Pre-dilation cable termination

Abstract

The utility model provides a kind of pre-expansion cable terminal.In one embodiment, the pre-expansion cable terminal includes: stress cone and umbrella skirt assembly, one end of stress cone is equipped with semiconductive conical structure, umbrella skirt assembly is arranged around stress cone.The stress cone and the umbrella skirt assembly are independent components of each other, and the stress cone and the umbrella skirt assembly are assembled together.The umbrella skirt assembly includes a plurality of umbrella skirt elements, each umbrella skirt element has a central opening, the stress cone is assembled with the umbrella skirt element in a manner that passes through the central opening of the umbrella skirt element, wherein the initial aperture of the central opening is smaller than the initial diameter of the stress cone.

Description

Technical Field

[0001] This utility model relates to the field of power equipment technology, and in particular to a pre-expanded cable terminal. Background Technology

[0002] Cable terminations are crucial components in power systems, connecting cables to other electrical equipment and playing a vital role in power transmission and distribution. Their main functions include providing electrical connection between cables and equipment, controlling electric field distribution to prevent partial discharge, providing mechanical support, and offering environmental protection. Traditional cable terminations typically employ an integrated structure of stress cones and shed assemblies. The stress cone controls the electric field distribution at the cable termination, preventing insulation breakdown caused by electric field concentration. The shed assembly provides external insulation and protection against flashover. With increasingly stringent reliability requirements in power systems (e.g., high-altitude power systems), there is an urgent need to develop a new cable termination technology that is simple in structure, low in manufacturing cost, easy to maintain, and highly flexible in production to meet the development needs of power systems in high-altitude areas. Utility Model Content

[0003] The purpose of this utility model is to solve at least one aspect of the aforementioned problems and defects existing in the prior art.

[0004] According to one aspect of the present invention, a pre-expanded cable terminal is provided, comprising: a stress cone having a semi-conductive conical structure at one end; and a skirt assembly arranged around the stress cone; wherein the stress cone and the skirt assembly are independent components, and the stress cone and the skirt assembly are assembled together; and the skirt assembly includes a plurality of skirt elements, each skirt element having a central opening, the stress cone being assembled with the skirt element through the central opening of the skirt element, wherein the initial aperture of the central opening is smaller than the initial diameter of the stress cone.

[0005] In an exemplary embodiment of this invention, each skirt element is a component independent of the stress cone and the other skirt elements, and each skirt element is assembled with the stress cone; each skirt element includes a first end and a second end with opposite ends, the first end having an annular stepped portion and the second end having an annular receiving portion; wherein the annular stepped portion of each skirt element is fitted into the annular receiving portion of another skirt element adjacent to it in an interference fit; wherein the edges of the annular stepped portion and / or the edges of the annular receiving portion of each skirt element are rounded. Preferably, the interference fit is between approximately 5% and 8%.

[0006] In an exemplary embodiment of the present invention, the ratio of the spacing between each skirt element and another skirt element adjacent to it to the outermost diameter of the skirt element is approximately in the range of 1.0 to 1.1; and the semi-conductive conical structure is flared, the skirt assembly includes an end-side skirt element, the end-side skirt element being positioned closest to the end of the stress cone where the semi-conductive conical structure is located, wherein the distance between the first end of the end-side skirt element and the maximum outer diameter portion of the semi-conductive conical structure in the axial direction of the stress cone is approximately between 10 mm and 20 mm.

[0007] In an exemplary embodiment of the present invention, the stress cone and each skirt element in the skirt assembly are assembled together with an interference fit. Preferably, the interference fit between the stress cone and each skirt element in the skirt assembly is greater than about 5%.

[0008] In one exemplary embodiment of the present invention, the interference between the stress cone and each skirt element in the skirt assembly is approximately between 8% and 20%.

[0009] In an exemplary embodiment of the present invention, the stress cone and each skirt element in the skirt assembly are formed integrally by an expansion process.

[0010] In one exemplary embodiment of the present invention, the stress cone and each skirt element in the skirt assembly are made of the same material.

[0011] In one exemplary embodiment of the present invention, the stress cone and each skirt element in the skirt assembly are made of silicone rubber.

[0012] In an exemplary embodiment of the present invention, the umbrella skirt assembly is assembled to the stress cone by a cold shrinking process.

[0013] In an exemplary embodiment of this utility model, the pre-expanded cable terminal is a 6kV-110kV cable terminal.

[0014] The pre-expanded cable terminal provided according to the foregoing embodiments of this utility model has achieved at least the following technical effects.

[0015] 1. The separate design of the stress cone and the umbrella skirt assembly simplifies the manufacturing process and reduces production costs.

[0016] 2. The pre-expansion assembly method ensures good sealing and electrical performance.

[0017] 3. The modular design facilitates maintenance and replacement, improving the product's usability.

