Pressure buffering type copper-aluminum alloy photovoltaic cable

Abstract

The invention belongs to the technical field of photovoltaic cables, and particularly relates to a slow pressure type copper-aluminum alloy photovoltaic cable. Comprising a filling layer arranged on a plurality of conductors, an armor layer is wound outside the filling layer, a plurality of buffer layer groups and a plurality of layers of pressure buffering strips are arranged outside the armor layer, a plurality of pressure buffering strips are arranged on each layer in the circumferential direction, and the buffer layer groups and the pressure buffering strips arranged in the circumferential direction are alternately distributed layer by layer; a cavity is formed between every two adjacent pressure buffering strips on the same layer, and the outer portions of the pressure buffering strips on the outermost layer are jointly and fixedly connected with an outer skin. The multiple layers of pressure buffering strips are sequentially pressed and deformed, when a vehicle passes through the cable and the cable is pressed, the multiple layers of pressure buffering strips from the outer layer to the inner layer are sequentially deformed in the direction perpendicular to the stressed pressure, and the cavities provide space for deformation of the pressure buffering strips, so that the pressure borne by the cable is absorbed step by step; local stress generated when the cable is pressed is dispersed, and the risk that the cable is pressed and broken is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic cables, and particularly aims at a pressure-relieving copper-aluminum alloy photovoltaic cable. Background Art

[0002] Photovoltaic cables are special cables designed specifically for solar photovoltaic systems. As a key component connecting solar modules and power systems, photovoltaic cables will be exposed to complex environments (such as ground laying, mechanical rolling, temperature difference changes, etc.) for a long time during use, and need to have excellent compressive, torsional and tensile properties. Traditional photovoltaic cables mostly use pure copper conductors. Although they have good electrical conductivity, they have high costs and weak creep resistance; while pure aluminum conductors, although they have low costs, have problems such as insufficient mechanical strength, easy fracture and poor electrical conductivity compared with copper. The stranded copper-aluminum alloy conductor, as a compromise solution, can achieve a certain balance between electrical conductivity and mechanical properties.

[0003] Existing photovoltaic cables are laid on the ground or buried shallowly, and the existing cables only rely on the deformation of the outer skin to buffer the pressure received. When a vehicle passes over the cable and the cable is compressed, the local pressure will be directly transmitted to the conductor inside the cable, resulting in the outer skin of the cable being compressed and cracked under pressure, and the deformation of the internally stranded wires, thus affecting the normal use of the cable. Summary of the Invention

[0004] In order to overcome the disadvantages pointed out in the above background, the present invention provides a pressure-relieving copper-aluminum alloy photovoltaic cable.

[0005] The technical solution is as follows: A pressure-relieving copper-aluminum alloy photovoltaic cable includes a filling layer provided on a plurality of conductors. An armor layer is wound around the filling layer. A plurality of buffer layer groups for buffering pressure and a plurality of pressure-relieving strips are provided outside the armor layer. Each layer of the pressure-relieving strips has a plurality of circumferentially arranged ones. The buffer layer groups and the circumferentially arranged pressure-relieving strips are alternately distributed layer by layer; A chamber is formed between adjacent pressure-relieving strips in the same layer, and an outer skin is fixedly connected to the outside of the outermost pressure-relieving strip.

[0006] Further explanation, the pressure-relieving strip is in a spiral shape.

[0007] Further explanation, the spiral directions of the pressure-relieving strips in adjacent two layers are opposite.

[0008] Further explanation, the elastic coefficients of all the pressure-relieving strips decrease successively from the inner layer to the outer layer.

[0009] Further explanation: The buffer layer group includes an inner layer. The inner layer of the innermost buffer layer group is fixedly connected to the armor layer, and the inner layer of the remaining buffer layer groups is fixedly connected to the pressure relief strip on its axis side. An intermediate layer is fixedly connected to the outside of the inner layer, an outer layer is fixedly connected to the intermediate layer, and the outer layer is attached to the adjacent pressure relief strip.

[0010] Further explanation: The outer layer close to the outer skin is made of a flame-retardant material.

[0011] Further explanation: The outer layer is fixedly connected with limiting strips arranged circumferentially and having the same number as the pressure relief strips on its outer layer. The limiting strips are thread-shaped, and the thread rotation direction of the limiting strips is the same as that of the adjacent pressure relief strips. The limiting strips are attached to the adjacent pressure relief strips, and the limiting strips are used to block the adjacent pressure relief strips.

