Energy-saving medium-voltage power cable for power system

Abstract

The utility model discloses an energy-saving medium-voltage power cable for a power system. The energy-saving medium-voltage power cable comprises a cable core, the cable comprises a cable core, a plurality of annularly distributed wire cores are arranged in the cable core, each wire core is composed of a conductor, a co-extrusion insulating layer and a metal shielding layer, a filling layer is arranged in a gap between the cable core and the wire cores, a wrapping layer is arranged outside the cable core, an isolating layer is arranged outside the wrapping layer, an armor layer is arranged outside the isolating layer, and a sheath layer is arranged outside the armor layer. The armor layer is composed of a buffer layer, a compression-resistant layer and an enhancement layer, an outer sheath is arranged outside the armor layer, and the scheme solves the problems that the transmission efficiency is affected by high resistance loss of the cable and the structural stability is poor.

Description

Technical Field

[0001] The utility model relates to the technical field of power cables, in particular to an energy-saving medium-voltage power cable for a power system. Background Art

[0002] Medium-voltage power cables in power systems refer to power cables with rated voltages between 1kV and 35kV. They are commonly used in distribution grids, urban power supply, and power transmission and distribution systems, and are an important link between substations and distribution networks. The structure of medium-voltage cables generally includes conductors, insulation layers, conductor shielding layers, insulating cable cores, metal sheaths, metal sheaths, and outer sheaths. They have excellent electrical properties, chemical corrosion resistance, and mechanical strength, and can protect cables from mechanical damage, chemical corrosion, ultraviolet rays, oxidation, and other environmental factors. In power systems, medium-voltage cables play an important role in energy and signal transmission. They are widely used in power supply systems in urban central areas, power supply to large transportation hubs such as highways, railways, and airports, as well as power supply to public places such as squares, commercial areas, hotels, and hospitals, and various industrial equipment. They are a key part of power transmission.

[0003] For example, the Chinese patent application "A Medium-Voltage Power Cable," with publication number CN210073432U, includes a cable body with a plurality of cable cells evenly arranged around an axis; a filler material filled between the cable body and the cable cells; and a heat conductor disposed in the gaps between the cable cells. This utility model provides a medium-voltage power cable that, by disposing heat conductors in the gaps between the cable cells, promptly transfers heat between the cable cells to the filler material in the cable body.

[0004] The high resistivity of the conductor materials in the above-mentioned prior art leads to significant resistance losses, which not only reduces the transmission efficiency of the cable but also increases the heat generated during operation, thereby exacerbating energy waste. Furthermore, the insulation materials of traditional cables lack heat resistance, aging resistance, and mechanical strength, making them difficult to operate stably over the long term. Their performance is particularly susceptible to degradation in complex and changing environments, thus failing to meet existing requirements. Therefore, we have proposed an energy-saving medium-voltage power cable for power systems. Utility Model Content

[0005] The purpose of the present invention is to provide an energy-saving medium-voltage power cable for a power system, so as to solve the problems in the above-mentioned background technology of high cable resistance loss affecting transmission efficiency and poor structural stability.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an energy-saving medium-voltage power cable for an electric power system, comprising a cable core; a plurality of annularly distributed wire cores are provided inside the cable core, each of the wire cores is composed of a conductor, a co-extruded insulation layer and a metal shielding layer, a filling layer is provided in the gap between the cable cores, a wrapping layer is provided outside the cable core, an isolation layer is provided outside the wrapping layer, an armor layer is provided outside the isolation layer, the armor layer is composed of a buffer layer, a pressure-resistant layer and a reinforcement layer, and an outer sheath is provided outside the armor layer.

[0007] Preferably, the conductor is formed by twisting a plurality of nano-graphene composite copper monofilaments into a bundle, the co-extruded insulating layer is wrapped around the outside of the conductor, and the metal shielding layer is spirally wound around the outside of the co-extruded insulating layer.

[0008] Preferably, the co-extruded insulating layer comprises a first co-extruded layer, a second co-extruded layer and a third co-extruded layer, which are wrapped around the outer wall of the conductor through a three-layer co-extrusion process.

[0009] Preferably, the wrapping layer is a glass fiber wrapping tape, which is spirally wrapped around the outside of the cable core.

[0010] Preferably, the isolation layer is made of cross-linked polyethylene and is wrapped around the outer wall of the wrapping layer by an extrusion device.

[0011] Preferably, the buffer layer is wrapped on the outer wall of the isolation layer by an extrusion device, the pressure-resistant layer is wound on the outer wall of the buffer layer, and the reinforcement layer is wound on the outer wall of the pressure-resistant layer.

