Flame-retardant waterproof photovoltaic cable

Abstract

This utility model provides a flame-retardant and waterproof photovoltaic cable, relating to the field of cable design technology. The cable, from the inside out, comprises a conductor core, a first water-blocking layer, a flame-retardant insulation layer, a second water-blocking layer, a metal shielding layer, a third water-blocking layer, and a high-temperature resistant sheath layer. The first water-blocking layer includes wrapped semi-conductive water-resistant tape and water-blocking yarn; the second water-blocking layer includes wrapped non-conductive water-resistant tape; and the third water-blocking layer includes longitudinally wrapped aluminum-plastic composite tape. The aluminum-plastic composite tape of the third water-blocking layer first prevents moisture from penetrating the cable's interior. The water-absorbing resin of the second water-blocking layer and / or the semi-conductive water-resistant tape and water-blocking yarn of the first water-blocking layer rapidly absorb moisture and expand upon contact with water, forming a dense watertight barrier. The metal shielding layer enhances the cable's electromagnetic interference resistance. The flame-retardant insulation layer and the high-temperature resistant sheath possess excellent weather resistance and flame-retardant properties. This structure ensures the cable's normal operation under harsh environments with high-intensity sunlight and humidity.

Description

Technical Field

[0001] This utility model relates to the field of cable technology, and in particular to a flame-retardant and waterproof photovoltaic cable. Background Technology

[0002] Photovoltaic power plants are developing towards larger scales. Ultra-large photovoltaic power plants used in photovoltaic hydrogen production and large-scale energy storage coupling projects have reached a maximum DC system voltage level of 2000V for their photovoltaic strings. Higher voltage levels place higher demands on photovoltaic cables, including: electromagnetic interference resistance under high-voltage environments, waterproofing challenges in complex outdoor scenarios, and more stringent flame-retardant standards.

[0003] In the long-term operation of photovoltaic power plants, traditional photovoltaic cables have gradually revealed many shortcomings in practical applications, posing significant challenges to system reliability and safety. Insufficient water resistance: Their structural design is unable to effectively prevent the penetration of moisture and rainwater that is present in the outdoor environment, easily leading to insulation layer deterioration due to moisture, and causing leakage or short circuit risks. Weak electromagnetic interference (EMI) resistance: Faced with the strong interference generated by the high-frequency power switching of inverters and complex electromagnetic environments, the shielding effectiveness of traditional cables is insufficient, threatening the monitoring accuracy and operational stability of the power plant. Limitations in high-temperature resistance and flame retardant properties: In outdoor environments such as high-temperature exposure, their materials age rapidly, creating potential electrical fire hazards. Combined with their lack of water resistance, this makes them unsuitable for meeting the stringent thermal stability requirements of photovoltaic power plants. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a flame-retardant and waterproof photovoltaic cable. This cable features a flame-retardant insulation layer, a metal shielding layer, and a high-temperature resistant sheath layer on the outside of the conductor cable core, along with multiple water-blocking layers from the inside out. This comprehensively meets the long-term stable operation requirements of high-voltage photovoltaic systems under harsh environments such as high temperature, humidity, and multiple electromagnetic interferences.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: A flame-retardant and waterproof photovoltaic cable, comprising, from the inside out: a conductor cable core, a first water-blocking layer, a flame-retardant insulation layer, a second water-blocking layer, a metal shielding layer, a third water-blocking layer, and a high-temperature resistant sheath layer; The first water-blocking layer includes a wrapped semi-conductive water-blocking tape and water-blocking yarn; the second water-blocking layer includes a wrapped non-conductive water-blocking tape; and the third water-blocking layer includes a longitudinally wrapped aluminum-plastic composite tape.

[0006] Optionally, the conductor cable core may include multi-strand stranded conductors.

[0007] Optionally, the semiconducting water-resistant tape is located inside the water-blocking yarn.

[0008] Optionally, the overlap rate of the semiconducting resistive water strip is 15-25%.

[0009] Optionally, the flame-retardant insulation layer and the high-temperature resistant sheath layer are made of low-smoke, halogen-free, flame-retardant, irradiated cross-linked polyolefin material.

[0010] Optionally, the overlap rate of the non-conductive resistive water strip is 15-25%.

[0011] Optionally, the metal shielding layer includes a wrapped copper strip with an overlap of 20-25%.

[0012] Optionally, the overlap rate of the aluminum-plastic composite strip is 10-15%.

[0013] Optionally, the aluminum-plastic composite strip includes one or more of double-sided aluminum-plastic composite strips and single-sided aluminum-plastic composite strips.

[0014] Optionally, the flame-retardant insulation layer and the high-temperature resistant sheath layer are both seamless sleeves.