[0018] 4. The interference fit design ensures the reliability and long-term stability of the assembly between the stress cone and the skirt assembly, as well as the assembly between adjacent skirt elements.

[0019] Other objects and advantages of the present invention will become apparent from the following description of the invention with reference to the accompanying drawings, and will help to provide a comprehensive understanding of the invention. Attached Figure Description

[0020] Figure 1 This is a partial cross-sectional structural diagram showing a pre-expanded cable terminal according to an exemplary embodiment of the present invention;

[0021] Figure 2 This is a perspective structural schematic diagram showing the stress cone in a pre-expanded cable terminal according to an exemplary embodiment of the present invention;

[0022] Figure 3 This is a perspective structural schematic diagram showing the umbrella skirt assembly in a pre-expanded cable terminal according to an exemplary embodiment of the present invention;

[0023] Figure 4 This is an enlarged perspective structural schematic diagram showing a single umbrella skirt element in the umbrella skirt assembly of a pre-expanded cable terminal according to an exemplary embodiment of the present invention;

[0024] Figure 5 This is a partial cross-sectional structural diagram showing the application of the display cable to a pre-expanded cable terminal according to an exemplary embodiment of the present invention. Detailed Implementation

[0025] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of this utility model with reference to the accompanying drawings is intended to explain the overall inventive concept of this utility model and should not be construed as a limitation thereof.

[0026] Furthermore, in the following detailed description, numerous specific details are set forth for ease of explanation to provide a thorough understanding of the embodiments disclosed herein. However, it will be apparent that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and apparatuses are illustrated to simplify the figures.

[0027] Figure 1 A partial cross-sectional view of a pre-expanded cable terminal 1 according to an exemplary embodiment of the present invention is shown. Figure 2 and Figure 3 The diagram shows a perspective view of the stress cone 10 and the awning assembly 20 in the pre-expanded cable terminal 1 according to an exemplary embodiment of the present invention. Figure 4 A perspective structural schematic diagram of a single umbrella skirt element 21 in the umbrella skirt assembly is shown.

[0028] See Figures 1 to 4 This invention provides a pre-expanded cable terminal 1, suitable for power cable systems with voltage levels of 6kV-110kV. The pre-expanded cable terminal 1 mainly includes a stress cone 10 and a skirt assembly 20. According to this invention, the stress cone 10 and the skirt assembly 20 are independent components; for example, they are manufactured independently. Furthermore, the stress cone 10 and the skirt assembly 20 are assembled together, for example, by a suitable assembly process.

[0029] Specifically, such as Figure 1 and Figure 2 As shown, the stress cone 10 includes a stress cone body 12 of a certain length, and one end of the stress cone body 12 is provided with a semi-conductive conical structure 11. This semi-conductive conical structure 11 is trumpet-shaped, which plays a role in uniformly distributing the electric field and effectively preventing partial discharge. The stress cone body 12 has a uniform outer diameter along the axial direction. At both ends of the stress cone body 12, the outer diameter of the stress cone 10 gradually changes along the axial direction, forming a conical profile. The stress cone 10 can be made of silicone rubber material, which has good insulation performance and mechanical strength. The pre-expanded cable terminal 1 of this utility model is suitable for power cable systems with voltage levels of 6kV-110kV. For different voltage levels, the size of the stress cone 10 can be adjusted to meet the corresponding insulation requirements. For example, for a 35kV cable terminal, the length of the stress cone 10 can be in the range of 80mm-150mm, and the cone angle at both ends can be in the range of 15 degrees-25 degrees.

[0030] Specifically, such as Figure 1 , Figure 3 as well as Figure 4As shown, the umbrella skirt assembly 20 includes multiple umbrella skirt elements 21, each of which may have the same shape and / or structure. For example, each umbrella skirt element 21 is trumpet-shaped with a central opening 210. The umbrella skirt elements 21 may also be made of silicone rubber material with good insulation properties and mechanical strength. That is, each umbrella skirt element 21 in the stress cone 10 and the umbrella skirt assembly 20 can be made of the same material. Using the same material avoids electrochemical corrosion between different materials and improves the long-term stability of the product. Each umbrella skirt element 21 is manufactured independently, which facilitates quality control and cost control. The thickness of the umbrella skirt element 21 can be in the range of 3mm-8mm. The outer diameter of the umbrella skirt element 21 is designed according to insulation requirements and is usually in the range of 80mm-200mm. The pre-expanded cable terminal 1 according to this utility model is suitable for power cable systems with voltage levels of 6kV-110kV. For different voltage levels, the number of umbrella skirt elements 21 can be adjusted to meet the corresponding insulation requirements. For example, for a 35kV cable terminal, 8-12 umbrella skirt elements 21 can be used.

