Conductive polyolefin coated metal grounding system and construction method thereof

Abstract

The invention belongs to the technical field of power equipment, and relates to a conductive polyolefin coated metal grounding system and a construction method thereof. The conductive polyolefin coated metal grounding system comprises a grounding material and a conductive polyolefin layer, wherein the grounding material comprises a metal core material and a conductive polyolefin layer coated on the outer surface of the metal core material; the resistance reducing layer is coated on the outer part of the grounding material; and the ion slow release agent is arranged in the mounting base body around the grounding material. In the grounding material adopted by the conductive polyolefin coated metal grounding system, the conductive polyolefin layer forms a physical barrier for the metal core material, so that the corrosion rate of the grounding material can be reduced; the resistance reducing layer and the ion slow-release agent cooperate to maintain long-term stability of the grounding resistance and adapt to a high-soil resistivity environment. The conductive polyolefin coated metal grounding system is simple and convenient to construct, high in environmental adaptability, green and environment-friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power equipment, more particularly, to a conductive polyolefin coated metal grounding system and a construction method thereof. BACKGROUND

[0002] A grounding system is a safety foundation device in power engineering, and its core function is to safely guide the current (such as fault current, lightning current, static electricity) of electrical equipment or facilities into the ground, thereby protecting personal safety, discharging high-voltage current on a power transmission line due to lightning strikes or short circuits, avoiding equipment insulation breakdown, stabilizing power grid voltage, and ensuring normal operation of equipment. With the expansion of the power grid scale, the construction of power transmission lines and substations gradually extends to high-soil-resistivity and high-corrosion areas. The grounding material (such as galvanized steel) of the traditional grounding system corrodes quickly in a high-corrosion environment, resulting in an increase in grounding resistance and a reduction in service life, which seriously affects the safe operation of the power system. In the prior art, in order to reduce the corrosion rate of the grounding material in a high-corrosion environment, the cross section of the grounding body is usually increased or copper or copper-coated steel is used as the grounding material. However, increasing the cross section of the grounding body can delay corrosion, but it increases material consumption and construction difficulty. Copper is high in cost and scarce in resources, and copper-coated steel is prone to pitting due to uneven plating. The above methods still have certain deficiencies in reducing the corrosion of the grounding system and maintaining the stability of the grounding system.

[0003] Therefore, there is an urgent need for a grounding system and a construction method that are strong in corrosion resistance, stable in grounding resistance, convenient in construction, and friendly to the environment. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a conductive polyolefin coated metal grounding system and a construction method thereof, which aims to solve the problems in the prior art.

[0005] According to a first aspect of the present application, a conductive polyolefin coated metal grounding system is provided, comprising: a grounding material, the grounding material comprising a metal core material and a conductive polyolefin layer coated on the outer surface of the metal core material; a resistance reduction layer, the resistance reduction layer being coated on the outside of the grounding material; an ion slow-release agent, the ion slow-release agent being arranged in an installation matrix around the grounding material.

[0006] Preferably, the resistance reduction layer is formed by mixing and gelling solidification of A components and B components; The preparation raw materials of the A components include: 60-70 parts by weight of superabsorbent polymer; 15-20 parts by weight of conductive reinforcing agent; and 10-15 parts by weight of temperature-responsive material; The preparation raw materials of the B component include: 80-85 parts by weight of ion-activated liquid; 10-15 parts by weight of cross-linking agent.

[0007] Preferably, the ion slow-release agent is embedded within a range of 20 cm from the outer surface of the grounding material, and at least partially overlaps with the spatial coverage area of the resistance reduction layer.

[0008] Preferably, the ion slow-release agent includes a slow-release carrier and conductive ion agent.

[0009] Preferably, the metal core material is made of galvanized steel wire or steel-cored aluminum wire, and the tensile strength of the metal core material is ≥ 1200 MPa.

[0010] Preferably, the conductive polyolefin layer includes the following components by weight: 60-80 parts of high-density polyethylene; 20-25 parts of conductive carbon black; 8-10 parts of graphite; 5-10 parts of maleic anhydride grafted polyethylene; 2-4 parts of antioxidant; and 2-4 parts of ultraviolet stabilizer.

