Grounding device, preparation method and construction method thereof

Abstract

The invention discloses a grounding device, a preparation method and a construction method thereof, and relates to the field of grounding devices, the grounding device comprises a metal grounding body, at least one conductive layer and at least one graphene composite layer, and the graphene composite layer comprises a copper foil layer and a graphene layer which are stacked; one side of the conductive layer is combined with the metal grounding body, and the other side of the conductive layer is combined with the copper foil layer. The grounding device has the advantages of corrosion resistance and good conductivity.

Description

Technical Field

[0001] This invention relates to the field of grounding device technology, specifically to a grounding device, its preparation method, and its construction method. Background Technology

[0002] In power transmission systems, transmission tower grounding devices are key components ensuring the safe and stable operation of the power system. Their function is to rapidly conduct lightning currents or fault currents to the ground, thereby preventing equipment damage and personnel casualties. Traditionally, transmission tower grounding devices are mostly made of galvanized steel or pure copper, which are widely used due to their good conductivity and certain mechanical strength.

[0003] With the rapid development of the power industry, the performance requirements for transmission tower grounding devices are also increasing. In practical applications, traditional metal grounding devices have revealed many problems. Galvanized steel is prone to corrosion of its galvanized layer in long-term humid, acidic, or alkaline soil environments, leading to decreased conductivity and a gradual increase in grounding resistance. While pure copper has excellent conductivity, it is expensive and also faces corrosion risks under certain soil conditions.

[0004] Therefore, improving the corrosion resistance of grounding devices has become an urgent technical problem to be solved. Summary of the Invention

[0005] This invention aims to address, to a certain extent, one of the technical problems in related technologies. To this end, this invention provides a grounding device, a preparation method, and a construction method thereof, which have the advantages of corrosion resistance and good conductivity.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A grounding device includes a metal grounding body, at least one conductive layer, and at least one graphene composite layer, wherein the graphene composite layer includes a copper foil layer and a graphene layer stacked together; one side of the conductive layer is bonded to the metal grounding body, and the other side is bonded to the copper foil layer.

[0007] Grounding devices are used to establish an electrical connection between electrical equipment or other objects and the earth, diverting potential leakage currents, static charges, and lightning currents to the ground to ensure the normal operation of electrical equipment such as transmission towers and personal safety. The grounding device in this application includes a metal grounding electrode, a conductive layer, and a graphene composite layer. The metal grounding electrode is used to connect to the electrical equipment via leads. The conductive layer not only tightly bonds the metal grounding electrode and the graphene composite layer, ensuring a stable electrical and mechanical connection, but also creates a gap between them, separating them and preventing direct contact. When the copper foil layer is in direct contact with the metal grounding electrode, a potential difference is created because the standard electrode potentials of copper and the metal grounding electrode (such as steel) in the soil electrolyte are different. In a moist soil environment, this potential difference causes electrons to flow from the metal with the lower potential (such as steel) to the copper with the higher potential, thus forming an anodic region on the surface of the metal grounding electrode and accelerating its corrosion. The conductive layer in this application avoids direct contact between the copper foil layer and the metal grounding body. As a transition layer between the two, the conductive layer blocks the electron flow path caused by the potential difference, eliminating the risk of electrochemical corrosion due to the potential difference. Furthermore, the graphene composite layer comprises stacked copper foil layers and graphene layers. The sp2 hybridized C atoms in graphene form saturated bonds, exhibiting high chemical stability and resistance to corrosion. Therefore, the graphene layer enhances the corrosion resistance of the copper foil layer, thereby improving the overall corrosion resistance of the grounding device. In addition, both graphene and copper foil possess excellent electrical conductivity. Graphene exhibits extremely low resistivity at room temperature, and copper foil also has highly stable conductivity. Their synergistic effect significantly improves the overall conductivity of the grounding device.

[0008] Compared to existing grounding devices, the grounding device of this application connects the metal grounding body to the graphene composite layer through a conductive layer. On one hand, this connection method improves the mechanical properties of the grounding device, enhancing its structural stability and resistance to external forces in complex environments, and reducing the risk of grounding failure due to mechanical damage. On the other hand, the conductive layer significantly reduces the contact resistance of the grounding device. This is because the conductive layer effectively forms a continuous conductive path within the grounding device, increasing the current flow area and thus effectively reducing the resistance to current conduction. Furthermore, this structure effectively inhibits electrochemical corrosion, extends the service life of the grounding device, reduces maintenance costs and replacement frequency, and has significant economic benefits and application value.

