A torsion-resistant cable for a photovoltaic system

Abstract

The application relates to the technical field of photovoltaic cables, in particular to a torsion-resistant cable for a photovoltaic system, which comprises a plurality of cores arranged in a ring array, a plurality of radiators arranged between two adjacent cores and attached to the cores, an inner winding layer for wrapping the cores and the radiators, a plurality of structure layers arranged in a ring array on the outer side of the inner winding layer and corresponding to the radiators one by one, a plurality of reinforcing rings arranged along the axial direction of the structure layers at intervals, each reinforcing ring being in a spiral shape surrounding all the structure layers and having at least one complete turn, each reinforcing ring clamping the structure layers after installation, an outer protective layer wrapping the reinforcing rings and the structure layers, the inner wall of the outer protective layer being provided with a groove, the width of the groove gradually increasing from one side to the other side, and the reinforcing rings extending into the groove and being attached to the side wall of the groove. The application can effectively solve the problem of poor torsion resistance of the photovoltaic cable in the background art.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cable technology, and more particularly to an anti-torsion cable for photovoltaic systems. Background Technology

[0002] Photovoltaic cables are specialized power transmission cables for photovoltaic systems, primarily used to connect photovoltaic modules, inverters, combiner boxes, and other equipment to transmit electrical energy. Since photovoltaic systems are typically installed outdoors, photovoltaic cables are also exposed to the elements for extended periods. Therefore, these cables must ensure high conductivity while also possessing sufficient environmental adaptability.

[0003] During the installation and use of photovoltaic cables, they are susceptible to torsional stress, which mainly includes: mechanical stress during installation (it is difficult to avoid twisting of the cable during the adjustment of the cable route), environmental influences during use (such as wind causing the cable to swing continuously and twist), and the influence of external objects (such as external objects snagging or hitting the cable, causing the cable to twist). Twist problems can directly lead to a decrease in conductivity, insulation failure, or short circuit risk. Therefore, photovoltaic cables need to have a certain degree of torsional resistance.

[0004] In existing photovoltaic cables, the main method of torsion resistance is to strengthen the overall cable structure, such as by adding fillers for support. However, these structures not only severely affect the cable's heat dissipation capacity but also have limited effect on improving the cable's torsion resistance. A better torsion resistance structure for photovoltaic cables is needed. Summary of the Invention

[0005] This invention provides an anti-torsion cable for photovoltaic systems, which can effectively solve the problem of poor torsion resistance of photovoltaic cables in the prior art.

[0006] This invention provides an anti-torsion cable for photovoltaic systems, comprising:

[0007] Multiple wire cores are arranged in a ring array;

[0008] Multiple heat pipes are respectively placed between two adjacent wire cores and are in close contact with the wire cores;

[0009] Inner winding layer, used to wrap the wire core and heat dissipation tube;

[0010] Multiple structural layers are arranged in a ring array outside the inner winding layer, and each corresponds to a heat sink; the outer side of each structural layer is curved, and the outer side of multiple structural layers is formed into a circle after being combined.

[0011] Multiple reinforcing rings are spaced apart along the axial direction of the structural layers; each reinforcing ring is a spiral that wraps around all structural layers, and the spiral has at least one complete turn; each reinforcing ring clamps the structural layers after installation.

[0012] The outer protective layer encloses the reinforcing ring and the structural layer; the inner wall of the outer protective layer is provided with a groove, the width of which gradually increases from one side to the other; the outer side of the reinforcing ring extends into the groove and fits against the side wall of the groove.

[0013] Furthermore, the diameter of the heat dissipation pipe is set so that the cross-section of the inner winding layer forms a convex polygon.

[0014] Furthermore, a V-shaped groove is provided on the inner side of the structural layer to fit the inner winding layer, and the heat dissipation pipe extends into the V-shaped groove.

[0015] Furthermore, the heat dissipation pipe is a metal braided flexible hose.

[0016] Furthermore, the reinforcing ring includes bent sections at both ends and a curved section in the middle, with a bending groove provided between the bent sections and the curved section.

[0017] Furthermore, the installation angle of each reinforcing ring is different from the installation angle of its two adjacent reinforcing rings.

