Wind power plant grounding system and soil parameter two-dimensional evaluation method thereof

Abstract

The invention discloses a wind power plant grounding system and a soil parameter two-dimensional evaluation method thereof, and belongs to the technical field of lightning protection of new energy power systems. The wind power plant grounding system mainly comprises an insulation fixing suite, a potential difference meter, a current recording device, a storage battery pack, a telescopic sub-rod, an insulation handle, a pole pushing buckle, a round steel electrode and the like; the method comprises the following steps: setting up a soil parameter test platform considering the wind power plant grounding system, and carrying out measurement thread arrangement and test on the ground where a wind turbine generator group is located, so as to obtain a soil parameter two-dimensional evaluation analysis expression considering the wind power plant grounding system. The test platform established by the invention has simplicity and practicability, can effectively measure soil apparent parameters in different environments, can perform quantitative evaluation on a multi-layer medium model under multiple test lines, can clearly and reliably describe model boundary characteristics of specific soil parameters, and can be applied to the field of measurement of soil parameters. And a theoretical basis and a scientific reference are provided for lightning protection safety design of a new energy unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightning protection for new energy power systems, and in particular relates to a two-dimensional soil parameter evaluation method taking into account a wind farm grounding system. Background Art

[0002] The application of green, clean and renewable energy is the main trend of energy development. Wind energy, as an important component of it, has led to an increasing proportion of wind power generation in energy supply. With the vigorous construction of wind power generation related facilities, how to ensure its safe and stable operation has become a key issue for power-related researchers.

[0003] Since wind turbines are relatively isolated in space, and the capacity of advanced wind turbines is also increasing rapidly, the relative height of the blade tip of the wind turbine blade is significantly increased, which further increases the probability of being struck by lightning. As a result, lightning strikes are the main cause of damage to wind turbines. Therefore, the precise design of wind turbine lightning protection grounding is of great significance to improving the stability of new energy power generation systems. Wind turbine lightning protection grounding measures focus on the grounding design of wind turbines. At present, the electrical design of wind turbine grounding mainly relies on the one-dimensional spatial parameter evaluation of the soil. However, wind turbines are generally installed in complex geological environments such as beaches, deserts, and mountaintops. The boundary line of the stratum is usually not a straight line. Considering only one-dimensional geometric parameters in the grounding design of large-scale wind turbines can no longer meet the precise lightning protection requirements. Once the grounding design is inaccurate, it will cause normal operation failure at the least, and in serious cases, it will cause accidents such as permanent damage to the wind turbine. In order to better improve the accuracy of wind turbine lightning protection, it is urgently necessary to study the precise evaluation method of soil parameters taking into account the grounding system of large-scale wind turbines, which can provide a theoretical basis for reducing the lightning damage rate of electrical and electronic equipment inside wind turbines and optimizing the design of grounding protection. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a two-dimensional soil parameter evaluation method taking into account the grounding system of a wind farm.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A wind farm grounding system, comprising: a first telescopic sub-rod, a second telescopic sub-rod and a third telescopic sub-rod arranged on the same thread, wherein two ends of the first telescopic sub-rod are respectively connected to a first insulating fixing set and a second insulating fixing set, two ends of the second telescopic sub-rod are respectively connected to the second insulating fixing set and a third insulating fixing set, and two ends of the third telescopic sub-rod (10) are respectively connected to the third insulating fixing set and a fourth insulating fixing set;

[0007] A first pole-pushing buckle is connected to the bottom of the first insulating fixing kit, and a first round steel electrode is connected to the bottom of the first pole-pushing buckle;

[0008] A second pole-pushing buckle is connected to the bottom of the second insulating fixing kit, and a second round steel electrode is connected to the bottom of the second pole-pushing buckle;

[0009] A third pole-pushing buckle is connected to the bottom of the third insulating fixing kit, and a third round steel electrode is connected to the bottom of the third pole-pushing buckle;

[0010] A fourth pole-pushing buckle is connected to the bottom of the fourth insulating fixing kit, and a fourth round steel electrode is connected to the bottom of the fourth pole-pushing buckle;

[0011] The first round steel electrode is connected to the current recording device through the first wire, the current recording device is connected to the battery pack through the second wire, and the battery pack is electrically connected to the fourth round steel electrode through the third wire;

[0012] The second round steel electrode is electrically connected to the potentiometer through a fourth conducting wire, and the third round steel electrode is electrically connected to the potentiometer through a fifth conducting wire.

[0013] The first round steel electrode is slidably arranged in the first pole-pushing buckle; the second round steel electrode is slidably arranged in the second pole-pushing buckle; the third round steel electrode is slidably arranged in the third pole-pushing buckle; and the fourth round steel electrode is slidably arranged in the fourth pole-pushing buckle.

