Weather-proof multi-core photovoltaic cable

Abstract

The utility model relates to the technical field of cables, in particular to a weather-proof multi-core photovoltaic cable, which comprises a plurality of wire cores, the plurality of filling strips are arranged in gaps of two adjacent wire cores, and the filling strips and the wire cores are mutually twisted to form a cable core with a circular cross section; the inner protective layer is extruded outside the cable core; and the outer protective layer is extruded outside the inner protective layer. According to the invention, the filling strips are arranged among the plurality of wire cores, and the holes are formed in the filling strips to facilitate the storage of the heat-conducting paste, so that the heat generated during the working of the wire cores can be quickly and efficiently absorbed, and can be quickly conducted to the outer layer of the cable, thereby achieving the effective dissipation of the heat, and avoiding the aging acceleration of an insulating material caused by the overhigh temperature in the cable. The heat-conducting paste in the holes of the filling strip can play a buffering role, stress generated by material shrinkage due to temperature change is relieved, and the probability that the cable cracks, is damaged and the like at low temperature is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power cable technology, and more specifically to weather-resistant multi-core photovoltaic cables. Background Technology

[0002] As an important transmission medium connecting photovoltaic modules with inverters, combiner boxes and other equipment, photovoltaic cables have increasingly higher performance requirements. In outdoor environments, photovoltaic cables need to withstand complex and variable climatic conditions, such as high temperature, low temperature, humidity, ultraviolet radiation, and salt spray corrosion. These environmental factors pose severe challenges to the insulation performance, mechanical strength and service life of the cables.

[0003] When multi-core photovoltaic cables transmit current, the cores generate a large amount of heat. The flame-retardant material filling the inside of the multi-core cable makes it difficult for the heat to dissipate efficiently, causing the internal temperature of the cable to rise. This not only accelerates the aging of the cable insulation material and reduces its service life, but may also cause electrical faults, affecting the stability and reliability of the photovoltaic power generation system.

[0004] In regions with large diurnal temperature variations, when the ambient temperature drops, the insulation and sheathing materials of cables become hard and brittle, significantly reducing their flexibility and mechanical properties. This makes the cables prone to cracking and damage at low temperatures, leading to a decline in their electrical performance and even causing serious faults such as short circuits. This greatly limits the application of photovoltaic power generation systems in northern and cold regions. Utility Model Content

[0005] To address the technical problems existing in current photovoltaic cables, this utility model proposes a weather-resistant multi-core photovoltaic cable, comprising:

[0006] Multiple wire cores that are tangent to each other and twisted together;

[0007] Multiple filler strips are disposed in the gaps between two adjacent wire cores, and the filler strips are twisted together with the wire cores to form a cable core with a circular cross-section;

[0008] The inner sheath extruded outside the cable core;

[0009] An outer protective layer extruded outside the inner protective layer;

[0010] The filler strip is configured to include an outer wall surface and two inner wall surfaces. The outer wall surface of the filler strip is attached to the inner wall of the inner sheath, and the inner wall surface of the filler strip is configured to be attached to the outer wall surface of the wire core. The surface of the filler strip is provided with a plurality of first through holes connecting the outer wall surface and the inner wall surface, and the first through holes are used to fill the paste-like thermally conductive medium.

[0011] Preferably, the first through hole is configured to extend from the inner wall surface of the filler strip to the outer wall surface along the radial direction of the cable.

[0012] Preferably, the plurality of the first through holes are arranged in a matrix on the outer wall surface.

[0013] Preferably, the total area of ​​the plurality of first through holes is 30% to 50% of the total area of ​​the outer wall surface.

[0014] Preferably, the filler strip is further provided with a second through hole, which is arranged along the length direction of the filler strip.

[0015] Preferably, the second through hole is configured to have an elliptical cross-section, with its minor axis along the diameter direction of the cable.

[0016] Preferably, the filler strip is a flame-retardant rubber strip or a polyurethane foam strip.

[0017] Preferably, the wire core comprises an oxygen-free copper or aluminum alloy stranded conductor and a cross-linked polyethylene insulation layer.

[0018] Preferably, the inner protective layer comprises an irradiated low-smoke halogen-free flame-retardant polyolefin.

[0019] Preferably, the outer protective layer comprises an irradiated low-smoke halogen-free flame-retardant polyolefin.

