Three-dimensional grounding body suitable for high-resistance region and construction process thereof

Abstract

The invention belongs to the technical field of grounding grids, and particularly relates to a three-dimensional grounding body suitable for a high-resistance region and a construction technology of the three-dimensional grounding body, and the three-dimensional grounding body comprises a horizontal grounding grid at the top layer, a vertical grounding electrode at the middle layer, and a horizontal grounding electrode and a flexible grounding body at the bottom layer, the four corners of the horizontal grounding grid are correspondingly connected with the tops of the vertical grounding electrodes. The bottoms of the vertical grounding electrodes are correspondingly connected with the four end points of the horizontal grounding grid. The vertical grounding electrode, the flexible grounding body and the horizontal grounding electrode form a continuous electric conductor. The vertical soil space is utilized to the maximum extent, the soil conductivity is continuously improved, the grounding resistance is reduced, and the long-term stability of grounding is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of grounding networks, and in particular relates to a three-dimensional grounding body suitable for high-resistance areas and a construction process thereof. Background Art

[0002] In high-resistivity areas, such as plateau permafrost areas, desert areas, rocky areas, etc., due to their special geographical and climatic conditions, the electrical properties of the soil show significant high resistivity characteristics. The soil resistivity is usually between several hundred and several thousand Ω·m, which is much higher than the soil resistivity in ordinary areas (usually less than 100 Ω·m).

[0003] Traditional grounding grids face many challenges in these areas. For example, high resistivity soil leads to poor grounding effectiveness. The grounding resistance of traditional grounding grids is difficult to meet design requirements. Especially in sudden situations such as lightning and short circuits, equipment damage or personnel safety accidents may occur.

[0004] In addition, traditional grounding grid reconstruction projects are difficult and costly to construct in high-resistivity areas. They usually require increasing the length of vertical grounding electrodes or expanding the grounding grid area, which may cause damage to the environment. Moreover, traditional grounding grids cannot simultaneously meet multiple functional requirements such as lightning protection, corrosion protection, and freeze-thaw resistance.

[0005] Prior art CN109873258A discloses a composite grounding grid comprising an upper horizontal grounding grid and a lower horizontal grounding grid, with a side grounding grid connecting the upper and lower horizontal grounding grids. The upper, lower, and side grounding grids form an enclosed space for electrical equipment. Both the upper and lower horizontal grounding grids are composed of a crisscrossing grid structure, forming a composite three-dimensional grounding grid. This grid can fully utilize the layout characteristics of underground substations, such as the substation's upper surface covered by soil and the substation's lower layer containing a foundation pit. This design, tailored to local conditions, maximizes the effective area of ​​the grounding grid, thereby reducing the substation's grounding resistance, minimizing the use of new materials, and lowering the cost of the grounding grid. By effectively reducing the grounding resistance of underground substations in urban centers, the grounding resistance of the substation meets existing design specifications and improves the substation's operational reliability and safety. This prior art still needs to be improved in reducing grounding resistance. Summary of the Invention

[0006] To address the problem that the traditional grounding grid has limited horizontal grounding area and the grounding resistance cannot meet the design requirements, the present invention proposes a three-dimensional grounding body suitable for high-resistance areas. The present invention provides the following technical solutions:

[0007] Firstly,

[0008] A three-dimensional grounding body suitable for use in high-resistance areas, comprising a horizontal grounding grid on the top layer, a vertical grounding electrode on the middle layer, and a horizontal grounding electrode and a flexible grounding body on the bottom layer. The four corners of the horizontal grounding grid are connected to the tops of the vertical grounding electrodes, and the bottoms of the vertical grounding electrodes are connected to the four end points of the horizontal grounding electrodes.

[0009] The vertical grounding electrode, the flexible grounding body and the horizontal grounding electrode form a continuous conductor.

[0010] Furthermore, the horizontal grounding electrode is diagonal.

[0011] Furthermore, the horizontal grounding electrode is in a square frame shape.

[0012] Furthermore, the horizontal grounding electrode has a structure that is a combination of a square shape and a diagonal shape.

[0013] Furthermore, the flexible grounding body is formed by solidifying the liquid flexible grounding material poured onto the surface of the horizontal grounding electrode and at the connection between the horizontal grounding electrode and the vertical grounding electrode.

[0014] Furthermore, the middle layer also includes an intermediate grounding electrode arranged in the middle part of the vertical grounding electrode.

[0015] Furthermore, the middle ground electrode is in a diagonal shape or a square shape.