[0009] Optionally, the graphene composite layer is a flexible sheet with an area greater than or equal to 0.05 m2.

[0010] The graphene composite layer is in the form of a flexible sheet with an area of ​​not less than 0.05 square meters. The flexible sheet possesses high toughness, allowing the graphene composite layer to adaptively conform to the actual surface morphology of the soil or rocks in the ground, achieving good conformality with the soil / rocks. This increases the contact area between the graphene composite layer and the surrounding medium, resulting in a tighter and more consistent contact, reducing contact resistance, and ensuring smooth current conduction between the grounding device and the soil / rocks. This, in turn, improves the overall performance and reliability of the grounding device.

[0011] Optionally, the metal grounding electrode is rod-shaped, and the length direction of the graphene composite layer forms an angle with the axis of the metal grounding electrode, the angle being 30° to 90°.

[0012] Multiple graphene composite layers may be placed on a metal grounding electrode. Controlling the angle between the graphene composite layer and the axis of the metal grounding wire within the range of 30° to 90° can prevent interference phenomena such as mutual compression and overlap between graphene composite layers of different regions or levels. If the angle is too small, multiple graphene composite layers may overlap spatially, resulting in an overly dense local structure, affecting the performance of the graphene composite layer itself, or adversely affecting the structural stability of the overall grounding device. Controlling this angle within the range of 30° to 90° ensures that each graphene composite layer maintains an appropriate distance and relatively independent space, guaranteeing the stability and reliability of the grounding device structure. Furthermore, when the length direction of the graphene composite layer forms an angle of 30° to 90° with the axis of the metal grounding electrode, the graphene composite layer can spread more fully, increasing the contact area with the soil, thus allowing for smoother current dissipation through the soil, thereby reducing grounding resistance and improving the current dissipation efficiency and conductivity of the grounding device.

[0013] Optionally, multiple graphene composite layers are spaced apart along the axial direction of the metal grounding body, and the graphene composite layers are provided on both opposite sides of the metal grounding body.

[0014] Along the axial direction of the metal grounding electrode, multiple graphene composite layers are distributed at regular intervals to ensure that each graphene composite layer can fully exert its excellent conductivity and current dissipation properties in the soil environment, avoiding mutual interference due to excessive density and resulting in local performance degradation. Graphene composite layers are placed on both opposite sides of the metal grounding electrode, increasing the conduction path and current dissipation channel of the current in the grounding device. When current flows from the metal grounding electrode into the soil, the graphene composite layers on both sides can work simultaneously to distribute the current more widely and evenly into the surrounding soil, greatly improving the current conduction efficiency and current dissipation effect, reducing grounding resistance, and ensuring the stable operation of the grounding device in the electrical system.

[0015] Optionally, each graphene composite layer is connected to the metal grounding body through two guide layers, with the two guide layers respectively connected to opposite ends of the graphene composite layer along the axial direction of the metal grounding body.

[0016] By placing two guide layers at opposite ends of the graphene composite layer and connecting them to the metal grounding electrode—that is, using guide layers only at critical locations within the graphene composite layer—the amount of conductive layer required is significantly reduced, saving costs and avoiding material waste caused by indiscriminate laying or large-area coverage. Furthermore, the guide layers optimize the overall structure of the grounding device. Because the guide layers connect the graphene composite layer to the metal grounding electrode and form a stable conductive path, there is no need to increase the thickness of the graphene composite layer or the metal grounding electrode to enhance connection strength, thus reducing material usage.

[0017] Optionally, the thickness of the conductive layer is 0.1 to 1 mm.

[0018] If the conductive layer thickness is less than 0.1 mm, its conductivity and mechanical strength are insufficient, making it unable to stably perform its conductive and connection functions. This can easily lead to unstable performance or even failure of the grounding device in actual use. While a conductive layer thickness exceeding 1 mm improves conductivity to some extent, it significantly increases material usage, resulting in unnecessary cost increases. For example, in some large-scale grounding projects, the amount of conductive layer material used is enormous; every 0.1 mm increase in thickness leads to a substantial increase in material costs. Therefore, controlling the thickness within the range of 0.1–1 mm minimizes material usage and reduces the manufacturing cost of the grounding device while meeting performance requirements.