[0014] The output end of the first wire is built into the first insulating fixing kit; the input end of the third wire is built into the fourth insulating fixing kit; the fourth wire is built into the second insulating fixing kit; and the fifth wire is built into the third insulating fixing kit.

[0015] The first insulating fixing kit is fixedly connected to the first insulating handle, and the fourth insulating fixing kit is fixedly connected to the second insulating handle.

[0016] A two-dimensional soil parameter evaluation method using the above system comprises the following steps:

[0017] The first step is to establish a soil parameter test platform taking into account the wind farm grounding system;

[0018] The second step is to arrange and test the measurement lines for the land where the wind turbine cluster is located: establish a vertical measurement line for each wind turbine, with a total of N vertical measurement lines, which are perpendicular to the horizontal measurement lines. Both the vertical measurement lines and the horizontal measurement lines are located on the ground plane, and the horizontal measurement lines are parallel to the corridor of the large-scale wind turbines. The vertical measurement lines are arranged at the same horizontal intervals.

[0019] The distance between two adjacent round steel electrodes on the same measuring thread is set to be the same, and the distance is D. Different distances D can be changed on one measuring thread for testing;

[0020] The third step is to conduct a two-dimensional evaluation of the soil parameters, and obtain the quantitative estimation expression of the soil parameters under different measurement threads by the following formula:

[0021]

[0022] Where j is the jth measuring line in the total number of measuring lines arranged, X is the estimated value of soil parameters under a single measuring line, W is the total number of changes in the distance between electrodes under a single measuring line, and D js is the distance between electrodes under the sth change of electrode arrangement under the jth measuring line, I js is the current recorded by the current recording device under the sth change electrode arrangement under the jth measuring line, V js is the voltage recorded by the potentiometer under the sth change electrode arrangement under the jth measuring line, ρ 1 is the resistivity of the first layer of soil, θ is the sampling parameter, J 0 (θD js ) and J 0 (2θD js ) are all first-kind zero-order Bessel functions, γ 1 (θ) is the kernel function;

[0023] By calculating the optimal system parameters of two-dimensional evaluation of soil parameters, the analytical expression of two-dimensional evaluation of soil parameters taking into account the grounding system of wind farm is obtained:

[0024]

[0025] Among them, h 1_q h is the quantitative estimate of the thickness of the surface soil under the qth vertical line, q = 1, 2, 3, ..., N; h_1 is the quantitative estimate of the surface soil thickness based on the horizontal line, n is a positive integer, k 0 ,k 1 ,…,k n-1 ,k n are the optimal system parameters under the polynomial.

[0026] Compared with the prior art, the present invention can quantitatively evaluate the multi-layer medium model under multiple measurement lines, and can clearly and reliably describe the model boundary characteristics of specific soil parameters, providing a theoretical basis and scientific reference for the lightning protection safety design of new energy units, and its beneficial effects are:

[0027] 1) The test platform established by the present invention is simple and practical, and can effectively measure the apparent parameters of soil under different environments;

[0028] 2) The soil parameter quantitative evaluation expression in the present invention can quantitatively evaluate the multi-layer medium model under multiple test lines;

[0029] 3) The proposed analytical method for two-dimensional estimation of soil parameters taking into account the wind farm grounding system can clearly and reliably describe the model boundary characteristics of specific soil parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of the soil parameter test platform when the present invention is used;

[0031] Figure 2 It is a schematic diagram of the soil testing route for the wind turbine corridor; DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] like Figure 1 As shown, a soil parameter test platform taking into account the grounding system of a wind farm comprises: a first telescopic sub-rod 8, a second telescopic sub-rod 9 and a third telescopic sub-rod 10 arranged on the same thread, wherein two ends of the first telescopic sub-rod 8 are respectively connected to the first insulating fixing kit 4 and the second insulating fixing kit 5, two ends of the second telescopic sub-rod 9 are respectively connected to the second insulating fixing kit 5 and the third insulating fixing kit 6, and two ends of the third telescopic sub-rod 10 are respectively connected to the third insulating fixing kit 6 and the fourth insulating fixing kit 7.

[0034] The first push-pole buckle 13 is connected to the bottom of the first insulating fixing kit 4, and the first round steel electrode 17 is connected to the bottom of the first push-pole buckle 13; preferably, the first round steel electrode 17 is slidably set in the first push-pole buckle 13, and after adjusting the position, the buckle of the first push-pole buckle 13 is buckled to achieve tightening.

[0035] The second push-pole buckle 14 is connected to the bottom of the second insulating fixing kit 5, and the second round steel electrode 18 is connected to the bottom of the second push-pole buckle 14; preferably, the second round steel electrode 18 is slidably set in the second push-pole buckle 14, and after adjusting the position, the buckle of the second push-pole buckle 14 is buckled to achieve tightening.