[0011] Preferably, the connecting joint for connecting multiple sections of the grounding material is further included; the connecting joint includes a connecting cavity, an internal conductor, a clamping jaw, and a fastening bolt; The internal conductor is arranged at a middle position in the connecting cavity; Two clamping jaws are symmetrically arranged on both sides of the internal conductor and connected with the internal conductor, and the clamping jaws are used for clamping the grounding material inserted into the connecting cavity; A plurality of fastening bolts are screwed on the pipe wall of the connecting cavity corresponding to the position of the clamping jaw, the fastening bolts penetrate the pipe wall of the connecting cavity, and the fastening bolts are used for pushing the clamping jaw to fasten the grounding material.

[0012] Preferably, the material of the connecting cavity is corrosion-resistant reinforced nylon, the material of the internal conductor is red copper, and the material of the clamping jaw is beryllium bronze.

[0013] Preferably, a sealant is arranged at the connection between the connecting joint and the grounding material, and the corrosion resistance grade of the sealant is higher than that of the conductive polyolefin layer.

[0014] According to the second aspect of the present application, a construction method of the conductive polyolefin coated metal grounding system is provided, which includes the following steps: Step one, laying multiple sections of grounding material along the foundation of the power facility; Step two, splicing multiple sections of grounding material through the connecting joint; Step three, arranging a resistance reduction layer outside the spliced grounding material; Step four, pouring ion slow-release agent around the grounding material.

[0015] The present invention has the following beneficial effects: In this conductive polyolefin-coated metal grounding system, the conductive polyolefin layer forms a physical barrier to the metal core, reducing the corrosion rate of the grounding material. The volume resistivity of the conductive polyolefin layer is much lower than that of the soil resistivity, and it is tightly bonded to the metal core, exhibiting good current dissipation performance. The resistivity-reducing layer establishes a highly efficient current dissipation channel primarily based on electron conduction. When lightning current or fault current arrives, the current can preferentially diffuse rapidly to the ground through this low-resistivity channel. The ion-releasing agent releases conductive ions, chemically improving the high-resistivity soil at the end of the current path, significantly reducing its resistivity and forming a wider ion-conducting region. This allows the current to be dispersed from a point to a surface over a broad area, achieving low-impedance current dissipation. The synergistic effect of the resistivity-reducing layer and the ion-releasing agent maintains long-term stable grounding resistance, adapting to environments with high soil resistivity. This conductive polyolefin-coated metal grounding system is simple to construct, highly adaptable to the environment, and environmentally friendly. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.

[0017] Figure 1 A schematic diagram of a conductive polyolefin-coated metal grounding system according to an embodiment of the present invention is shown.

[0018] Figure 2 A cross-sectional view of the grounding material in a conductive polyolefin-coated metal grounding system according to an embodiment of the present invention is shown.

[0019] Figure 3 A schematic diagram of the connection joint in a conductive polyolefin-coated metal grounding system according to an embodiment of the present invention is shown.

[0020] Figure 4 A flowchart illustrating a construction method for a conductive polyolefin-coated metal grounding system according to an embodiment of the present invention is shown.

[0021] In the diagram: 1. Grounding material; 11. Metal core material; 12. Conductive polyolefin layer; 2. Connecting joint; 21. Connecting cavity; 22. Internal conductor; 23. Claw; 24. Fastening bolt; 3. Resistance reducing layer; 4. Ion slow-release agent; 5. Cofferdam. Detailed Implementation

[0022] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0023] This invention provides a conductive polyolefin-coated metal grounding system, see [link to relevant documentation]. Figure 1 and Figure 2 The conductive polyolefin-coated metal grounding system includes: a grounding material 1, a resistance-reducing layer 3, and an ion-releasing agent 4. The grounding material 1 includes a metal core 11 and a conductive polyolefin layer 12 covering the outer surface of the metal core 11; the resistance-reducing layer 3 covers the exterior of the grounding material 1; and the ion-releasing agent 4 is disposed in a mounting substrate surrounding the grounding material 1.

[0024] The metal core 11 is made of galvanized steel strand or steel-cored aluminum strand, and the tensile strength of the metal core 11 is ≥1200MPa. The conductive polyolefin layer 12 has a volume resistivity ≤3Ω·cm, an annual corrosion rate ≤0.002mm / a, an elongation ≥30%, and a water absorption rate ≤0.05%.

[0025] The conductive polyolefin layer 12 comprises the following components in parts by weight: 60-80 parts of high-density polyethylene; 20-25 parts of conductive carbon black; 8-10 parts of graphite; 5-10 parts of maleic anhydride-grafted polyethylene; 2-4 parts of antioxidant; and 2-4 parts of UV stabilizer.