[0019] Optionally, the thickness of the graphene composite layer is 0.05 to 0.5 mm.

[0020] Graphene itself has extremely high electrical conductivity, but when the thickness of the graphene composite layer is less than 0.05 mm, the excessively thin composite layer may lead to discontinuous conductive pathways (such as insufficient stacking of graphene sheets), affecting the overall conductivity. When the thickness of the graphene composite layer exceeds 0.5 mm, the improvement in conductivity tends to saturate, and the material cost increases significantly.

[0021] Furthermore, the present invention also provides a method for preparing a grounding device, the grounding device including the aforementioned grounding device, the preparation method comprising the following steps: Provide a metallic grounding electrode; A copper foil layer and a graphene layer are provided, wherein the copper foil layer and the graphene layer are metallurgically bonded to form a graphene composite layer; A conductive layer is provided, one side of which is welded to the metal grounding electrode by a welding process, and the other side of which is welded to the copper foil layer in the graphene composite layer by a welding process.

[0022] In this application, the copper foil layer itself possesses excellent conductivity, while graphene, as a two-dimensional carbon nanomaterial, also exhibits extremely high conductivity. By tightly bonding the copper foil layer and graphene layer through metallurgical bonding, the conductivity advantages of both can be fully utilized, reducing contact resistance. The resistance encountered by current conduction in the graphene composite layer is significantly reduced, thereby greatly improving the conductivity reliability and safety of the grounding device. During the metallurgical bonding process, the copper foil layer and graphene layer undergo atomic diffusion and interpenetration under high temperature and high pressure conditions, forming a strong metallurgical interface. This results in a dense and uniform internal structure of the formed graphene composite layer, eliminating problems such as interface loosening and delamination that may occur with traditional adhesive or mechanical connection methods. The welding process uses high temperature to cause a metallurgical reaction between the conductive layer and the metal grounding body, as well as the copper foil layer in the graphene composite layer, forming a strong metallic bond connection. This gives the resulting grounding device extremely high mechanical strength and conductivity, enabling it to withstand large tensile forces, shear forces, and current surges. This reduces the risk of increased grounding resistance and grounding failure due to connection problems, improving the overall reliability and safety of the grounding device.

[0023] The copper content in the copper foil layer is greater than or equal to 99.9%.

[0024] The presence of impurities interferes with the free movement of electrons in metallic copper, increasing the probability of electron collisions and thus increasing resistance. When the copper content in the copper foil layer is greater than or equal to 99.9%, meaning the impurity content is extremely low, the resistance encountered by electrons during conduction in the copper foil is minimal, resulting in a low resistance in the copper foil layer. In grounding devices, a low-resistance copper foil layer can significantly reduce energy loss during current conduction, allowing current to pass through the copper foil layer more efficiently, thereby improving the conductivity of the entire grounding device.

[0025] The conductive layer is a nickel layer, and the nickel content in the nickel layer is greater than or equal to 99%.

[0026] Nickel possesses excellent electrical conductivity, and high-purity nickel further reduces the interference of impurities on electron conduction. Therefore, the nickel layer in this application exhibits stable low resistance and excellent conductivity. When faced with high-current surges (such as lightning currents), the high-purity nickel layer can rapidly conduct the current to the metal grounding electrode and the graphene composite layer, reducing heat accumulation caused by excessive resistance and preventing performance degradation or even damage to the grounding device due to overheating, thus ensuring the operation of the grounding device. Furthermore, the nickel layer, positioned between the copper foil layer and the metal grounding electrode, serves a dual function of physical isolation and electrical transition. It breaks the electron conduction path originally formed by direct contact between copper and the metal grounding electrode, preventing electrons from flowing directly from the lower potential metal grounding electrode to the higher potential copper foil layer, thereby inhibiting electrochemical corrosion. Additionally, the conductive layer can also be made of metals such as platinum or zinc.

[0027] The welding process is laser welding and / or brazing.

[0028] Laser welding offers advantages such as concentrated energy, high welding speed, and a small heat-affected zone. When welding copper foil layers, conductive layers, and metal grounding electrodes, laser welding allows for precise control of the welding area, avoiding excessive heat damage to surrounding non-welded areas. When the conductive layer uses thin-film materials with special functions, laser welding ensures that the integrity and performance of the film are not compromised during the welding process. Brazing, on the other hand, involves relatively low welding temperatures. For welding copper foil layers, conductive layers, and metal grounding electrodes, brazing avoids material property degradation caused by high temperatures.

