CN205230618U - Flexible water -resistant tree aluminum alloy cable of middling pressure - Google Patents

Abstract

The utility model discloses a medium-voltage flexible water-tree-resistant aluminum alloy cable. The cable includes a cable core, a waterproof layer, a non-metallic armor layer and an outer sheath arranged sequentially from the inside to the outside. The cable core includes a An insulated wire core or the cable core is formed by wrapping three insulated wire cores in a cable, and a water-blocking filler strip is filled between the three insulated wire cores, wherein the insulated wire core includes an aluminum alloy conductor and A conductor shielding layer, an anti-water tree insulating layer, an insulating shielding layer and a metal shielding layer are sequentially coated on the aluminum alloy conductor. Compared with the prior art, the medium-voltage flexible anti-water tree aluminum alloy cable of the utility model has the characteristics of excellent waterproof tree performance, light weight, small outer diameter, small bending radius, and excellent lateral pressure resistance, which greatly improves the performance of XLPE cables. service life.

Description

A medium voltage flexible anti-water tree aluminum alloy cable

technical field

The utility model relates to the technical field of power cable processing and manufacturing, in particular to a medium-voltage flexible water-tree-resistant aluminum alloy cable.

Background technique

Cross-linked polyethylene (XLPE) cables have a series of advantages such as good electrical performance, good mechanical strength, simple structure and light weight, and are widely used in power grid systems of 500kV and below. In general, XLPE cables are resistant to heat and oxygen aging, and their service life can reach 30-60 years. However, XLPE cables also face the problem of water tree aging, especially in wet or even submerged conditions, it is easy to form water trees in the insulation layer, and then Lead to electrical trees and partial discharges, seriously reducing the service life of the cable.

Since the end of the 1980s in China, XLPE cables were first used on a large scale in Tianjin, Jiangsu, Guangzhou and other coastal developed areas. After more than ten years of operation and since 2005, XLPE cables have been found to have breakdown failures. After dissection, it was found that: Water branches appeared in many places in the XLPE insulation of the cable, which could not be repaired and had to be scrapped and replaced. Since then, the water tree problem of XLPE cables has gradually attracted great attention from power supply bureaus, scientific research institutes and cable manufacturing enterprises.

For urban power supply and distribution networks, it is an irreplaceable trend to replace overhead laying of cables into the ground, because underground laying pipeline resources are scarce, and XLPE power cables are often laid in sewer pipelines, which are exposed to severe humidity or even long-term flooding for a long time. Therefore, the demand for waterproof tree XLPE cables will increase in the future, and the market prospect is broad.

Utility model content

In order to solve the problems existing in the prior art, the purpose of the utility model is to provide a flexible anti-water tree aluminum alloy cable with a rated voltage of 18/30kV, which has excellent waterproof tree performance and longer service life.

The utility model provides a medium-voltage flexible water-tree-resistant aluminum alloy cable. The cable includes a cable core, a waterproof layer, a non-metallic armor layer and an outer sheath arranged sequentially from the inside to the outside. The cable core includes a An insulated wire core or the cable core is formed by wrapping three insulated wire cores in a cable, and a water-blocking filler strip is filled between the three insulated wire cores, wherein the insulated wire core includes an aluminum alloy conductor and A conductor shielding layer, an anti-water tree insulating layer, an insulating shielding layer and a metal shielding layer are sequentially coated on the aluminum alloy conductor.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the aluminum alloy conductor is made of strands of trapezoidal aluminum alloy conductors.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the conductor shielding layer is extruded from cross-linked semi-conductive polyethylene.

According to an embodiment of the medium-voltage flexible water-tree-resistant aluminum alloy cable of the present invention, the water-tree-resistant insulating layer is extruded from water-tree-resistant medium-voltage cross-linked polyethylene.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the insulating shielding layer is formed by extruding cross-linked semi-conductive shielding polyethylene.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the conductor shielding layer, anti-water tree insulating layer and insulating shielding layer are wrapped on the aluminum alloy conductor by three-layer co-extrusion.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the metal shielding layer is formed by overlapping and wrapping copper tapes.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the waterproof layer is formed by longitudinally wrapping an aluminum-plastic composite film.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the non-metallic armor layer is extruded from a foamed polymer material.

According to an embodiment of the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention, the outer sheath is extruded from medium-density polyethylene.

