Mountain wind turbine generator grounding system with high soil resistivity

Abstract

The utility model provides a high-soil resistivity mountain wind turbine generator grounding system, which is applied to a wind turbine generator and comprises a first horizontal grounding grid, a second horizontal grounding grid and a grounding electrode, the first horizontal grounding grid is laid under a soil layer around the wind turbine generator by taking the wind turbine generator as a circle center and taking a first preset distance as a radius, and the second horizontal grounding grid is laid under the soil layer around the wind turbine generator by taking the wind turbine generator as a circle center and taking a second preset distance as a radius; the first horizontal grounding grid is connected with the second horizontal grounding grid; the plurality of grounding electrodes are respectively connected with the first horizontal grounding grid and the second horizontal grounding grid. The first horizontal grounding grid and the second horizontal grounding grid form a double-layer circular ring composite grounding grid, and the grounding electrode is matched, so that the total grounding resistance of the horizontal grounding grid is smaller than 4 ohms, and the problem that a wind turbine generator grounding system does not meet the grounding requirement is solved.

Description

Technical Field

[0001] The present application relates to the technical field of power generation, and in particular to a grounding system for a mountain wind turbine set with high soil resistivity. Background Art

[0002] The wind turbine grounding system refers to the establishment of a low-impedance electrical channel between the earth and the wind turbine. The purpose is to efficiently and quickly conduct the huge energy of lightning to the earth, so that the grounding grid potential value, step voltage value, and contact voltage value are limited to a safe range, thereby avoiding lightning damage to the wind turbine, improving power generation efficiency, and ensuring the personal safety of maintenance personnel.

[0003] The grounding grid of wind turbines is usually laid around the wind turbines with horizontal grounding electrodes as the main body and vertical grounding electrodes as the auxiliary body. The edge of the grounding grid is closed. The main function of the horizontal grounding electrode is to make the pressure around the wind turbine equalized, and the vertical grounding electrode is mainly used to evacuate lightning current. The total grounding resistance of the grounding grid is less than 4 ohms. However, for wind turbines installed in mountains, due to the high soil resistivity of the mountains and the small area of ​​the wind turbine hoisting platform, it is difficult to make the grounding resistance less than 4 ohms, which cannot meet the grounding requirements of the wind turbines. Utility Model Content

[0004] The present application provides a high soil resistivity mountain wind turbine grounding system to solve the problem that the wind turbine grounding system does not meet the grounding requirements.

[0005] The present application provides a high soil resistivity mountain wind turbine grounding system, which is applied to wind turbines, including: a first horizontal grounding grid, a second horizontal grounding grid and a grounding electrode; the first horizontal grounding grid is laid under the soil layer around the wind turbine with the wind turbine as the center and a first preset distance as the radius, and the second horizontal grounding grid is laid under the soil layer around the wind turbine with the wind turbine as the center and a second preset distance as the radius; the first horizontal grounding grid is connected to the second horizontal grounding grid; and a plurality of grounding electrodes are respectively connected to the first horizontal grounding grid and the second horizontal grounding grid.

[0006] Optionally, the distance between any two adjacent grounding electrodes on the first horizontal grounding network is the same; the distance between any two adjacent grounding electrodes on the second horizontal grounding network is the same.

[0007] Optionally, it also includes a voltage grading ring; the voltage grading ring is connected to the first horizontal grounding grid through a grounding terminal.

[0008] Optionally, the grounding electrode is a tubular structure, and the burial depth of the first horizontal grounding grid and the burial depth of the second horizontal grounding grid are both smaller than the burial depth of the grounding electrode.

[0009] Optionally, the grounding electrode further includes an ion grounding electrode and a vertical grounding electrode, and the ion grounding electrode and the vertical grounding electrode are spaced apart from each other.

[0010] Optionally, a graphite resistance reduction module is also included; the graphite resistance reduction module is connected to the first horizontal grounding grid.

[0011] Optionally, the ion grounding electrode, the vertical grounding electrode and the graphite resistance reduction module are all perpendicular to a horizontal plane.

[0012] Optionally, it also includes a box-type transformer and a box-type transformer grounding terminal; the box-type transformer is connected to the second horizontal grounding grid via the box-type transformer grounding terminal.