[0031] According to the pre-expanded cable terminal 1 of this utility model, such as Figure 1 As shown, each skirt element 21 in the skirt assembly 20 is arranged around the stress cone 10. Specifically, as Figure 2 and Figure 3 As shown, each umbrella skirt element 21 includes a first end with opposite ends (e.g. Figure 3 The upper end) and the second end (e.g. Figure 3 The lower end of the umbrella skirt element 21 has an annular stepped portion 211 at its first end and an annular receiving portion 212 at its second end. When the two umbrella skirt elements 21 are assembled together, as... Figure 2 As shown, the annular stepped portion 211 of each skirt element 21 is fitted with an interference fit into the annular receiving portion 212 of another adjacent skirt element 21. Preferably, the interference fit is between approximately 5% and 8%. More specifically, the edges of the annular stepped portion 211 and / or the edges of the annular receiving portion 212 of each skirt element 21 are rounded to facilitate the venting of gas between the annular stepped portion 211 and the mating annular receiving portion 212 during the assembly of the two skirt elements 21, thereby improving electrical conductivity. After the multiple skirt elements 21 are assembled together into the skirt assembly 20, the skirt assembly 20 is fitted to the stress cone 10 by a cold shrinking process.

[0032] According to the pre-expanded cable terminal 1 of this utility model, the size design of each umbrella skirt element 21 and the spacing design between adjacent umbrella skirt elements 21 comply with electrical insulation requirements. The ratio of the spacing between each umbrella skirt element 21 and another adjacent umbrella skirt element 21 to the outermost diameter of the umbrella skirt element 21 is in the range of 1.0 to 1.1. That is, if the outer diameter of each umbrella skirt element 21 is 100mm, the spacing between adjacent umbrella skirt elements 21 can be in the range of 100mm-110mm. The spacing ratio in the range of 1.0 to 1.1 can be adjusted according to specific insulation requirements. In an exemplary embodiment, assuming that the ratio of the spacing between adjacent umbrella skirt elements 21 to the outermost diameter of the umbrella skirt element 21 is set to 1.05, then if the outermost diameter of the umbrella skirt element 21 is 100mm, the spacing between adjacent umbrella skirt elements 21 is 105mm. This design ensures sufficient insulation distance while making the overall structure compact. In addition, the umbrella skirt element (i.e., the one closest to the stress cone 10 in the umbrella skirt assembly 20) that has the semi-conductive conical structure 11 (i.e. Figure 1 The skirt element 21 located at the bottommost side can be called the end-side skirt element 21, wherein the first end of the end-side skirt element 21 (i.e. Figure 1 The distance between the upper end of the stress cone 10 and the maximum outer diameter portion of the semiconductive conical structure 11 in the axial direction of the stress cone 10 can be set within the range of 10mm-20mm, specifically approximately 15mm ± 3mm. This design ensures that the surface discharge distance meets the relevant standard requirements, while avoiding excessive concentration of the electric field at the conical end of the stress cone 10.

[0033] According to this invention, each skirt element 21 is a component independent of the stress cone 10 and the other skirt elements 21, and each skirt element 21 is assembled with the stress cone 10. According to this invention, the stress cone 10 and each skirt element 21 in the skirt assembly 20 can be integrally formed through an expansion process. During assembly, the skirt elements 21 can be fitted onto the stress cone 10 one by one. Since the initial aperture of the central opening 210 of each skirt element 21 is smaller than the diameter of the stress cone 10, the skirt elements 21 need to be pre-expanded during assembly to enlarge their central opening 210 to a size suitable for fitting onto the stress cone 10. After assembly, due to the elastic restoring force of the skirt elements 21, a tight fit is formed between the skirt elements 21 and the stress cone 10, ensuring good sealing.

[0034] Specifically, the stress cone 10 is assembled to the skirt element 21 by passing through the central opening 210 of the skirt element 21. The initial diameter of the central opening 210 is smaller than the initial diameter of the stress cone 10, that is, the initial diameter of the central opening 210 is smaller than the initial diameter of the corresponding position of the stress cone body 12 of the stress cone 10. Thus, when the skirt element 21 is assembled onto the stress cone 10, an interference fit can be formed between the skirt element 21 and the stress cone 10. According to the present invention, the stress cone 10 and each skirt element 21 in the skirt assembly 20 are assembled together by an interference fit, and the interference amount between the stress cone 10 and each skirt element 21 in the skirt assembly 20 is greater than 5%. Preferably, the interference amount between the stress cone 10 and each skirt element 21 in the skirt assembly 20 is approximately between 8% and 20%. For example, if the diameter of the stress cone 10 at a certain location is 50 mm, then the initial aperture of the center opening 210 of the corresponding skirt element 21 is 45 mm, and the interference is (50-45) / 45×100%=11.1%. The interference is preferably between approximately 8% and 20% to ensure assembly reliability. Too small an interference will lead to a loose fit, while too large an interference will increase assembly difficulty and may damage the skirt element 21.