Compared with the prior art, the medium-voltage flexible anti-water tree aluminum alloy cable of the utility model has the characteristics of excellent waterproof tree performance, light weight, small outer diameter, small bending radius, and excellent lateral pressure resistance, which greatly improves the performance of XLPE cables. service life.

Description of drawings

Fig. 1 is a schematic structural view of a medium voltage flexible water tree resistant aluminum alloy cable according to an exemplary embodiment of the present invention.

Explanation of reference signs:

1-aluminum alloy conductor, 2-conductor shielding layer, 3-anti-water tree insulation layer, 4-insulation shielding layer, 5-metal shielding layer, 6-cable core, 7-waterproof layer, 8-non-metallic armor layer, 9-outer sheath, 10-water blocking filling strip.

detailed description

All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any manner, except for mutually exclusive features and/or steps.

Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless expressly stated otherwise, may be replaced by alternative features which are equivalent or serve a similar purpose. That is, unless expressly stated otherwise, each feature is one example only of a series of equivalent or similar features.

The structure and principle of the utility model medium-voltage flexible anti-water tree aluminum alloy cable will be described in more detail below.

Fig. 1 is a schematic structural view of a medium voltage flexible water tree resistant aluminum alloy cable according to an exemplary embodiment of the present invention.

As shown in Figure 1, according to an exemplary embodiment of the present utility model, the medium-voltage flexible water-tree-resistant aluminum alloy cable includes a cable core 6, a waterproof layer 7, a non-metallic armor layer 8 and Outer sheath9. Wherein, the cable core 6 may include one insulated wire core, or may include three insulated wire cores, which may be specifically set according to the size of the wire cores. According to an exemplary embodiment of the present invention, the cable core 6 is formed by wrapping three insulated wire cores in a cable, and a water-blocking filling strip 10 is filled between the three insulated wire cores.

Wherein, the waterproof layer 7 is formed by longitudinally wrapping aluminum-plastic composite film, and is directly wrapped outside the cable core 6 . Preferably, a double-sided aluminum-plastic composite film is used to longitudinally wrap the cable core 6, and a hot air gun is used to heat and weld the seams of the longitudinal wrapping to form an airtight waterproof layer, thereby preventing moisture from penetrating in the radial direction. The advantages of simple structure, light weight, airtight and moisture-proof.

The non-metallic armor layer 8 is extruded from a foamed polymer material, and is directly extruded outside the waterproof layer 7 . Polymer materials have the advantages of aging resistance, high mechanical strength, good electrical properties, and water impermeability, while polymer materials added with foaming agents also have the advantages of weight reduction, vibration resistance, and automatic recovery of deformation after compression when meeting the above advantages. Features. Compared with the currently commonly used bimetallic armor layer, the non-metallic armor layer has a series of outstanding advantages such as light weight, corrosion resistance, no magnetic loss, soft and easy to bend, airtight and waterproof, mechanical vibration resistance, and compression deformation resistance.

The outer sheath 9 is formed by extruding medium-density polyethylene, and is directly extruded outside the non-metallic armor layer 8 . Compared with the commonly used PVC sheath, it has the characteristics of excellent mechanical properties, waterproof, wear-resistant, and excellent electrical properties.

According to the utility model, the insulated wire core includes an aluminum alloy conductor 1 and a conductor shielding layer 2, an anti-water tree insulating layer 3, an insulating shielding layer 4 and a metal shielding layer coated on the aluminum alloy conductor 1 sequentially from the inside to the outside. 5.

Wherein, the aluminum alloy conductor 1 is formed by stranding a plurality of trapezoidal aluminum alloy wires. Compared with commonly used copper conductors or aluminum conductors, it has the advantages of light weight, creep resistance, corrosion resistance, etc.; compared with the compact conductor structure, it has the advantages of small single-line deformation rate, good roundness, and high conductor filling factor , The outer diameter of the conductor is small.

The conductor shielding layer 2 is extruded from cross-linked semi-conductive polyethylene. It has the same potential as the shielded aluminum alloy conductor 1 and is in good contact with the anti-water tree insulating layer 3, so as to avoid partial discharge between the aluminum alloy conductor 1 and the anti-water tree insulating layer 3. Moreover, setting the conductor shielding layer 2 can not only shield the electromagnetic field generated by the current in the cable in the cable, but also play a certain role of grounding protection and safety protection.

