Impact resistant high conductive efficiency solar photovoltaic cable

Abstract

The utility model provides a kind of high electrically conductive efficiency solar photovoltaic cable of impact resistance, including conductor core, insulating layer and sheath layer, the conductor core includes the multiple layers of lead core distributed from inside to outside, multiple layers of lead core is twisted in normal stranding mode, and the lead core includes first lead core and second lead core, the second lead core is more loose compared to the first lead core, except center layer, the first lead core and second lead core are evenly alternately distributed in circumferential direction, the thermal expansion coefficient of the insulating layer is greater than the thermal expansion coefficient of the sheath layer, wherein two groups of lead cores in different levels are alternately distributed in circumferential direction, not only lead wire between its inner and outer layers is limited under thermal expansion, offset axial creep, enhance the impact resistance of cable, and the insulating layer can absorb internal stress, avoid peeling or cracking between conductor and insulating layer due to thermal stress, and the overall cable deformation is limited by the sheath layer with small thermal expansion amount.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, and more specifically to an impact-resistant, high-conductivity solar photovoltaic cable. Background Technology

[0002] Photovoltaic cables are special cables designed specifically for solar photovoltaic power plants, primarily used for DC power transmission. Their conductors are typically tinned copper wire, with cross-linked polyethylene or irradiated cross-linked polyolefin as insulation. Photovoltaic cables also feature low DC resistance, high insulation resistance, and excellent voltage withstand performance, resulting in high transmission efficiency and minimal signal attenuation. They are widely used in module series connection, string-parallel connection, and inverter connection scenarios, and are also suitable for wind power generation, energy storage systems, and building-integrated photovoltaics (BIPV), serving as a key component ensuring the efficient and stable operation of photovoltaic systems.

[0003] The impact resistance of photovoltaic cables is mainly reflected in their resistance to pressure, bending, tension, cross tensile loads, and strong impacts. For example, when photovoltaic cables are laid on the sharp edge of a roof structure, the cable is in a bent state in that part. Its outer part is stretched and its inner part is compressed. In addition, due to the temperature difference between day and night, the outer sheath material of the cable in this part repeatedly expands and contracts. The adhesion between the inner conductor and the outer sheath material decreases and creep occurs, causing wear between the metal conductor and the outer sheath. Over time, this will lead to a decrease in insulation performance and eventually cause a short circuit. Utility Model Content

[0004] In view of the shortcomings of existing photovoltaic cables, this utility model proposes an impact-resistant, high-conductivity solar photovoltaic cable, comprising:

[0005] Conductor core, located at the cable core position;

[0006] An insulating layer is extruded and covered on the outside of the conductor core;

[0007] Sheath layer, extruded and covered on the outside of the insulation layer;

[0008] The conductor core comprises multiple layers of conductor cores distributed from the inside out. The multiple layers of conductor cores are stranded in a regular stranding manner. The conductor core includes a first conductor core and a second conductor core. The second conductor core is looser than the first conductor core. Except for the central layer, the first conductor core and the second conductor core are evenly and alternately distributed in the circumferential direction. The thermal expansion coefficient of the insulation layer is greater than that of the sheath layer.

[0009] Preferably, the first conductor core includes multiple regularly stranded first conductors, and the second conductor core includes multiple stranded second conductors. After the second conductors are bundled or regularly stranded into single bundles, the multiple single bundles are regularly stranded to form the second conductor core. The diameter of the first conductor is larger than the diameter of the second conductor.

[0010] Preferably, the diameter of the single filament of the first conductor is 2 to 5 times that of the single filament of the second conductor.

[0011] Preferably, after the first and second conductor cores are compressed, the insulating layer is extruded and covers the outside of the conductor cores, wherein the compression deformation at the second conductor core is greater than the compression deformation at the first conductor core.

[0012] Preferably, the insulating layer includes an inner bonding portion that is bonded to the outer walls of the first conductor core and the second conductor core, and an outer bonding portion that is bonded to the outer wall of the sheath layer. The inner surface contour of the inner bonding portion is a non-circular cross-section, and the outer surface contour of the outer bonding portion is a circular cross-section.

[0013] Preferably, the insulating layer comprises a cross-linked polyethylene insulating layer.

[0014] Preferably, the sheath layer comprises a polyethylene or polyvinyl chloride sheath layer.