[0035] Figure 5 This is a cross-sectional structural schematic diagram showing the cable applied to the pre-expanded cable terminal 1 according to an exemplary embodiment of the present invention. It should be noted that before the cable is applied to the pre-expanded cable terminal 1 according to the present invention, the pre-expanded cable terminal 1 can be pre-expanded using a suitable core material to facilitate the cable's application to the pre-expanded cable terminal.

[0036] The pre-expanded cable terminal 1, stress cone 10, and shed assembly 20 provided by this utility model are independently manufactured components, but are assembled together through a suitable assembly process. In this way, the stress cone 10 and shed assembly 20 form an integrated structure after assembly, while maintaining the advantage of independent manufacturing of each component. The assembled structure has good sealing and electrical performance, fully meeting the requirements of AC withstand testing, partial discharge detection, and lightning impulse testing. It is suitable for power cable systems with voltage levels of 6kV-110kV, especially power cable systems in high-altitude areas.

[0037] Although the present invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to illustrate preferred embodiments of the present invention and should not be construed as a limitation thereof.

[0038] While some embodiments of the present invention have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A pre-expanded cable terminal (1), comprising: Stress cone (10), one end of which is provided with a semi-conductive conical structure (11); and A skirt assembly (20) is arranged around the stress cone (10); Its features are, The stress cone (10) and the skirt assembly (20) are independent components, and the stress cone (10) and the skirt assembly (20) are assembled together; and The skirt assembly (20) includes a plurality of skirt elements (21), each skirt element (21) having a central opening (210), and the stress cone (10) is fitted to the skirt element (21) through the central opening (210) of the skirt element (21), wherein the initial aperture of the central opening (210) is smaller than the initial diameter of the stress cone (10).

2. The pre-expanded cable terminal (1) according to claim 1, characterized in that, Each skirt element (21) is a component independent of the stress cone (10) and the other skirt elements (21), and each skirt element (21) is assembled with the stress cone (10); Each skirt element (21) includes a first end and a second end with opposite ends, the first end having an annular step portion (211) and the second end having an annular receiving portion (212); wherein the annular step portion (211) of each skirt element (21) is fitted into the annular receiving portion (212) of another skirt element (21) adjacent to the skirt element (21) in an interference fit; wherein the edges of the annular step portion (211) and / or the edges of the annular receiving portion (212) of each skirt element (21) are rounded.

3. The pre-expanded cable terminal (1) according to claim 2, characterized in that, The interference amount of the aforementioned interference fit is between 5% and 8%.

4. The pre-expanded cable terminal (1) according to claim 2, characterized in that, The ratio of the distance between each skirt element (21) and the adjacent skirt element (21) to the outermost diameter of the skirt element (21) is in the range of 1.0 to 1.1; and The semiconductive conical structure (11) is trumpet-shaped, and the umbrella skirt assembly (20) includes an end-side umbrella skirt element (21). The end-side umbrella skirt element (21) is positioned closest to the end of the stress cone (10) where the semiconductive conical structure (11) is located. The distance between the first end of the end-side umbrella skirt element (21) and the maximum outer diameter portion of the semiconductive conical structure (11) in the axial direction of the stress cone (10) is between 10 mm and 20 mm.

5. The pre-expanded cable terminal (1) according to claim 1, characterized in that, The stress cone (10) and each skirt element (21) in the skirt assembly (20) are assembled together in an interference fit.

6. The pre-expanded cable terminal (1) according to claim 5, characterized in that, The interference fit between the stress cone (10) and each skirt element (21) in the skirt assembly (20) is greater than 5%.

7. The pre-expanded cable terminal (1) according to claim 5, characterized in that, The interference fit between the stress cone (10) and each skirt element (21) in the skirt assembly (20) is between 8% and 20%.

8. The pre-expanded cable terminal (1) according to claim 1, characterized in that, The stress cone (10) and each skirt element (21) in the skirt assembly (20) are formed into one piece by an expansion process.

9. The pre-expanded cable terminal (1) according to any one of claims 1 to 8, characterized in that, The stress cone (10) and each skirt element (21) in the skirt assembly (20) are made of the same material.

10. The pre-expanded cable terminal (1) according to claim 9, characterized in that, Each of the stress cone (10) and each skirt element (21) in the skirt assembly (20) is made of silicone rubber.

11. The pre-expanded cable terminal (1) according to any one of claims 1 to 8, characterized in that, The umbrella skirt assembly (20) is assembled to the stress cone (10) by a cold shrinking process.

12. The pre-expanded cable terminal (1) according to any one of claims 1 to 8, characterized in that, The pre-expanded cable terminal (1) is a 6kV-110kV cable terminal.

Images