[0026] In a preferred embodiment, the conductive polyolefin layer 12 comprises the following components in parts by weight: 70 parts high-density polyethylene (HDPE); 22 parts conductive carbon black; 9 parts graphite; 8 parts maleic anhydride grafted polyethylene (MAH-g-PE); 3 parts antioxidant; and 3 parts UV stabilizer. The HDPE used is grade HDPE5000S, with a melt flow rate of 2.1 g / 10 min and a density of 0.95 g / cm³, providing the conductive polyolefin layer 12 with basic mechanical strength and weather resistance, meeting the manufacturing requirements of "factory extrusion coating". The conductive carbon black is selected as the main conductive filler, using conductive carbon black (model XC-72) with a particle size of 30 nm and a DBP oil absorption value of 150 mL / 100 g, ensuring the conductivity of the conductive polyolefin layer 12 and meeting the requirement of "volume resistivity ≤ 3 Ω·cm". The graphite used is flake graphite (50μm particle size), which forms a "carbon black-graphite" conductive network with conductive carbon black, reducing the volume resistivity fluctuation of the conductive polyolefin layer 12 and improving the adhesion between the conductive polyolefin layer 12 and the metal core material 11. Maleic anhydride-grafted polyethylene with a grafting rate of 1.2% acts as a compatibilizer, improving the interfacial compatibility between high-density polyethylene and conductive carbon black and graphite, preventing cracking of the conductive polyolefin layer 12, and meeting the requirements of "tensile strength ≥10MPa, elongation ≥30%". Antioxidant 1010 (hindered phenol) is selected to inhibit the oxidative aging of the conductive polyolefin layer 12 in high-temperature environments (such as 115℃ under short-circuit current) and in humid and hot soil environments, meeting the requirement of "no performance degradation after 100℃, 240h thermal aging". UV stabilizer UV-531 (benzophenone) is selected to resist outdoor ultraviolet radiation, meeting the requirement of "no change in tensile properties after 2000h ultraviolet aging".

[0027] The preparation process of grounding material 1 in this preferred embodiment is as follows: Mixing process: Add high-density polyethylene, conductive carbon black, graphite, maleic anhydride grafted polyethylene, antioxidant, and UV stabilizer into a high-speed mixer according to the formula, and stir at 120°C for 15 minutes to ensure uniform dispersion of components. Extrusion coating process: A single-screw extruder (screw length-to-diameter ratio 30:1) is used, and the extrusion temperature is set to 160℃ (feed section), 180℃ (melting section), and 200℃ (die head section). The molten conductive polyolefin material is coated onto the surface of the metal core material 11 to form a conductive polyolefin layer 12. The thickness of the conductive polyolefin layer 12 is controlled to be 3mm (adjusted by the precision of the extrusion die). Cooling and shaping: The conductive polyolefin layer 12 is rapidly cooled by water cooling (water temperature 25℃) to ensure that the conductive polyolefin layer 12 is tightly bonded to the metal core material 11 without bubbles or missing coating defects.

[0028] Galvanized steel wire stranded with steel core (model JD-PLJG-95-3) conforming to GB / T3082 is selected as the metal core material 11, with a nominal tensile strength of 1370MPa and a thermal stability coefficient C=70 (set according to the internal steel core thermal stability performance), ensuring that the temperature of the metal core material 11 does not exceed 400℃ under short-circuit current and there is no deterioration in electrical performance.

[0029] In this embodiment, the conductive polyolefin layer 12 is formulated with a combination of conductive carbon black and graphite to form a dense conductive network. This results in a volume resistivity of 2.4 Ω·cm for the conductive polyolefin layer 12, which is far lower than the soil resistivity of 300 Ω·m and meets the requirement of a volume resistivity ≤3 Ω·cm. Maleic anhydride-grafted polyethylene enhances compatibility, allowing the conductive polyolefin layer 12 to bond tightly with the metal core material 11, providing excellent current dissipation performance and ensuring rapid dissipation of lightning current and fault current. The synergistic effect of antioxidants and UV stabilizers ensures that the conductive polyolefin layer 12 exhibits almost no performance degradation after 240 hours of thermal aging at 100°C and 2000 hours of UV aging, solving the problem of traditional galvanized steel requiring replacement every 15 years. The conductive polyolefin layer 12 completely isolates the grounding material from soil corrosion media, with an annual corrosion rate of 0.002 mm / a, which is only 1 / 5 of that of pure copper and 1 / 22.5 of that of galvanized steel, ensuring a 60-year lifespan without the need for replacement.

