Integral prefabricated intermediate joint for power cables

Abstract

The utility model discloses a kind of integral prefabricated intermediate joints for power cable, it is related to cable accessory technical field, including connecting assembly, insulating cylinder and sheath assembly, connecting assembly is used to electrically connect two cable;Insulating cylinder is sleeved on the outside of connecting assembly, both ends of insulating cylinder are equipped with stress cone, at least one end of insulating cylinder is equipped with annular skirt part, skirt part extends towards the direction away from insulating cylinder, and skirt part surrounds the outside of stress cone;Sheath assembly is sleeved on the outside of insulating cylinder, sheath assembly is used to protect insulating cylinder and connecting assembly.The utility model discloses a kind of integral prefabricated intermediate joints for power cable, can further improve the insulating property of intermediate joint, has better reliability in extra-high voltage working environment.

Description

Technical Field

[0001] This utility model relates to the field of cable accessories technology, and in particular to an integral prefabricated intermediate joint for AC ultra-high voltage, AC extra-high voltage, DC high voltage, and DC extra-high voltage power cables. Background Technology

[0002] With the development of new energy construction, ultra-high voltage power transmission technology has the advantages of low loss and long-distance transmission. However, high-voltage power transmission has extremely stringent requirements for system reliability. During the laying of transmission lines, intermediate joints are used as components to connect two sections of cable, rebuild the cable body structure, and ensure the continuity of the electrical performance of the entire line.

[0003] For ultra-high voltage power transmission, the performance requirements and long-term operational reliability requirements for intermediate joints are extremely high. The ultra-high operating voltage causes the electric field strength inside the joint to reach unprecedented levels. Existing intermediate joint solutions still have the risk of partial discharge and breakdown. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an integral prefabricated intermediate joint for power cables, which can further improve the insulation of the intermediate joint and has better reliability in ultra-high voltage operating environments.

[0005] An integral prefabricated intermediate joint for power cables according to an embodiment of the present utility model includes: a connecting component, the connecting component being used to electrically connect two sections of cable; An insulating cylinder is fitted onto the outside of the connecting assembly. Both ends of the insulating cylinder are provided with stress cones. At least one end of the insulating cylinder is provided with an annular skirt portion. The skirt portion extends in a direction away from the insulating cylinder and surrounds the outside of the stress cone. A protective shell assembly is fitted onto the outside of the insulating cylinder, and the protective shell assembly is used to protect the insulating cylinder and the connecting assembly.

[0006] The prefabricated intermediate joint for power cables according to the present invention has at least the following beneficial effects: the connecting component is used to electrically connect two cable segments to form a conductive path; the insulating cylinder and stress cone are used to restore the insulation of the cable joint and optimize charge accumulation, reducing the risk of electrical breakdown; an annular skirt is provided at the end of the insulating cylinder to further improve the insulation performance near the stress cone and meet the requirements for working in an ultra-high voltage environment; the sheath assembly protects the intermediate joint of the cable.

[0007] According to some embodiments of the present invention, the insulating cylinder is provided with skirt portions at both ends.

[0008] According to some embodiments of the present invention, a shielding tube is provided on the inner side of the insulating cylinder, the shielding tube is fitted onto the outer side of the connecting assembly, and the inner wall of the shielding tube is flush with the inner wall of the insulating cylinder.

[0009] According to some embodiments of this utility model, a semi-conductive tube is fitted on the outer side of the insulating cylinder, and the semi-conductive tube is in contact with the insulating cylinder.

[0010] According to some embodiments of this utility model, the insulating cylinder, the shielding tube, and the semi-conductive tube are prefabricated to form an integral structure.

[0011] According to some embodiments of the present invention, the connecting assembly includes a first connecting tube and an equalizing sleeve. The first connecting tube is used to connect the conductors of two cable segments, and the equalizing sleeve is disposed on the outside of the first connecting tube and wraps around the first connecting tube.

[0012] According to some embodiments of the present invention, the connecting assembly includes a second connecting tube and a semi-conductive tape. The second connecting tube is used to connect the conductors of two cable segments, and the semi-conductive tape is wrapped around the outside of the second connecting tube.