[0036] The third push-pole buckle 15 is connected to the bottom of the third insulating fixing kit 6, and the third round steel electrode 19 is connected to the bottom of the third push-pole buckle 15; better, the third round steel electrode 19 is slidably set in the third push-pole buckle 15, and after adjusting the position, the buckle of the third push-pole buckle 15 is buckled to achieve tightening.

[0037] The fourth push-pole buckle 16 is connected to the bottom of the fourth insulating fixing kit 7, and the fourth round steel electrode 20 is connected to the bottom of the fourth push-pole buckle 16; better, the fourth round steel electrode 20 is slidably set in the fourth push-pole buckle 16, and after adjusting the position, the buckle of the fourth push-pole buckle 16 is buckled to achieve tightening.

[0038] The first round steel electrode 17 is connected to the current recording device 1 through the first wire 23 , the current recording device 1 is connected to the battery pack 2 through the second wire 24 , and the battery pack 2 is electrically connected to the fourth round steel electrode 20 through the third wire 25 .

[0039] The second round steel electrode 18 is electrically connected to the potentiometer 3 via a fourth conductive wire 26 , and the third round steel electrode 19 is electrically connected to the potentiometer 3 via a fifth conductive wire 27 .

[0040] Furthermore, the output end of the first wire 23 is built into the first insulating fixing kit 4; the input end of the third wire 25 is built into the fourth insulating fixing kit 7; the fourth wire 26 is built into the second insulating fixing kit 5; and the fifth wire 27 is built into the third insulating fixing kit 6.

[0041] Furthermore, the first insulating fixing kit 4 is fixedly connected to the first insulating handle 11, and the fourth insulating fixing kit 7 is fixedly connected to the second insulating handle 12. In this way, by rotating the first insulating handle 11 or the second insulating handle 12 respectively, the first telescopic sub-rod 8 or the third telescopic sub-rod 10 can be rotated, thereby adjusting the length of the first telescopic sub-rod 8 or the third telescopic sub-rod 10.

[0042] A two-dimensional soil parameter evaluation method taking into account a wind farm grounding system comprises the following steps:

[0043] The first step is to establish a soil parameter test platform taking into account the wind farm grounding system.

[0044] In the second step, measurement lines are arranged and tested for the land where the wind turbine cluster is located: a vertical survey line is established for each wind turbine, and a total of N vertical survey lines are arranged. The vertical survey lines are perpendicular to the horizontal survey lines 34, and the horizontal survey lines 34 and the vertical survey lines are both located on the ground plane. The horizontal survey line 34 is parallel to the corridor of the large-scale wind turbines 21, and the vertical survey lines are arranged at the same horizontal intervals; in the figure, a first vertical survey line 30, a second vertical survey line 31, a third vertical survey line 32 and a Qth vertical survey line 33 are set, and the vertical survey lines are all perpendicular to the horizontal survey line 34.

[0045] The distance between two adjacent round steel electrodes on the same measuring thread is set to be the same, and the distance is D. Different distances D can be changed on one measuring thread for testing.

[0046] The third step is to conduct a two-dimensional evaluation of the soil parameters, and obtain the quantitative estimation expression of the soil parameters under different measurement threads by the following formula:

[0047]

[0048] Where j is the jth measuring line in the total number of measuring lines arranged, X is the estimated value of soil parameters under a single measuring line, W is the total number of changes in the distance between electrodes under a single measuring line, and D js is the distance between electrodes under the sth change of electrode arrangement under the jth measuring line, I js is the current recorded by the current recording device 1 under the sth change electrode arrangement under the jth measuring line, V js is the voltage recorded by the potentiometer 3 under the s-th change electrode arrangement under the j-th measuring line, ρ 1 is the resistivity of the first layer of soil, θ is the sampling parameter, J 0 (θD js ) and J 0 (2θD js ) are all first-kind zero-order Bessel functions, γ 1 (θ) is the kernel function;

[0049] By calculating the optimal system parameters of two-dimensional evaluation of soil parameters, the analytical expression of two-dimensional evaluation of soil parameters taking into account the grounding system of wind farm is obtained:

[0050]

[0051] Among them, h 1_q h is the quantitative estimate of the thickness of the surface soil under the qth vertical line, q = 1, 2, 3, ..., N; h_1 is the quantitative estimate of the surface soil thickness based on the horizontal line, n is a positive integer, k 0 ,k 1 ,…,k n-1 ,k n are the optimal system parameters under the polynomial.

