CN111753247B - Method for acquiring horizontal layered soil grounding parameters by using segmented sampling - Google Patents
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Abstract
The invention discloses a method for acquiring horizontal stratified soil grounding parameters by means of segmented sampling, which is a method for computing the green function by means of segmented sampling according to integral kernel function extreme points of the green function in stratified soil. Through the analysis of the examples and the comparison of CDEGS calculation results, the effectiveness and the correctness of the work of the invention are verified. The research result shows that the calculation method provided by the invention has excellent calculation efficiency and adaptability, and can provide theoretical reference for ground parameter analysis and ground device design in layered soil.
Description
Technical Field
The invention belongs to the field of power systems, and particularly relates to a method for acquiring horizontal layered soil grounding parameters by using segmented sampling.
Background
The grounding device is a precondition for safe and stable operation of the power system and the power equipment. Accurate grounding parameter calculation lays a theoretical foundation for the design and operation and maintenance of a grounding device. The grounding device is buried in the soil, and the layering phenomenon of the soil medium greatly increases the calculation difficulty of the grounding parameters. Thus, ground parameter calculation in horizontally stratified soil media has been a focus problem in the field of power grounding.
At present, many researches are developed at home and abroad successively, and the ground grounding parameter calculation method is improved based on a complex mirror image method under global sampling, so that the calculation problem caused by global sampling is not fundamentally solved. The global sampling generally cannot accurately invert the integral kernel function of the complex layered soil green function with a large number of layers and large thickness, and the situations of inaccurate calculation result or complete non-convergence are easily caused. In addition, the number of the double mirror image method is 2 times of the number of the soil layers, and the calculated amount is linearly increased along with the number of the soil layers. For example, taking a 10-layer soil as an example, the soil resistivity of the 1 st layer of the soil is 100, 233, 42.9, 185.7, 11.1, 185.7, 900, 150, 42.9, 17.6, the soil thicknesses of the 1 st layer to the 9 th layer are 2m,6m,33m,120m,188m,270m,301m,332m,368m, and the integral kernel function cannot be fitted completely by a global sampling method.
Disclosure of Invention
The existing calculation method of the grounding parameters in the layered soil is mainly based on a complex mirror image method under global sampling. On one hand, for complex soil models with a large number of layers and large thickness, global sampling may cause the problems of larger error or non-convergence of calculation results and the like; on the other hand, the number of the double mirror images is usually 2 times the number of soil layers, and the calculated amount always linearly increases with the number of soil layers. In view of the above, the invention provides a method for acquiring the grounding parameters in the horizontal layered soil. The calculation of the grounding parameters of the grounding device in the layered soil is researched by analyzing the sectional sampling calculation method of the Grignard function in the horizontal layered soil.
The technical scheme adopted by the invention is as follows:
a method for obtaining horizontal stratified soil-grounding parameters by segment sampling, comprising the following steps:
building a horizontal layered soil calculation model under a column coordinate system, and dividing the soil level into n layers;
constructing an integral kernel function containing soil layered structure parameters, further constructing a second integral kernel function, carrying out sectional sampling according to extreme points of the second integral kernel function, carrying out 3-order fitting on different sections, replacing by integral variables, solving the integral according to integral properties of the Bessel function and combining a fractional integral method, and obtaining a soil green function with a source point on a first layer;
dividing the grounding device into a plurality of small sections, and defining two types of nodes on the grounding device: the first type of nodes are e type conductor nodes, external injection current is considered to pass through the e type nodes, the second type of nodes are m type ground nodes, and leakage current only exists on the nodes;
a node voltage method is adopted to establish a node voltage equation containing e-class nodes and m-class nodes and a voltage equation only for the m-class nodes;
according to the two groups of node voltage equations, the potential of any node on the grounding grid is solved, and the leakage current I of each m-class node is further solved mi ；
Leakage current I of each section mi And taking the ground resistance as a point source, combining the soil green function of the first layer, and adopting a superposition principle to obtain the ground resistance and the ground potential distribution of the grounding device.