[0020] Compared with existing technologies, the significant advantages of this weather-resistant multi-core photovoltaic cable are:

[0021] This utility model of a weather-resistant multi-core photovoltaic cable incorporates filler strips between multiple cores, with openings in the filler strips to facilitate the storage of thermally conductive grease. This allows for the rapid and efficient absorption of heat generated during core operation, which is then quickly conducted to the outer layer of the cable. This effective heat dissipation prevents accelerated aging of the insulation material due to excessively high internal temperatures, extending the cable's lifespan and reducing the risk of electrical faults caused by overheating. Simultaneously, the thermally conductive grease in the filler strip openings acts as a buffer, mitigating stress caused by material shrinkage due to temperature changes. This reduces the probability of cracking or damage at low temperatures, ensuring the cable maintains good electrical and mechanical properties even in cold regions, thus expanding the applicability of photovoltaic power generation systems. Attached Figure Description

[0022] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of the weather-resistant multi-core photovoltaic cable shown in this utility model.

[0024] Figure 2This is a schematic diagram of the cross-sectional structure of the weather-resistant multi-core photovoltaic cable shown in this utility model.

[0025] Figure 3 This is a schematic diagram of the structure of the filler strip shown in this utility model. Detailed Implementation

[0026] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0027] Combination Figure 1 As shown, this utility model proposes a weather-resistant multi-core photovoltaic cable, including multiple cores 1, filler strips 2, and an inner sheath 3 and an outer sheath 4 extruded outside the cores.

[0028] Multiple cores 1 are tangent to each other and twisted together. Multiple filler strips 2 are placed in the gap between two adjacent cores 1. The filler strips 2 and cores 1 are twisted together to form a cable core with a circular cross-section. The inner sheath 3 is extruded outside the cable core, and the outer sheath 4 is extruded outside the inner sheath 3.

[0029] Optionally, the inner sheath 3 comprises irradiated low-smoke halogen-free flame-retardant polyolefin, and the outer sheath 4 comprises irradiated low-smoke halogen-free flame-retardant polyolefin. By setting a double sheath layer, cracks in the outer sheath can be prevented from extending inward after aging, thus extending the service life of the cable.

[0030] Optionally, the conductor 1 includes an oxygen-free copper or aluminum alloy stranded conductor 11 and a cross-linked polyethylene insulation layer 12.

[0031] The stranded conductor 11 is made of multi-strand stranded wire made of high-purity oxygen-free copper or aluminum alloy material, and the cross-linked polyethylene insulation layer 12 is made of cross-linked polyethylene with excellent cold resistance. By adding appropriate amounts of antioxidants, ultraviolet absorbers and other additives, the long-term stability of the insulation layer is improved.

[0032] Furthermore, due to the large heat generation of the cable, in order to effectively dissipate the heat and avoid aging of the insulation and inner sheath caused by long-term high temperature, the filler strip 2 is configured to include an outer wall surface 201 and two inner wall surfaces 202. The outer wall surface 201 of the filler strip 2 is attached to the inner wall of the inner sheath 3, and the inner wall surface 202 of the filler strip 2 is configured to be attached to the outer wall surface of the core 1. The surface of the filler strip 2 is provided with a plurality of first through holes 22 connecting the outer wall surface 201 and the inner wall surface 202. The first through holes 22 are used to fill the paste-like heat-conducting medium.

[0033] In an optional embodiment, the paste-like thermal conductive medium may be selected as thermal grease, which includes a substrate and a filler. The substrate may be selected as silicone grease, and the filler may be selected as alumina particles, ceramic particles, or graphite particles, etc. The thermal grease has good thermal conductivity and heat storage capacity, and can quickly conduct heat and store some heat.

[0034] In this way, the heat generated by the core 1 is conducted to the outside of the cable in a timely manner through the paste-like heat-conducting medium in the first through hole 22, so as to achieve effective heat dissipation and avoid the insulation material inside the cable aging accelerated due to excessive temperature, thereby extending the service life of the cable.

[0035] Furthermore, the first through-hole 22 is configured to extend from the inner wall surface 202 of the filler strip 2 to the outer wall surface 201 along the radial direction of the cable. In this way, the first through-hole 22 forms multiple divergent heat dissipation channels, which helps to increase the outward diffusion of heat from the wire core 1.

[0036] Optionally, the plurality of first through holes 22 are arranged in a matrix on the outer wall surface 201. The total area of ​​the plurality of first through holes 22 is 30% to 50% of the total area of ​​the outer wall surface 201.

[0037] Furthermore, the filler strip 2 is also provided with a second through hole 21, which is arranged along the length of the filler strip 2. In this way, the second through hole 21 can serve as a storage channel for the paste-like thermal conductive medium, which can increase the capacity of the paste-like thermal conductive medium and also improve the elasticity of the filler strip 2, so as to reduce stress concentration under cable bending conditions.