[0016] Furthermore, the middle ground electrode is made of galvanized flat steel.

[0017] Secondly,

[0018] A construction process for a three-dimensional grounding body, used for implementing the aforementioned three-dimensional grounding body, comprises:

[0019] digging a soil pit for burying the three-dimensional grounding body;

[0020] Install a horizontal grounding electrode at the bottom of the pit;

[0021] Vertical grounding electrodes are set at the four ends of the horizontal grounding electrode, and the bottoms of the vertical grounding electrodes are connected to the horizontal grounding electrodes;

[0022] Pour liquid flexible grounding material along the surface of the horizontal grounding electrode until the liquid flexible grounding material covers the surface of the horizontal grounding electrode; the amount of flexible grounding material poured needs to be increased at the connection between the horizontal grounding electrode and the vertical grounding electrode;

[0023] After the liquid flexible grounding material solidifies, backfill the soil. When the backfill reaches the preset horizontal grounding grid position, set up the horizontal grounding grid, connect the four corners of the horizontal grounding grid to the vertical grounding electrodes, and then continue to backfill the soil.

[0024] Furthermore, after the liquid flexible grounding material solidifies and before it is backfilled to a preset horizontal grounding grid position, it also includes: when backfilling to half the burial depth, an intermediate grounding electrode is set in the middle part of the vertical grounding electrode.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. In view of the fact that the grounding grid area is limited in the horizontal direction, the present invention proposes a three-layer stereo grounding body suitable for high-resistance areas. The stereo grounding body is modified based on the traditional horizontal grounding grid. The present invention adopts a three-dimensional layered grounding structure to maximize the use of vertical soil space.

[0027] 2. The flexible grounding body of the present invention is formed by solidifying a liquid flexible grounding material. The liquid flexible grounding material has high conductivity and solidification properties. It can be slowly released according to soil conditions to form a continuous block of conductive grounding body, continuously improving soil conductivity. The vertical grounding electrode, the flexible grounding body, and the horizontal grounding electrode form a continuous conductor. The liquid flexible grounding material can penetrate into the soil pores, significantly increasing the dispersion channel at the bottom of the three-dimensional grounding body, while also strengthening the connection between the vertical and horizontal grounding electrodes, ensuring long-term grounding stability.

[0028] 3. The present invention adapts to complex soil conditions, reduces construction difficulty and cost, and at the same time meets multiple functional requirements such as lightning protection, corrosion resistance, and freeze-thaw resistance.

[0029] 4. In the present invention, the bottom of the vertical grounding electrode is connected to the end point of the horizontal grounding electrode. The horizontal grounding electrode is in a diagonal or square shape, which expands the grounding range of the entire three-dimensional grounding body and reduces the grounding resistance.

[0030] 5. The present invention adds an intermediate grounding electrode in the middle part of the vertical grounding electrode, further increasing the contact area between the three-dimensional grounding body and the soil, thereby improving the resistance reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of the three-dimensional grounding body of the present invention, which only includes a metal frame;

[0032] Figure 2 The schematic diagram of the structure of the three-dimensional grounding body of the present invention is shown in FIG. Figure 1 The foundation also includes a flexible grounding body;

[0033] Figure 3 The schematic diagram of the structure of the three-dimensional grounding body of the present invention is shown in FIG. Figure 2 The basis also includes the middle ground electrode;

[0034] Figure 4 For the comparison of resistance reduction performance of traditional grounding grid;

[0035] Figure 5 The three-dimensional grounding body of Example 1 of the present invention is used for comparison of resistance reduction performance;

[0036] Figure 6 for Figure 5 The distribution diagram of leakage current density per unit area of ​​each conductor segment of the three-dimensional grounding body;

[0037] Figure 7 for Figure 4 The distribution diagram of leakage current density per unit area of ​​each conductor section of the grounding grid;

[0038] Figure 8 for Figure 5 Scalar potential distribution diagram of the three-dimensional grounding body;

[0039] Figure 9 for Figure 4 Scalar potential distribution diagram of the grounding grid;

[0040] Figure 10 for Figure 5 Contact voltage distribution diagram of the three-dimensional grounding body;

[0041] Figure 11 for Figure 4 Contact voltage distribution diagram of the grounding grid;

[0042] Figure 12 for Figure 5 Step voltage distribution diagram of the three-dimensional grounding body;

[0043] Figure 13 for Figure 4 Step voltage distribution diagram of the grounding grid.