The invention also calculates the grounding parameters of the typical grounding device in 3 typical layered soils, compares the calculation results of CDEGS, and verifies the effectiveness and accuracy of the work of the invention.
The method for calculating the sectional sampling value of the grounding parameter in the horizontal layered soil provided by the invention carries out sectional sampling according to the extreme points of the integral kernel function, avoids the defect that the calculated amount is linearly increased along with the layer number of the soil in the traditional double mirror image method, and has higher calculation efficiency. If the earth resistance with monotonicity of the soil resistivity is calculated, no matter how many layers of the soil are, as long as the integral kernel function F (lambda) does not have extreme points, only a fixed number of sampling points are needed, and the calculated amount is not increased.
The global sampling method is not suitable for the situation that the soil layering thickness is thicker, and when the soil layering thickness is too thick, the sampling step length is too small easily, so that the calculation result is scattered. In addition, actual soil layering is complex and changeable, and key features of an integral kernel function cannot be avoided by adopting a global sampling mode. The grounding parameters in the layered soil with any complex level can be calculated more accurately after the sectional sampling, and the method has stronger adaptability.
In the calculation of the grounding parameters, the grounding device is divided into several small segments and m and e class sections are defined. The e-type node is two end nodes of each section, the external injection current is considered to pass through the e-type node, the m-type node is the midpoint of each section, and only leakage current exists on the node, so that the node is not connected with external electrical equipment, and no external current is injected. The processing makes the different nodes have tiny potential difference, and solves the problem that the different nodes are in unequal potential in practice.
The calculation method provided by the invention lays a tamping theoretical foundation for the design of the grounding device in the layered soil medium and the accurate calculation of the grounding parameters.
Drawings
FIG. 1 is a green's function in stratified soil;
FIG. 2 is a distribution of F (λ);
FIG. 3 is a rectangular block ground net actual model;
FIG. 4 is a rectangular block ground network circuit model;
FIG. 5 is a computational model of a horizontal ground electrode;
fig. 6 is a horizontal ground leakage current calculation.
Detailed Description
A non-limiting example is given below to further illustrate the process of the present invention.
The following is a specific analysis of the method of the invention:
(1) Establishment of green's function in horizontally stratified soil
According to the basic electromagnetic field theory, a horizontal layered soil calculation model under a cylindrical coordinate system is established as shown in fig. 1. Adopting a method for solving a space poisson equation, and adopting a potential equation of any point in the ith layer of soil:
in the formula (1), delta is a point current source positioned in the 1 st layer of soil in the soil medium, ρ 1 Is the resistivity of the layer 1 soil where the point current source is located.The potential of any point in the soil, r and z are the coordinates in the r and z directions under the cylindrical coordinate system.
The boundary conditions of the layered soil are as follows:
for the potential of the first layer soil interface, +.>H is the potential of the soil interface of the ith layer 0 H is the vertical distance of the source point from the earth surface i For the vertical distance of the i-th layer of the soil underside interface in the subsurface, ρ i The resistivity of the i-th layer soil is represented, i=1, 2,3 … … n, and n is the number of soil layers.
Using the separation variant method in cylindrical coordinates, formula (1) can be written as follows:
wherein the method comprises the steps ofFor the potential of the source point in the layer 1 soil, J 0 (λr) is a Bessel function of the first kind, A i (lambda, X) and B i (lambda, X) is an integral kernel function, X is resistivity and thickness of the stratified soil, lambda is an integral constant.
When the source point is located in layer 1 soil, formula (3) can be rewritten as:
wherein G is 1 (r, z) is the Green function of the source point in the first layer of soil, h 0 The burial depth of the source point, f (lambda), is the integral kernel function containing the soil layering structure parameters.
The expression f (λ) is:
(2) Segmented sampling computation of greens
Defining a new integral kernel function (i.e. a second integral kernel function) F (λ):
f (lambda) does not give an analytical expression as the number of layers of soil increases. To ensure that the approximate expression can well approximate the actual function F (lambda), the distribution rule of F (lambda) needs to be studied, z 0 Is the vertical distance of the field point from the point source.