[0038] At the same time, more paste-like thermal conductive medium can play a buffering role, alleviate the stress caused by material shrinkage due to diurnal temperature changes, reduce the probability of cable cracking and damage at low temperatures, and ensure that the cable can maintain good electrical and mechanical properties in cold regions.

[0039] In an optional embodiment, the second through hole 21 is configured with an elliptical cross-section, with its minor axis aligned with the diameter of the cable, and the filler strip 2 is a flame-retardant rubber strip or a polyurethane foam strip. Thus, the filler strip 2 not only serves to store the paste-like heat-conducting medium but also possesses good elasticity, satisfying the bending performance requirements of the cable.

[0040] Specifically, before extruding the inner protective layer 3 and the outer protective layer 4 of a predetermined length, thermal paste is injected into the first through hole 22 by means of vacuum injection or pressure filling, and the second through hole 21 is filled. After removing the excess thermal paste, the inner protective layer 3 and the outer protective layer 4 are formed by extrusion.

[0041] In conjunction with the above embodiments, this application, by setting filler strips between multiple wire cores and opening holes in the filler strips to facilitate the storage of thermally conductive paste, can quickly and efficiently absorb the heat generated during the operation of the wire cores and rapidly conduct it to the outer layer of the cable, achieving effective heat dissipation. This avoids accelerated aging of the insulation material inside the cable due to excessively high temperatures, extends the cable's service life, and reduces the risk of electrical faults caused by overheating. At the same time, the thermally conductive paste in the openings of the filler strips can play a buffering role, alleviating the stress caused by material shrinkage due to temperature changes, reducing the probability of cracking and damage in the cable at low temperatures, ensuring that the cable maintains good electrical and mechanical properties even in cold regions, and expanding the application range of photovoltaic power generation systems.

[0042] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A weather resistant multi-core photovoltaic cable, characterized by, include: Multiple wire cores that are tangent to each other and twisted together (1); Multiple filler strips (2) are disposed in the gap between two adjacent wire cores (1), and the filler strips (2) are twisted together with the wire cores (1) to form a cable core with a circular cross section; The inner sheath (3) is extruded outside the cable core; An outer sheath (4) is extruded over the inner sheath (3); The filler strip (2) is configured to include an outer wall surface (201) and two inner wall surfaces (202). The outer wall surface (201) of the filler strip (2) is attached to the inner wall of the inner protective layer (3). The inner wall surface (202) of the filler strip (2) is configured to be attached to the outer wall surface of the wire core (1). The surface of the filler strip (2) is provided with a plurality of first through holes (22) connecting the outer wall surface (201) and the inner wall surface (202). The first through holes (22) are used to fill the paste-like heat-conducting medium.

2. The weather resistant multi-core photovoltaic cable of claim 1, wherein, The first through hole (22) is configured to extend from the inner wall surface (202) of the filler strip (2) to the outer wall surface (201) along the radial direction of the cable.

3. The weatherable multi-core photovoltaic cable of claim 1, wherein, Multiple first through holes (22) are arranged in a matrix on the outer wall surface (201).

4. The weatherable multi-core photovoltaic cable of claim 1, wherein, The total area of ​​the plurality of first through holes (22) is 30% to 50% of the total area of ​​the outer wall surface (201).

5. The weather-resistant multi-core photovoltaic cable according to any one of claims 1-4, characterized in that, The filling strip (2) is also provided with a second through hole (21), which is arranged along the length direction of the filling strip (2).

6. The weatherable multi-core photovoltaic cable of claim 5, wherein, The second through hole (21) is configured to have an elliptical cross-section, with its minor axis along the diameter of the cable.

7. The weatherable multi-core photovoltaic cable of claim 1, wherein, The filler strip (2) is a flame-retardant rubber strip or a polyurethane foam strip.

8. The weatherable multi-core photovoltaic cable of claim 1, wherein, The core (1) includes an oxygen-free copper or aluminum alloy stranded conductor (11) and a cross-linked polyethylene insulation layer (12).

9. The weatherable multi-core photovoltaic cable of claim 1, wherein, The inner protective layer (3) comprises an irradiated low-smoke halogen-free flame-retardant polyolefin.

10. The weatherable multi-core photovoltaic cable of claim 1, wherein, The outer protective layer (4) comprises an irradiated low-smoke halogen-free flame-retardant polyolefin.

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