High-voltage cable with insulating water-blocking structure

Abstract

The utility model discloses a high-voltage cable with an insulating and water-blocking structure. The high-voltage cable comprises a first hydrophobic layer, a second hydrophobic layer, a first insulating layer, a first water-blocking layer, a second insulating layer, a second water-blocking layer, a filling layer and a conductor which are sequentially arranged from outside to inside. A drainage strip extending in the axial direction of the cable is arranged on the inner side of the first hydrophobic layer and used for guiding water to be discharged. A plurality of water blocking rings are arranged on the outer side of the second hydrophobic layer and used for preventing water from axially permeating. The first insulating layer and the second insulating layer are made of polypropylene materials and have good insulating performance. The first waterproof layer and the second waterproof layer are made of high-waterproof materials, so that the waterproof effect is improved; the filling layer is made of a flexible water-resistant material, so that the stability of the cable is enhanced. The cable has the advantages of being compact in structure, good in waterproof performance, reliable in insulation and high in environmental adaptability.

Description

Technical Field

[0001] This utility model relates to the field of power transmission technology, and more specifically to a high-voltage cable with an insulating and water-blocking structure. Background Technology

[0002] High-voltage cables, as a key component of power transmission systems, are widely used in urban power grids, industrial parks, large building complexes, and new energy power plants. With the continuous growth of society's demand for electricity and the development of power systems towards high voltage and large capacity, high-voltage cables not only need to meet high electrical performance requirements, but also must have good environmental adaptability and safety stability during long-term operation.

[0003] In actual operating environments, high-voltage cables often face adverse conditions such as high humidity, underground laying, and moisture penetration. Especially high-voltage cables used in humid environments such as tunnels, shafts, canals, and coastal areas are highly susceptible to external moisture or water vapor seeping into the cable structure through gaps, causing insulation degradation, conductor oxidation, and even serious problems such as partial discharge or breakdown. Once these problems occur, they can range from affecting the efficiency of the power system to causing power outages or even equipment accidents, significantly impacting production and daily life. Therefore, improving the waterproofing and insulation stability of high-voltage cables is a critical issue that urgently needs to be addressed in the field of cable design and manufacturing.

[0004] Traditional high-voltage cables typically employ a multi-layered sheathing structure. The insulation layer often uses materials such as cross-linked polyethylene (XLPE) or ethylene propylene rubber (EPR), and a water-blocking layer is added outside the conductor or insulation layer, such as by coating with water-blocking adhesive, covering with water-blocking tape, or filling with water-blocking powder. While these structures offer some water-blocking effect, they also have several technical limitations:

[0005] (1) Weak moisture conduction capacity: Traditional cable structures lack a structural design specifically for guiding moisture migration. When water enters the outside of the cable, the moisture can easily spread along the axial or radial direction of the cable to the inside, causing large-area insulation deterioration.

[0006] (2) The water-blocking structure is dispersed and has poor continuity: For example, the water-blocking powder is mostly distributed in dots, and its expansion capacity is limited; the tape covering is prone to gaps due to thermal expansion and contraction or mechanical stress.

[0007] (3) The insulation material ages quickly: Cross-linked polyethylene material is prone to thermal oxidative aging when operating in a high temperature and high humidity environment for a long time, and its breakdown strength and dielectric properties decrease significantly over time.

[0008] (4) Complex structure and difficult processing: The superposition of multiple layers of water-blocking and insulating materials often increases the overall diameter of the cable. The processing process requires multiple composite processes, resulting in low production efficiency and high manufacturing costs.

[0009] (5) Poor flexibility and easy fatigue failure: Some traditional cable structures are too rigid and are not suitable for frequent bending or laying in complex paths, which reduces their engineering adaptability.

[0010] In addition, most existing waterproof cables focus on single-point protection or partial wrapping in their design, neglecting the coordination of the overall structure and the integrated effect of multi-dimensional water-blocking strategies, making it difficult to achieve multi-level waterproof protection from the outer layer to the inner core of the cable.

[0011] To address the aforementioned technical challenges, the industry has been continuously exploring new polymer materials, nano-water-blocking coatings, and microstructure designs. However, numerous challenges remain in cost control, mass production, and long-term weather resistance. Therefore, there is an urgent need for a new type of high-voltage cable structure that is more structurally sound, highly integrated with water-blocking and insulation functions, has a simple manufacturing process, and can adapt to complex operating environments. Utility Model Content

[0012] To address the problems existing in the prior art, this utility model provides a high-voltage cable with an insulating and water-blocking structure, which features a novel structure, significant waterproof effect, excellent electrical insulation performance, and strong adaptability to complex environments.

[0013] To achieve the above objectives, this utility model provides a high-voltage cable with an insulating and water-blocking structure, comprising, from the outside to the inside, a first hydrophobic layer, a second hydrophobic layer, a first insulating layer, a first water-blocking layer, a second insulating layer, a second water-blocking layer, a filling layer, and a conductor.