[0013] Optionally, the distance from the box transformer to the wind turbine generator set is greater than the second preset distance.

[0014] It can be seen from the above technical scheme that the present application provides a high soil resistivity mountain wind turbine grounding system, which is applied to wind turbines, including: a first horizontal grounding grid, a second horizontal grounding grid and a grounding electrode; the first horizontal grounding grid is laid under the soil layer around the wind turbine with the wind turbine as the center and a first preset distance as the radius, and the second horizontal grounding grid is laid under the soil layer around the wind turbine with the wind turbine as the center and a second preset distance as the radius; the first horizontal grounding grid is connected to the second horizontal grounding grid; a number of the grounding electrodes are respectively connected to the first horizontal grounding grid and the second horizontal grounding grid. A double-layer circular ring composite grounding grid is formed by the first horizontal grounding grid and the second horizontal grounding grid, and the grounding electrode is matched to make the total grounding resistance of the horizontal grounding grid less than 4 ohms, so as to solve the problem that the grounding system of the wind turbine does not meet the grounding requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 A high soil resistivity mountain wind turbine grounding system provided in an embodiment of the present application;

[0017] Figure 2 A mountain wind turbine grounding system with a soil resistivity of 300-500Ω.m provided in an embodiment of the present application;

[0018] Figure 3 A mountain wind turbine grounding system with a soil resistivity of 500-1000Ω.m provided in an embodiment of the present application;

[0019] Figure 4A grounding system for a mountain wind turbine with a soil resistivity of 1000-3000Ω.m provided in an embodiment of the present application;

[0020] Reference numerals:

[0021] Among them, 1-the first horizontal grounding grid; 2-the second horizontal grounding grid; 3-the vertical grounding electrode; 4-the ion grounding electrode; 5-the graphite resistance reduction module; 6-the box transformer; 7-the equalizing ring. DETAILED DESCRIPTION

[0022] The following embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following embodiments do not represent all implementations consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application as detailed in the claims.

[0023] The grounding system of a wind turbine refers to the establishment of a low-impedance electrical channel between the earth and the wind turbine, with the purpose of efficiently and quickly conducting the huge energy of lightning to the earth, so that the potential value, step voltage value, and contact voltage value of the grounding grid are limited to a safe range, thereby avoiding lightning damage to the wind turbine, improving power generation efficiency, and ensuring the personal safety of maintenance personnel. The grounding grid of a wind turbine is usually laid around the wind turbine with a horizontal grounding body as the main body and a vertical grounding body as the auxiliary body. The edge of the closed grounding grid, the main function of the horizontal grounding body is to make the pressure around the wind turbine equalized, and the vertical grounding body is mainly used to evacuate lightning current. The total grounding resistance of the grounding grid is less than 4 ohms. However, for wind turbines set in mountains, due to the high soil resistivity of the mountains and the small area of ​​the wind turbine hoisting platform, it is difficult to make the grounding resistance less than 4Ω, which cannot meet the grounding requirements of the wind turbine.

[0024] To solve the problem that the grounding system of wind turbines does not meet the grounding requirements, refer to Figure 1 The embodiment of the present application provides a resistivity mountain wind turbine grounding system, including: a first horizontal grounding grid 1, a second horizontal grounding grid 2 and a grounding electrode; the first horizontal grounding grid 1 is laid under the soil layer around the wind turbine with the wind turbine as the center and a first preset distance as the radius, and the second horizontal grounding grid 2 is laid under the soil layer around the wind turbine with the wind turbine as the center and a second preset distance as the radius; the first horizontal grounding grid 1 is connected to the second horizontal grounding grid 2; a plurality of grounding electrodes are respectively connected to the first horizontal grounding grid 1 and the second horizontal grounding grid 2.