Claims

1. A grounding system for a wind farm, characterized in that: The invention comprises: a first telescopic sub-rod (8), a second telescopic sub-rod (9) and a third telescopic sub-rod (10) arranged on the same thread, wherein two ends of the first telescopic sub-rod (8) are respectively connected to a first insulating fixing set (4) and a second insulating fixing set (5), two ends of the second telescopic sub-rod (9) are respectively connected to a second insulating fixing set (5) and a third insulating fixing set (6), and two ends of the third telescopic sub-rod (10) are respectively connected to a third insulating fixing set (6) and a fourth insulating fixing set (7); A first pole-pushing buckle (13) is connected to the bottom of the first insulating fixing kit (4), and a first round steel electrode (17) is connected to the bottom of the first pole-pushing buckle (13); A second pole-pushing buckle (14) is connected to the bottom of the second insulating fixing kit (5), and a second round steel electrode (18) is connected to the bottom of the second pole-pushing buckle (14); A third pole-pushing buckle (15) is connected to the bottom of the third insulating fixing kit (6), and a third round steel electrode (19) is connected to the bottom of the third pole-pushing buckle (15); A fourth pole-pushing buckle (16) is connected to the bottom of the fourth insulating fixing kit (7), and a fourth round steel electrode (20) is connected to the bottom of the fourth pole-pushing buckle (16); The first round steel electrode (17) is connected to the current recording device (1) via a first wire (23), the current recording device (1) is connected to the battery pack (2) via a second wire (24), and the battery pack (2) is electrically connected to the fourth round steel electrode (20) via a third wire (25); The second round steel electrode (18) is electrically connected to the potentiometer (3) via a fourth conductor (26), and the third round steel electrode (19) is electrically connected to the potentiometer (3) via a fifth conductor (27).

2. The wind farm grounding system according to claim 1, characterized in that: The first round steel electrode (17) is slidably arranged in the first pole-pushing buckle (13); the second round steel electrode (18) is slidably arranged in the second pole-pushing buckle (14); the third round steel electrode (19) is slidably arranged in the third pole-pushing buckle (15); and the fourth round steel electrode (20) is slidably arranged in the fourth pole-pushing buckle (16).

3. The wind farm grounding system according to claim 1, characterized in that: The output end of the first wire (23) is built into the first insulating fixed set (4); the input end of the third wire (25) is built into the fourth insulating fixed set (7); the fourth wire (26) is built into the second insulating fixed set (5); and the fifth wire (27) is built into the third insulating fixed set (6).

4. The wind farm grounding system according to claim 1, characterized in that: The first insulating fixing set (4) is fixedly connected to the first insulating handle (11), and the fourth insulating fixing set (7) is fixedly connected to the second insulating handle (12).

5. A two-dimensional soil parameter evaluation method using the system according to any one of claims 1 to 4, characterized in that: The steps include: The first step is to establish a soil parameter test platform taking into account the wind farm grounding system; The second step is to arrange and test the measurement lines for the land where the wind turbine group is located: establish a vertical measurement line for each wind turbine group, and arrange N vertical measurement lines in total. The vertical measurement lines are perpendicular to the horizontal measurement lines (34). The horizontal measurement lines (34) and the vertical measurement lines are both located on the ground plane. The horizontal measurement lines (34) are parallel to the corridor of the large-scale wind turbine group (21), and the vertical measurement lines are arranged at the same horizontal intervals. The distance between two adjacent round steel electrodes on the same measuring thread is set to be the same, and the distance is D. Different distances D can be changed on one measuring thread for testing; The third step is to conduct a two-dimensional evaluation of the soil parameters, and obtain the quantitative estimation expression of the soil parameters under different measurement threads by the following formula: Where j is the jth measuring line in the total number of measuring lines arranged, X is the estimated value of soil parameters under a single measuring line, W is the total number of changes in the distance between electrodes under a single measuring line, and D js is the distance between electrodes under the sth change of electrode arrangement under the jth measuring line, I js is the current recorded by the current recording device (1) under the sth change electrode arrangement under the jth measuring line, V js is the voltage recorded by the potentiometer (3) under the s-th change electrode arrangement under the j-th measuring line, ρ1 is the resistivity of the first layer of soil, θ is the sampling parameter, J0(θD js ) and J0(2θD js ) are all first-kind zero-order Bessel functions, and γ1(θ) is the kernel function; By calculating the optimal system parameters of two-dimensional evaluation of soil parameters, the analytical expression of two-dimensional evaluation of soil parameters taking into account the grounding system of wind farm is obtained: Among them, h 1_q h is the quantitative estimate of the thickness of the surface soil under the qth vertical line, q = 1, 2, 3, ..., N; h_1 is a quantitative estimate of the thickness of the surface soil based on the horizontal line, n is a positive integer, k0, k1, …, k n-1 ,k n are the optimal system parameters under the polynomial.

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