[0029] Furthermore, the present invention also provides a method for constructing a grounding device, the grounding device including the aforementioned grounding device, the method comprising the following steps: Select a transmission tower and dig a grounding pit next to the base of the transmission tower; Multiple grounding devices are placed in the grounding pit and the multiple grounding devices are evenly arranged in a radial pattern; A resistance-reducing agent is filled between adjacent graphene composite layers of the grounding device. The resistance-reducing agent comprises graphite powder and bentonite, and the mass ratio of the graphite powder to the bentonite is 1:3. The metal grounding body of the grounding device is connected to the grounding terminal of the transmission tower via a lead wire.

[0030] Multiple grounding devices are evenly arranged radially within the grounding pit, increasing the contact area between the grounding devices and the soil. This radial arrangement allows the grounding devices to extend in different directions, creating a three-dimensional current-dissipating network within the soil. When a transmission tower fails, the fault current can be quickly dissipated into the earth through the grounding devices in all directions, preventing problems such as overheating and potential rise caused by excessive local current, thus ensuring the stability and reliability of the grounding system.

[0031] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of the present invention will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. In addition, each of these features, elements and components appearing in the following text and drawings is a plurality of, and different symbols or numbers are used for convenience of representation, but all represent parts with the same or similar construction or function. Attached Figure Description

[0032] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the grounding device in this invention; Figure 2 This is an exploded schematic diagram of the grounding device in this invention; Figure 3 This is a schematic diagram of the assembly of the metal grounding body, the conductive layer, and the graphene composite layer in this invention. Figure 4 This is a schematic diagram of the construction of the grounding device in this invention; Figure 5 This is a process diagram of a method for preparing a grounding device according to the present invention; Figure 6 This is a process diagram illustrating the construction method of a grounding device according to the present invention.

[0033] Among them, 1. Metal grounding body; 2. Conductive layer; 3. Graphene composite layer; 31. Copper foil layer; 32. Graphene layer; 4. Grounding pit. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain the present invention and should not be construed as limiting the invention.

[0035] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this patent. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0036] Example: like Figures 1 to 3 As shown, this embodiment provides a grounding device, including a metal grounding body 1, at least one conductive layer 2, and at least one graphene composite layer 3. The graphene composite layer 3 includes a copper foil layer 31 and a graphene layer 32 stacked together. One side of the conductive layer 2 is combined with the metal grounding body 1, and the other side is combined with the copper foil layer 31.

[0037] In existing grounding devices, if the copper foil layer 31 is in direct contact with the metal grounding body 1 (such as steel), a potential difference will be formed due to the difference in their standard electrode potentials in the soil electrolyte. In a moist soil environment, this causes electrons to flow from the metal with the lower potential to the copper with the higher potential, forming an anodic region on the surface of the metal grounding body 1 and accelerating its corrosion. In this embodiment, the conductive layer 2 is disposed between the metal grounding body 1 and the copper foil layer 31, avoiding direct contact between them. The conductive layer 2, as a transition layer, blocks the electron flow path caused by the potential difference, reducing the risk of damage to the metal grounding body 1 due to electrochemical corrosion and extending the service life of the grounding device. The graphene composite layer 3 is composed of a copper foil layer 31 and a graphene layer 32 stacked together. Both copper and graphene have excellent conductivity, and their combination fully utilizes their conductivity advantages to form a composite structure with superior conductivity. At the same time, the good combination of the conductive layer 2 with the metal grounding body 1 and the copper foil layer 31 ensures smooth current conduction in the grounding device, further optimizing the conductivity of the grounding device and improving current dissipation efficiency. Furthermore, graphene exhibits good chemical stability and is not easily corroded. Therefore, the graphene layer 32 can enhance the corrosion resistance of the copper foil layer 31, thereby improving the overall corrosion resistance of the grounding device. Specifically, in this embodiment, the metal grounding body 1 is made of steel. In other embodiments, the metal grounding body 1 can also be made of aluminum, galvanized steel, etc.