[0015] The beneficial effects of this utility model are as follows: This invention employs a three-layer composite water-blocking structure to protect the cable core, flame-retardant insulation layer, and metal shielding layer within the cable, which require waterproofing. The aluminum-plastic composite tape of the third water-blocking layer provides excellent internal sealing, initially preventing moisture intrusion. When a small amount of moisture gradually penetrates the third water-blocking layer, the water-absorbing resin of the second water-blocking layer and / or the semi-conductive water-resistant tape and water-blocking yarn of the first water-blocking layer rapidly absorb the moisture and expand, filling the gaps or water intrusion paths between the third water-blocking layer and the flame-retardant insulation layer. The pressure generated by this expansion promotes the formation of a dense watertight barrier, preventing longitudinal penetration and radial diffusion of moisture, effectively blocking water and preventing insulation performance degradation due to moisture, thus improving the cable's reliability in humid environments. The metal shielding layer enhances the cable's electromagnetic interference resistance, reducing electromagnetic radiation caused by inverter switching and partial shading of components in photovoltaic systems, preventing interference with surrounding sensitive equipment. The flame-retardant insulation layer and high-temperature resistant sheath possess excellent weather resistance and flame-retardant properties. The above structure improves cable performance in multiple ways, ensuring the cable's normal operation under harsh environments with high-intensity sunlight and humidity, and enabling the cable to meet the requirements of high-voltage photovoltaic systems. Attached Figure Description

[0016] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0017] Figure 1 This is a radial cross-sectional view of the flame-retardant and waterproof photovoltaic cable of Example 1 in the specific implementation.

[0018] The components include: 1. Conductor cable core; 2. Semi-conductor water-resistant tape; 3. Water-blocking yarn; 4. Flame-retardant insulation layer; 5. Non-conductor water-resistant tape; 6. Metal shielding layer; 7. Aluminum-plastic composite tape; and 8. High-temperature resistant sheath layer. Detailed Implementation

[0019] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] Example 1 In response to the higher requirements for photovoltaic cables at higher voltage levels, this embodiment provides a flame-retardant and waterproof photovoltaic cable, which is configured from the inside out as follows: conductor cable core 1, first water-blocking layer, flame-retardant insulation layer 4, second water-blocking layer, metal shielding layer 6, third water-blocking layer and high-temperature resistant sheath layer 8. The first water-blocking layer includes a semi-conductive water-blocking tape 2 and a water-blocking yarn 3; the second water-blocking layer includes a non-conductive water-blocking tape 5; and the third water-blocking layer includes an aluminum-plastic composite tape 7.

[0021] The above structure adopts a multi-layered collaborative structure: the conductor cable core 1, flame-retardant insulation layer 4, and metal shielding layer 6 provide the cable with standard conductive, insulating, and electromagnetic shielding characteristics; the high-temperature resistant sheath layer 8 is used to protect the cable on the outermost side; the conductor cable core 1, flame-retardant insulation layer 4, and metal shielding layer 6 inside the high-temperature resistant sheath 8 all have waterproof requirements, therefore, independent water-blocking layers are set on the outer sides of each of them, providing multiple layers of protection; and because the water-blocking layer is set in multiple layers, the thickness of a single water-blocking layer can be limited within a set range, strengthening the restraint effect and preventing the problem of excessively thick single-layer water-blocking layers causing gaps during cable bending, leading to internal structural displacement or even slippage through the gaps; water-blocking yarn 3 and water-blocking tape (wrapping) The non-conductive water-resistant tape 5 and the semi-conductive water-resistant tape 2 contain water-absorbing and swelling resins that expand upon contact with water to block water seepage or moisture intrusion in high-humidity environments. The outer layer is combined with an aluminum-plastic composite tape 7 to form a double longitudinal barrier, which improves waterproof reliability through a physically sealed structure. In terms of electromagnetic interference, a metal shielding layer 6 is made by wrapping copper tape to construct a highly efficient electromagnetic shielding barrier, which significantly reduces the impact of electromagnetic radiation on surrounding equipment. In terms of material selection, the flame-retardant insulation layer 4 and the high-temperature resistant sheath layer 8 are made of high-temperature irradiated cross-linked polyolefin, which has environmentally friendly and safe characteristics. This solution fully meets the long-term stable operation requirements of 2000V voltage-level photovoltaic systems in harsh environments such as high temperature, humidity, and multiple electromagnetic interferences.

[0022] Accordingly, the flame-retardant and waterproof photovoltaic cable provided in this embodiment can also be compatible with application scenarios of different voltage levels. For example, it includes a 1.0kV photovoltaic system suitable for residential rooftop photovoltaic projects or small industrial and commercial rooftop projects, or a 1.5kV photovoltaic system suitable for large ground power station projects or large-scale "fishery-solar complementary" or "agricultural-solar complementary" projects.