[0018] Furthermore, a flexible wrapping layer is provided on the outer side of the reinforcing ring, and the two ends of the flexible wrapping layer extend to the structural layers on both sides of the reinforcing ring.

[0019] Furthermore, the flexible wrapping layer is a heat-shrinkable film wrapping layer.

[0020] Furthermore, the wire core includes a conductor, an insulation layer, and a metal shielding layer arranged sequentially from the inside out.

[0021] Furthermore, the insulating layer is characterized by having a double-layer structure, comprising an inner cross-linked polyethylene layer and an outer flame-retardant polyolefin layer.

[0022] The technical solution of this invention can achieve the following technical effects:

[0023] This cable uses an alternating arrangement of conductors and heat dissipation tubes to ensure efficient heat dissipation of the conductors. Furthermore, the combination of reinforcing rings and the gradually expanding grooves of the outer protective layer allows the cable to convert some of the external force into energy for the reinforcing ring when subjected to torsion. The deformation support of the reinforcing rings also isolates the inner and outer layers of the cable, effectively improving the cable's torsional resistance. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the anti-torsion cable used in the photovoltaic system of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the anti-torsion cable for the photovoltaic system in this invention after the outer protective layer has been removed;

[0027] Figure 3 This is a schematic diagram of the structure of the anti-torsion cable for the photovoltaic system in this invention after removing the outer protective layer and the flexible wrapping layer;

[0028] Figure 4 This is a schematic diagram of the structure before and after the installation of the reinforcing ring in this invention;

[0029] Figure 5 This is a schematic diagram of the structure of the outer protective layer in this invention.

[0030] Reference numerals: 1. Core wire; 2. Heat dissipation tube; 3. Inner winding layer; 4. Structural layer; 5. Reinforcing ring; 51. Bending section; 52. Curved surface section; 53. Bending groove; 6. Outer protective layer; 61. Groove; 7. Flexible wrapping layer. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0032] In the description of this invention, it should be noted that the orientations or positional relationships indicated by terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inner", and "outer" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] This invention relates to an anti-torsion cable for photovoltaic systems, such as... Figures 1-3 As shown, from the inside out, it includes a wire core 1, a heat dissipation pipe 2, an inner winding layer 3, a structural layer 4, a reinforcing ring 5, and an outer protective layer 6. The following are the specific structures of each component and their arrangement:

[0035] Multiple conductors 1 are located at the center of the cable and are arranged in a ring array, with adjacent conductors 1 touching each other; inside each conductor are multiple copper wires twisted together to form a conductor, which enables the cable to transmit electricity.

[0036] Multiple hollow heat dissipation tubes 2 are located at the center of the cable and are also distributed in a ring array. The number of heat dissipation tubes 2 is the same as the number of wire cores 1, so that each heat dissipation tube 2 can be embedded between two adjacent wire cores 1, and the outer wall of each heat dissipation tube 2 is in contact with the outer wall of the two adjacent wire cores 1. The outer surfaces of the wire cores 1 and the heat dissipation tubes 2 are sprayed with a thermally conductive layer (such as silicone grease) and tightly bonded to the winding layer 3 to form a direct heat transfer path, which is used to absorb the heat generated during the power transmission of the wire cores 1 and transfer it outward to achieve heat dissipation.

[0037] The inner winding layer 3 is made of alternating spiral winding of aramid fiber tape and polyester film to form a flame-retardant layer and a waterproof layer. The inner winding layer 3 can be used to wrap the wire core 1 and the heat dissipation tube 2, so that the wrapped wire core 1 and the heat dissipation tube 2 are tightly attached to each other to prevent them from loosening, and other spaces in the inner winding layer 3 can be left open, thereby increasing the heat dissipation space of the wire core 1 and reducing the overall weight of the cable.

[0038] Multiple structural layers 4 are arranged in a ring array outside the inner winding layer 3. The number of structural layers 4 is the same as the number of heat sinks 2, and they correspond one-to-one with each heat sink 2. The center of each structural layer 4 is aligned with the heat sink 2. The outer side of each structural layer 4 is an arc-shaped surface, and the multiple outer sides of multiple structural layers 4 are combined to form a circle.