[0015] Compared with the prior art, the significant advantages of the photovoltaic cable of this utility model are:

[0016] In the photovoltaic cable design of this utility model, by setting the conductor core as two sets of conductor cores with different wire diameters and twisting the two sets of conductor cores in a regular twisting manner, and the two sets of conductor cores are alternately distributed in the circumferential direction in different layers, not only do the conductors between the inner and outer layers restrict each other under thermal expansion, thus balancing the thermomechanical stress inside and offsetting axial creep, but when the cable is subjected to external impact, the conductor core with smaller wire diameter can provide deformation space, enhancing the impact resistance of the cable. At the same time, an insulation layer with greater thermal expansion deformation is set on the inner side of the sheath layer. This insulation layer can absorb internal stress and prevent the conductor and insulation layer from peeling or cracking due to thermal stress. The overall cable deformation is limited by the sheath layer with small thermal expansion. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the layered structure of a high-conductivity, impact-resistant solar photovoltaic cable according to an embodiment of this utility model.

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of a high-conductivity solar photovoltaic cable with impact resistance, as shown in an embodiment of this utility model.

[0020] Figure 3This is a schematic diagram of the cross-sectional structure of the conductor core in an uncompressed state, as shown in an embodiment of this utility model.

[0021] Figure 4 This is a schematic diagram of the cross-sectional structure of the conductor core under the compressed state shown in the embodiment of this utility model.

[0022] The attached figures are labeled as follows:

[0023] 10. Conductor core; 11. First conductor core; 111. First conductor; 12. Second conductor core; 121. Second conductor; 20. Insulation layer; 21. Inner bonding part; 22. Outer bonding part; 30. Sheath layer. Detailed Implementation

[0024] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0025] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the impact-resistant, high-conductivity solar photovoltaic cable of this utility model aims to solve the problem of sheath wear caused by conductor creep, and mainly includes a conductor core 10, an insulation layer 20 and a sheath layer 30.

[0026] As an optional embodiment, the conductor core 10, located at the cable core position, serves as a current carrier for efficiently transmitting the direct current generated by the solar panel to an inverter or energy storage device.

[0027] The insulation layer 20 is extruded and covers the outside of the conductor core 10, providing electrical insulation and ensuring that the current is transmitted along a predetermined path.

[0028] The sheath layer 30 is extruded and covers the outside of the insulation layer 20 to resist physical damage (such as compression, cutting, bending) and prevent the cable from being damaged during laying or operation.

[0029] As an optional embodiment, the conductor core 10 includes multiple conductor cores distributed from the inside to the outside. The multiple conductor cores are stranded in a regular stranding manner. The conductor core includes a first conductor core 11 and a second conductor core 12. The second conductor core 12 is looser than the first conductor core 11. Except for the central layer, the first conductor core 11 and the second conductor core 12 are evenly and alternately distributed in the circumferential direction.

[0030] The regular stranding is a 1+6+12+18 stranding pattern. The center layer is either the first conductor 11 or the second conductor 12. Each outer layer consists of the first conductor 11 and the second conductor 12 evenly alternating in the circumferential direction, and the stranding directions of adjacent conductor layers are opposite. Thus, when the conductor expands thermally, the left-hand and right-hand conductors restrict each other, which can limit the creep deformation of the conductor and make it almost undeformed in the axial direction.

[0031] As an optional embodiment, the insulation layer 20 is a cross-linked polyethylene insulation layer.

[0032] The sheath layer 30 can be made of polyethylene or polyvinyl chloride.

[0033] Among them, the coefficient of thermal expansion of the insulation layer 20 (cross-linked polyethylene insulation layer) is greater than that of the sheath layer 30 (polyethylene or polyvinyl chloride sheath layer). When the insulation layer 20 and the sheath layer 30 undergo thermal deformation, the expansion of the insulation layer 20 is greater than that of the sheath layer 30. The insulation layer 20 can absorb internal stress and prevent the conductor from peeling or cracking due to thermal stress between it and the insulation layer 20, while the sheath layer 30 restricts the overall cable deformation.

[0034] like Figure 3 In the example shown, the first conductor 11 includes multiple regularly twisted first conductors 111, and the second conductor 12 includes multiple twisted second conductors 121. The diameter of a single filament of the first conductor 111 is 2 to 5 times the diameter of a single filament of the second conductor 121. After the second conductors 121 are bundled or regularly twisted into single bundles, multiple single bundles are regularly twisted together to form the second conductor 12.

[0035] Among them, the first conductor 111 with a larger wire diameter is twisted in a regular twisting manner. The conductors between its inner and outer layers restrict each other under thermal expansion, so that the internal thermomechanical stress is balanced and the axial creep is counteracted.

