A lightning-resistant discharge cable
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-13
- Publication Date
- 2026-08-11
AI Technical Summary
[0003]然而，现阶段连接避雷器的泄流接地线大多为钢绞线或绝缘铜绞线，安全性能及泄流能力有限，使用寿命较短，使得避雷器及泄流线损坏需要经常更换
[0015]1、通过中空填充芯、疏绕铜丝及重叠绕包铜带的组合设计，有效降低雷击后泄流过程中导体的温升现象，降温效果达到30%以上，具有优异的雷击后散热及泄流能力，有效提高接地的可靠性，延长避雷装置的使用寿命。中空填充芯中空气或者硅油流通，在导体截面大小不改变的情况下，增强了导体的散热能力，同时也提高了电缆的整体弯曲性能。
Smart Images
Figure CN224625241U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of cable design technology, and in particular relates to a lightning-resistant discharge cable that connects to devices such as surge arresters and lightning rods for discharge, thereby extending the life of lightning protection devices. Background Technology
[0002] Lightning strikes during thunderstorms are an unpredictable natural phenomenon. Thunderstorms are frequent in summer, and the huge current generated after a lightning strike poses a great danger to equipment and people. Therefore, surge arresters are installed on buildings and important equipment to reduce the impact of lightning discharge on buildings and equipment.
[0003] However, at present, most of the grounding wires connecting surge arresters are made of steel stranded wire or insulated copper stranded wire, which have limited safety performance and current discharge capacity, and short service life, making it necessary to replace surge arresters and grounding wires frequently when damaged. Utility Model Content
[0004] The purpose of this invention is to provide a lightning-resistant discharge cable that improves lightning discharge capacity and effectively reduces the temperature rise of the conductor during the discharge process after a lightning strike.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] A lightning-resistant discharge cable includes a hollow core with a hollow internal structure. Loosely wound copper wires are provided outside the hollow core. A first copper strip is wrapped around the loosely wound copper wires, and a first semiconducting strip is wrapped around the first copper strip. A conductor shielding layer, a cross-linked polyethylene insulation layer, and an insulating shielding layer are extruded together in a three-layer co-extrusion process around the first semiconducting strip. A second copper strip is wrapped around the insulating shielding layer, and a second semiconducting strip is wrapped around the second copper strip. An outer sheath covers the second semiconducting strip.
[0007] Preferably, the hollow filling core is extruded from semi-conductive polyvinyl chloride material, and the inner diameter and outer diameter of the hollow filling core are adjusted according to the cross-sectional size of the unwound copper wire.
[0008] Preferably, silicone oil is disposed within the hollow structure inside the filling core.
[0009] Preferably, the loosely wound copper wire is oxygen-free copper wire with a copper content ≥99.95%, and the total cross-section of the loosely wound copper wire does not exceed 50mm². 2 At that time, the diameter of its single filament is no greater than 1.32mm.
[0010] Preferably, the first copper strip is a high-purity copper strip with a nominal thickness of 0.12mm, which is wrapped around the loosely wound copper wire with an overlap rate of not less than 15%.
[0011] Preferably, the first and second semiconducting strips are made of 0.2mm semiconducting terylene tape, and the wrapping overlap rate is not less than 15%.
[0012] Preferably, the nominal thickness of the cross-linked polyethylene insulation layer is 2.5-10.5 mm.
[0013] Preferably, the outer sheath is made of semi-conductive polyvinyl chloride sheath material with a nominal thickness of not less than 1.8 mm and a minimum thickness of not less than 90% of the nominal thickness.
[0014] The beneficial effects of this utility model are:
[0015] 1. Through a combination design of hollow core, loosely wound copper wire, and overlapping copper strip, the temperature rise of the conductor during current discharge after a lightning strike is effectively reduced, with a cooling effect of over 30%. This results in excellent heat dissipation and current discharge capabilities after a lightning strike, effectively improving grounding reliability and extending the service life of the lightning arrester. The air or silicone oil circulation within the hollow core enhances the conductor's heat dissipation capacity without changing the conductor's cross-sectional size, while also improving the cable's overall bending performance.