[0044] Reference numerals: 1-horizontal grounding grid, 2-vertical grounding electrode, 3-horizontal grounding electrode, 4-flexible grounding body, 5-middle grounding electrode. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] Example 1

[0047] Combine Figure 1-2As shown, the present invention provides a three-dimensional grounding body suitable for high-resistance areas. The three-dimensional grounding body adopts a three-dimensional layered grounding structure, including a horizontal grounding grid 1 at the top layer, vertical grounding electrodes 2 at the middle layer, and horizontal grounding electrodes 3 and flexible grounding bodies 4 at the bottom layer. The three-dimensional grounding body fully utilizes the conductive properties of soil at different depths to reduce grounding resistance. The top horizontal grounding grid 1, the middle vertical grounding electrodes 2, and the bottom horizontal grounding electrodes 3 form a metal frame.

[0048] The horizontal grounding grid 1 adopts a traditional grid-like structure, has a burial depth of 0.8-1.5 meters, is made of highly conductive materials, and is usually composed of galvanized flat steel. The surface of the horizontal grounding grid 1 is coated with an anti-corrosion coating.

[0049] Vertical grounding electrodes 2, the tops of which are connected to the four corners of the horizontal grounding grid 1 by welding or thick wire. Vertical grounding electrodes 2 are typically made of copper rods and serve as the supporting portion of the three-dimensional grounding body in the middle layer.

[0050] The length of vertical grounding electrode 2 is adjusted according to the soil resistivity distribution. In this example, the length of vertical grounding electrode 2 is 1-4 meters. The distance between the top of vertical grounding electrode 2 and the soil surface is 0.8-1.5 meters.

[0051] Horizontal grounding electrodes 3 are constructed of galvanized flat steel in a diagonal and / or frame-like configuration. Diagonal configurations involve galvanized flat steel arranged diagonally, while frame configurations involve galvanized flat steel arranged in a rectangular or square closed loop. These diagonal and / or frame-like configurations expand the grounding range of the entire three-dimensional grounding structure and reduce grounding resistance.

[0052] The bottom of the vertical grounding electrode 2 is connected to the four ends of the horizontal grounding electrode 3 by welding or thick wire. The horizontal grounding electrode 3 is made of galvanized flat steel like the horizontal grounding grid 1.

[0053] The flexible grounding body 4 is covered on the surface of the horizontal grounding electrode 3. The flexible grounding body 4 is formed by the solidification of liquid flexible grounding material poured between the horizontal grounding electrodes 3. More flexible grounding material needs to be poured at the connection between the horizontal grounding electrode 3 and the vertical grounding electrode 2 to ensure that the vertical grounding electrode 2 and the horizontal grounding electrode 3 form a continuous three-dimensional grounding body.

[0054] The liquid flexible grounding material can penetrate into the soil pores, better establishing an electrical connection between the horizontal grounding electrode 3 and the soil; greatly increasing the diffusion channel at the bottom of the three-dimensional grounding body, while consolidating the connection firmness between the vertical grounding electrode 2 and the horizontal grounding electrode 3, ensuring the long-term stability of the three-dimensional grounding body.

[0055] Liquid flexible grounding material has high conductivity and solidification properties. It can be slowly released according to soil conditions to form a continuous block-shaped conductive grounding body, continuously improving the soil's conductivity.

[0056] CDEGS (Current Distribution, Electromagnetic Fields, Grounding and Soil Structure Analysis is a professional software for analyzing the grounding system, electromagnetic field distribution, soil structure and current distribution of power systems) is used to analyze the grounding system of power systems. Figure 4 The traditional grid structure of the grounding grid shown, and Figure 5 The three-dimensional grounding body of the three-dimensional grounding grid structure presented in the present invention is simulated and modeled, and the electrical parameters of the two are analyzed and compared to obtain the advantages of the three-dimensional grounding body of the present invention. Specifically, the present invention has the following advantages:

[0057] Advantage 1: With the horizontal footprint unchanged, the drag reduction performance is significantly improved:

[0058] In a high-resistance complex environment, the technology of the present invention significantly improves the resistance reduction performance by expanding the contact area between the grounding body and the soil in three-dimensional space while using the same horizontal area.

[0059] In a 1000Ω·m soil environment, when using Figure 4 When the conventional grid structure grounding grid is used, the grounding resistance of the conventional grounding grid is 14.66Ω; when the conventional grid structure grounding grid is used, the grounding resistance of the conventional grounding grid is 14.66Ω. Figure 5 The three-dimensional grounding body of the present invention has a three-dimensional grounding grid structure, and the grounding resistance of the three-dimensional grounding body is 9.26Ω. Under the condition of the same horizontal space occupation area, the grounding resistance is reduced by 36.83%.