[0039] Multiple reinforcing rings 5 ​​are distributed along the axial direction of the structural layer 4 (i.e., the axial direction of the cable), with a certain interval between adjacent reinforcing rings 5; each reinforcing ring 5 is made of metal, and the reinforcing ring 5 is in the shape of a spiral that wraps around the outside of all the structural layers 4, and the spiral has at least one complete turn, usually within 1 to 1.5 turns, so that each reinforcing ring 5 can achieve elastic compression deformation like a spring; after each reinforcing ring 5 is installed, the inner side of the reinforcing ring 5 will clamp the structural layer 4.

[0040] The outer protective layer 6 is a relatively thick rubber layer used to wrap the reinforcing ring 5 and the structural layer 4; the inner wall of the outer protective layer 6 is provided with grooves 61, such as... Figure 5 As shown, the width of the groove 61 gradually increases from one side to the other; the outer ring of the reinforcing ring 5 extends into the groove 61, and both sides of the portion of the reinforcing ring 5 extending into the groove 61 are in contact with the sidewall of the groove 61.

[0041] The main reason for the poor torsional resistance of traditional photovoltaic cables is that the inner conductor and the outer protective layer are basically integrated. Therefore, no matter how the outer protective layer is reinforced, it will still twist under stress, and the inner conductor will inevitably rotate along with it, affecting the normal operation of the conductor. Therefore, the torsional resistance is always poor.

[0042] This cable employs an internal and external separation mechanism during torsion to address the poor torsional resistance of existing structures. The specific principle is as follows:

[0043] When torsion occurs perpendicular to the axial direction, the grooves 61 on the outer protective layer 6 divide it into multiple segments. Each segment's ends are abutted by a metal reinforcing ring 5, which is less prone to deformation. This reduces the deflection of each segment, making bending less likely. Furthermore, when external force is applied to the outer protective layer 6, if it were a continuous long segment, the entire force would act on it, causing significant deformation. However, in this cable, after the outer protective layer 6 is subjected to force, part of the force is transmitted to the end faces of each segment and then to the reinforcing ring 5. The force is used to compress the reinforcing ring 5, thereby reducing the force used to deform the outer protective layer 6. At the same time, after the reinforcing ring 5 is compressed, not only can its reaction force further limit the deformation of the cable, but the diameter of the reinforcing ring 5 will also increase as the reinforcing ring 5 is compressed, thereby separating the inside of the reinforcing ring 5 from the structural layer 4, and the outside will move outward to support the outer protective layer 6, thereby isolating the internal core 1 from the external force. Furthermore, the core 1, heat dissipation pipe 2, inner winding layer 3, and structural layer 4 as a whole can have a slight rotation space, thereby reducing the deformation inside the cable and achieving the purpose of protecting the core 1.

[0044] When axial torsion occurs, the structure of the groove 61, which gradually increases in width from one side to the other, is originally adapted to the outer shape of the reinforcing ring 5. However, when subjected to external force that causes the outer protective layer 6 to rotate, the reinforcing ring 5 will initially not rotate due to the constraint of the internal structure. As the groove 61 rotates, the widest side of the reinforcing ring 5 will move from the widest part of the groove 61 to the narrowest part, thereby compressing the reinforcing ring 5. Similarly, as mentioned above, the compression of the reinforcing ring 5 gives the internal structure of the cable a slight rotation space, thereby reducing the deformation inside the cable and achieving the purpose of protecting the core 1. Furthermore, the deformation of the reinforcing ring 5 can also generate a reaction force that prevents the outer protective layer 6 from rotating, thereby further reducing the twisting of the cable.

[0045] Preferably, when setting the heat dissipation pipe 2, it is necessary to control the diameter of the heat dissipation pipe 2. If the diameter of the heat dissipation pipe 2 is too small, the inner winding layer 3 will only be wound on the wire core 1, and the heat dissipation pipe 2 will be in a free swinging state in the inner winding layer 3, affecting the heat conduction function. Therefore, the diameter of the heat dissipation pipe 2 needs to be set large enough so that the cross section of the inner winding layer 3 can form a convex polygon after winding. The convex polygon is a polygon with all interior angles less than 180°. In this way, the heat dissipation pipe 2 can be pressed against the wire core 1 by the inner winding layer 3.