[0025] Among them, the first preset distance is smaller than the second preset distance, and the burial depth and quantity of the first horizontal grounding grid 1 and the second horizontal grounding grid 2 can be set according to the specific resistivity of the soil. For example, when the resistivity of the soil is less than 300Ω.m, the burial depth of the first horizontal grounding grid 1 and the second horizontal grounding grid 2 are both 1m. The quantity of the first horizontal grounding grid 1 and the second horizontal grounding grid 2 is both one. Figure 2 As shown, when the resistivity of the soil is between 300-500Ω.m, the number of the first horizontal grounding grid 1 is 1, and the burial depth is 1m, and the number of the second horizontal grounding grid 2 is 2, and the burial depths can be set to 1m and 3.5m respectively. In order to reduce the shielding effect of adjacent grounding bodies, the spacing between the grounding bodies should be no less than twice the length of the grounding bodies, and the spacing between the first horizontal grounding grid 1 and the second horizontal grounding grid 2 should be no less than 5m. Therefore, the interval between the first preset distance and the second preset distance should be greater than or equal to 5m. Therefore, when the first preset distance is 5.9m, the second preset distance is 10.9m. In addition, Figure 2 The rectangular grounding grid is also included in the list, where circular and rectangular are two grounding grid shapes, each with different advantages. For example, the circular grounding grid is easy to radiate, so that the current is relatively evenly distributed within the circumference, which is conducive to the diffusion and radiation of the current. It helps to reduce the grounding resistance and improve the grounding effect. The rectangular grounding grid has the advantage of high land utilization rate. The rectangular grounding grid can make more full use of land resources, especially when land resources are limited. Through reasonable planning, the rectangular grounding grid can achieve a larger grounding area within a limited land area. At the same time, the rectangular grounding grid is easier to adapt to different terrains and landforms, and can be flexibly designed and adjusted according to actual needs.

[0026] Therefore, circular and rectangular grounding grids each have their own advantages and applicable scenarios. When choosing the shape of the grounding grid, it is necessary to comprehensively consider factors such as land resources, grounding effect, maintenance management, etc. to select the most suitable grounding grid shape.

[0027] In addition, if Figure 3As shown, when the resistivity of the soil is between 500-1000Ω.m, a 15.9m horizontal grounding grid can be set outside the second horizontal grounding grid. For example, the horizontal grounding grid is laid under the soil layer around the wind turbine with a radius of 15.9m and the wind turbine as the center. The number of the first horizontal grounding grid 1 is 1, and the burial depth is 1m. The number of the second horizontal grounding grid 2 is 2, and the burial depths are set to 1m and 3.5m respectively. The number of the third horizontal grounding grid is 2, and the burial depths are set to 1.0m and 3.5m respectively. By setting three groups of horizontal grounding grids, all grounding devices can be connected to the same ground potential, thereby reducing voltage fluctuations and current interference in the system, thereby improving the reliability of the system. At the same time, the first horizontal grounding grid 1 and the second horizontal grounding grid 2 can protect equipment and personal safety. When a lightning strike or a circuit fault occurs, the current can be introduced into the earth through the grounding grid, thereby preventing the current from causing damage to equipment and people. At the same time, the grounding grid can also shield electromagnetic interference and protect electronic equipment from being affected.

[0028] like Figure 4 As shown, when the resistivity of the soil is between 1000-3000Ω.m, a circle of horizontal grounding grid with a radius of 22.9m is set outside the horizontal grounding grid with a radius of 15.9m. For example, the horizontal grounding grid is laid under the soil layer around the wind turbine with a radius of 22.9m, with the wind turbine as the center. Therefore, in the embodiment of the present application, the shape and number of the horizontal grounding grid can be flexibly set according to the specific resistivity of the soil.

[0029] In some embodiments, the distance between any two adjacent grounding electrodes on the first horizontal grounding grid 1 is the same; the distance between any two adjacent grounding electrodes on the second horizontal grounding grid 2 is the same. The main purpose of the grounding electrode is to conduct current or charge into the earth to reduce damage to electrical equipment. When the grounding electrodes are equally spaced, the current can be more evenly dispersed into the earth, improving the efficiency of grounding. The grounding resistance mainly depends on the resistance of the current returning to the source through the earth. When the grounding electrodes are equally spaced, the length of the current path in the earth is also equal, and the resistance is relatively small, which helps to reduce the grounding resistance. Equal spacing between grounding electrodes can reduce problems caused by uneven current distribution, thereby improving the stability of the entire system. Equal spacing between grounding electrodes can reduce the risk of electric shock caused by potential differences and improve the safety of the working environment.