[0060] Advantage 2: With the horizontal footprint unchanged, the grounding grid current dissipation efficiency is significantly improved:

[0061] Under 1000Ω·m soil,

[0062] according to Figure 6 shown Figure 5 The leakage current density per unit area of ​​each conductor segment of the three-dimensional grounding body is expressed in amperes per square meter (A / SQ.M). It can be seen that the three-dimensional grounding grid of the present invention fully utilizes the spatial structure, and the current leakage is mainly concentrated in the vertical grounding electrode 2 and the horizontal grounding electrode 3 at the bottom layer. The unit leakage amount far exceeds that of the traditional square grid grounding grid at the top layer, which plays a key role in improving the current leakage amount.

[0063] Among them, the horizontal one is the horizontal grounding electrode 3, the vertical one is the vertical grounding electrode 2, and the grid represents the horizontal grounding grid 1.

[0064] according to Figure 7 shown Figure 4 The leakage current density per unit area of ​​each conductor segment of the traditional grounding grid (A / SQ.M) shows that the current dissipation efficiency of the traditional grid-shaped grounding grid is low, and the leakage of the traditional grounding grid is concentrated on the four sides.

[0065] Advantage 3: Uniform potential distribution:

[0066] Under the condition of the same grounding resistance, a current of 1000A was injected into the three-dimensional grounding body of the present invention and the traditional square grounding grid, and the scalar potential, contact voltage and step voltage distribution of the two were compared and analyzed.

[0067] Comparison of scalar potential distribution:

[0068] Depend on Figure 8 、 9 It can be seen that the scalar potential distribution of the three-dimensional grounding body is consistent with that of the traditional grounding grid, but the three-dimensional grounding body has more dissipation channels. The maximum scalar potential of the three-dimensional grounding body is 10770V, while the maximum scalar potential of the traditional square grounding grid is 14172V, a 24% decrease. The minimum scalar potential of the three-dimensional grounding body is 2277V, while the minimum scalar potential of the traditional square grounding grid is 2276V, with the minimum values ​​of the two being almost the same.

[0069] Comparison of contact voltage distribution:

[0070] Depend on Figure 10 、 11 It can be seen that in terms of contact voltage distribution, the two grounding grids present almost the same distribution, both showing the characteristics of low inside and high outside. However, since the composite three-dimensional grounding body of the present invention has a better spatial leakage channel, the maximum contact voltage of the three-dimensional grounding body of the present invention is 8403V, ​​while the maximum contact voltage of the traditional square grounding grid is 12493V, and the maximum value is reduced by 32.7%.

[0071] Comparison of step voltage distribution:

[0072] Depend on Figure 12 、 13 It can be seen that in the step voltage distribution, the highest step voltage is distributed along the outer circle of the grounding grid. However, since the three-dimensional grounding body has a longer vertical grounding electrode 2, its distribution circle is larger and its current dissipation capacity is better; while the high step voltage area of ​​the traditional grounding grid is concentrated on the four sides of the grounding grid.

[0073] The maximum step voltage of the three-dimensional grounding body is 529V, while the maximum step voltage of the traditional square grounding grid is 1129V, a reduction of 53.14%; the minimum step voltage of the three-dimensional grounding body is 5V, while the minimum step voltage of the traditional square grounding grid is 23.447V, a reduction of 78.67%.

[0074] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0075] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent replacements of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

[0076] Example 2

[0077] like Figure 3 As shown, the present invention provides a three-dimensional grounding body suitable for high-resistance areas. On the basis of Example 1, the middle layer also includes an intermediate grounding electrode 5 arranged in the middle part of the vertical grounding electrode 2. The intermediate grounding electrode 5 adopts multiple sections of galvanized flat steel. The intermediate grounding electrode 5 further increases the contact area between the three-dimensional grounding body and the soil, increases the leakage channel, reduces the grounding resistance, and improves the resistance reduction effect.