[0030] The conductive polyolefin-coated metal grounding system also includes a connection joint 2 for connecting multiple sections of the grounding material 1. See also Figure 3 The connecting connector 2 includes a connecting cavity 21, an internal conductor 22, claws 23, and fastening bolts 24. The internal conductor 22 is located in the middle of the connecting cavity 21. Two claws 23 are symmetrically arranged on both sides of the internal conductor 22 and connected to it. The claws 23 are used to clamp the grounding material 1 inserted into the connecting cavity 21. Multiple fastening bolts 24 are screwed onto the tube wall of the connecting cavity 21 corresponding to the positions of the claws 23. The fastening bolts 24 penetrate the tube wall of the connecting cavity 21 and are used to push the claws 23 to fasten the grounding material 1. In this embodiment, both the connecting cavity 21 and the internal conductor 22 are circular tubular structures.

[0031] Specifically, the connecting cavity 21 is made of corrosion-resistant reinforced nylon (model PA66+GF30). The inner diameter of the connecting cavity 21 is adapted to the outer diameter of the grounding material 1, so that the end of the grounding material 1 can be inserted into the connecting cavity 21. A threaded hole is pre-drilled in the tube wall of the connecting cavity 21 so that after the fastening bolt 24 is screwed into the threaded hole, the fastening bolt 24 can penetrate the tube wall and act on the claw 23. The internal conductor 22 is made of copper sheet and is coaxially arranged with the connecting cavity 21. The outer wall of the internal conductor 22 is fitted to the inside of the connecting cavity 21. The internal conductor 22 is located at the center of the length direction of the connecting cavity 21. The inner diameter of the internal conductor 22 must ensure that the grounding material 1 can be inserted to ensure full contact between the grounding material 1 and the conductor and reduce contact resistance. Two claws 23 are symmetrically arranged on both sides of the internal conductor 22 along its length. The claws 23 are made of beryllium bronze and are coaxially arranged with the internal conductor 22. Each claw 23 includes multiple inwardly curved arc-shaped teeth for clamping and fixing the grounding material 1 inserted into the connecting cavity 21. In this embodiment, each claw 23 includes three arc-shaped teeth, which are evenly distributed around the circumference of the claw 23. The curvature of the arc-shaped teeth matches the outer diameter of the grounding material 1. In its natural state, the inner diameter of the claw 23 is 2 mm smaller than the outer diameter of the grounding material 1. When the grounding material 1 is inserted, pre-clamping of the grounding material 1 is achieved through elastic deformation. The claws 23 can be connected to the end of the internal conductor 22 by welding, pressing, or riveting. The arc-shaped teeth on the claws 23 face away from the internal conductor 22. The fastening bolt 24 is made of 304 stainless steel, which has good corrosion resistance. One end of the fastening bolt 24 passes through the threaded hole provided on the pipe wall of the connecting cavity 21. After the fastening bolt 24 passes through the pipe wall of the connecting cavity 21, it can push the outside of the claw 23 by screwing, so that the claw 23 retracts inward, thereby further clamping the grounding material 1 and ensuring that the grounding material 1 is firmly connected. After tightening, the pull-out force should be greater than 5kN to ensure that the grounding material 1 does not loosen.

[0032] Furthermore, a sealant is provided at the connection between the connecting joint 2 and the grounding material 1. The corrosion resistance of the sealant is higher than that of the conductive polyolefin layer 12. The sealant fills the gap between the connecting joint 2 and the grounding material 1 to form a sealed structure and prevent soil moisture intrusion. Specifically, the sealant is a two-component silicone-modified sealant; its corrosion resistance is: annual corrosion rate of 0.001 mm / a (lower than 0.002 mm / a for the conductive polyolefin layer 12); after immersion in simulated soil environments with pH=2 (strong acid) and pH=12 (strong alkali) for 120 days, the volume change rate is less than 0.5%; its water absorption rate is 0.01% (lower than 0.03% for the conductive polyolefin layer 12); it withstands 2000 hours of UV aging without cracking or peeling; after curing, its Shore A hardness is 60; and its bonding strength with the grounding material 1 and the connecting cavity 21 is greater than 1.5 MPa. During construction, after the grounding material 1 and the connecting joint 2 are assembled, a 3mm thick sealant layer is evenly applied along the joint seam and allowed to fully cure at room temperature for 24 hours. In this embodiment, the connecting joint 2 is double-fixed by "pre-clamping with claws 23 + tightening with bolts 24", avoiding poor joint contact caused by traditional arc welding. The pull-out force at the connection point should be greater than 5kN, the contact resistance less than 5mΩ, and the electrical conductivity stable. Moreover, no open flame construction is required, making it suitable for construction needs in outdoor areas without power supply and in flammable and explosive areas (such as forest towers), significantly improving construction efficiency compared to traditional welding.

