Single-phase AC railway cable

Abstract

The utility model discloses a single-phase AC railway cable, which is characterized in that the inner surface of an anticorrosive coating outer sheath is provided with a corrugated aluminum alloy sheath, the inner part of the corrugated aluminum alloy sheath is provided with a buffer waterproof layer, the inner surface of the buffer waterproof layer is provided with a polyethylene inner sheath, the inner surface of the polyethylene inner sheath is provided with a belting layer, and the inner surface of the belting layer is provided with an anti-corrosion layer. A copper wire and copper strip shielding layer is fixedly installed in the wrapping tape layer, an insulation shielding layer is arranged on the inner surface of the copper wire and copper strip shielding layer, an XLPE insulation layer is arranged on the inner surface of the insulation shielding layer, a conductor shielding layer is arranged on the inner surface of the XLPE insulation layer, and a special-shaped compressed copper conductor is fixedly installed in the conductor shielding layer. The cable for the single-phase alternating current railway, provided by the utility model, brings a better use prospect.

Description

Technical Field

[0001] This utility model relates to the field of cable technology, specifically to a single-phase AC railway cable. Background Technology

[0002] With the development of the cable industry, 27.5kV ordinary power cables still have some shortcomings when facing special operating environments such as waterproofing, fireproofing, corrosion resistance, and tensile strength. These shortcomings are mainly fourfold: First, insufficient waterproofing performance, as water treeing in the insulation layer can damage the cable; second, poor corrosion resistance, as ordinary cables cannot provide adequate protection against long-term exposure to oils and chemical solvents, leading to chemical corrosion; third, low transmission capacity and poor mechanical resistance of single-core armored cables; and fourth, poor fire resistance, which brings certain adverse effects to users. Therefore, we propose a single-phase AC railway cable. Utility Model Content

[0003] This utility model addresses the problems existing in the prior art by providing a single-phase AC railway cable.

[0004] This utility model solves the above-mentioned technical problems through the following technical means:

[0005] A single-phase AC railway cable includes an anti-corrosion outer sheath, an inner surface of which is provided with a corrugated aluminum alloy sheath, a buffer water-blocking layer inside the corrugated aluminum alloy sheath, an inner surface of which is provided with a polyethylene inner sheath, an inner surface of which is provided with a wrapping layer, a copper wire / copper tape shielding layer fixedly installed inside the wrapping layer, an insulating shielding layer inside the copper wire / copper tape shielding layer, an XLPE insulation layer inside the insulating shielding layer, a conductor shielding layer inside the XLPE insulation layer, and a shaped, tightly compressed copper conductor fixedly installed inside the conductor shielding layer.

[0006] Furthermore, the irregularly shaped compacted copper conductor is wrapped inside the conductor shielding layer, and the irregularly shaped compacted copper conductor is fixedly installed inside the conductor shielding layer. The irregularly shaped compacted copper conductor is formed by twisting T-shaped or tile-shaped monofilaments. The monofilaments of the irregularly shaped compacted copper conductor are in close contact, smooth and flat, and the surface of the irregularly shaped compacted copper conductor has no grooves.

[0007] Furthermore, the conductor shielding layer is extruded from a cross-linked semi-conductive shielding material, and the conductor shielding layer is tightly bonded to the XLPE insulation layer.

[0008] Furthermore, the XLPE insulation layer is extruded from peroxide cross-linked polyethylene insulation material, and the insulation shielding layer is extruded from non-peelable cross-linked semi-conductive shielding material. The insulation shielding layer and the XLPE insulation layer are tightly bonded together, and the insulation shielding layer, the XLPE insulation layer and the conductor shielding layer are co-extruded in three layers onto the outer surface of the irregularly shaped compacted copper conductor through a cross-linking production line.

[0009] Furthermore, the copper wire and copper strip shielding layer is shielded on the outer surface of the insulating shielding layer. The copper wire and copper strip shielding layer is made by uniformly and loosely winding copper wire around the core of the insulating shielding layer and then binding it tightly with copper strip and wrapping layer at the same point. The polyethylene inner sheath is extruded onto the outer surface of the wrapping layer.