[0038] It should be noted that most grounding devices in related technologies are made of a single metal material, which has poor electrochemical stability and is easily corroded by environmental factors. In contrast, the grounding device in this application is made of multiple materials such as copper and graphene, which improves the overall electrochemical stability, reduces the corrosion rate of materials in complex environments, extends the service life of materials, and reduces the risk of equipment failure and maintenance costs caused by material corrosion.

[0039] The graphene composite layer 3 is a flexible sheet with an area greater than or equal to 0.05 m2.

[0040] In this embodiment, the graphene composite layer 3 has an area greater than or equal to 0.05m². 2The flexible sheet allows it to adapt to various complex soil shapes and adaptively bend and deform, ensuring full contact with the soil surface. This increases the effective contact area between the grounding device and the soil, thereby reducing grounding resistance and improving the performance of the grounding system. For example, in grounding projects for transmission towers in mountainous areas, the soil may contain many rocks. The flexible sheet-like graphene composite layer 3 can be easily laid in the soil and achieve good conformality with the soil / rocks, ensuring good contact between the grounding device and the soil. Specifically, the thickness of the graphene layer 32 is much smaller than that of the copper foil layer 31, and the copper foil layer 31 has a flexible structure. Therefore, the graphene composite layer 3, formed by combining the graphene layer 32 and the copper foil layer 31, also exhibits strong adaptability and flexibility.

[0041] In real-world grounding scenarios, soil environments are complex and diverse, with potential for undulating terrain and uneven rock distribution. Existing rigid grounding materials are difficult to fit closely to these irregular terrains, thus affecting the grounding effect.

[0042] The metal grounding electrode 1 is rod-shaped, and the length direction of the graphene composite layer 3 forms an angle with the axis of the metal grounding electrode 1, with the angle being 30° to 90°.

[0043] In this embodiment, the direction of arrow X represents the "length direction of graphene composite layer 3", and the direction of arrow Y represents the "axial direction of metal grounding electrode 1". Specifically, metal grounding electrode 1 is steel bar, which is relatively inexpensive, readily available, and has high strength. After the graphene composite layer 3 and the axis of metal grounding electrode 1 form an angle, the current conduction path in graphene composite layer 3 becomes more diversified. That is, the current is no longer limited to conduction along a single direction of metal grounding electrode 1, but can be dispersed in different extension directions of different graphene composite layers 3. The current distribution in the soil around the grounding device is more uniform, avoiding situations where the local current is too large or too small, thus improving stability and safety. In addition, controlling the angle between the axis of graphene composite layer 3 and metal grounding wire within the range of 30° to 90° can also avoid interference phenomena such as mutual compression and overlap between graphene composite layers 3 in different regions or at different levels. In other embodiments, metal grounding electrode 1 can also be a copper rod, galvanized steel pipe, etc.

[0044] Along the axial direction of the metal grounding body 1, multiple graphene composite layers 3 are spaced apart, and graphene composite layers 3 are provided on both opposite sides of the metal grounding body 1.

[0045] In this embodiment, multiple graphene composite layers 3 are arranged at certain intervals along the axial direction of the metal grounding electrode 1, ensuring that each graphene composite layer 3 can fully exert its excellent conductivity and current dissipation performance in the soil environment, avoiding mutual interference due to excessive density and resulting in local performance degradation. Graphene composite layers 3 are provided on both opposite sides of the metal grounding electrode 1, increasing the conduction path and current dissipation channel of the current in the grounding device. When current flows from the metal grounding electrode 1 into the soil, the graphene composite layers 3 on both sides can function simultaneously, dispersing the current more widely and evenly into the surrounding soil, greatly improving the current conduction efficiency and current dissipation effect, reducing grounding resistance, and ensuring the stable operation of the grounding device in the electrical system. Specifically, the graphene composite layers 3 on both sides of the metal grounding electrode 1 can be symmetrically or asymmetrically arranged. The number of graphene composite layers 3 on both sides of the metal grounding electrode 1 can be the same or different.

[0046] Each graphene composite layer 3 is connected to the metal grounding body 1 through two guide layers. Along the axial direction of the metal grounding body 1, the two guide layers are respectively connected to the opposite ends of the graphene composite layer 3.

