Method and device for evaluating impact response of near-earth line

Abstract

The invention belongs to the technical field of nuclear power, and particularly relates to a method and device for evaluating the impact response of a near-earth line. According to the method for evaluating the impact response of the near-earth line, firstly, the model is established according to the actual line and the condition of the line to the ground, the response condition of the whole line to the impact under the condition that the whole line is influenced by the lossy earth is determined according to the measured earth parameters and the line condition, and then the impact response of the line is evaluated according to the input impact waveform. And calculating the response waveform of any point of the line to the impact.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power, and in particular relates to a method and a device for evaluating the impulse response of a near-ground line. Background Art

[0002] In buildings, intrusion into lines and surge shocks induced by lines are an important cause of equipment damage. By evaluating and analyzing the surge response of lines in buildings, it can provide a useful reference for wiring in buildings and provide a basis for the setting of surge protection devices in buildings.

[0003] The surge impact of the line can be calculated using analytical methods in free space and in the case of perfect earth. However, in the case of near-ground, due to the influence of the earth, its amplitude and waveform will change significantly. Due to the complex electromagnetic conditions of the actual lossy earth, most of the previous studies on line impact have avoided the impact of lossy earth on line impact. In view of this, it is urgent to improve the accuracy of the assessment of the impact response of near-ground lines. Summary of the invention

[0004] In order to overcome the problems existing in the related art, a method and device for evaluating the impulse response of a near-ground line are provided.

[0005] According to one aspect of an embodiment of the present disclosure, a method for evaluating an impulse response of a near-ground line is provided, the method comprising:

[0006] Step 1, for the near-ground line to be tested, determining the evaluation parameters of the near-ground line, the evaluation parameters including the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth's surface, and the wire diameter of the wire used in the line, placing the line in a spatial coordinate system according to the evaluation parameters, taking the earth's horizontal plane as the XY plane, obtaining the coordinates of each key point on the near-ground line and the surrounding lines in the spatial coordinate system, forming a line model diagram, dividing the near-ground line into N segments and the surrounding lines into K segments according to the line model diagram, each segment including a current unit and a potential unit, wherein the one with inductance is called a current unit, and the one with capacitance is called a potential unit;

[0007] Step 2: Measure the conductivity σ and dielectric constant ε of the ground below the near-ground line at each measurement frequency from power frequency to high frequency. r ;

[0008] Step 3: Based on the conductivity σ and dielectric constant ε at each measurement frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

[0009] In one possible implementation, a monopole probe of a preset length is inserted into the soil as a positive electrode, and a metal plate of a preset size is placed flat on the ground as a negative electrode;

[0010] Measure the impedance value R+j'X corresponding to the measurement frequency f within the preset frequency range between the positive and negative electrodes, where N is the number of measurement frequencies, where R is the real part of the impedance and X is the imaginary part of the impedance; measure the capacitance value C of the measurement subsystem in the air 0 ; Use equations 1 and 2 to determine the conductivity σ and dielectric constant ε at the measurement frequency f r :

[0011]

[0012] Among them, ω=2πf, ε 0 is the dielectric constant of vacuum.

[0013] In a possible implementation, the upper frequency limit of the measurement is set to 10 MHz.

[0014] In one possible implementation, the current response φ of the current unit i As shown in formula 3 to formula 5:

[0015]

[0016] in,

[0017]

[0018] Among them, a i represents the length of the segment numbered i belonging to the near-ground line, a j represents the length of the segment with sequence number j belonging to the surrounding line, G(i,j) is the Green function of the segment with sequence number i reaching the segment with sequence number j in the line system of this calculation;

[0019] The voltage response of the inductor unit φ i 'As shown in formula 6 and formula 7:

[0020]

[0021] in,

[0022] According to equations 3 to 5, as well as the impact source and the final load of the line, the current I of each segment of the near-ground line is i ,I jAs unknowns, according to Kirchhoff's current law, a system of simultaneous equations is established; among them, when there is an impulse source and the final load of the line is certain, for the number of line segments M (M = N + K), M equations can be listed, so the system of equations must have a solution. According to the system of equations, the current I on each segment is solved i ,I j , according to the determined I i ,I j And equations 6 and 7, determine φ i ';

[0023] According to equations 1 to 6, the current response φ of any point in the system at different frequencies f can be determined i Or voltage response φ i '; Get the frequency response of the entire line system to be evaluated to all impacts.