[0010] Furthermore, the buffer water-blocking layer consists of two overlapping wrapping layers, the corrugated aluminum alloy sheath is made by longitudinal argon arc welding of aluminum alloy plate and corrugating it into a corrugated aluminum alloy sheath, and the outer surface of the anti-corrosion layer outer sheath is coated with cable-specific asphalt. Beneficial effects

[0011] Compared with the prior art, this utility model provides a single-phase AC railway cable, which has the following advantages:

[0012] This single-phase AC railway cable effectively solves the problems of small grooves between the single filaments on the outer surface of the circular conductor. During the cross-linked three-layer co-extrusion process, the conductor shield is easily embedded in the grooves and gaps due to nitrogen pressure, resulting in uneven conductor shield thickness and shielding material trapped between the single filaments. This causes uneven conductor shielding field strength during cable operation. It also enhances the water-blocking effect of the conductor. The corrugated aluminum alloy sheath, replacing the aluminum wire armor, not only solves the problem of the aluminum wire armor not having water-blocking function, but also effectively prevents animal chewing. During vertical installation, the single aluminum wire breaks due to uneven stress. It also overcomes the shortcomings of flame-retardant sheaths, such as poor tensile strength and easy cracking, greatly increasing the service life of the product and enhancing the cable's anti-corrosion, anti-interference, resistance to strong mechanical impact, and tensile strength. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of a single-phase AC railway cable according to the present invention.

[0014] Figure 2 This is an internal cross-sectional view of a single-phase AC railway cable according to the present invention.

[0015] In the diagram: 1. Anti-corrosion outer sheath; 2. Corrugated aluminum alloy sheath; 3. Buffer water-blocking layer; 4. Polyethylene inner sheath; 5. Wrapping tape layer; 6. Copper wire and copper tape shielding layer; 7. Insulating shielding layer; 8. XLPE insulation layer; 9. Conductor shielding layer; 10. Irregularly shaped compacted copper conductor. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] like Figure 1 and Figure 2 As shown, a single-phase AC railway cable includes an anti-corrosion outer sheath 1, an inner surface of which is provided with a corrugated aluminum alloy sheath 2, a buffer water-blocking layer 3 inside the corrugated aluminum alloy sheath 2, an inner surface of which is provided with a polyethylene inner sheath 4, an inner surface of which is provided with a wrapping layer 5, a copper wire and copper tape shielding layer 6 fixedly installed inside the wrapping layer 5, an insulating shielding layer 7 on the inner surface of the copper wire and copper tape shielding layer 6, an XLPE insulating layer 8 on the inner surface of the insulating shielding layer 7, a conductor shielding layer 9 on the inner surface of the XLPE insulating layer 8, and a shaped compressed copper conductor 10 fixedly installed inside the conductor shielding layer 9.

[0018] The irregularly shaped compacted copper conductor 10 is wrapped inside the conductor shielding layer 9, and the irregularly shaped compacted copper conductor 10 is fixedly installed inside the conductor shielding layer 9. The irregularly shaped compacted copper conductor 10 is formed by twisting T-shaped or tile-shaped monofilaments. The monofilaments of the irregularly shaped compacted copper conductor 10 have close contact, are smooth and flat, and have no grooves on the surface.

[0019] The conductor shielding layer 9 is extruded from a cross-linked semi-conductive shielding material, and the conductor shielding layer 9 is tightly bonded to the XLPE insulation layer 8.

[0020] The XLPE insulation layer 8 is extruded from peroxide cross-linked polyethylene insulation material, and the insulation shielding layer 7 is extruded from non-peelable cross-linked semi-conductive shielding material. The insulation shielding layer 7 and the XLPE insulation layer 8 are tightly bonded together, and the insulation shielding layer 7, the XLPE insulation layer 8 and the conductor shielding layer 9 are co-extruded in three layers on the outer surface of the irregularly shaped compacted copper conductor 10 through a cross-linking production line.

[0021] The copper wire and copper tape shielding layer 6 is shielded on the outer surface of the insulating shielding layer 7. The copper wire and copper tape shielding layer 6 is made by uniformly and loosely winding copper wire around the core of the insulating shielding layer 7 and then binding it tightly with copper tape and wrapping layer 5 at the same point. The polyethylene inner sheath 4 is extruded onto the outer surface of the wrapping layer 5.

[0022] The buffer water-blocking layer 3 consists of two overlapping wrapping layers. The corrugated aluminum alloy sheath 2 is made of aluminum alloy plate longitudinally argon arc welded and rolled into a corrugated aluminum alloy sheath. The outer surface of the anti-corrosion outer sheath 1 is coated with cable-specific asphalt.