[0012] Preferably, the outer sheath is made of polyurethane and is fixed to the outside of the armor layer by extrusion equipment.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. The cable core of the present invention can significantly improve transmission efficiency and reduce resistance loss. The conductor is made of nanographene composite copper material, which combines the excellent conductive properties of graphene with the high conductivity of copper, effectively reducing the resistance of the cable, thereby significantly reducing the resistance loss during current transmission. At the same transmission power, the heat generated by the cable is reduced, and the energy waste caused by thermal effects is reduced. The insulation composite layer uses polyethylene, polypropylene composite chemical cross-linked material and water-tree resistant chemical cross-linked polyethylene insulation material, and a high-strength, high-heat-resistant insulation barrier is formed through three-layer co-extrusion technology. This design not only significantly reduces energy loss during power transmission, but also significantly improves the heat resistance, aging resistance and mechanical strength of the cable. The anti-water tree property effectively prevents tree-like deterioration caused by water intrusion inside the insulation layer, further ensuring the long-term stable operation of the cable. The metal shielding layer improves the electric field distribution inside the cable, effectively avoiding the local discharge phenomenon caused by electric field concentration between the conductor and the insulation layer, and improving the cable's initial corona discharge and free discharge resistance.

[0015] 2. The utility model is provided with an armored composite layer, and the buffer layer has good elasticity and shock absorption performance. When the cable is subjected to external impact or vibration, the elastic rubber can effectively absorb this energy, reduce the direct impact and damage to the key components such as the internal conductor and insulation layer of the cable, and protect the electrical performance and structural integrity of the cable. The pressure-resistant layer has high strength and toughness, providing the main mechanical protection barrier for the cable, which can effectively prevent the cable from being damaged by external extrusion, impact or animal bites during laying and use, ensuring the safe operation of the cable. The reinforcement layer not only enhances the overall strength of the armor layer, but also effectively prevents the armor layer from rusting or corroding due to long-term exposure to humid or corrosive environments. With the three-layer structure design, the cable armor layer performs well in protecting the cable from external damage. This design not only improves the reliability and durability of the cable, but also reduces the risk of cable failure due to external environmental factors, providing a strong guarantee for the stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional diagram of the utility model;

[0017] Figure 2 This is a schematic diagram of the internal structure of the utility model;

[0018] Figure 3 This is a schematic diagram of the co-extruded insulation layer structure of the present utility model;

[0019] Figure 4 This is a schematic diagram of the armor layer structure of the present utility model.

[0020] In the figure: 1. Cable core; 2. Wire core; 21. Conductor; 22. Co-extruded insulation layer; 221. First co-extruded layer; 222. Second co-extruded layer; 223. Third co-extruded layer; 23. Metal shielding layer; 3. Wrapping layer; 4. Isolation layer; 5. Armor layer; 51. Buffer layer; 52. Pressure-resistant layer; 53. Reinforcement layer; 6. Outer sheath; 7. Filling layer. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] See also Figure 1-4 The utility model provides an embodiment: an energy-saving medium-voltage power cable for an electric power system, comprising a cable core 1; a plurality of ring-shaped cores 2 are arranged inside the cable core 1, each core 2 is composed of a conductor 21, a co-extruded insulation layer 22 and a metal shielding layer 23, a filling layer 7 is provided at the gap between the cable core 1 and the core 2, a wrapping layer 3 is provided outside the cable core 1, an isolation layer 4 is provided outside the wrapping layer 3, an armor layer 5 is provided outside the isolation layer 4, the armor layer 5 is composed of a buffer layer 51, a pressure-resistant layer 52 and a reinforcement layer 53, and an outer sheath 6 is provided outside the armor layer 5.

[0023] See also Figure 1 and Figure 2 The conductor 21 is made of multiple nano-graphene composite copper filaments twisted together into a bundle. A co-extruded insulation layer 22 is wrapped around the outside of the conductor 21, and a metal shielding layer 23 is spirally wound around the outside of the co-extruded insulation layer 22. The conductor 21 is made of nano-graphene composite copper material, which can effectively reduce resistance loss and improve the transmission efficiency of the cable. The metal shielding layer 23 is made of nano-graphene composite copper tape, which not only improves the electric field distribution, avoids local discharge between the conductor and the insulation layer, and improves the cable's initial corona discharge and resistance to free discharge. It also has a stronger shielding effect against electromagnetic waves, can effectively block interference from external electromagnetic fields, and ensure the stability and safety of cable transmission.

[0024] See also Figure 3 The co-extruded insulation layer 22 includes a first co-extruded layer 221, a second co-extruded layer 222 and a third co-extruded layer 223, which are wrapped on the outer wall of the conductor 21 through a three-layer co-extrusion process. The co-extruded insulation layer 22 adopts polyethylene, polypropylene composite chemical cross-linked material and water-tree resistant chemical cross-linked polyethylene insulation material, which significantly reduces the energy loss during power transmission and improves the heat resistance, aging resistance and mechanical strength of the cable.