Let the point source be buried deep h 0 0.8m, z 0 Is 0.006m (the calculated position of the potential is selected on the surface of a round steel ground conductor with a radius of 0.006 m). And selecting the level 2-layer soil with monotonicity of the soil resistivity to the level 5-layer soil, and calculating F (lambda) of the layered soil.
Wherein the level 5 layer soil parameter ρ 1 ＝50,ρ 2 ＝100，ρ 3 ＝150，ρ 4 ＝200，ρ 5 ＝250，h 1 ＝2，h 2 ＝1，h 3 ＝1.5，h 4 =1, level 4 layer soil parameters ρ 1 ,ρ 2 ,ρ 3 ,ρ 4 And h 1 ,h 2 ,h 3 And the like for 2 layers of soil and 3 layers of soil. The parameter of the complex level 8 layer soil is ρ 1 ＝100,ρ 2 ＝550,ρ 3 ＝250,ρ 4 ＝190,ρ 5 ＝30,ρ 6 ＝900,ρ 7 ＝350,ρ 8 ＝50，h 1 ＝2,h 2 ＝10,h 3 ＝30,h 4 ＝130,h 5 ＝50,h 6 ＝350,h 7 =450. The calculation result is shown in fig. 2.
FIG. 2 shows 1) F (lambda) distribution rules of any multi-layer soil are similar to those of horizontal 2 layers when the resistivity of the soil is monotonous; 2) The F (lambda) distribution of complex stratified soil is such that there may be multiple extreme points.
Sampling F (lambda) in segments according to the extreme point of F (lambda), and then using 3-order least squares to sample F on the ith segment i Fitting (lambda) to obtain:
a k for fitting coefficients of each term in the polynomial.
The green function in stratified soil is converted into:
wherein lambda is 0 Is 0, lambda n With F (lambda) being a value of 0.01 or lambda at-0.01, lambda > lambda n When F (lambda) is considered to be equal to 0.
Let x=λr replace the integral variable, and the integral can be solved according to the integral property of the Bessel function and by combining the fractional integral method, so as to obtain the green function G (r) of the layered soil with the source point at the 1 st layer.
(3) Numerical calculation of segment sampling grounding parameters
Two types of nodes are defined, the first type of node is an e-type conductor node, the node is two end nodes of each section, and the external injection current is considered to pass through the e-type node. The second type node is an m type node to ground (leakage current), the node is at the midpoint of each segment, only leakage current exists on the node, no connection with external electrical equipment occurs, and no external current is injected.
Taking a rectangular box grounding grid as an example, wherein the number of segments is 4, the side lengths of the segments and the actual rectangular box are kept consistent, and four corners of the box are e-type nodes for external current injection; current flows from the midpoint of each segment, which should be 4 m-class nodes. The analytical model of the square grounding grid is shown in fig. 3 and 4.
Node voltage equations for all class e nodes and class m nodes are written according to the column of fig. 4:
wherein Y is j,i For the transadmittance of node j and node i, Y j,j For the self admittance of node j, I ei For injection current at class e node ei, I mi Is the leakage current on the m-class node mi. In the calculation process of the grounding grid, I ei The current into the ground, typically of an earthed electrical device, can be measured, but the leakage current I on the ground mi Is unknown and cannot be obtained by measurement. To cancel the leakage current variable, the following node voltage equation should be written for m classes of nodes only:
R j,i is the mutual resistance of m-class nodes, R j,j Is the self-resistance of the m-class node.
The combined type (10) (11) eliminates leakage current I mi Obtaining all node voltages and injection current I ei Is a matrix equation of (2).
The analysis is based on a simple node network model, and can be generalized to any node by the formulas (10) and (11):
RI m ＝U m (13)
wherein Y is ee And Y mm Self-guiding of e-class node and self-guiding of m-class node respectively, Y em And Y me Equal, is the mutual conductance of class e nodes and class m nodes. U (U) e Node voltage of class e node, U m Node voltage of m class node, I e Representing the injection current of the class e node, I m And the leakage current of the m-class node is represented, and R is the mutual resistance or the self resistance of the m-class node.
