layer B 24, and a left copper tape shielding layer 25. The right cable section includes a right conductor core 31, a right semiconductor layer A 32, a right insulating layer 33, a right semiconductor layer B 34, and a right copper tape shielding layer 35. The conductor core connection part fixedly and electrically connects the left conductor core 21 and the right conductor core 31. The heat-shrinkable semi-conductor inner tube 44 is fixedly and hermetically connected to the left semiconductor layer A 22 and the right semiconductor layer A 32. The insulating layer 46 insulates and isolates the heat-shrinkable semi-conductor inner tube 44 and the heat-shrinkable semi-conductor outer tube 47. The heat-shrinkable semi-conductor outer tube 47 is fixedly and hermetically connected to the left semiconductor layer B 24 and the right semiconductor layer B 34. The tensile resistance device is fixedly connected to the left copper tape shielding layer 25 and the right copper tape shielding layer 35.

[0044] The present invention has been described in detail above in conjunction with the drawings and embodiments. It should be understood that it is impossible to exhaustively illustrate all possible implementation manners in practice. Here, the inventive concept of the present invention is elaborated as much as possible by way of examples. Without departing from the inventive concept of the present invention and without creative efforts, those skilled in the art in this technical field make combinations of the technical features in the above embodiments, make experimental changes to the specific parameters, or make conventional replacements of the disclosed technical means of the present invention with the existing technologies in this technical field to form specific embodiments, which should all belong to the content implicitly disclosed by the present invention.

Claims

1. A method for connecting high-voltage cables, characterized in that, it includes the following steps: Process the left cable end and the right cable end so that the copper tape shielding layer, semiconductor layer B, insulating layer, semiconductor layer A, and wire core of the left cable end and the right cable end form an annular step, mold the wire cores of the left cable end and the right cable end, and sleevethe heat-shrinkable semi-conductor inner tube and the heat-shrinkable semi-conductor outer tube on the left cable; Insert the wire cores of the left cable end and the right cable end into the connecting tube, crimp and connect the connecting tube to the wire core of the left cable end, and crimp and connect the connecting tube to the wire core of the right cable end; Apply conductive grease on the wire cores of the left cable end, the connecting tube, and the wire core of the right cable end, move the heat-shrinkable semi-conductor inner tube so that the left end of the heat-shrinkable semi-conductor inner tube coincides with the semiconductor layer A of the left cable end, and the right end of the heat-shrinkable semi-conductor inner tube coincides with the semiconductor layer A of the right cable end, heat the heat-shrinkable semi-conductor inner tube so that the left end of the heat-shrinkable semi-conductor inner tube is hermetically connected to the right end of the semiconductor layer A of the left cable end, and the right end of the heat-shrinkable semi-conductor inner tube is hermetically connected to the left end of the semiconductor layer A of the right cable end; Wind insulating tape outside the heat-shrinkable semi-conductor inner tube so that the left end of the insulating tape is fixedly connected to the semiconductor layer A of the left cable end, and the right end of the insulating tape is fixedly connected to the semiconductor layer A of the right cable end; Move the heat-shrinkable semi-conductor outer tube so that the left end of the heat-shrinkable semi-conductor outer tube coincides with the semiconductor layer B of the left cable end, and the right end of the heat-shrinkable semi-conductor outer tube coincides with the semiconductor layer B of the right cable end, heat the heat-shrinkable semi-conductor outer tube so that the left end of the heat-shrinkable semi-conductor outer tube is hermetically connected to the right end of the semiconductor layer B of the left cable end, and the right end of the heat-shrinkable semi-conductor outer tube is hermetically connected to the left end of the semiconductor layer B of the right cable end; Use a tensile-resistant device to fixedly connect the left copper tape shielding layer and the right copper tape shielding layer.

2. The method for connecting high-voltage cables according to claim 1, characterized in that, After applying conductive grease on the wire cores of the left cable end, the connecting tube, and the wire core of the right cable end, use a conductive plate to wind around the connecting tube, and make the left end of the conductive plate electrically connected to the undeformed section of the wire core of the left cable end, and the right end of the conductive plate electrically connected to the undeformed section of the wire core of the right cable end, restrain the movable end of the conductive plate, and then fixedly connect the heat-shrinkable semi-conductor inner tube, the semiconductor layer A of the left cable end, and the semiconductor layer A of the right cable end.

3. The method for connecting high-voltage cables according to claim 1, characterized in that, A tensile-resistant rib is arranged on the side of the cable, use a fixed clamping ring to fixedly connect the tensile-resistant rib and the left copper tape shielding layer, and use another fixed clamping ring to fixedly connect the tensile-resistant rib and the right copper tape shielding layer.

4. The method for connecting high-voltage cables according to claim 3, characterized in that, There are at least three tensile-resistant ribs, and at least three tensile-resistant ribs are evenly distributed on the side of the cable.

5. The method for connecting high-voltage cables according to claim 3, characterized in that, The tensile-resistant rib is a tubular rib.

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