[0047] In this embodiment, guide layers are only provided at opposite ends of the graphene composite layer 3 for connection of critical parts, avoiding unnecessary coverage by the conductive layer 2, thereby saving conductive materials and reducing costs. Furthermore, the stable conductive path formed by the guide layers not only ensures efficient current conduction but also enhances the structural stability of the entire grounding device. When subjected to external forces or changes in the soil environment, the guide layers maintain the connection between the graphene composite layer 3 and the metal grounding body 1, preventing performance degradation due to loosening or deformation. Of course, in other embodiments, the conductive layer 2 can also cover the entire end face of the graphene composite layer 3 used to connect to the metal grounding body 1 to strengthen the connection effect.

[0048] The thickness of conductive layer 2 is 0.1 to 1 mm.

[0049] In this embodiment, the thickness of conductive layer 2 is 0.1–1 mm. When the thickness of conductive layer 2 is less than 0.1 mm, its conductivity and mechanical strength are insufficient, making it unable to stably perform its conductive and connection functions, which can easily lead to unstable performance or even failure of the grounding device in actual use. Conversely, when the thickness of conductive layer 2 exceeds 1 mm, the amount of material used increases significantly, resulting in unnecessary cost increases. For example, in some large-scale grounding device projects, the amount of material used in conductive layer 2 is enormous; every 0.1 mm increase in thickness leads to a substantial increase in material costs. Therefore, controlling the thickness within the range of 0.1–1 mm can minimize the amount of material used and reduce the manufacturing cost of the grounding device while meeting performance requirements.

[0050] The thickness of graphene composite layer 3 is 0.05–0.5 mm.

[0051] In this embodiment, when the thickness of the graphene composite layer 3 is less than 0.05 mm, the excessively thin composite layer may lead to discontinuous conductive pathways (such as insufficient graphene sheet stacking), affecting the overall conductivity. When the thickness of the graphene composite layer 3 exceeds 0.5 mm, the improvement in conductivity tends to saturate, and the material cost increases significantly. Furthermore, the graphene layer 32 covers the surface of the copper foil layer 31 away from the metal grounding body 1, wherein the thickness ratio of the graphene layer 32 to the copper foil layer 31 is 1:99, therefore the thickness of the graphene layer 32 is much smaller than the thickness of the copper foil layer 31. The length dimension of the copper foil layer 31 is 200–500 mm, that is, the unfolded dimension of the copper foil layer 31 is 200–500 mm.

[0052] This embodiment also provides a method for preparing a grounding device, the grounding device including one of the aforementioned grounding devices, such as... Figure 5 As shown, the preparation method includes the following steps: S110: Provides a metallic grounding electrode 1; S120: Provides a copper foil layer 31 and a graphene layer 32, which are metallurgically bonded to form a graphene composite layer 3. S130: Provide a conductive layer 2, one side of which is welded to a metal grounding body 1 by a welding process, and the other side of which is welded to a copper foil layer 31 in the graphene composite layer 3 by a welding process.

[0053] In this embodiment, the two are bonded together to form a graphene composite layer 3 through metallurgical bonding, creating a strong atomic-level bond between the copper foil and graphene, which significantly improves the conductivity of the graphene composite layer 3. The welding process enables a high-strength metallurgical bond between the conductive layer 2 and the metal grounding body 1, allowing it to withstand greater tensile and compressive forces and ensuring a stable connection for the grounding device under various harsh environments. The preparation method in this application has good process compatibility and can be combined with other grounding device preparation processes. For example, the surface treatment and anti-corrosion treatment of the grounding device can be seamlessly integrated with the welding process, further improving the performance and reliability of the grounding device. Regarding surface treatment, galvanizing or powder coating can be applied to the grounding device after welding to enhance its corrosion resistance; regarding anti-corrosion treatment, special anti-corrosion coatings or anti-corrosion materials can be used to extend the service life of the grounding device.

[0054] The copper content in copper foil layer 31 is greater than or equal to 99.9%.

[0055] The resistivity of copper is closely related to its purity; the higher the copper content, the lower the resistivity. Therefore, in this embodiment, a copper foil layer 31 with a high copper content is selected to reduce the resistance of the grounding device and enhance its conductivity. Specifically, the copper foil layer 31 is made of T2 pure copper foil.

[0056] The conductive layer 2 is a nickel layer with a nickel content greater than or equal to 99%.