The combined type (12) (13) can be obtained:
according to the formula (14), the potential of any node on the grounding grid can be solved, and further according to the formula (11), the leakage current I of each m-class node can be solved mi . Leakage current I of each section mi The ground resistance and the ground potential distribution of any grounding device can be obtained by adopting the superposition principle as a point source. The calculation can realize the calculation of the grounding parameters of any non-equipotential grounding device.
The invention is mainly directed to the low frequency steady state characteristics of the grounding device, ignoring the inductive part of the grounding device, the admittance in equation (14) becomes conductive. The target node and the adjacent nodes are connected by a ground conductor, and the other nodes are connected by a soil medium. The conductance of the conductor is far greater than that of the soil medium, the self-conductance of the node can be approximately regarded as that of the adjacent segmented metal conductor, and the self-conductance and the mutual conductance of m-class nodes can be obtained as follows:
wherein ρ is the resistivity of the metal conductor, S is the cross-sectional area of the conductor, l is the length of the segmented conductor, and is the conductivity of the conductor.
The self-conductance of the class e node is:
wherein N represents a total of N conductors connected to end node e, ρ i Resistivity of the i-th segment conductor connected to node e, S i Is the section area of the ith conductor, l i Is the length of the i-th segment conductor.
And solving the mutual conductance of the target node and the non-adjacent node through a green function of a point source in the layered soil. The physical meaning of the point current source is the line current density over the micro-segments, which has been assumed previously to be evenly distributed over each segment. Matching point selection at the midpoint of each segment, the mutual resistance of the source point segment at the matching point is:
wherein I is i Is the leakage current of the ith section, and is expressed as A, l i For the length of the ith segment, ds is the length of the segment l for the source point i Is a curve integral of (c). G is the green's function of stratified soil, r j A position vector of the midpoint of the jth segment, r i Is the position vector of the midpoint of the i-th segment.
In order to further improve the calculation accuracy, the average value of the electric potential generated by the source point segment at the matching point segment is generally used as the electric potential coefficient of the matching point, and the expression thereof needs to integrate once and average the micro segment where the matching point is located, as follows:
wherein l j Is the length of the micro-segment where the matching point is located.
In this example, the leakage current distribution and the ground resistance of the horizontal ground electrode in three different horizontal layered soils are calculated, and the parameters of the different layered soils are shown in table 1.
1. The diameter of the horizontal grounding electrode is 12mm, so the radius r 0 ＝0.006m＝z 0 The burial depth is 0.8m, so h 0 =0.8m. Will h 0 And z 0 Substitution formula (7) can obtain a specific integral kernel function. Sampling is carried out by a smaller step length to obtain all extreme points corresponding to the kernel function. Then the 3 rd order least square method is adopted to carry out F on the ith segment i Fitting (lambda) and by replacing the integral variable, again based on the integral properties of the Bessel functionAnd combining the fractional integration method to obtain the green function G (r) of the layered soil with the source point at the 1 st layer.
2. The horizontal grounding electrode length is 10m, and is divided into 10 sections, namely, the m-class node numbers are from 1 to 10,1A, and the current is injected from the endpoint of the m-class node 1, as shown in fig. 5. The conductivity ρ of the grounding electrode is 1e-7, the length l=1m of each segment, and the sectional area S of the grounding electrode can be calculated from the conductor diameter. From this, the self-conductance of the m-class node can be calculated from equation (17), and since there is no e-node, the other conductance is 0. Then the potential of any node on the grounding grid can be solved according to the formula (13), and the leakage current I of each m-class node can be further solved according to the formula (10) mi 。
3. The ground resistance value can be obtained from equation (17) based on the green function of the first layer soil and the leakage current at each node obtained as described above. And comparing the calculated result with the calculated result of CDEGS software, as shown in figure 6 and table 2, the accuracy of the method provided by the invention is proved.