[0030] In some embodiments, a voltage grading ring 7 is further included; the voltage grading ring 7 is arranged in the wind turbine set, and the voltage grading ring 7 is connected to the first horizontal grounding grid 1 through a grounding terminal. By arranging the voltage grading ring 7, when the wind turbine set is struck by lightning, the wind turbine set is in an equipotential state, and the lightning current can be transmitted to the first horizontal grounding grid 1 through the voltage grading ring 7, and then transmitted to the second horizontal grounding grid 2 through the first horizontal grounding grid 1, and finally the current is transmitted to the earth through the grounding bodies on the first horizontal grounding grid 1 and the second horizontal grounding grid 2.

[0031] In some embodiments, the grounding electrode is a tubular structure, and the buried depth of the first horizontal grounding grid and the buried depth of the second horizontal grounding grid are both less than the buried depth of the grounding electrode. The tubular structure is not only more convenient to install, but also can guide the current more effectively to reduce interference with the surrounding environment and equipment. At the same time, this design can more effectively prevent corrosion and increase the service life of the grounding system. In addition, this tubular structure grounding electrode also has lower inductance and lower resistivity, which makes the current flow more smoothly in the grounding electrode, thereby reducing the energy consumption of the grounding system.

[0032] In some embodiments, the grounding electrode further includes an ion grounding electrode 4 and a vertical grounding electrode 3, and the ion grounding electrode 4 is spaced apart from the vertical grounding electrode 3. Both the vertical grounding electrode 3 and the ion grounding electrode 4 are devices for reducing grounding resistance. The vertical grounding electrode 3 usually uses a metal conductor, such as a steel rod or a copper rod, and directly drives the metal rod into the ground by hammering or drilling, and uses the conductivity of the metal to introduce the lightning current into the earth, thereby avoiding damage to equipment or people caused by lightning strikes. The ion grounding electrode 4 is a way of grounding using the principle of ion conduction. The ion grounding electrode 4 is mainly composed of two parts: one is an anode for releasing positive ions, and the other is a cathode for releasing negative ions. When the ion grounding electrode 4 is buried in the soil, an electric field will be formed between the anode and the cathode. Through the action of this electric field, the ions in the soil will be attracted between the anode and the cathode to form a conductive channel. When the lightning current passes through this channel, due to the conductivity of the ions, the resistance can be effectively reduced, thereby avoiding damage to equipment or people caused by lightning strikes.

[0033] It is understandable that the number of ion grounding electrodes 4 to be set varies with the soil resistivity. For example, when the soil resistivity is 500-1000Ω.m, 8 ion grounding electrodes 4 can be set, when the soil resistivity is 1000-2000Ω.m, 19 ion grounding electrodes 4 can be set, and when the soil resistivity is 2000-3000Ω.m, 22 ion grounding electrodes 4 can be set. The higher the soil resistivity, the more ion grounding electrodes 4 are used, so that the total grounding resistance of the grounding grid can be less than 4 ohms, meeting the grounding requirements.

[0034] In some embodiments, a graphite resistance reduction module 5 is also included; the graphite resistance reduction module 5 is connected to the first horizontal grounding grid 1. The main body of the graphite resistance reduction module 5 is a conductive non-metallic material, and the conductive material includes a non-metallic material with good conductivity and stability, an anti-corrosion metal electrode, a desiccant and an electrolyte. The graphite resistance reduction module 5 is an anti-corrosion metal electrode, and a layer of non-metallic high-conductivity conductive material is wrapped around the metal electrode. The graphite resistance reduction module 5 can increase the contact area between the anti-corrosion metal electrode and the soil, and can reduce the grounding resistance. Since the graphite material is less sensitive to the surrounding soil environment, it can effectively reduce the grounding resistance of the wind turbine. At the same time, the main body of the graphite resistance reduction module 5 is made of non-metallic materials and graphite materials, and the material stability is good and there is no pollution to the environment.

[0035] In some embodiments, the ion grounding electrode 4, the vertical grounding electrode 3 and the graphite resistance reduction module 5 are all perpendicular to the horizontal plane. Since the vertically arranged grounding electrode is directly inserted into the soil and has good contact with the ground, the grounding resistance can be effectively increased, thereby improving the transmission efficiency and reducing the risk of signal interference and equipment damage.