[0014] Among them: the inner side of the first hydrophobic layer is provided with multiple drainage strips that extend along the cable axis and are distributed in a ring;

[0015] The outer side of the second hydrophobic layer is provided with multiple water-blocking rings spaced apart along the cable axis;

[0016] Both the first and second insulating layers are made of polypropylene.

[0017] The conductor is a stranded wire structure formed by multiple copper monofilaments twisted together.

[0018] Furthermore: the drainage strip is a longitudinally arranged protruding strip structure, which is uniformly distributed in a ring inside the first hydrophobic layer;

[0019] The water-blocking ring consists of multiple axially spaced protruding ring structures, forming a segmented water-blocking effect.

[0020] The first water-blocking layer and the second water-blocking layer are made of highly water-blocking materials and are respectively wrapped around the outside of the first insulating layer and the second insulating layer;

[0021] The filling layer, which is disposed between the second water-blocking layer and the conductor, is made of a flexible material with water-resistant properties and is used to fill the gaps and improve structural stability.

[0022] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] (1) Improved waterproof performance: By setting longitudinal drainage strips in the first hydrophobic layer, water is guided to drain along the cable to avoid water accumulation; in conjunction with the water-blocking ring set on the outside of the second hydrophobic layer, water is effectively inhibited to diffuse along the axis, significantly enhancing the overall waterproof capability of the cable.

[0024] (2) Reliable insulation effect: Polypropylene material is used as the insulation layer, which has good electrical properties and thermal stability, ensuring the safety of high voltage transmission.

[0025] (3) Strong structural stability: The filling layer uses flexible water-resistant material to fill the gaps, which not only improves the waterproof performance, but also enhances the overall mechanical strength and flexibility of the cable.

[0026] (4) High production efficiency: Polypropylene materials do not require high-temperature cross-linking process during processing, the process is simple, which is conducive to large-scale continuous production, energy saving and high efficiency. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] Figure 1 This is a cross-sectional view of the structure of this utility model.

[0029] Figure 2 This is a cross-sectional view of the internal structure of the first hydrophobic layer of this utility model.

[0030] Figure 3 This is a schematic diagram of the surface structure of the second hydrophobic layer of this utility model.

[0031] 1-First hydrophobic layer, 101-Draining strip, 2-Second hydrophobic layer, 201-Water-blocking ring, 3-First insulating layer, 4-First water-blocking layer, 5-Second insulating layer, 6-Second water-blocking layer, 7-Filling layer, 8-Conductor. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Example

[0034] like Figures 1 to 3 As shown, a high-voltage cable with an insulating and water-blocking structure includes, from the outside to the inside, a first hydrophobic layer 1, a second hydrophobic layer 2, a first insulating layer 3, a first water-blocking layer 4, a second insulating layer 5, a second water-blocking layer 6, a filling layer 7, and a conductor 8.

[0035] The first hydrophobic layer 1 is the outermost layer of the cable and is made of a hydrophobic polyolefin material. Its main function is to prevent external moisture from penetrating into the cable through the regulation of surface tension. Furthermore, multiple drainage strips 101 extending along the cable axis are arranged on the inner side of the first hydrophobic layer 1. These drainage strips 101 have a convex strip structure and are evenly distributed on the inner wall of the first hydrophobic layer 1, forming a ring arrangement. This structure not only effectively guides moisture that has entered the cable surface to be quickly discharged along the drainage channels, but also accelerates moisture migration under gravity and capillary action, preventing it from remaining on the surface or in the interface gaps, thus reducing the risk of internal corrosion or insulation aging caused by water accumulation.

[0036] The second hydrophobic layer 2 is disposed inside the first hydrophobic layer 1. Its material can be a polyolefin substrate similar to that of the first hydrophobic layer 1, or a structurally foamed plastic can be used to improve overall flexibility and adhesion. Multiple water-blocking rings 201 are disposed on the outer surface of the second hydrophobic layer 2. The water-blocking rings 201 are raised annular structures arranged at intervals along the cable axis. This design forms multiple physical blocking nodes as moisture propagates along the cable length, interrupting the moisture migration path and improving water-blocking performance. Furthermore, this structure can maintain the continuity of the annular water-blocking nodes when the cable is subjected to radial pressure or bending deformation, improving the long-term protective stability of the cable.

[0037] The first insulating layer 3 is disposed inside the second hydrophobic layer 2 and is made of polypropylene. Compared with traditional cross-linked polyethylene, polypropylene has higher dielectric strength and lower dielectric loss factor, and can be directly formed by physical extrusion without complex cross-linking treatment, significantly improving the manufacturing efficiency and environmental friendliness of cables. In addition, polypropylene has good thermal stability and mechanical properties, and can operate stably for a long time under high pressure and high temperature environments.

[0038] The first water-blocking layer 4 is closely attached to the inner side of the first insulation layer 3 and is made of a highly water-blocking composite material, such as water-blocking tape, composite polyester film, or butyl rubber layer. Its function is to further enhance the moisture isolation effect in the cable structure. The first water-blocking layer 4 is in a continuous covering shape, effectively sealing all possible water seepage channels on the surface of the first insulation layer 3 and improving the longitudinal and transverse water-blocking performance of the cable.