[0013] According to some embodiments of the present invention, the protective shell assembly includes a first metal shell, a second metal shell, and an insulating connector. The first metal shell and the second metal shell are both disposed on the outside of the insulating cylinder. The first metal shell is located at one end of the insulating cylinder, and the second metal shell is located at the other end of the insulating cylinder. The insulating connector is connected between the first metal shell and the second metal shell.

[0014] According to some embodiments of this utility model, both the first metal casing and the second metal casing are provided with grounding posts.

[0015] According to some embodiments of the present invention, a filling cavity for filling insulating and waterproof adhesive is formed between the protective shell assembly and the insulating cylinder.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of the integral prefabricated intermediate joint for power cables according to an embodiment of the present invention; Figure 2This is a partially enlarged structural diagram of an integral prefabricated intermediate joint for power cables according to an embodiment of this utility model; Figure 3 This is a schematic diagram of the structure of the first connecting component according to an embodiment of the present utility model; Figure 4 This is a schematic diagram of the structure of the second type of connecting component in this embodiment of the present utility model.

[0018] Icon labels: The components include: connecting assembly 100, first connecting pipe 110, equalizing sleeve 120, second connecting pipe 130, semi-conductive strip 140, insulating cylinder 200, stress cone 210, skirt 220, shielding pipe fitting 230, semi-conductive pipe fitting 240, protective shell assembly 300, first metal shell 310, second metal shell 320, insulating connector 330, grounding post 340, and filling cavity 350. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0020] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] In the description of this utility model, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or their sequential relationship.

[0022] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0023] Reference Figure 1 and Figure 2 As shown, an embodiment of the present invention provides an integral prefabricated intermediate joint for power cables, comprising a connecting assembly 100, an insulating cylinder 200, and a protective shell assembly 300.

[0024] The connecting assembly 100 is used to electrically connect two cable segments; the insulating cylinder 200 is fitted onto the outside of the connecting assembly 100, and stress cones 210 are provided at both ends of the insulating cylinder 200. At least one end of the insulating cylinder 200 is provided with an annular skirt 220, which extends away from the insulating cylinder 200 and surrounds the outside of the stress cones 210; the protective shell assembly 300 is fitted onto the outside of the insulating cylinder 200 and is used to protect the insulating cylinder 200 and the connecting assembly 100.

[0025] It is important to understand that before connecting cables, end treatment is required, which involves stripping the outer sheath and metal jacket of a certain length to expose a certain length of conductor. The connecting assembly 100 is used to electrically connect the conductor portions of two cable sections, and the connecting assembly 100 can be made of a material with high conductivity.

[0026] The insulating cylinder 200 is used to restore the insulation of the cable joint, while the stress cone 210 is used to improve the electric field distribution and solve the problem of space charge accumulation at the interface of the insulating medium, effectively improving the electric field distribution at the cable break and reducing the risk of electrical breakdown. The stress cone 210 is made of EPDM rubber or silicone rubber and is molded using an injection molding process. In ultra-high voltage operating environments, the electric field strength is greater than that under normal voltage. A skirt 220 is provided at the end of the stress cone 210 to enhance insulation and improve insulation performance. It should be understood that the skirt 220 can be part of the insulating cylinder 200, meaning that the skirt 220 and the insulating cylinder 200 are made of the same material.

[0027] The protective housing assembly 300 is used to protect the insulating cylinder 200 and the connecting assembly 100 from external environmental influences or damage from external stress. Preferably, heat shrink tubing can be further provided on the outside of the protective housing assembly 300.

[0028] In a cable joint, the two cable segments can be distinguished as cable A and cable B. In some embodiments, the cable joint itself has an asymmetrical electrical stress structure; for example, one end of cable A is a shielded connection zone, and the other end of cable B is an insulation protection zone. Grounding is required at the shielded connection zone. Therefore, the insulation performance requirements of the cable joint differ, with higher insulation performance needed in the insulation protection zone. In this embodiment, the insulating cylinder 200 has a skirt 220 at only one end, and this end with the skirt 220 is located on the cable B side, i.e., the insulation protection zone, to provide higher insulation. It should be understood that, in order to facilitate the fabrication of cable joints, the end of the insulating cylinder 200 without the skirt 220 can be inserted towards the end of cable A until the conductor of cable A is exposed from the other end of the insulating cylinder 200. Then, the conductors of cable A and cable B are electrically connected using the connecting assembly 100. Next, the end of the insulating cylinder 200 with the skirt 220 is moved towards cable B so that the stress cones 210 at both ends of the insulating cylinder 200 are in the set position, that is, the stress cones 210 are located at the cable insulation shield break.