[0036] In some embodiments, the box transformer 6 and the box transformer grounding terminal are also included; the box transformer 6 is connected to the second horizontal grounding grid 2 through the box transformer grounding terminal. Connecting the box transformer to the second horizontal grounding grid 2 through the box transformer grounding terminal can protect the box transformer 6 and reduce damage to the box transformer 6 caused by lightning strikes.

[0037] In some embodiments, the distance between the transformer 6 and the wind turbine is greater than the second preset distance. The wind turbine is high and easily damaged by lightning, so setting the transformer 6 at a distance greater than the second preset distance from the wind turbine can protect the transformer 6.

[0038] It can be seen from the above technical scheme that the present application provides a high soil resistivity mountain wind turbine grounding system, which is applied to wind turbines, including: a first horizontal grounding grid 1, a second horizontal grounding grid 2 and a grounding electrode; the first horizontal grounding grid 1 is laid under the soil layer around the wind turbine with the wind turbine as the center and the first preset distance as the radius, and the second horizontal grounding grid 2 is laid under the soil layer around the wind turbine with the wind turbine as the center and the second preset distance as the radius; the first horizontal grounding grid 1 is connected to the second horizontal grounding grid 2; and a number of grounding electrodes are respectively connected to the first horizontal grounding grid 1 and the second horizontal grounding grid 2. A double-layer circular ring composite grounding grid is formed by the first horizontal grounding grid 1 and the second horizontal grounding grid 2, and the grounding electrodes are matched to make the total grounding resistance of the horizontal grounding grid less than 4 ohms, so as to solve the problem that the grounding system of the wind turbine does not meet the grounding requirements.

[0039] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope of this application.

Claims

1. A high soil resistivity mountain wind turbine grounding system, applied to wind turbines, characterized in that: include: A first horizontal grounding grid (1), a second horizontal grounding grid (2) and a grounding electrode; The first horizontal grounding grid (1) is laid under the soil layer around the wind turbine generator set with the wind turbine generator set as the center and a first preset distance as the radius, and the second horizontal grounding grid (2) is laid under the soil layer around the wind turbine generator set with the wind turbine generator set as the center and a second preset distance as the radius; the first horizontal grounding grid (1) is connected to the second horizontal grounding grid (2); and a plurality of grounding electrodes are respectively connected to the first horizontal grounding grid (1) and the second horizontal grounding grid (2).

2. The high soil resistivity mountain wind turbine grounding system according to claim 1 is characterized in that: The distance between any two adjacent grounding electrodes on the first horizontal grounding grid (1) is the same; the distance between any two adjacent grounding electrodes on the second horizontal grounding grid (2) is the same.

3. The high soil resistivity mountain wind turbine grounding system according to claim 1 is characterized in that: It also comprises a voltage grading ring (7); the voltage grading ring (7) is connected to the first horizontal grounding grid (1) via a grounding terminal.

4. The high soil resistivity mountain wind turbine grounding system according to claim 1 is characterized in that: The grounding electrode is a tubular structure, and the burial depth of the first horizontal grounding grid and the burial depth of the second horizontal grounding grid are both smaller than the burial depth of the grounding electrode.

5. The high soil resistivity mountain wind turbine grounding system according to claim 1 is characterized in that: The grounding electrode further comprises a vertical grounding electrode (3) and an ion grounding electrode (4), wherein the ion grounding electrode (4) is arranged at an interval from the vertical grounding electrode (3).

6. The high soil resistivity mountain wind turbine grounding system according to claim 5 is characterized in that: It also comprises a graphite resistance reduction module (5); the graphite resistance reduction module (5) is connected to the first horizontal grounding grid (1).

7. The high soil resistivity mountain wind turbine grounding system according to claim 6 is characterized in that: The ion grounding electrode (4), the vertical grounding electrode (3) and the graphite resistance reduction module (5) are all perpendicular to a horizontal plane.

8. The high soil resistivity mountain wind turbine grounding system according to claim 1 is characterized in that: It also comprises a box-type transformer (6) and a box-type transformer grounding terminal; the box-type transformer (6) is connected to the second horizontal grounding network (2) via the box-type transformer grounding terminal.

9. The high soil resistivity mountain wind turbine grounding system according to claim 8, characterized in that: The distance between the box transformer (6) and the wind turbine generator set is greater than the second preset distance.

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