[0024] According to another aspect of an embodiment of the present disclosure, a method for evaluating an impulse response of a near-ground line is provided, the method comprising:

[0025] Step 1, forming a line model diagram according to the evaluation parameters of the near-ground line to be tested, wherein the near-ground line is divided into N segments, and the surrounding lines are divided into K segments, each segment includes a current unit and a potential unit, wherein the unit with inductance is called a current unit, and the unit with capacitance is called a potential unit; the evaluation parameters include the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth surface, and the wire diameter of the wire used in the line;

[0026] Step 2: Obtain the conductivity σ and dielectric constant ε of the ground below the near-ground line corresponding to each measurement frequency from the power frequency to the high frequency range r ;

[0027] Step 3: Based on the conductivity σ and dielectric constant ε at each measurement frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

[0028] According to another aspect of an embodiment of the present disclosure, a device for evaluating an impulse response of a near-ground line is provided, the device comprising:

[0029] A generation module is used to form a line model diagram according to the evaluation parameters of the near-ground line to be tested, wherein the near-ground line is divided into N segments, and the surrounding lines are divided into K segments, each of which includes a current unit and a potential unit, wherein the unit with inductance is called a current unit, and the unit with capacitance is called a potential unit; the evaluation parameters include the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth surface, and the wire diameter of the wire used in the line;

[0030] The acquisition module is used to obtain the conductivity σ and dielectric constant ε of the ground below the near-ground line corresponding to each measurement frequency from the power frequency to the high frequency range r ;

[0031] Determination module for the conductivity σ and the dielectric constant ε at each measuring frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

[0032] According to another aspect of an embodiment of the present disclosure, a device for evaluating an impulse response of a near-ground line is provided, the device comprising:

[0033] processor;

[0034] a memory for storing processor-executable instructions;

[0035] Wherein, the processor is configured to execute the above method.

[0036] According to another aspect of an embodiment of the present disclosure, a non-volatile computer-readable storage medium is provided, on which computer program instructions are stored, and the computer program instructions implement the above method when executed by a processor.

[0037] The beneficial effects of the present disclosure are as follows: the evaluation method of the impulse response of the near-ground line provided by the present disclosure first establishes a model based on the actual line and the line-to-ground condition, determines the response condition of the entire line to the impulse under the influence of the damaged ground according to the measured earth parameters and line conditions, and then calculates the response waveform of any point of the line to the impulse according to the input impulse waveform. The line model is simple in segmentation and can completely simulate the distribution condition of the near-ground line; it can consider the influence of the real earth on the impulse current flowing through the line, which is closer to the actual condition; it can calculate various conditions such as transmission and induction of the impulse on the line, and can analyze more complex impulse response conditions; it can calculate the line grounding and other conditions, avoiding the problem that similar software such as EMTP may not converge when calculating the waveform of the grounding point; the method of the present disclosure provides a calculation basis for the response of the near-ground line under the impact condition, and provides a basis for optimizing the line configuration and installing protective devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of a transmission line segment and its corresponding circuit structure shown in an embodiment of the present disclosure.

[0039] Figure 2 is a schematic diagram of a current unit shown in an embodiment of the present disclosure.

[0040] Figure 3 Schematic diagram of a potential unit shown in an embodiment of the present disclosure.

[0041] Figure 4 is a schematic diagram of a transmission line shown in an application example of the present disclosure.

[0042] Figure 5 It is a schematic diagram of the calculation result of the impulse response shown in an application example of the present disclosure.

[0043] Figure 6 It is a schematic diagram of actual measurement results of impulse response shown in an application example of the present disclosure.

[0044] Figure 7 It is a block diagram of an evaluation device for impulse response of a near-ground line shown in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] The present disclosure is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Unless otherwise defined, the technical and scientific terms used in the present disclosure have the same meanings as those generally understood by those skilled in the art to which the present disclosure belongs; the terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the term "including" and any variations thereof in the present disclosure are intended to cover non-exclusive inclusions. Obviously, the embodiments described in the present disclosure are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative efforts are within the scope of protection of the present disclosure.

[0047] Reference to "embodiments" in this disclosure means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] Figure 1 is a schematic diagram of a transmission line segment and its corresponding circuit structure shown in an embodiment of the present disclosure, referring to Figure 1 , the method for evaluating the impulse response of the near-ground line disclosed in the present invention includes:

[0049] Step 1, for the near-ground line to be tested, determine the evaluation parameters of the near-ground line, the evaluation parameters include the horizontal line length and vertical line length to be calculated in the near-ground line, the distance between the line and the earth's surface, the wire diameter of the wire used for the line, the number of the near-ground line and the peripheral lines that have an impact on the near-ground line (the peripheral lines can be on the same conductor as the near-ground line or on adjacent conductors, and the peripheral lines can also be line segments of the earth's mirror image), and determine the extension direction of the near-ground line and the peripheral lines. According to the evaluation parameters, put the line into the spatial coordinate system, take the horizontal plane of the earth as the XY plane, and obtain the coordinates of each key point on the near-ground line and the peripheral lines in the spatial coordinate system to form a line model diagram. The key points on the near-ground line and the peripheral lines include: discrete points of the line, connection points between lines, and grounding points of the line. Figure 1 As shown, according to the circuit model diagram ( Figure 1 The line a in the figure is divided into N segments, and the surrounding lines are divided into K segments ( Figure 1 b), each segment includes a current unit and a potential unit ( Figure 1 The circuit c) in the figure, the one with inductance is called a current unit, and the one with capacitance is called a potential unit.