[0033] In practical applications, corrosion of traditional grounding material 1 leads to an increase in grounding resistance (e.g., the grounding resistance of galvanized steel is expected to increase by 100% over 10 years). However, in this application, the grounding material 1 has a conductive polyolefin layer 12 covering the metal core 11. Due to the excellent corrosion resistance of the conductive polyolefin material, the grounding resistance of the grounding material 1 remains almost unchanged. The sealant has a higher corrosion resistance rating, which can maintain the sealing integrity of the connection joint 2 for a long time, avoiding the increase in joint contact resistance due to seal failure, ensuring a low impedance path for the entire grounding system, maintaining the safe current dissipation capability of lightning current and fault current, and synergizing with the excellent current dissipation characteristics of the conductive polyolefin layer 12.

[0034] The drag-reducing layer 3 is formed by gel-curing a mixture of components A and B, with an electrical conductivity ≥2.5 mS / cm and a gel-curing time ≤120 seconds. The raw materials for component A include: 60-70 parts by weight of a highly absorbent polymer; 15-20 parts by weight of a conductive enhancer; and 10-15 parts by weight of a temperature-responsive material. The raw materials for component B include: 80-85 parts by weight of an ion-activating liquid; and 10-15 parts by weight of a crosslinking agent. The conductive enhancer in component A significantly reduces the volume resistivity of the drag-reducing layer 3, forming a low-impedance pathway with the conductive polyolefin layer 12 (volume resistivity ≤3 Ω·cm), thus enhancing current dissipation. The conductive enhancer can be one of acetylene black, superconducting carbon black, graphene, or composite conductive materials (such as PEDOT:PSS). Simultaneously, in conjunction with the ion-activating liquid in component B, it continuously releases conductive ions, penetrating into the surrounding soil, improving soil conductivity, and achieving long-term stable drag reduction. In addition, the highly absorbent polymer in component A can absorb and lock in moisture in the soil, maintaining the moisture state of the drag-reducing layer 3 and the surrounding soil. The current-dissipating performance of the grounding material 1 is closely related to the soil contact state. This component can avoid the increase in resistivity caused by soil dryness, ensuring that the drag-reducing effect remains stable in arid environments, and making up for the defect of traditional drag-reducing agents (such as galvanized flat steel physical drag-reducing agents) being easily affected by moisture and failing. The temperature-responsive material in component A can make the drag-reducing layer 3 maintain physical stability when the temperature changes, avoiding cracks caused by thermal expansion and contraction. The temperature-responsive material can be a thermoplastic elastomer (TPE), which, as part of the drag-reducing layer gel matrix, can directly endow the material with "thermal self-healing" or "thermal adaptation" properties. When temperature changes cause small stresses to be generated internally, the elastomer segments can release the stress through movement, avoiding the generation and propagation of cracks. This matches the excellent UV and thermal aging resistance of the conductive polyolefin layer 12, ensuring that the resistance-reducing layer 3 remains tightly bonded to the grounding material 1 under conditions such as current-temperature cycling and freeze-thaw cycles, without affecting the overall electrical performance of the system. In a preferred embodiment, components A and B are mixed in a mass ratio of 3:1. During construction, components A and B are mixed with an electric mixer until bubbles appear on the surface and the container wall becomes slightly warm (about 2 minutes). The mixture is then quickly and evenly poured around the grounding material 1, and automatically gels and solidifies within 2 minutes, forming a lightweight resistance-reducing layer 3 that covers the outside of the grounding material 1 and is tightly bonded to it.