[0078] Example 3

[0079] A construction process for a three-dimensional grounding body, used for implementing the three-dimensional grounding body of embodiment 1 and embodiment 2, comprising:

[0080] Digging a pit for burying the three-dimensional grounding body, the depth of the pit is usually 1-4 meters;

[0081] A horizontal grounding electrode 3 is set up at the bottom of the pit, and the horizontal grounding electrode 3 is a diagonal or square structure;

[0082] Vertical grounding electrodes 2 are set at the four ends of the horizontal grounding electrode 3, and the bottom of the vertical grounding electrode 2 is connected to the horizontal grounding electrode 3 at the bottom of the pit by welding or thick wire;

[0083] Pour liquid flexible grounding material along the surface of the horizontal grounding electrode 3 at the bottom until the liquid flexible grounding material covers the surface of the horizontal grounding electrode 3; increase the amount of liquid flexible grounding material poured at the connection between the horizontal grounding electrode 3 and the vertical grounding electrode 2; the liquid flexible grounding material has high conductivity and high fluidity, can penetrate into the soil pores, form a continuous conductive structure, and significantly improve the soil's electrical conductivity;

[0084] After the liquid flexible grounding material solidifies, backfill the soil until it reaches the position of the horizontal grounding grid 1. If the distance from the soil surface is 0.8-1.5m, set up the traditional block-shaped horizontal grounding grid 1. Connect the horizontal grounding grid 1 to the top of the vertical grounding electrode 2 with a thick wire or welding, and then continue to backfill the soil.

[0085] Furthermore, after the liquid flexible grounding material is injected and solidified, the soil pit is gradually backfilled and compacted to ensure that the three-dimensional grounding body is in close contact with the soil. When backfilling is half of the burial depth, an intermediate grounding electrode 5 composed of multiple sections of galvanized flat steel is set in the middle part of the vertical grounding electrode 2 to further increase the leakage channel. Subsequently, backfilling is continued and a horizontal grounding grid 1 is erected.

[0086] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0087] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A three-dimensional grounding body suitable for high resistance areas, comprising a horizontal grounding grid on the top layer, characterized in that: It also includes a vertical grounding electrode in the middle layer, and a horizontal grounding electrode and a flexible grounding body in the bottom layer. The four corners of the horizontal grounding grid are connected to the top of the vertical grounding electrode respectively, and the bottom of the vertical grounding electrode is connected to the four end points of the horizontal grounding electrode respectively. The vertical grounding electrode, the flexible grounding body and the horizontal grounding electrode form a continuous conductor.

2. The three-dimensional grounding body according to claim 1, characterized in that: Horizontal grounding electrode, diagonal shape.

3. The three-dimensional grounding body according to claim 1, characterized in that: Horizontal grounding electrode, in the shape of a square frame.

4. The three-dimensional grounding body according to claim 1, characterized in that: The horizontal grounding electrode has a structure that is a combination of square and diagonal shapes.

5. The three-dimensional grounding body according to claim 1, characterized in that: The flexible grounding body is formed by solidifying the liquid flexible grounding material poured on the surface of the horizontal grounding electrode and at the connection between the horizontal grounding electrode and the vertical grounding electrode.

6. The three-dimensional grounding body according to claim 1, characterized in that: The middle layer also includes an intermediate grounding electrode arranged in the middle portion of the vertical grounding electrode.

7. The three-dimensional grounding body according to claim 6, characterized in that: The middle ground electrode is diagonal or square shaped.

8. The three-dimensional grounding body according to claim 6, characterized in that: The middle grounding electrode is made of galvanized flat steel.

9. A construction process for a three-dimensional grounding body, used for implementing the three-dimensional grounding body according to any one of claims 6 to 8, characterized in that: include: digging a soil pit for burying the three-dimensional grounding body; Install a horizontal grounding electrode at the bottom of the pit; Vertical grounding electrodes are set at the four ends of the horizontal grounding electrode, and the bottoms of the vertical grounding electrodes are connected to the horizontal grounding electrodes; Pour liquid flexible grounding material along the surface of the horizontal grounding electrode until the liquid flexible grounding material covers the surface of the horizontal grounding electrode; the amount of flexible grounding material poured needs to be increased at the connection between the horizontal grounding electrode and the vertical grounding electrode; After the liquid flexible grounding material solidifies, backfill the soil. When the backfill reaches the preset horizontal grounding grid position, set up the horizontal grounding grid, connect the four corners of the horizontal grounding grid to the vertical grounding electrodes, and then continue to backfill the soil.

10. The construction process according to claim 9, characterized in that: After the liquid flexible grounding material solidifies and is backfilled to a preset horizontal grounding grid position, it also includes: when backfilling to half the burial depth, an intermediate grounding electrode is set in the middle part of the vertical grounding electrode.

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