[0023] The irregularly shaped compacted copper conductor has a tight contact between the individual wires and a large contact surface, resulting in low eddy current loss during cable operation. The outer surface of the irregularly shaped conductor is basically seamless, smooth and flat, and without grooves, which can create a uniform electric field, effectively prevent tip discharge, and improve the conductor's water resistance. When applied to medium and high voltage cross-linked cables, it results in a low failure rate and can extend the cable's service life.

[0024] The irregularly shaped compacted copper conductor requires meticulous attention to the arrangement and structure of each individual filament. Most filaments are tile-shaped or T-shaped, and during stranding, the layers adhere tightly, achieving a compaction coefficient exceeding 97%. Furthermore, the filaments maintain close, smooth, and flat contact without grooves, ensuring a uniform electric field. The shielding and insulation layers are also tightly extruded, effectively preventing tip discharge. The compacted conductor's small outer diameter saves on insulation and sheathing materials. Therefore, high-voltage cross-linked cables with this irregularly shaped compacted conductor structure can meet electrical performance requirements while reducing the cable's outer diameter.

[0025] The irregularly shaped compacted copper conductor design, while meeting the minimum number of strands and resistance standards for the second type of stranded conductor in GB / T3956-2008, maintains the same production process. The difference lies in the wire drawing process; instead of round single wires, the conductors are designed into irregular shapes (T-shaped or corrugated) according to different specifications. During stranding, they are pre-twisted and shaped using a forming die. The irregularly shaped compacted conductor has no grooves between the single wires, a smooth surface without burrs, and virtually no gaps. This improves the water resistance of the cable conductor while minimizing partial discharge.

[0026] Taking copper core 240mm², 300mm² and 400mm² cable conductors as examples, the number of conductor wires and the DC resistance of the conductor at 20℃ both meet the requirements of GB / T3956-2008 standard.

[0027] The conductor shielding layer is extruded from cross-linked semi-conductive shielding material. The semi-conductive shielding layer is tightly bonded to the conductor and insulation, and the interface with the insulation layer is smooth with no obvious stranding marks.

[0028] The XLPE insulation layer is extruded from peroxide cross-linked polyethylene insulation material. To ensure the uniformity of the cable electric field, an online eccentricity measuring device is provided to ensure that the insulation eccentricity is controlled within 10%.

[0029] The insulating shielding layer is extruded from a non-peelable cross-linked semi-conductive shielding material, and the insulating shielding layer is tightly bonded to the insulating layer.

[0030] The insulating shielding layer, XLPE insulating layer, and conductor shielding layer are co-extruded onto a shaped, compacted copper conductor using a cross-linking production line. This process ensures stable insulation performance that meets standard requirements.

[0031] The copper wire and copper tape shielding layer is located on the outer surface of the insulating shielding core. Copper wire is evenly and loosely wound on the surface of the insulating core and then tied tightly at the same point with copper tape and wrapping layer. This can effectively uniformize the electric field and uniformly conduct short-circuit fault current.

[0032] The polyethylene inner sheath is extruded over the outer layer of the wrapping tape, and its function is to protect the insulated wire core and provide a waterproof effect.

[0033] The buffer water-blocking layer uses two overlapping wrapping layers, which not only protects the cable from damage caused by subsequent processes, but also acts as a longitudinal water barrier. If water enters due to damage to the sheath caused by external factors, the buffer layer will quickly absorb water and expand, blocking the damaged area of ​​the sheath, preventing water from entering again, and preventing water from spreading longitudinally along the cable.

[0034] The corrugated aluminum alloy sheath is made by longitudinal argon arc welding and corrugating of aluminum alloy plates into a corrugated aluminum alloy sheath, and is equipped with an ultrasonic online testing device to ensure the sealing of the weld. To verify the integrity of the weld, an airtightness test is performed on the entire cable reel to ensure good radial waterproofing and prevent water treeing discharge from cross-linked polyethylene insulation upon contact with moisture, which would affect the cable's service life. The corrugated aluminum alloy sheath protects the insulated core, preventing pressure damage from external forces and thermal expansion damage caused by insulation heating. Since cables are subjected to mechanical stress during installation and operation, the corrugated aluminum alloy sheath provides appropriate mechanical protection for the cable core, preventing damage. The corrugated aluminum alloy sheath has high mechanical strength, low creep, and high fatigue strength, exhibiting significant resistance to compression, shearing, and lateral support during installation. Therefore, it provides excellent mechanical protection for the cable core and fills the technical gap of flame-retardant sheaths with poor tensile strength and easy cracking.