[0012] Further explanation: The surface of the outer layer in contact with the adjacent circumferentially arranged pressure relief strips is a friction surface.

[0013] Further explanation: The intermediate layer is composed of a plurality of elastic strips with a V-shaped cross-section.

[0014] Further explanation: The angles of the inner bends of the elastic strips on all the intermediate layers gradually decrease from the inner layer to the outer layer.

[0015] In summary, the present application includes at least one of the following beneficial technical effects: 1. By causing the multi-layer pressure relief strips to be sequentially deformed under pressure, when a vehicle passes over the cable and causes the cable to be pressed, the multi-layer pressure relief strips from the outer layer to the inner layer are sequentially deformed in the direction perpendicular to the pressure received, and the cavity provides space for the deformation of the pressure relief strips, thereby absorbing the pressure on the cable step by step, dispersing the local stress generated when the cable is pressed, and reducing the risk of the cable being broken due to pressure; 2. By making the pressure relief strips thread-shaped and the thread rotation directions of the adjacent two layers of pressure relief strips opposite, no matter which direction the cable twists, a part of the pressure relief strips rotates along the thread rotation direction, and the other part of the pressure relief strips rotates in the opposite direction of the thread rotation direction. The diameter of the pressure relief strips rotating along the thread rotation direction will become smaller, and the rotation resistance of the pressure relief strips rotating against the thread rotation direction is large and the diameter will increase. While increasing the buffering capacity after the cable is pressed, the anti-torsion performance of the cable is ensured, and the diameter change of the pressure relief strips when twisted is reduced, thereby reducing the probability of the outer skin wrinkling, breaking or being damaged, and improving the structural strength of the cable; 3. By using the limiting strips to block the adjacent pressure relief strips to reduce the probability of the pressure relief strips twisting, thereby enhancing the anti-torsion performance of the cable, and when the cable is pulled, by the mutual engagement of the thread-shaped pressure relief strips and the thread-shaped limiting strips, the probability of the misalignment between the outer skin and its internal structure when the outer skin is hard-pulled is reduced, thereby increasing the tensile strength of this structure.

[0016] In summary, compared with the existing structure, this structure enhances the cable buffering performance while ensuring the cable's anti-torsion performance and anti-tensile performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional structure schematic diagram of the present invention; Figure 2 is a three-dimensional structure cross-sectional view of the outer skin of the present invention; Figure 3 is a three-dimensional structure schematic diagram of the pressure relief strip and the limiting strip of the present invention; Figure 4 is a three-dimensional structure schematic diagram of the inner layer, the middle layer and the outer layer of the present invention.

[0018] Wherein: 1 - conductor, 2 - filling layer, 3 - armor layer, 4 - buffer layer group, 401 - inner layer, 402 - middle layer, 403 - outer layer, 5 - pressure relief strip, 501 - chamber, 6 - outer skin, 7 - limiting strip. SPECIFIC EMBODIMENTS

[0019] The present invention will be further described below with reference to the drawings and embodiments. Embodiment 1

[0020] Disclosed in this embodiment is a pressure relief type copper-aluminum alloy photovoltaic cable, which is used to buffer pressure when the cable is under pressure.

[0021] Such as Figures 1 - 3As shown in the figure, it includes a filling layer 2 provided on several conductors 1. The conductor 1 is an existing structure, which is composed of multiple stranded wires. The material of the conductor 1 is copper-aluminum alloy. The conductivity of the copper-aluminum alloy conductor is slightly lower than that of pure copper, but the flexibility can be improved through the multi-strand stranded design, and the tensile strength and anti-creep performance are better than those of pure aluminum. The material of the filling layer 2 can be selected according to specific scenarios, such as PP (for flame retardant requirements), mineral materials (for fire protection performance), or polyester fiber (for mechanical strength). An armor layer 3 is wound around the filling layer 2. The armor layer 3 is used to enhance the tensile, compressive, and impact resistance of the cable. A multi-layer buffer layer group 4 for buffering pressure and a multi-layer pressure relief strip 5 are provided outside the armor layer 3. The pressure relief strip 5 is made of an elastic material. Only two layers of pressure relief strips 5 and two layers of buffer layer groups 4 distributed alternately are shown in the figure. In the actual production process, multiple layers of pressure relief strips 5 and buffer layer groups 4 can be set according to needs. Each layer of pressure relief strip 5 is provided with several circumferentially arranged ones. The buffer layer group 4 and the circumferentially arranged pressure relief strips 5 are distributed alternately layer by layer. A chamber 501 is formed between adjacent pressure relief strips 5 in the same layer. The outer skin 6 is fixedly connected to the outside of the outermost pressure relief strip 5. When the cable is under pressure (such as when the cable is laid on the ground or buried shallowly, and a vehicle passes over the cable, causing the cable to be under pressure), the outer skin 6 is first compressed and deformed, then the outermost pressure relief strip 5 is compressed and deformed, the space of the outermost chamber 501 is deformed, and then the outermost buffer layer group 4 is compressed. Then, the next layer of pressure relief strip 5 is compressed and deformed. In this way, through the sequential compression and deformation of the above multi-layer structure, the multi-layer pressure relief strips 5 from the outer layer to the inner layer are deformed in the vertical direction of the applied pressure in turn. The chamber 501 provides the space required for the deformation of the adjacent pressure relief strips 5. The pressure applied to the cable is gradually absorbed through the deformation of the pressure relief strip 5, the local stress generated when the cable is under pressure is dispersed, and the risk of the cable being broken due to pressure is reduced.