[0016] 2. The use of a semi-conductive PVC outer sheath is beneficial for assisting in current discharge under high current conditions. As a grounding material or conductive path, the material's volume resistivity is as low as 10⁻¹⁰. 3 Ω·cm ensures rapid charge discharge. It also protects the semiconducting strip, copper strip, and shielding layer from oxidation caused by direct contact with air and rain, thus extending the cable's lifespan. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the lightning-resistant discharge cable of this utility model.
[0018] In the figure: 1. Hollow filling core; 2. Loosely wound copper wire; 3. First copper strip; 4. First semiconducting strip; 5. Conductor shielding layer; 6. Cross-linked polyethylene insulation layer; 7. Insulating shielding layer; 8. Second copper strip; 9. Second semiconducting strip; 10. Outer sheath. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0020] Reference Figure 1A lightning-resistant discharge cable includes a hollow core 1, which has a hollow structure inside. The hollow core 1 is surrounded by loosely wound copper wires 2. A first copper strip 3 is wrapped around the loosely wound copper wires 2. A first semiconducting strip 4 is wrapped around the first copper strip 3. A conductor shielding layer 5, a cross-linked polyethylene insulation layer 6, and an insulation shielding layer 7 are extruded around the first semiconducting strip 4 using a three-layer co-extrusion method. A second copper strip 8 is wrapped around the insulation shielding layer 7. A second semiconducting strip 9 is wrapped around the second copper strip 8. An outer sheath 10 covers the second semiconducting strip 9.
[0021] Specifically, the hollow filling core 1 is extruded from semi-conductive polyvinyl chloride material, and the inner and outer diameters of the hollow filling core 1 are adjusted according to the cross-sectional size of the unwound copper wire 2. By controlling the inner and outer diameters through the design of the mold core and sleeve, the eccentricity of the central filling core is effectively controlled to be below 10%.
[0022] The hollow filler core 1 separates the conductor, which is usually a whole structure, into a structure of loosely wound copper wire 2 and an outer copper strip (3, 8). Air flows in the hollow filler core 1, which enhances the heat dissipation capacity of the conductor without changing the cross-sectional size of the conductor, and also improves the overall bending performance of the cable.
[0023] Silicone oil can also be placed inside the hollow structure of the filler core 1 to enhance the heat dissipation capacity of the conductor and improve the overall bending performance of the cable.
[0024] The unwound copper wire 2 is made of high-precision oxygen-free copper wire with a copper content ≥99.95%. The total cross-section of the unwound copper wire 2 should not exceed 50mm². 2 At that time, the diameter of its single wire is no greater than 1.32mm. The pitch ratio of the loosely wound copper wire 2 is between 10 and 14 times, and the loosening direction is to the left. The conductor structure adopts a loose winding form, which splits a whole conductor into multiple wires, thereby improving the heat dissipation capacity of the conductor.
[0025] The first copper strip 3 is a high-purity copper strip with a nominal thickness of 0.12mm. It is wrapped around the loosely wound copper wire 2 with an overlap rate of not less than 15%, so that the loosely wound copper wire and the copper strip are in full contact, ensuring the continuity of the loosely wound copper wire after being energized.
[0026] The first semiconducting strip 4 and the second semiconducting strip 9 are made of 0.2mm semiconducting Tedoron tape, with a wrapping overlap rate of not less than 15%.
[0027] The conductor shielding layer 5, the cross-linked polyethylene insulation layer 6, and the insulation shielding layer 7 are produced by three-layer co-extrusion on a catenary production line, ensuring that the eccentricity of the cable insulation is 8% or less. The nominal thickness of the cross-linked polyethylene insulation layer 6 is 2.5-10.5mm, which is selected according to different applications.