[0057] In this embodiment, the conductive layer 2 is a nickel layer. High-purity nickel has excellent conductivity, meaning the nickel layer in this application has stable low resistance. When faced with high-current surges (such as lightning current), the high-purity nickel layer can quickly conduct the current to the metal grounding electrode 1 and the graphene composite layer 3, reducing heat accumulation caused by excessive resistance and preventing performance degradation or even damage to the grounding device due to overheating, thus ensuring the operation of the grounding device. Furthermore, the nickel layer, positioned between the copper foil layer 31 and the metal grounding electrode 1, serves a dual function of physical isolation and electrical transition. It breaks the electron conduction path formed by the direct contact between copper and the metal grounding electrode 1, preventing electrons from flowing directly from the lower potential metal grounding electrode 1 to the higher potential copper foil layer 31, thereby inhibiting electrochemical corrosion. In other embodiments, the conductive layer 2 can also be made of metals such as platinum or zinc. The conductive layer 2 only needs to be made of a material with good electrochemical compatibility with both the copper foil layer 31 and the metal grounding electrode 1, ensuring that conductivity is maintained without introducing new potential difference corrosion problems.

[0058] The welding process is laser welding and / or brazing.

[0059] In this embodiment, laser welding uses a focused laser beam to irradiate the workpiece surface, causing the material to melt rapidly and locally, forming a weld. Laser welding has advantages such as concentrated energy, high welding speed, and a small heat-affected zone. When welding the copper foil layer 31, conductive layer 2, and metal grounding body 1, laser welding can accurately control the welding area, avoiding excessive thermal damage to surrounding non-welded areas. When the conductive layer 2 uses thin film materials with special functions, laser welding can ensure that the integrity and performance of the film are not damaged during the welding process. Brazing uses a metal material with a lower melting point than the base material as the filler metal. The workpiece and filler metal are heated to a temperature higher than the filler metal's melting point but lower than the base material's melting temperature. The liquid filler metal wets the base material, fills the joint gap, and diffuses with the base material to achieve the connection of the workpiece. The brazing welding temperature is relatively low, and for welding the copper foil layer 31, conductive layer 2, and metal grounding body 1, brazing can avoid material performance degradation caused by high temperatures.

[0060] This embodiment also provides a construction method for a grounding device, such as... Figure 6 As shown, the grounding device includes one of the aforementioned grounding devices, and the construction method includes the following steps: S210: Select a transmission tower and dig a grounding pit 4 next to the base of the transmission tower; S220: Multiple grounding devices are placed in the grounding pit 4 and the multiple grounding devices are evenly arranged in a radial pattern; S230: A resistance-reducing agent is filled between adjacent graphene composite layers 3 of the grounding device. The resistance-reducing agent includes graphite powder and bentonite, and the mass ratio of graphite powder to bentonite is 1:3. S240: The metal grounding body 1 of the grounding device is connected to the grounding terminal of the transmission tower via a lead wire.

[0061] In this embodiment, a transmission tower is selected, and a grounding pit 4 is dug next to its base. This shortens the connection distance between the grounding device and the grounding terminal of the transmission tower, reduces the lead length, thereby lowering the lead resistance and improving grounding efficiency. When digging the grounding pit 4, the shape and size of the pit should be designed reasonably according to the size and number of the grounding device. Figure 4 As shown, multiple grounding devices are evenly arranged radially to increase the contact area between the grounding devices and the soil, improve the current dissipation effect, and allow the current to be evenly conducted into the ground from multiple directions, thus reducing the grounding resistance. A resistance-reducing agent made by mixing graphite powder and bentonite in a 1:3 mass ratio has a significant resistance-reducing effect. Graphite powder has good conductivity, which can increase the conductivity of the soil; bentonite has the property of absorbing water and swelling, keeping the soil moist, which is beneficial for reducing soil resistivity. The metal grounding body 1 of the grounding device is connected to the grounding terminal of the transmission tower through a lead wire; the connection method can be welding or bolting.