[0022] Pressure relief strip 5: As Figure 3 shown in the figure, during the installation process of the cable or when the cable moves under external force, the whole cable will twist (such as when a vehicle passes by, causing the whole cable to be pushed and twisted), which will cause the insulating layer (i.e., the outer skin 6) to wrinkle, break, and be damaged. The pressure relief strip 5 is in a spiral shape to enhance the anti-twist performance of the pressure relief strip 5.

[0023] As Figure 3As shown, the thread rotation directions of two adjacent layers of the pressure relief strips 5 are opposite. No matter in which direction the cable is twisted, a part of the pressure relief strips 5 rotates along its thread rotation direction, and the other part of the pressure relief strips 5 rotates in the opposite direction of its thread rotation direction. The pressure relief strips 5 rotating against the thread rotation direction are subject to a large rotation resistance, which increases the buffering capacity of the cable after being compressed while ensuring the torsion resistance of the cable. The diameter of the pressure relief strips 5 will change when they rotate. The diameter of the pressure relief strips 5 rotating along the thread rotation direction will become smaller, and the diameter of the pressure relief strips 5 rotating against the thread rotation direction will increase. By alternately arranging pressure relief strips 5 with different thread rotation directions, the diameter change of the cable when twisted can be reduced, thereby reducing the probability of wrinkling, breaking or damage of the outer skin 6, and improving the structural strength of the cable.

[0024] The elastic coefficients of all the pressure relief strips 5 decrease from the inner layer to the outer layer, so that the overall compression resistance of the cable is gradually enhanced from the outside to the inside, thereby enhancing the layer-by-layer pressure relief capability of the cable.

[0025] The specific structure of the buffer layer group 4 is as follows: like Figure 2 and Figure 4 As shown, the buffer layer group 4 includes an inner layer 401, the inner layer 401 of the innermost buffer layer group 4 is fixedly connected to the armor layer 3, the inner layers 401 of the remaining buffer layer groups 4 are fixedly connected to the pressure relief strips 5 close to the axial side thereof, the outer side of the inner layer 401 is fixedly connected to the middle layer 402, the middle layer 402 is fixedly connected to the outer layer 403, the inner layer 401, the middle layer 402 and the outer layer 403 are all made of elastic materials, the outer layer 403 is in contact with the adjacent pressure relief strips 5, and when the cable is under pressure, the pressure is buffered by the deformation of the inner layer 401, the middle layer 402 and the outer layer 403.

[0026] The outer layer 403 close to the outer sheath 6 is made of flame retardant material, such as halogen-free flame retardant TPE, and is used to protect the conductor 1 in the cable. Example 2

[0027] This embodiment discloses a pressure-slowing copper-aluminum alloy photovoltaic cable, which, based on the first embodiment, has the effect of further enhancing the compression and torsional resistance of the cable.