[0046] Preferably, the inner side of the structural layer 4 is provided with a V-shaped groove that fits with the inner winding layer 3, which facilitates heat conduction to the outside; the V-shaped groove can also restrict the position of the heat dissipation pipe 2, and the heat dissipation pipe 2 will extend into the V-shaped groove and be stuck by the V-shaped groove to prevent the heat dissipation pipe 2 from tilting and shaking.

[0047] Preferably, the heat dissipation pipe 2 is a metal braided hose. The metal braided hose is a tubular structure formed by braiding stainless steel wire into a mesh wall. It can produce slight deformation after being pressed, which increases the contact area between the heat dissipation pipe 2 and the wire core 1 and the inner winding layer 3, thereby improving the heat dissipation efficiency. Moreover, the metal braided hose will not deform further after deforming to a certain extent, ensuring that the heat dissipation pipe 2 is always hollow and ensuring the heat dissipation effect.

[0048] In normal circumstances, the entire cable is processed continuously, so the reinforcing ring 5 is not convenient to be installed in a set manner. In this cable, it is preferable to design the reinforcing ring 5 to include bent sections 51 at both ends and a curved section 52 in the middle. A bending groove 53 is provided between the bent sections 51 and the curved section 52, and the opening of the bending groove 53 faces the inside of the reinforcing ring 5.

[0049] Before the installation of reinforcing ring 5, its structure is as follows: Figure 4As shown, the bending sections 51 at both ends bend outwards, forming a U-shape for the reinforcing ring 5. This allows the reinforcing ring 5 to be manufactured on a large scale and at low cost through stamping. During installation, the reinforcing ring 5 is simply slipped onto the cable component through the U-shaped opening, and then the bending sections 51 at both ends of the U-shape are bent inwards using a tooling fixture. The tooling fixture restricts the position of the bent sections 51 after bending, forming a spiral shape for the reinforcing ring 5, thus completing the installation. The bending groove 53 can be used to determine the bending rotation center of the bending section 51, preventing the reinforcing ring 5 from becoming other shapes.

[0050] Preferably, when setting the reinforcing rings 5, the installation angle of each reinforcing ring 5 is different from the installation angle of its two adjacent reinforcing rings 5. For example, taking Figure 3 as an example, based on the angle of the same end of each reinforcing ring 5, the following will occur: the first reinforcing ring 5 is installed at 0°, the second reinforcing ring 5 is installed at 120°, the third reinforcing ring 5 is installed at 240°, the fourth reinforcing ring 5 is installed at 0°, and so on. In this way, no matter which direction the outer protective layer 6 is subjected to force, there will always be a reinforcing ring 5 that is at the optimal working angle, thereby ensuring the overall torsional resistance of the cable.

[0051] The outer protective layer 6 is typically formed by directly extruding molten rubber material onto the internal structure of the cable. Therefore, forming the groove 61 through post-processing is difficult, especially when the installation angle of each reinforcing ring 5 differs from that of its two adjacent reinforcing rings 5, making it even harder to ensure the fit between the groove 61 and the reinforcing ring 5. Therefore, this cable also includes a flexible wrapping layer 7 on the outside of the reinforcing ring 5. The two ends of the flexible wrapping layer 7 extend to the structural layers 4 on both sides of the reinforcing ring 5. After the flexible wrapping layer 7 wraps around the reinforcing ring 5, it automatically forms a shape identical to the desired groove 61, and completely seals the reinforcing ring 5. This ensures that when the molten rubber material reaches the reinforcing ring 5, it is blocked by the flexible wrapping layer 7, forming the groove 61. Furthermore, after cable processing, the flexible wrapping layer 7 does not interfere with the deformation function of the reinforcing ring 5, ensuring the cable's torsional resistance is maintained.