[0023] For example, the conductor cable core 1 includes multi-strand stranded tinned copper conductors conforming to GB / T 3956 standard, which have both good conductivity and corrosion resistance, can reduce current transmission loss, and at the same time improve the conductor's anti-aging ability in outdoor environments, thus extending the cable's service life.

[0024] The semi-conductive resistive water tape 2 is wrapped around the outside of the conductive conductor cable core 1, which can appropriately fill the gaps on the surface of the stranded conductor cable core. Its semi-conductive properties are suitable for high-voltage applications. Water-blocking yarn 3 is wrapped around the outside of the semi-conductive resistive water tape 2 to fill the gaps between adjacent semi-conductive resistive water tapes 2, improve the tightness of the wrapping, and play a reinforcing role.

[0025] The semiconducting water-blocking tape 2 is wrapped in a loop with an overlap rate of 15%, and the water-blocking yarn 3 is also wrapped in a loop. Both of them play a radial water-blocking role.

[0026] The flame-retardant insulation layer 4 can constrain the internal first water-blocking layer to prevent its displacement. It is made of low-smoke halogen-free flame-retardant irradiated cross-linked polyolefin material, which is cross-linked by high-energy irradiation, making the material molecules more compact and reducing the gaps, hindering the migration of electrons or ions, and improving the volume resistivity and breakdown field strength. At the same time, the cross-linked network molecular structure enhances the material's environmental stability. Combined with the material's chemical inertness and effective control of impurities, it ensures its excellent and long-lasting insulation performance. This allows the long-term operating temperature to reach 125℃, reduces the release of toxic gases when facing the risk of combustion, and achieves the environmentally friendly and safe characteristics of low smoke, halogen-free, and flame retardant. The low-smoke halogen-free flame-retardant irradiated cross-linked polyolefin material used in this utility model is existing technology and does not represent a technological improvement.

[0027] The non-conductive water-resistant tape 5 in the second water-blocking layer is wrapped in a circular motion, serving a radial water-blocking function. This protects the flame-retardant insulation layer 4 and the inner cable core. Since the non-conductive water-resistant tape 5 is located further away from the conductor cable core 1 than in the first water-blocking layer and is situated outside the flame-retardant insulation layer, it does not require appropriate conductivity. Therefore, the non-conductive water-resistant tape 5, which is less expensive than the semi-conductive water-resistant tape 2, is used in this location. Compared to using the semi-conductive water-resistant tape 2 in both the first and second water-blocking layers, this approach reduces costs without compromising cable performance.

[0028] The fiber fabric in the semi-conductive resistive water tape 2 and the non-conductive resistive water tape 5 is non-woven fabric, which is used to wrap the water-absorbing and swelling resin inside.

[0029] The metal shielding layer 6 includes a copper strip wrapped around the photovoltaic system, which can effectively reduce electromagnetic radiation in the photovoltaic system, avoid interference with surrounding sensitive equipment, and ensure the normal operation of the photovoltaic system and surrounding equipment.

[0030] The aluminum-plastic composite tape 7 is wrapped longitudinally with an overlap rate of 10%. The aluminum-plastic composite tape 7 is used to ensure good sealing inside the cable and acts as an outer waterproof barrier to prevent water intrusion. The aluminum-plastic composite tape 7 is a double-sided aluminum-plastic composite tape, and its structure consists of two layers of plastic film sandwiched between two layers of aluminum film (a total of three layers). In the overlapping area of ​​adjacent aluminum-plastic composite tapes, the highly hydrophobic plastic films are in contact with each other, which can improve the water-blocking ability.

[0031] The aluminum-plastic composite strip 7 is longitudinally wrapped, while the semi-conductive resistive water strip 2 and the non-conductive resistive water strip 5 are wrapped around the surface. Because the gap directions of the wrapping and longitudinal wrapping are different, they can effectively block the penetration of water between the layers.

[0032] The high-temperature resistant sheath layer 8 is made of low-smoke, halogen-free, flame-retardant, radiation-crosslinked polyolefin material, which has good weather resistance and can extend the service life in outdoor environments with strong ultraviolet radiation and alternating high temperature differences. The aluminum-plastic composite tape 7 wrapped inside can prevent the longitudinally wrapped aluminum-plastic composite tape 7 from shifting. It is made of the same material as the flame-retardant insulation layer 4 and meets the long-term temperature resistance requirement of 125℃.

[0033] The flame-retardant insulation layer 4 and the high-temperature resistant sheath layer 8 are seamless sleeves, which can prevent moisture from entering from the surface seams and are easy to prepare by extrusion.