TABLE 1 layered soil parameters
Table 2 horizontal ground electrode ground resistance
Claims (3)
1. A method for obtaining a horizontal stratified soil-grounding parameter by means of segment sampling, comprising the steps of:
building a horizontal layered soil calculation model under a column coordinate system, and dividing the soil level into n layers;
constructing an integral kernel function containing soil layered structure parameters, further constructing a second integral kernel function, carrying out sectional sampling according to extreme points of the second integral kernel function, carrying out 3-order fitting on different sections, replacing by integral variables, solving the integral according to integral properties of the Bessel function and combining a fractional integral method, and obtaining a soil green function with a source point on a first layer;
the integral kernel f (lambda)
The second integral kernel F (lambda),wherein z is 0 The vertical distance of the field point from the point source;
dividing the grounding device into a plurality of small sections, and defining two types of nodes on the grounding device: the first type of nodes are e type conductor nodes, external injection current is considered to pass through the e type nodes, the second type of nodes are m type ground nodes, and leakage current only exists on the nodes;
a node voltage method is adopted to establish a node voltage equation containing e-class nodes and m-class nodes and a voltage equation only for the m-class nodes;
the two sets of node voltage equations are:
RI m ＝U m
wherein Y is ee And Y mm Self-guiding of e-class node and self-guiding of m-class node respectively, Y em And Y me Equal, U is the mutual conductance of class e node and class m node e Node voltage of class e node, U m Node voltage of m class node, I e Injection current for class e node, I m The leakage current of the m-class node is represented by R, which is the mutual resistance or the self resistance of the m-class node;
the self-conductance and mutual-conductance of the m-class node are:
wherein ρ is the resistivity of the metal conductor, S is the sectional area of the conductor, and l is the length of the segmented conductor;
the self-conductance of the class e node is:
wherein N represents a common N-segment conductor connected to end node e, ρ i Resistivity of the i-th segment conductor connected to node e, S i Is the section area of the ith conductor, l i Is the length of the i-th section conductor;
according to the two groups of node voltage equations, the potential of any node on the grounding grid is solved, and the leakage current I of each m-class node is further solved mi ；
Leakage current I of each section mi And taking the ground resistance as a point source, combining the soil green function of the first layer, and adopting a superposition principle to obtain the ground resistance and the ground potential distribution of the grounding device.
2. A method for obtaining horizontal stratified soil-earthing parameters by segment sampling as claimed in claim 1, wherein: the 3-order fitting adopts a 3-order least square method.
3. A method for obtaining horizontal stratified soil-earthing parameters by segment sampling as claimed in claim 1, wherein: the class e node is two end nodes of each small segment, and the class m node is at the midpoint of each small segment.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003043057A2 (en) * | 2001-11-13 | 2003-05-22 | Mentor Graphics Corporation | Synthesis strategies based on the appropriate use of inductance effects |
| CN104965134A (en) * | 2015-06-10 | 2015-10-07 | 国网上海市电力公司 | Echo state network-based transformer station grounding grid earth surface potential distribution calculation method |
| CN109101463A (en) * | 2018-06-28 | 2018-12-28 | 武汉大学 | A kind of more precision method for solving of wide area multi-layered earth Green's function |
| CN110118896A (en) * | 2018-11-13 | 2019-08-13 | 清华大学 | A kind of method and system measuring stratified soil resistivity and dielectric constant frequency dependent characteristic |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003043057A2 (en) * | 2001-11-13 | 2003-05-22 | Mentor Graphics Corporation | Synthesis strategies based on the appropriate use of inductance effects |
| CN104965134A (en) * | 2015-06-10 | 2015-10-07 | 国网上海市电力公司 | Echo state network-based transformer station grounding grid earth surface potential distribution calculation method |
| CN109101463A (en) * | 2018-06-28 | 2018-12-28 | 武汉大学 | A kind of more precision method for solving of wide area multi-layered earth Green's function |
| CN110118896A (en) * | 2018-11-13 | 2019-08-13 | 清华大学 | A kind of method and system measuring stratified soil resistivity and dielectric constant frequency dependent characteristic |
Non-Patent Citations (1)
| Title |
|---|
| CDEGS 软件包及其在多层土壤接地设计中的应用;曾嵘等;《华东电力》(第6期);第29-32页 * |
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