[0052] Preferably, the flexible wrapping layer 7 is set as a heat shrink film wrapping layer. In this way, during the production process, the heat shrink film can be quickly wrapped around the approximate position of the reinforcing ring 5. Then, as long as hot air is blown on it, the heat shrink film wrapping layer can automatically shrink to form a flexible wrapping layer 7 that wraps around and fits the reinforcing ring 5, which greatly facilitates the forming of the flexible wrapping layer 7.

[0053] Core 1 comprises, from the inside out, a conductor, an insulation layer, and a metal shielding layer. The conductor employs a layered stranded structure: a single annealed copper wire at the center, inner copper wires stranded in a right-hand spiral, and outer stranded in a left-hand spiral to counteract stranding torque. The insulation layer is a double-layer structure, consisting of an inner cross-linked polyethylene layer and an outer flame-retardant polyolefin layer. A corrugated pattern is pressed into the surface of the rubber layer along the axial direction to extend the creepage distance. The shielding layer uses a composite structure of longitudinally wrapped aluminum foil and tinned copper wire braiding. Conductive adhesive is applied to the overlapping edges of the aluminum foil to ensure continuous shielding. The braiding density gradually changes from the center of the core towards both ends to accommodate bending flexibility.

[0054] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A torsion-resistant cable for a photovoltaic system, characterized in that, include: Multiple wire cores (1) are arranged in a ring array; Multiple heat dissipation tubes (2) are respectively disposed between two adjacent wire cores (1) and are in contact with the wire cores (1); An inner winding layer (3) is used to wrap the wire core (1) and the heat dissipation tube (2); Multiple structural layers (4) are arranged in a ring array outside the inner winding layer (3) and correspond one-to-one with the heat dissipation pipe (2); the outer side of each structural layer (4) is curved, and the outer side of multiple structural layers (4) is formed into a circle after being combined. Multiple reinforcing rings (5) are spaced apart along the axial direction of the structural layer (4); each reinforcing ring (5) is a spiral that wraps around all the structural layers (4), and the spiral has at least one complete turn; each reinforcing ring (5) clamps the structural layer (4) after installation; An outer protective layer (6) is provided to wrap the reinforcing ring (5) and the structural layer (4); a groove (61) is provided on the inner wall of the outer protective layer (6), and the width of the groove (61) gradually increases from one side to the other side; the outer side of the reinforcing ring (5) extends into the groove (61) and fits against the side wall of the groove (61).

2. The anti-torsion cable for photovoltaic systems according to claim 1, characterized in that, The diameter of the heat dissipation pipe (2) is set such that the cross-section of the inner winding layer (3) forms a convex polygon.

3. The anti-torsion cable for photovoltaic systems according to claim 2, characterized in that, The inner side of the structural layer (4) is provided with a V-shaped groove that fits with the inner winding layer (3), and the heat dissipation pipe (2) extends into the V-shaped groove.

4. The anti-torsion cable for photovoltaic systems according to claim 2, characterized in that, The heat dissipation pipe (2) is a metal braided flexible hose.

5. The anti-torsion cable for photovoltaic systems according to claim 1, characterized in that, The reinforcing ring (5) includes bent sections (51) at both ends and a curved section (52) in the middle, with a bending groove (53) provided between the bent sections (51) and the curved section (52).

6. The anti-torsion cable for photovoltaic systems according to claim 1, characterized in that, The installation angle of each of the reinforcing rings (5) is different from the installation angle of the two adjacent reinforcing rings (5).

7. The anti-torsion cable for photovoltaic systems according to claim 1, characterized in that, A flexible wrapping layer (7) is provided on the outside of the reinforcing ring (5), and the two ends of the flexible wrapping layer (7) extend to the structural layer (4) on both sides of the reinforcing ring (5).

8. The anti-torsion cable for photovoltaic systems according to claim 7, characterized in that, The flexible wrapping layer (7) is a heat-shrinkable film wrapping layer.

9. The anti-torsion cable for photovoltaic systems according to claim 1, characterized in that, The core (1) includes a conductor, an insulation layer, and a metal shielding layer arranged sequentially from the inside out.

10. The anti-torsion cable for photovoltaic systems according to claim 9, characterized in that, The insulation layer has a double-layer structure, comprising an inner cross-linked polyethylene layer and an outer flame-retardant polyolefin layer.

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