[0039] The second insulation layer 5 is disposed inside the first water-blocking layer 4, and its material is the same as that of the first insulation layer 3, which is also polypropylene, further improving the overall cable's withstand voltage performance and insulation stability. The double-layer insulation structure can maintain good withstand voltage breakdown capability even when microscopic defects occur in the main insulation, ensuring safety and reliability during high-voltage power transmission.

[0040] The second water-blocking layer 6 is set in close contact with the second insulating layer 5. The material can be the same polymer water-blocking film as the first water-blocking layer 4, or it can be an expandable water-blocking powder coating layer as needed. When it comes into contact with water, it expands rapidly to form a tight sealing layer, preventing water from continuing to penetrate into the inner layer.

[0041] The filler layer 7 is disposed between the second water-blocking layer 6 and the conductor 8, and is mainly used to fill the central space of the cable, maintain the overall roundness of the cable, and enhance its mechanical strength. The filler layer 7 is made of a flexible filler material with water resistance, such as nitrile rubber or water-resistant silicone composite material. These materials can not only effectively resist moisture intrusion, but also buffer stress and resist impact, which helps to improve the cable's resistance to damage during laying or use.

[0042] The conductor 8 is a stranded wire structure made of highly conductive copper monofilaments, specifically manufactured using a multi-layer stranding process with multiple fine-diameter copper wires, achieving a balance between conductivity and flexibility. This type of conductor features low resistivity, high heat resistance, and resistance to oxidation, making it suitable for power transmission applications at voltage levels of 10kV, 35kV, and even higher.

[0043] Furthermore, in this embodiment, the cable's structural layers are formed in one step using a co-extrusion process, ensuring strong adhesion between the layers and a natural interface transition, thus avoiding partial discharge and breakdown caused by delamination or gaps. Simultaneously, this structure can be adapted with additional structures such as sheathing layers and armor layers to meet the application requirements of special environments such as underground laying, heavy-load operation, or humid salt spray areas.

[0044] In summary, this utility model effectively improves the longitudinal drainage efficiency and overall water-blocking capacity of the cable by optimizing the structure of the first hydrophobic layer with a drainage strip and the second hydrophobic layer with a water-blocking ring. The use of polypropylene material to construct a double-layer insulation system improves electrical performance while simplifying the production process. The combination design of the water-blocking layer and the filling layer enhances the sealing performance and mechanical stability of the cable, thereby solving the technical problems of existing high-voltage cables, such as large water seepage risks, complex structure, and low manufacturing efficiency.

[0045] This utility model has a reasonable structure and ingenious design, and has the following beneficial effects:

[0046] (1) Significantly improve waterproofing capability: By combining the use of axial drainage strips and water-blocking rings, the longitudinal and lateral propagation paths of water are effectively blocked, significantly improving the waterproofing performance of the cable.

[0047] (2) Improve insulation performance and production efficiency: Polypropylene material is used as the insulation layer to replace traditional cross-linked polyethylene material, which simplifies the manufacturing process and improves the insulation quality.

[0048] (3) Enhanced structural stability: The multi-layer water-blocking and flexible filling structure improves the mechanical properties and long-term stability of the cable;

[0049] (4) Wide range of applicable scenarios: It is especially suitable for high-voltage transmission lines in complex or harsh environments such as high humidity, high temperature, and underground.

[0050] (5) Controllable production costs: The materials used can be mass-produced using existing industrial methods without the need for additional high-energy-consuming processes, resulting in excellent cost control.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-voltage cable with an insulating and water-blocking structure, characterized in that, It includes, from the outside in, a first hydrophobic layer, a second hydrophobic layer, a first insulating layer, a first water-blocking layer, a second insulating layer, a second water-blocking layer, a filling layer, and a conductor; The first hydrophobic layer (1) has multiple drainage strips (101) extending along the cable axis and distributed in a ring on its inner side; The second hydrophobic layer (2) has multiple water-blocking rings (201) spaced apart along the cable axis on its outer side; The first insulating layer (3) and the second insulating layer (5) are both made of polypropylene material; The conductor (8) is a stranded wire structure formed by twisting together multiple copper monofilaments.

2. The high-voltage cable with an insulating and water-blocking structure according to claim 1, characterized in that, The drainage strip (101) is a longitudinally arranged protruding strip structure, and the drainage strip (101) is evenly distributed in a ring on the inner side of the first hydrophobic layer (1).

3. The high-voltage cable with an insulating and water-blocking structure according to claim 1, characterized in that, The water-blocking ring (201) consists of multiple protruding ring structures, which are spaced apart on the outer surface of the second hydrophobic layer (2).

4. The high-voltage cable with an insulating and water-blocking structure according to claim 1, characterized in that, The first water-blocking layer (4) and the second water-blocking layer (6) are both made of highly water-blocking materials and are wrapped around the outside of the first insulating layer (3) and the second insulating layer (5).

5. The high-voltage cable with an insulating and water-blocking structure according to claim 1, characterized in that, The filling layer (7) is located between the second water-blocking layer (6) and the conductor (8), and the filling layer (7) is a flexible filling material with water-resistant properties.

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