[0036] Correspondingly, the second conductor 121 has a smaller wire diameter. After the second conductor 121 is twisted or regularly twisted into a single core, multiple single cores are then regularly twisted together. Compared with the first conductor 11, the second conductor 12 has more gaps. When the cable is subjected to external impact, the second conductor 12 can provide deformation space, enhance the impact resistance of the cable, and provide stronger flexibility and resistance to bending fatigue compared to the first conductor 11.

[0037] As an optional embodiment, in order to further limit the axial creep of the conductor core 10, after the first conductor core 11 and the second conductor core 12 are compressed, the insulating layer 20 is extruded and covered on the outside of the conductor core 10, wherein the compression deformation at the second conductor core 12 is greater than the compression deformation at the first conductor core 11.

[0038] As an optional embodiment, the insulating layer 20 includes an inner bonding portion 21 that is bonded to the outer wall of the first conductor 11 and the second conductor 12, and an outer bonding portion 22 that is bonded to the outer wall of the sheath layer 30.

[0039] The inner surface profile of the inner bonding portion 21 is a non-circular cross section, while the outer surface profile of the outer bonding portion 22 is a circular cross section. Thus, in the axial direction of the cable, the inner bonding portion 21 follows the winding of the conductor core 10 in a spiral distribution, which increases the resistance to axial creep of the conductor core 10 due to the irregular inner bonding portion 21, further restricting the axial creep of the conductor core 10.

[0040] In conjunction with the above embodiments, by setting the conductor core 10 as two sets of conductor cores with different wire diameters and twisting the two sets of conductor cores in a regular twisting manner, and with the two sets of conductor cores being alternately distributed in the circumferential direction within different layers, not only do the conductors between their inner and outer layers restrict each other under thermal expansion, thus balancing the thermomechanical stress inside and offsetting axial creep, but when the cable is subjected to external impact, the conductor core with smaller wire diameter can provide deformation space, enhancing the cable's impact resistance. At the same time, an insulation layer 20 with greater thermal expansion deformation is provided on the inner side of the sheath layer 30. This insulation layer 20 can absorb internal stress, preventing the conductor and insulation layer 20 from peeling or cracking due to thermal stress, and the overall cable deformation is limited by the sheath layer 30 with smaller thermal expansion.

[0041] 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 shock-resistant, high-conductivity solar photovoltaic cable, characterized in that, include: Conductor core (10) is located at the cable core position; An insulating layer (20) is extruded and covered on the outside of the conductor core (10); The sheath layer (30) is extruded and covered on the outside of the insulating layer (20); The conductor core (10) includes multiple conductor cores distributed from the inside to the outside. The multiple conductor cores are stranded in a regular stranding manner. The conductor core includes a first conductor core (11) and a second conductor core (12). The second conductor core (12) is looser than the first conductor core (11). Except for the central layer, the first conductor core (11) and the second conductor core (12) are evenly and alternately distributed in the circumferential direction. The thermal expansion coefficient of the insulation layer (20) is greater than that of the sheath layer (30).

2. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 1, characterized in that, The first conductor (11) includes multiple regular stranded first conductors (111), and the second conductor (12) includes multiple stranded second conductors (121). The second conductors (121) are stranded or regularly stranded into single bundles, and multiple single bundles are regularly stranded to form the second conductor (12). The diameter of the first conductor (111) is larger than the diameter of the second conductor (121).

3. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 2, characterized in that, The diameter of the monofilament of the first conductor (111) is 2 to 5 times that of the monofilament of the second conductor (121).

4. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 1, characterized in that, After the first conductor (11) and the second conductor (12) are compressed, the insulating layer (20) is extruded and covers the outside of the conductor core (10), wherein the compression deformation at the second conductor (12) is greater than the compression deformation at the first conductor (11).

5. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 4, characterized in that, The insulating layer (20) includes an inner bonding portion (21) that is bonded to the outer wall of the first conductor (11) and the second conductor (12) and an outer bonding portion (22) that is bonded to the outer wall of the sheath layer (30).

6. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 5, characterized in that, The inner surface profile of the inner fitting part (21) is a non-circular cross section.

7. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 5, characterized in that, The outer surface contour of the outer bonding part (22) is a circular cross section.

8. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 1, characterized in that, The insulation layer (20) includes a cross-linked polyethylene insulation layer.

9. The impact-resistant, high-conductivity solar photovoltaic cable according to claim 1, characterized in that, The sheath layer (30) includes a polyethylene or polyvinyl chloride sheath layer.

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