[0034] When the outer high-temperature resistant sheath is damaged due to aging or other reasons, and moisture penetrates the sheath structure into the cable, the three-layer structure of the aluminum-plastic composite tape 7 provides excellent airtightness to the internal structure, effectively preventing moisture from penetrating the cable longitudinally and radially. When moisture or water vapor breaks through the third water-blocking layer and further penetrates, the water-absorbing resin in the non-conductive water-blocking tape 5, water-blocking yarn 3, and semi-conductive water-blocking tape 2 will quickly absorb the moisture and expand in volume, filling the gaps or damage in the cable to form a dense watertight barrier. At the same time, the pressure generated by the expansion, under the radial restraint of the flame-retardant insulation layer 4 or the metal shielding layer 6, can further prevent the longitudinal penetration and radial diffusion of moisture, thereby achieving effective water blocking, avoiding the decline in insulation performance due to moisture, and improving the reliability of the cable in humid environments.

[0035] The method for preparing the flame-retardant and waterproof photovoltaic cable of this embodiment includes the following steps: S1. Conductor cable core 1 is obtained by stranding multiple tinned copper single wires conforming to Category 5 of GB / T 3956 standard; S2. Wrap semi-conductive nylon water-blocking tape 2 and water-blocking yarn 3 around the outside of conductor cable core 1 with an overlap rate of 15% to obtain the first water-blocking layer. S3. A flame-retardant insulating layer 4 is prepared on the outside of the first water-blocking layer by extrusion tube method. S4. Wrap the non-conductive water-blocking tape 5 around the outside of the flame-retardant insulation layer 4 with an overlap rate of 15% to obtain the second water-blocking layer. S5. Using a soft copper strip with a thickness of 0.05mm as raw material, a metal shielding layer 6 is obtained by wrapping it around the outside of the second water-blocking layer 5 with an overlap rate of 20%. When wrapping, wrap the soft copper strip with a wrapping tape to prevent the soft copper strip from loosening, ensuring that the soft copper strip is wrinkle-free and evenly covers the entire cable. S6. On the outside of the metal shielding layer 6, longitudinally wrap aluminum-plastic composite tape 7 with an overlap rate of 10% to obtain the third water-blocking layer. When wrapping longitudinally, it is necessary to ensure that there are no wrinkles and that the cable surface is evenly covered. S7. A high-temperature resistant sheath layer 8 is prepared on the outside of the third water-blocking layer by extrusion, thereby obtaining a flame-retardant and waterproof photovoltaic cable.

[0036] Example 2 A flame-retardant and waterproof photovoltaic cable differs from Example 1 in that: the overlap rate of the semi-conductive nylon water-blocking tape is 25%, the overlap rate of the non-conductive water-blocking tape is 25%, the overlap rate of the soft copper tape is 25%, and the overlap rate of the aluminum-plastic composite tape is 15%; the fiber fabric in the semi-conductive and non-conductive water-blocking tapes is woven fabric, and the aluminum-plastic composite tape is a single-sided aluminum-plastic composite tape.

[0037] Other raw material requirements and preparation methods are the same as in Example 1. Higher overlap and denser fiber fabrics are suitable for laying scenarios with high cable bending.

[0038] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A flame-retardant and waterproof photovoltaic cable, characterized in that, The structure, from the inside out, consists of: a conductor cable core, a first water-blocking layer, a flame-retardant insulation layer, a second water-blocking layer, a metal shielding layer, a third water-blocking layer, and a high-temperature resistant sheath layer; the first water-blocking layer comprises a wrapped semi-conductive water-blocking tape and water-blocking yarn; the second water-blocking layer comprises a wrapped non-conductive water-blocking tape; and the third water-blocking layer comprises a longitudinally wrapped aluminum-plastic composite tape.

2. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The conductor cable core comprises multiple stranded conductors.

3. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The semiconducting water-resistant tape is located inside the water-blocking yarn.

4. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The overlap rate of the semiconducting resistive water strip is 15-25%.

5. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The flame-retardant insulation layer and the high-temperature resistant sheath layer are both made of low-smoke, halogen-free, flame-retardant, irradiated cross-linked polyolefin.

6. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The flame-retardant insulation layer and the high-temperature resistant sheath layer are both seamless sleeves.

7. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The overlap rate of the non-conductive resistive water strip is 15-25%.

8. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The metal shielding layer comprises a copper strip wrapped around a base with an overlap rate of 20-25%.

9. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The overlap rate of the aluminum-plastic composite strip is 10-15%.

10. The flame-retardant and waterproof photovoltaic cable as described in claim 1, characterized in that, The aluminum-plastic composite strip includes one or more of double-sided and single-sided aluminum-plastic composite strips.

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