The anti-water tree insulating layer 3 is formed by extruding the water tree-resistant medium-voltage cross-linked polyethylene. It not only insulates the live part of the cable from the outside, but also protects the cable from external damage, and also plays a role in resisting water trees, effectively preventing the formation of water trees.

The insulating shielding layer 4 is extruded from cross-linked semi-conductive shielding polyethylene. The insulating shielding layer 4 can improve the electric field distribution of the cable. On the one hand, it plays the role of protecting the insulating core. On the other hand, it is in good contact with the anti-water tree insulating layer 3 and forms an equipotential on the insulating surface, which can effectively avoid partial discharge.

Preferably, the conductor shielding layer 2 , the anti-water tree insulating layer 3 and the insulating shielding layer 4 are wrapped on the aluminum alloy conductor 1 through three-layer co-extrusion, forming at one time and realizing continuous cross-linking.

The metal shielding layer 5 is formed by overlapping and wrapping copper strips, which not only can realize electric field shielding, but also enables good electrical contact between different insulated wire cores.

Moreover, the medium-voltage flexible anti-water tree aluminum alloy cable of the present invention is preferably suitable for an AC rated voltage of 18/30kV.

In summary, the medium-voltage flexible anti-water tree aluminum alloy cable of the utility model has the following beneficial effects:

1) The conductor is made of aluminum alloy conductor, which has the advantages of light weight, creep resistance and corrosion resistance compared with the commonly used copper conductor or aluminum conductor; Compared with it, it has the characteristics of small deformation rate of single line, good roundness, high filling factor and small outer diameter;

2) The waterproof layer is made of double-sided aluminum-plastic composite film longitudinally welded to form an airtight waterproof layer that prevents moisture from penetrating in the radial direction, and has the advantages of simple structure, light weight, airtight and moisture-proof;

3) The armor layer is made of extruded foamed polymer material. Compared with the metal armor layer, it has light weight, corrosion resistance, no magnetic loss, soft and easy to bend, airtight waterproof, mechanical vibration resistance, and compression deformation resistance A series of outstanding advantages;

4) The outer sheath is made of extruded medium-density polyethylene. Compared with the commonly used PVC sheath, it has the characteristics of excellent mechanical properties, waterproof, wear-resistant, and excellent electrical properties.

5) It has the characteristics of excellent waterproof tree performance, light weight, small outer diameter, small bending radius, and excellent lateral pressure resistance.

The utility model is not limited to the aforementioned specific embodiments. The utility model extends to any new feature or any new combination disclosed in this specification, as well as the steps of any new method or process or any new combination disclosed.

Claims (10)

1. A medium-voltage flexible water-tree-resistant aluminum alloy cable, characterized in that, the cable includes a cable core, a waterproof layer, a non-metallic armor layer and an outer sheath that are sequentially arranged from the inside to the outside, and the cable core includes An insulated wire core or the cable core is formed by wrapping three insulated wire cores in a cable, and a water-blocking filler strip is filled between the three insulated wire cores, wherein the insulated wire core includes an aluminum alloy conductor and a A conductor shielding layer, an anti-water tree insulating layer, an insulating shielding layer and a metal shielding layer are sequentially covered on the aluminum alloy conductor from the inside to the outside. 2. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the aluminum alloy conductor is made of strands of trapezoidal aluminum alloy conductors. 3. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the conductor shielding layer is extruded from cross-linked semi-conductive polyethylene. 4. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the water-tree-resistant insulating layer is extruded from water-tree-resistant medium-voltage cross-linked polyethylene. 5. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the insulating shielding layer is extruded from cross-linked semi-conductive shielding polyethylene. 6. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to any one of claims 1 to 5, wherein the conductor shielding layer, the water-tree-resistant insulating layer and the insulating shielding layer are co-extruded by three layers wrapped on the aluminum alloy conductor. 7. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the metal shielding layer is formed by overlapping and wrapping copper tapes. 8. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the waterproof layer is formed by longitudinally wrapping an aluminum-plastic composite film. 9. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the non-metallic armor layer is extruded from a foamed polymer material. 10. The medium-voltage flexible water-tree-resistant aluminum alloy cable according to claim 1, wherein the outer sheath is extruded from medium-density polyethylene.