[0029] Understandably, both ends of the insulating cylinder 200 are provided with skirts 220, providing symmetrical insulation protection for both ends of the cable joint. This structure is suitable for environments with uncertain conditions. Because the structure at both ends of the insulating cylinder 200 is symmetrical, the creepage distance at both ends is the same, eliminating the need to distinguish directions during installation and simplifying the operation for installers.

[0030] In embodiments where skirts 220 are provided at both ends of the insulating cylinder 200, even if the cable joint is in a direct-buried or long-term immersion environment, causing moisture to enter the joint body, the skirts 220 at both ends of the insulating cylinder 200 can still form good insulation isolation for the metal sheaths of the cables on both sides, and have stronger adaptability.

[0031] Understandably, the inner side of the insulating cylinder 200 is provided with a shielding tube 230, which is fitted onto the outer side of the connecting assembly 100, with the inner wall of the shielding tube 230 flush with the inner wall of the insulating cylinder 200. The shielding tube 230 is used to shield the electric field at the connecting assembly 100.

[0032] Understandably, a semi-conductive tube 240 is fitted onto the outside of the insulating cylinder 200, and the semi-conductive tube 240 is in contact with the insulating cylinder 200. The semi-conductive tube 240 is used to prevent partial discharge caused by defects such as cracks on the surface of the insulating cylinder 200, thereby further enhancing the shielding effect.

[0033] It is understandable that the insulating cylinder 200, shielding pipe 230, and semi-conductive pipe 240 are prefabricated into an integral structure, which facilitates transportation and on-site installation, improving installation efficiency. It should be understood that the insulating cylinder 200, shielding pipe 230, and semi-conductive pipe 240 can be formed into an integral structure through injection molding.

[0034] Reference Figure 3 As shown, it can be understood that the connection assembly 100 includes a first connecting tube 110 and an equalizing sleeve 120. The first connecting tube 110 is used to connect the conductors of two cable segments, and the equalizing sleeve 120 is disposed on the outside of the first connecting tube 110 and wraps around the first connecting tube 110.

[0035] Furthermore, the first connecting tube 110 is fitted onto the conductors of the two cable sections, then a copper braided wire is inserted, and a suitable crimping die is used to crimp them. Finally, the equalizing sleeve 120 is fitted onto the first connecting tube 110, and the equalizing sleeve 120 protects the cable conductors.

[0036] Reference Figure 4 As shown, it can be understood that the connecting assembly 100 includes a second connecting tube 130 and a semi-conductive tape 140. The second connecting tube 130 is used to connect the conductors of two cable segments, and the semi-conductive tape 140 is wrapped around the outside of the second connecting tube 130.

[0037] Similarly, the second connecting tube 130 is fitted onto the conductors of the two cable segments, then a copper braided wire is inserted, and a suitable die is used to press it together. Finally, the semi-conductive tape 140 is wrapped around the second connecting tube 130 to enclose it.

[0038] It is understood that the protective shell assembly 300 includes a first metal shell 310, a second metal shell 320, and an insulating connector 330. The first metal shell 310 and the second metal shell 320 are both disposed on the outside of the insulating cylinder 200. The first metal shell 310 is located at one end of the insulating cylinder 200, the second metal shell 320 is located at the other end of the insulating cylinder 200, and the insulating connector 330 is connected between the first metal shell 310 and the second metal shell 320.

[0039] Preferably, both the first metal housing 310 and the second metal housing 320 use copper protective shells, and the insulating connector 330 uses an epoxy insulating ring made of glass fiber impregnated with epoxy resin. The first metal housing 310 and the second metal housing 320 are connected as a whole structure by the epoxy insulating ring.

[0040] It is understandable that both the first metal casing 310 and the second metal casing 320 are equipped with grounding posts 340. Grounding cables are led out from the grounding posts 340 to complete grounding protection.

[0041] Understandably, a filling cavity 350 for filling with insulating and waterproof adhesive is formed between the protective housing assembly 300 and the insulating cylinder 200. The filling cavity 350 is filled with insulating and waterproof adhesive to isolate and fix the protective housing assembly 300 and the insulating cylinder 200.