[0062] Preparation example: This example provides a method for preparing the aforementioned grounding device, the method comprising the following steps: Clean galvanized steel bars are selected as the metal grounding electrode 1, and the diameter of the galvanized steel bars is 16mm; Clean copper foil and graphene were selected and metallurgically bonded to form a graphene composite layer 3 with a thickness of 0.1 mm. The area of ​​a single graphene composite layer 3 is 0.15 m². 2 ; Two nickel alloy sheets (99.6% nickel content), each 0.3 mm thick and 20 mm wide, were selected. One side of the nickel alloy sheets was welded to the reinforcing bar, and the other side was welded to the copper foil layer 31 in the graphene composite layer 3. The two nickel alloy sheets were then welded to opposite ends of the graphene composite layer 3 along the axial direction of the reinforcing bar. Specifically, a fiber laser welding machine (2 kW power, 10 mm / s scanning speed) was used. One side of the nickel alloy sheet was attached to and welded to the copper foil layer 31, with a weld width of 1.5 mm. Simultaneously, the other side of the nickel alloy sheet was welded to the surface of the reinforcing bar, forming a metallurgical bond between the copper foil, nickel sheet, and reinforcing bar. Finally, the graphene composite layer 3 was unfolded, so that the length direction of the graphene composite layer 3 formed a 45° angle with the axis of the metal grounding body 1.

[0063] This example also provides a construction method for the aforementioned grounding device, the construction method comprising the following steps: Select a transmission tower and dig a grounding pit 4 next to the base of the transmission tower; Six grounding devices are placed in grounding pit 4 and the multiple grounding devices are evenly arranged in a radial pattern, with the included angle between two adjacent grounding devices being 60°. A resistance-reducing agent is filled between adjacent graphene composite layers 3 of the grounding device. The resistance-reducing agent includes graphite powder and bentonite, and the mass ratio of graphite powder to bentonite is 1:3. The metal grounding body 1 of the grounding device is bolted to the grounding terminal of the transmission tower via a lead wire.

[0064] The grounding device in this application and the galvanized steel grounding body in the prior art were measured using a grounding resistance tester. The grounding resistance of the grounding device in this application was 16.65Ω, while the resistance of the galvanized steel grounding body was 32.6Ω. Therefore, it can be seen that the grounding device in this application has good conductivity.

[0065] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A grounding device, characterized in that, It includes a metal grounding electrode, at least one conductive layer, and at least one graphene composite layer, wherein the graphene composite layer comprises a copper foil layer and a graphene layer stacked together; one side of the conductive layer is bonded to the metal grounding electrode, and the other side is bonded to the copper foil layer.

2. The grounding device according to claim 1, characterized in that, The graphene composite layer is a flexible sheet with an area greater than or equal to 0.05 m2.

3. The grounding device according to claim 1, characterized in that, The metal grounding electrode is rod-shaped, and the length direction of the graphene composite layer forms an angle with the axis of the metal grounding electrode, the angle being 30° to 90°.

4. The grounding device according to claim 3, characterized in that, Along the axial direction of the metal grounding body, multiple graphene composite layers are spaced apart, and the graphene composite layers are provided on both opposite sides of the metal grounding body.

5. The grounding device according to claim 3, characterized in that, Each graphene composite layer is connected to the metal grounding body through two guide layers. Along the axial direction of the metal grounding body, the two guide layers are respectively connected to the opposite ends of the graphene composite layer.

6. The grounding device according to any one of claims 1-5, characterized in that, The conductive layer has a thickness of 0.1–1 mm, and the graphene composite layer has a thickness of 0.05–0.5 mm.

7. A method for preparing a grounding device, characterized in that, The grounding device includes a grounding device according to any one of claims 1-6, and the preparation method includes the following steps: Provide a metallic grounding electrode; A copper foil layer and a graphene layer are provided, wherein the copper foil layer and the graphene layer are metallurgically bonded to form a graphene composite layer; A conductive layer is provided, one side of which is welded to the metal grounding electrode by a welding process, and the other side of which is welded to the copper foil layer in the graphene composite layer by a welding process.

8. The preparation method according to claim 7, characterized in that, The copper foil layer has a copper content of 99.9% or higher, and the conductive layer is a nickel layer with a nickel content of 99% or higher.

9. The preparation method according to claim 7, characterized in that, The welding process is laser welding and / or brazing.

10. A construction method for a grounding device, characterized in that, The grounding device includes a grounding device according to any one of claims 1-6, and the construction method includes the following steps: Select a transmission tower and dig a grounding pit next to the base of the transmission tower; Multiple grounding devices are placed in the grounding pit and the multiple grounding devices are evenly arranged in a radial pattern; A resistance-reducing agent is filled between adjacent graphene composite layers of the grounding device. The resistance-reducing agent comprises graphite powder and bentonite, and the mass ratio of the graphite powder to the bentonite is 1:

3. The metal grounding body of the grounding device is connected to the grounding terminal of the transmission tower via a lead wire.

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