[0028] like Figures 2 - 4As shown in the figure, the outer layer 403 is fixedly connected with limiting strips 7 arranged circumferentially and having the same number as the slow-pressure strips 5 on its outer layer. The hardness of the limiting strips 7 is higher than that of the slow-pressure strips 5. The limiting strips 7 are spiral-shaped, and the spiral direction of the limiting strips 7 is the same as that of the adjacent slow-pressure strips 5. The limiting strips 7 are in contact with the adjacent slow-pressure strips 5. When the slow-pressure strip 5 rotates in the reverse direction along its spiral direction, the slow-pressure strip 5 squeezes the adjacent limiting strip 7, and the limiting strip 7 blocks the adjacent slow-pressure strip 5 to reduce the amplitude of the slow-pressure strip 5's torsion, thereby enhancing the anti-torsion performance of the cable. And when the cable is under tension (such as being pulled by a drag chain system during installation), through the engagement of the spiral slow-pressure strip 5 and the spiral limiting strip 7, the probability of relative dislocation between the layers of the cable is reduced, similar to the engagement between the thread structure of a mineral water bottle and the thread structure of a mineral water bottle cap. Taking the outermost slow-pressure strip 5 as an example, the outer skin 6 and the slow-pressure strip 5 are similar to the thread structures of the bottle cap and the bottle cap, and the outer layer 403 and the limiting strip 7 are the bottle mouth and the bottle mouth thread, reducing the probability of dislocation between the outer skin 6 and its internal structure when the outer skin 6 is hard-pulled, and thus increasing the tensile strength of this structure.

[0029] The surface of the outer layer 403 in contact with the adjacent circumferentially arranged slow-pressure strips 5 is a friction surface to increase the resistance when the slow-pressure strip 5 twists and enhance the anti-torsion performance of the slow-pressure strip 5. Embodiment 3

[0030] The slow-pressure type copper-aluminum alloy photovoltaic cable disclosed in this embodiment is a further improvement on the basis of Embodiment 2.

[0031] As Figure 4 shown in the figure, the intermediate layer 402 is composed of several elastic strips with a V-shaped cross-section. Taking the elastic strip on the upper side of the intermediate layer 402 when the upper side of the cable is under pressure as an example, through the left and right parts of the V-shaped elastic strip respectively expanding and deforming to the left and right sides, the pressure is further buffered.

[0032] The angles at the inner bends of all the elastic strips in the intermediate layer 402 gradually decrease from the inner layer to the outer layer, so that the overall compressive capacity of the cable gradually increases from the outside to the inside to enhance the layer-by-layer pressure relief capacity of the cable.

[0033] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A pressure-slowing copper-aluminum alloy photovoltaic cable, comprising a filling layer (2) arranged on a plurality of conductors (1), wherein an armor layer (3) is wound around the filling layer (2), wherein: A plurality of buffer layer groups (4) and a plurality of pressure relief strips (5) for buffering pressure are arranged outside the armor layer (3), each layer of the pressure relief strips (5) having a plurality of circumferentially arranged ones, and the buffer layer groups (4) and the circumferentially arranged ones are alternately distributed layer by layer; a chamber (501) is formed between adjacent ones of the pressure relief strips (5) of the same layer, and the outer parts of the outermost layer of the pressure relief strips (5) are fixedly connected to an outer skin (6).

2. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 1, characterized in that: The pressure relief strip (5) is in a threaded shape.

3. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 2, characterized in that: The thread rotation directions of the two adjacent layers of the pressure relief strips (5) are opposite.

4. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 3, characterized in that: The elastic coefficients of all the pressure relief strips (5) decrease from the inner layer to the outer layer.

5. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 4, characterized in that: The buffer layer group (4) comprises an inner layer (401), the inner layer (401) of the innermost buffer layer group (4) is fixedly connected to the armor layer (3), the inner layers (401) of the remaining buffer layer groups (4) are fixedly connected to the pressure relief strip (5) close to the axial side thereof, the outer side of the inner layer (401) is fixedly connected to an intermediate layer (402), the intermediate layer (402) is fixedly connected to an outer layer (403), and the outer layer (403) is bonded to the adjacent pressure relief strip (5).

6. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 5, characterized in that: The outer layer (403) close to the outer skin (6) is made of flame retardant material.

7. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 5, characterized in that: The outer layer (403) is fixedly connected with circumferentially arranged limiting strips (7) whose number is the same as the number of the pressure relief strips (5) on the outer layer; the limiting strips (7) are threaded; the thread direction of the limiting strips (7) is the same as the thread direction of the adjacent pressure relief strips (5); the limiting strips (7) fit the adjacent pressure relief strips (5); and the limiting strips (7) are used to block the adjacent pressure relief strips (5).

8. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 7, characterized in that: The surface where the outer layer (403) contacts the adjacent circumferentially arranged pressure relief strips (5) is a friction surface.

9. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 5, characterized in that: The middle layer (402) is composed of a plurality of elastic strips with V-shaped cross-sections.

10. A pressure-slowing copper-aluminum alloy photovoltaic cable according to claim 9, characterized in that: The angles of the inner bends of the elastic strips on all the intermediate layers (402) decrease from the inner layer to the outer layer.

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