[0028] Conductor shielding layer 5 is a 10kV~35kV grade chemically cross-linked semiconducting inner shielding layer. The 10kV~35kV grade chemically cross-linked semiconducting inner shielding material includes a base material (EVA / LDPE), conductive carbon black, antioxidant, cross-linking agent (DCP), and lubricant.
[0029] Cross-linked polyethylene insulation layer 6 is a thermosetting material formed by cross-linking polyethylene (PE) molecular chains through chemical or physical methods. It exhibits high insulation strength: breakdown voltage can reach 20~30 kV / mm (compared to approximately 18~22 kV / mm for ordinary PE); low dielectric constant (2.3~2.5); and low dielectric loss (tanδ < 0.001), making it suitable for high-frequency transmission. It also has high volume resistivity (>10). 16 (Ω·cm), its corona resistance is better than that of PE.
[0030] The insulating shielding layer 7 is a chemically cross-linked outer shielding material of 10kV~35kV grade, which smooths the surface of the insulating layer, avoids electric field distortion, and reduces partial discharge (PD).
[0031] The outer sheath 10 is made of semi-conductive polyvinyl chloride sheath material with a nominal thickness of not less than 1.8 mm and a minimum thickness of not less than 90% of the nominal thickness.
[0032] The conductivity of the semi-conductive PVC outer sheath prevents discharge and arcing on the cable surface, creating a uniform electric field that ensures normal cable operation. After a lightning strike, the surge arrester can efficiently release large currents to the ground without damaging the cable itself, reducing the risk of injury to equipment and personnel and extending the service life of the surge arrester and discharge cable.
[0033] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.
Claims
1. A lightning-resistant discharge cable, characterized in that: The device includes a hollow core (1), which has a hollow structure inside. The hollow core (1) is provided with a loosely wound copper wire (2) outside. A first copper strip (3) is wrapped around the loosely wound copper wire (2), and a first semiconducting strip (4) is wrapped around the first copper strip (3). A conductor shielding layer (5), a cross-linked polyethylene insulation layer (6), and an insulation shielding layer (7) are extruded around the first semiconducting strip (4) in a three-layer co-extrusion manner. A second copper strip (8) is wrapped around the insulation shielding layer (7), and a second semiconducting strip (9) is wrapped around the second copper strip (8). An outer sheath (10) covers the second semiconducting strip (9).
2. The lightning-resistant discharge cable according to claim 1, characterized in that: The hollow filling core (1) is extruded from semi-conductive polyvinyl chloride material. The inner diameter and outer diameter of the hollow filling core are adjusted according to the cross-sectional size of the loosely wound copper wire (2).
3. The lightning-resistant discharge cable according to claim 1, characterized in that: Silicone oil is disposed inside the hollow structure of the filling core (1).
4. The lightning-resistant discharge cable according to claim 1, characterized in that: The loosely wound copper wire (2) is made of oxygen-free copper wire with a copper content ≥99.95%, and the total cross-section of the loosely wound copper wire (2) does not exceed 50 mm. 2 At that time, the diameter of its single filament is no greater than 1.32mm.
5. The lightning-resistant discharge cable according to claim 1, characterized in that: The first copper strip (3) is a high-purity copper strip with a nominal thickness of 0.12mm, and is wrapped around the loosely wound copper wire (2) with an overlap rate of not less than 15%.
6. The lightning-resistant discharge cable according to claim 1, characterized in that: The first semiconducting strip (4) and the second semiconducting strip (9) are made of 0.2mm semiconducting tertrol tape, and the wrapping overlap rate is not less than 15%.
7. The lightning-resistant discharge cable according to claim 1, characterized in that: The nominal thickness of the cross-linked polyethylene insulation layer (6) is 2.5-10.5 mm.
8. The lightning-resistant discharge cable according to claim 1, characterized in that: The outer sheath (10) is made of semi-conductive polyvinyl chloride sheath material with a nominal thickness of not less than 1.8 mm and a minimum thickness of not less than 90% of the nominal thickness.