[0035] The ion-releasing agent 4 is embedded in the mounting substrate within a 20cm radius of the grounding material 1, and at least partially overlaps with the spatial coverage area of ​​the resistance-reducing layer 3. In this embodiment, the ion-releasing agent 4 is of type PIC-1, comprising a release carrier and a conductive ion agent. The release carrier is bentonite, and the conductive ion agent comprises potassium chloride and sodium sulfate. The specific parameters of the ion-releasing agent 4 are: gel time 80s (less than 120s), and conductivity 3.0mS / cm (greater than 2.5mS / cm). During construction, a trench is dug in the soil around the grounding material 1 along the extension direction of the grounding material 1, the ion-releasing agent is filled into the trench, and water is poured until it is completely moistened, allowing it to gel quickly and penetrate into the soil crevices.

[0036] Ion-release agent 4 is buried within 20cm of the grounding material 1. After gelation, it forms a "weakly alkaline protective area" that can neutralize the acidic corrosive medium in the soil and reduce the corrosion risk of the conductive polyolefin layer 12. The overlapping area of ​​the resistance-reducing layer 3 and the ion-release agent 4 forms a "double physical barrier" that isolates the direct contact between soil moisture and salt and the grounding material 1, avoiding "crevice corrosion" and "pitting corrosion" (such as accelerated corrosion after the copper-clad steel coating is damaged). If the resistance-reducing layer 3 fails (such as cracking), the grounding resistance will rise sharply, forcing the grounding system to fail prematurely. The ion-release agent 4 in the overlapping area can serve as a "backup resistance-reducing source." Even if the resistance-reducing layer 3 cracks locally, the ion-release agent 4 can still maintain the low resistance characteristics of the surrounding soil, avoiding a sudden drop in grounding performance and ensuring the overall lifespan of the grounding system is ≥60 years.

[0037] The conductive polyolefin-coated metal grounding system provided in this application utilizes a conductive polyolefin layer that forms a physical barrier against the metal core material, reducing the corrosion rate of the grounding material. The structure of the connection joints ensures convenient and reliable connection between the grounding materials, and the sealant applied at the connection points prevents crevice corrosion. Combined with the protection of the resistance-reducing layer and the ion-releasing agent, the service life of the entire grounding system can be extended. The volume resistivity of the conductive polyolefin layer is much lower than that of the soil and it is tightly bonded to the metal core material, exhibiting superior current dissipation performance compared to traditional metal materials. The synergistic effect of the resistance-reducing layer and the ion-releasing agent ensures long-term stability of the grounding resistance, thus solving the problem of rapid resistance increases with corrosion in traditional galvanized steel. Furthermore, the conductive polyolefin material is free of heavy metal pollution, and the ion-releasing agent has minimal impact on the soil, making this grounding system highly adaptable to the environment and environmentally friendly.

[0038] This invention also provides a construction method for the conductive polyolefin-coated metal grounding system as described above, see [link to relevant documentation]. Figure 4 The construction method includes the following steps: Step 1: Lay multiple sections of grounding material along the foundation of the power facility.

[0039] Specifically, taking the construction of the grounding grid for a transmission line tower in a certain area as an example, a ring-shaped grounding grid trench with a depth of 0.8m and a width of 0.5m is excavated around the tower foundation. Simultaneously, four radial trenches, each 50m long, 0.8m deep, and 0.5m wide, are excavated radiating outwards from the four tower feet. Sharp stones and other debris are removed from the trenches. Then, prefabricated grounding material 1, each 20m long, is laid in the ring-shaped grounding grid and the radial trenches.

[0040] Step 2: Connect multiple sections of grounding material 1 using connector 2.

[0041] Specifically, the segmented grounding material 1 is connected section by section using connecting joints 2. The fastening bolts 24 are tightened to 35 N•m using a torque wrench to ensure a reliable mechanical connection. Subsequently, sealant is evenly applied to all joints 2 and grounding material 1, and the sealing effect is checked to form a complete sealing ring.

[0042] Step 3: Install a resistance-reducing layer 3 on the outside of the grounding material 1 after splicing.

[0043] Specifically, in the trench where the grounding material 1 is laid, a resistance-reducing unit dam 5 is set up. The A and B components of the resistance-reducing layer 3 are mixed and poured into the dam 5 of the grounding material 1, forming a resistance-reducing layer 3 on the outside of the grounding material 1.

[0044] Step 4: Pour ion-releasing agent 4 around the grounding material 1.

[0045] Specifically, an ion-release agent 4 is injected around the grounding material 1 in the radial trenches and the ring-shaped grounding grid trenches. The injection area is located outside the resistance-reducing layer 3. Then, water is poured to completely wet it and allow it to quickly gel and penetrate into the surrounding soil crevices.