[0035] Compared with aluminum wire, the corrugated aluminum alloy sheath has greater mechanical strength, better sealing performance, radial water-blocking function, appropriate thermo-mechanical properties, and stable long-term operation; its tensile strength is twice that of the corrugated aluminum sheath, and it has better compressive and tensile strength.

[0036] The anti-corrosion outer sheath is applied before the extrusion sheath. The anti-corrosion layer on the outer surface of the aluminum sheath is coated with cable-specific asphalt. During the coating process, the uniformity of the coating is strictly controlled to ensure the anti-corrosion performance of the cable. The outer sheath is made of environmentally friendly material and extruded by a special extruder.

[0037] In addition to possessing all the mechanical, physical, and electrical properties of ordinary power cables, the above structure also features waterproof, corrosion-resistant, interference-resistant, strong mechanical impact-resistant, and tensile-resistant properties, making it easy to install and suitable for use in humid environments and environments with high electromagnetic compatibility requirements.

[0038] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A single-phase AC railway cable, comprising an anti-corrosion outer sheath (1), characterized in that: The inner surface of the outer sheath (1) of the anti-corrosion layer is provided with a corrugated aluminum alloy sheath (2), the inside of the corrugated aluminum alloy sheath (2) is provided with a buffer water-blocking layer (3), the inner surface of the buffer water-blocking layer (3) is provided with a polyethylene inner sheath (4), the inner surface of the polyethylene inner sheath (4) is provided with a wrapping layer (5), a copper wire and copper strip shielding layer (6) is fixedly installed inside the wrapping layer (5), an insulating shielding layer (7) is provided on the inner surface of the copper wire and copper strip shielding layer (6), an XLPE insulating layer (8) is provided on the inner surface of the insulating shielding layer (7), a conductor shielding layer (9) is provided on the inner surface of the XLPE insulating layer (8), and a shaped compacted copper conductor (10) is fixedly installed inside the conductor shielding layer (9).

2. The single-phase AC railway cable according to claim 1, characterized in that: The irregularly shaped compacted copper conductor (10) is wrapped inside the conductor shielding layer (9), and the irregularly shaped compacted copper conductor (10) is fixedly installed inside the conductor shielding layer (9). The irregularly shaped compacted copper conductor (10) is formed by twisting T-shaped or tile-shaped monofilaments. The monofilaments of the irregularly shaped compacted copper conductor (10) are in close contact, smooth and flat, and the surface of the irregularly shaped compacted copper conductor (10) has no grooves.

3. A single-phase AC railway cable according to claim 1, characterized in that: The conductor shielding layer (9) is extruded from a cross-linked semi-conductive shielding material, and the conductor shielding layer (9) is tightly bonded to the XLPE insulation layer (8).

4. A single-phase AC railway cable according to claim 1, characterized in that: The XLPE insulation layer (8) is extruded from peroxide cross-linked polyethylene insulation material, and the insulation shielding layer (7) is extruded from non-peelable cross-linked semi-conductive shielding material. The insulation shielding layer (7) and the XLPE insulation layer (8) are tightly bonded together, and the insulation shielding layer (7), the XLPE insulation layer (8) and the conductor shielding layer (9) are co-extruded in three layers on the outer surface of the irregularly shaped compacted copper conductor (10) through a cross-linking production line.

5. A single-phase AC railway cable according to claim 1, characterized in that: The copper wire and copper strip shielding layer (6) is shielded on the outer surface of the insulating shielding layer (7). The copper wire and copper strip shielding layer (6) is made by uniformly winding copper wire around the core of the insulating shielding layer (7) and then binding it tightly with copper strip and wrapping layer (5) at the same point. The polyethylene inner sheath (4) is extruded onto the outer surface of the wrapping layer (5).

6. A single-phase AC railway cable according to claim 1, characterized in that: The buffer water-blocking layer (3) consists of two overlapping wrapping layers. The wrinkled aluminum alloy sheath (2) is made by longitudinal argon arc welding of aluminum alloy plate and rolling into a wrinkled aluminum alloy sheath. The outer surface of the anti-corrosion outer sheath (1) is coated with cable-specific asphalt.

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