[0025] See also Figure 1 and Figure 2The wrapping layer 3 is a glass fiber wrapping tape, which is spirally wrapped around the outside of the cable core 1. It not only has excellent mechanical strength, but also provides additional waterproof and moisture-proof functions. The corrosion resistance of the composite fiber also makes it suitable for a variety of complex environments.

[0026] See also Figure 1 and Figure 2 The isolation layer 4 is made of cross-linked polyethylene (XLPE), which is extruded onto the outer surface of the wrapping layer 3. Cross-linked polyethylene (XLPE) chemically or physically cross-links the polyethylene molecular chains, significantly improving its heat resistance, aging resistance, and mechanical strength. As an isolation layer material, XLPE offers improved long-term stability and durability, making it particularly suitable for protecting cables in high-temperature or harsh environments.

[0027] See also Figure 4 The buffer layer 51 is wrapped on the outer wall of the isolation layer 4 through an extrusion device, the pressure-resistant layer 52 is wound on the outer wall of the buffer layer 51, and the reinforcement layer 53 is wound on the outer wall of the pressure-resistant layer 52. The buffer layer 51 is elastic rubber, which is used to absorb external shocks and vibrations and reduce the direct impact on the internal structure of the cable; the pressure-resistant layer 52 is an aluminum alloy belt, which provides the main mechanical protection to prevent the cable from being damaged by external extrusion, impact or animal bites; the reinforcement layer 53 is a galvanized steel belt, which is used to prevent the armor layer from rusting or corroding due to long-term exposure to a humid or corrosive environment.

[0028] See also Figure 1 The outer sheath 6 is made of polyurethane and is fixed to the exterior of the armor layer 5 via extrusion. The polyurethane material has a high surface hardness and excellent wear resistance. This effectively protects the cable's internal structure from damage during installation and use, even from external friction or scratches, extending the cable's service life. The cable is highly resistant to chemicals such as acids, alkalis, and salts, making it less susceptible to corrosion over time. This characteristic ensures that the cable maintains stable electrical performance and mechanical strength when operating in corrosive environments such as chemical and metallurgical environments. It also withstands high temperatures for extended periods of time, with a temperature resistance range of -40°C to +80°C (even wider in some high-performance polyurethane materials). This ensures stable performance even in high-temperature environments, preventing insulation aging or failure due to elevated temperatures.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. An energy-saving medium-voltage power cable for a power system, comprising a cable core (1); characterized in that: The cable core (1) is provided with a plurality of annularly distributed wire cores (2), each of which is composed of a conductor (21), a co-extruded insulating layer (22) and a metal shielding layer (23). A filling layer (7) is provided at the gap between the cable core (1) and the wire core (2). The cable core (1) is provided with a wrapping layer (3) on the outside, an isolation layer (4) is provided on the outside of the wrapping layer (3), an armor layer (5) is provided on the outside of the isolation layer (4), and the armor layer (5) is composed of a buffer layer (51), a pressure-resistant layer (52) and a reinforcement layer (53). The armor layer (5) is provided with an outer sheath (6) on the outside.

2. The energy-saving medium-voltage power cable for a power system according to claim 1, characterized in that: The conductor (21) is formed by twisting a plurality of nano-graphene composite copper monofilaments into a bundle, the co-extruded insulating layer (22) is wrapped around the outside of the conductor (21), and the metal shielding layer (23) is spirally wound around the outside of the co-extruded insulating layer (22).

3. The energy-saving medium-voltage power cable for a power system according to claim 2, characterized in that: The co-extruded insulating layer (22) comprises a first co-extruded layer (221), a second co-extruded layer (222) and a third co-extruded layer (223), and is wrapped around the outer wall of the conductor (21) through a three-layer co-extrusion process.

4. The energy-saving medium-voltage power cable for a power system according to claim 1, characterized in that: The wrapping layer (3) is a glass fiber wrapping tape, which is wrapped spirally around the outside of the cable core (1).

5. The energy-saving medium-voltage power cable for a power system according to claim 1, characterized in that: The isolation layer (4) is made of cross-linked polyethylene and is wrapped around the outer wall of the wrapping layer (3) by an extrusion device.

6. The energy-saving medium-voltage power cable for a power system according to claim 1, characterized in that: The buffer layer (51) is wrapped on the outer wall of the isolation layer (4) through an extrusion device, the pressure-resistant layer (52) is wound on the outer wall of the buffer layer (51), and the reinforcement layer (53) is wound on the outer wall of the pressure-resistant layer (52).

7. The energy-saving medium-voltage power cable for a power system according to claim 1, characterized in that: The outer sheath (6) is made of polyurethane and is fixed to the outside of the armor layer (5) by an extrusion device.

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