[0042] In some embodiments, the two cable segments are still divided into cable A and cable B. The splicing point of the intermediate joint is determined, and cable A and cable B are marked respectively. A certain length of cable is left from the marked point to the end of the cable, and the excess cable is cut off. Then, the ends of the cable outer sheath and metal sheath are determined, and the corresponding length of the outer sheath and metal sheath are stripped off. The cable is then heated and straightened. A certain length of cable is measured from the end, and the cable insulation layer and shielding layer are stripped off to expose a certain length of conductor. After appropriate surface treatment, the intermediate joint is prepared. The first metal shell 310 and the second metal shell 320 are respectively fitted onto cable A and cable B. It should be understood that in this embodiment, the first metal shell 310 is fitted onto cable A, and the second metal shell 320 is fitted onto cable B. The corresponding number of heat shrink tubing are fitted simultaneously. After cleaning and drying the insulating cylinder 200, silicone oil is applied to the inside of the insulating cylinder 200, and then the insulating cylinder 200 is fitted onto cable A. After connecting the conductors of cables A and B using the connecting assembly 100, the insulating cylinder 200 is moved towards cable B and inserted until it completely wraps around the connecting assembly 100. Wrapping tape is then placed at the corresponding positions. Next, the first metal housing 310 and the second metal housing 320 are moved closer together and connected and fixed using the insulating connector 330. It should be understood that before fixing, insulating and waterproof adhesive is filled into the filling cavity 350.

[0043] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A prefabricated integral intermediate joint for power cables, characterized in that, include: A connecting assembly for electrically connecting two cable segments; An insulating cylinder is fitted onto the outside of the connecting assembly. Both ends of the insulating cylinder are provided with stress cones. At least one end of the insulating cylinder is provided with an annular skirt portion. The skirt portion extends in a direction away from the insulating cylinder and surrounds the outside of the stress cone. A protective shell assembly is fitted onto the outside of the insulating cylinder, and the protective shell assembly is used to protect the insulating cylinder and the connecting assembly.

2. The integral prefabricated intermediate joint for power cables according to claim 1, characterized in that, Both ends of the insulating cylinder are provided with the skirt portion.

3. The integral prefabricated intermediate joint for power cables according to claim 1, characterized in that, The inner side of the insulating cylinder is provided with a shielding tube, which is fitted onto the outer side of the connecting assembly. The inner wall of the shielding tube is flush with the inner wall of the insulating cylinder.

4. The integral prefabricated intermediate joint for power cables according to claim 3, characterized in that, A semi-conductive tubing is fitted onto the outer side of the insulating cylinder, and the semi-conductive tubing is in contact with the insulating cylinder.

5. The integral prefabricated intermediate joint for power cables according to claim 4, characterized in that, The insulating cylinder, the shielding tube, and the semi-conductive tube are prefabricated to form an integral structure.

6. The integral prefabricated intermediate joint for power cables according to claim 1, characterized in that, The connection assembly includes a first connecting tube and an equalizing sleeve. The first connecting tube is used to connect the conductors of two cable segments, and the equalizing sleeve is disposed on the outside of the first connecting tube and wraps around the first connecting tube.

7. The integral prefabricated intermediate joint for power cables according to claim 1, characterized in that, The connecting assembly includes a second connecting tube and a semi-conductive tape. The second connecting tube is used to connect the conductors of two cable segments, and the semi-conductive tape is wrapped around the outside of the second connecting tube.

8. The integral prefabricated intermediate joint for power cables according to claim 1, characterized in that, The protective shell assembly includes a first metal shell, a second metal shell, and an insulating connector. The first metal shell and the second metal shell are both disposed on the outside of the insulating cylinder. The first metal shell is located at one end of the insulating cylinder, and the second metal shell is located at the other end of the insulating cylinder. The insulating connector is connected between the first metal shell and the second metal shell.

9. The integral prefabricated intermediate joint for power cables according to claim 8, characterized in that, Both the first metal casing and the second metal casing are provided with grounding posts.

10. The integral prefabricated intermediate joint for power cables according to claim 1, characterized in that, A filling cavity for filling with insulating and waterproof adhesive is formed between the protective shell assembly and the insulating cylinder.

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