[0046] Finally, the excavated original soil was used to backfill the trench in layers, with each layer not exceeding 30cm in thickness. A small rammer was used to compact each layer, ensuring a compaction degree of ≥90%. After backfilling, a Fluke grounding resistance test system was used to measure the grounding resistance, ensuring it was ≤4Ω.

[0047] The grounding system constructed using this method ensures a tight bond between the resistance-reducing layer and the grounding material, preventing increased contact resistance due to gaps. Simultaneously, the rapid curing of the two-component mixed gel in the resistance-reducing layer reduces the impact of external factors (such as rainwater and soil disturbance) on the resistance-reducing effect during construction, ensuring the continuity of the current dissipation path. Furthermore, the connection joints ensure a firm and reliable connection between multiple sections of grounding material, and the tight bond between the resistance-reducing layer and the grounding material avoids the problem of frequent excavation and maintenance due to corrosion-induced increases in grounding resistance in traditional grounding grids. Additionally, the long-lasting effect of the ion-release agent reduces the cost of repeatedly adding resistance-reducing agents.

[0048] In summary, this invention provides a high-performance, long-life, easy-to-construct, and environmentally friendly grounding system and construction method, which has good prospects for widespread application.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A conductive polyolefin-coated metal grounding system, characterized in that, include: The grounding material includes a metal core and a conductive polyolefin layer covering the outer surface of the metal core. A resistance-reducing layer, which covers the outside of the grounding material; An ion-releasing agent is disposed in the mounting substrate surrounding the grounding material.

2. The conductive polyolefin-coated metal grounding system according to claim 1, characterized in that, The drag-reducing layer is formed by curing a mixture of component A and component B into a gel. The raw materials for preparing component A include: 60-70 parts by weight of superabsorbent polymer; 15-20 parts by weight of conductive reinforcing agent; and 10-15 parts by weight of temperature-responsive material. The raw materials for preparing component B include: 80-85 parts by weight of ion activating liquid and 10-15 parts by weight of crosslinking agent.

3. The conductive polyolefin-coated metal grounding system according to claim 1, characterized in that, The ion-releasing agent is embedded within 20 cm of the outer surface of the grounding material and at least partially overlaps with the spatial coverage area of ​​the resistance-reducing layer.

4. The conductive polyolefin-coated metal grounding system according to claim 3, characterized in that, The ion-release agent includes a release carrier and a conductive ion agent.

5. The conductive polyolefin-coated metal grounding system according to claim 1, characterized in that, The metal core material is made of galvanized steel strand or steel-cored aluminum strand, and the tensile strength of the metal core material is ≥1200MPa.

6. The conductive polyolefin-coated metal grounding system according to claim 1, characterized in that, The conductive polyolefin layer comprises the following components in parts by weight: 60-80 parts high-density polyethylene; 20-25 parts conductive carbon black; 8-10 parts graphite; 5-10 parts maleic anhydride-grafted polyethylene; 2-4 parts antioxidant; and 2-4 parts ultraviolet stabilizer.

7. The conductive polyolefin-coated metal grounding system according to claim 1, characterized in that, It also includes a connector for connecting multiple segments of the grounding material; the connector includes a connecting cavity, an internal conductor, a clamp, and a fastening bolt. The internal conductor is located in the middle of the connecting cavity. The two claws are symmetrically arranged on both sides of the internal conductor and connected to the internal conductor. The claws are used to clamp the grounding material inserted into the connecting cavity. Multiple fastening bolts are screwed onto the pipe wall of the connecting cavity corresponding to the position of the clamp. The fastening bolts penetrate the pipe wall of the connecting cavity and are used to push the clamp to fasten the grounding material.

8. The conductive polyolefin-coated metal grounding system according to claim 7, characterized in that, The connecting cavity is made of corrosion-resistant reinforced nylon, the internal conductor is made of copper, and the claws are made of beryllium bronze.

9. The conductive polyolefin-coated metal grounding system according to claim 1, characterized in that, A sealant is provided at the connection between the connector and the grounding material, and the corrosion resistance level of the sealant is higher than that of the conductive polyolefin layer.

10. A construction method for a conductive polyolefin-coated metal grounding system as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Lay multiple sections of grounding material along the foundation of the power facility; Step 2: Connect multiple sections of grounding material using connectors; Step 3: Install a resistance-reducing layer on the outside of the grounding material after splicing; Step 4: Inject ion-releasing agent around the grounding material.

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