[0050] The key point of the impact input can be used as the starting point, and the key points can be assigned serial numbers in order from near to far from the starting point, and the coordinates of each key point can be associated with the serial number.

[0051] Step 2: Measure the conductivity σ and dielectric constant ε of the ground below the near-ground line at each measurement frequency from power frequency to high frequency. r According to the conductivity and dielectric constant corresponding to the measured frequency point, the Green's function value of the frequency point in each direction can be obtained by calculation. The Green's function value will not change with the change of the line setting above the earth and the line itself. After a conclusion is drawn after one calculation, it can be used as the basis for multiple calculations in the future.

[0052] For example, the loose soil is dug out from the ground below the near-ground line, a monopole probe of a preset length is inserted into the soil as the positive electrode, and a metal plate of a preset size is placed flat on the ground as the negative electrode. For example, a measurement subsystem consisting of a single-pole probe with a length of 30 cm and a metal plate with a size of 1m*1m can match the measurement of ground parameters within 10MHz.

[0053] Measure the impedance value R+j'X corresponding to the measurement frequency f within the preset frequency range between the positive and negative electrodes, where N is the number of measurement frequencies, where R is the real part of the impedance and X is the imaginary part of the impedance; measure the capacitance value C of the measurement subsystem in the air 0; Use equations 1 and 2 to determine the conductivity σ and dielectric constant ε at the measurement frequency f r :

[0054]

[0055] Among them, ω=2πf, ε 0 is the dielectric constant of vacuum.

[0056] In a possible implementation, the upper limit of the measured frequency is set to 10 MHz, which is helpful to improve the accuracy of frequency calculation for impact during frequency domain calculation.

[0057] Step 3: Based on the conductivity σ and dielectric constant ε at each measurement frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency.

[0058] Figure 2 is a schematic diagram of a current unit shown in an embodiment of the present disclosure, such as Figure 2 As shown, the current response of the current unit is shown in equations 3 to 5:

[0059]

[0060] in,

[0061]

[0062] Among them, a i represents the length of the segment numbered i belonging to the near-ground line, a j It represents the length of the segment with number j belonging to the surrounding line, and G(i,j) is the Green's function of the segment with number i reaching the segment with number j in the line system calculated this time.

[0063] Figure 3 is a schematic diagram of a potential unit shown in an embodiment of the present disclosure, such as Figure 3 As shown, the voltage response of the inductor unit is shown in equations 6 and 7:

[0064]

[0065] in,

[0066] According to equations 3 to 5, as well as the impact source and the final load of the line, the current I of each segment of the near-ground line is i ,I jAs unknowns, according to Kirchhoff's current law, a simultaneous equation system is established. Among them, when there is an impulse source and the final load of the line is certain, for the number of line segments M (M = N + K), M equations can be listed, so the equation system must have a solution. According to the equation system, the current I on each segment is solved i ,I j , according to the determined I i ,I j And equations 6 and 7 are used to determine the potential φ on each segment of the near-ground line. i '.

[0067] According to equations 1 to 6, the current response φ of any point in the system at different measurement frequencies f can be determined i Or voltage response φ i If the preset frequency range covers all frequencies of line impacts, the frequency response of the entire line system to be evaluated to all impacts can be obtained.

[0068] The evaluation method of the impact response of the near-ground line provided by the present disclosure first establishes a model based on the actual line and the line-to-ground condition, determines the response condition of the entire line to the impact under the influence of the damaged ground according to the measured earth parameters and line conditions, and then calculates the response waveform of any point of the line to the impact according to the input impact waveform. The line model is simple in segmentation and can completely simulate the distribution of the near-ground line; it can consider the influence of the real earth on the impact current flowing through the line, which is closer to the actual situation; it can calculate various conditions such as transmission and induction of the impact on the line, and can analyze more complex impact response conditions; it can calculate the line grounding and other conditions, avoiding the problem that similar software such as EMTP may not converge for the waveform calculation of the grounding point; the method disclosed in the present disclosure provides a calculation basis for the response of the near-ground line under the impact condition, and provides a basis for optimizing the line configuration and installing protection devices.

[0069] In one application example, an impact calculation is performed on a line above a test site, such as Figure 4 As shown, there are three lines parallel to the ground, with heights of 0.7m, 0.6m, and 0.3m above the ground, respectively named L, N, and E, and each of them is 50m long. The impulse enters the line system from the head end of line E, the end of line E is open to the ground, and L and N are short-circuited at the head end. The voltage induced at the short-circuit point of L and N when the impulse invades line E is calculated by the method of the present invention.

[0070] A coordinate system is formed for the line to obtain the coordinate points of the line.

[0071] For this piece of land, the ground parameter measurement was carried out, and the ground conductivity and dielectric constant data shown in Table 1 were obtained.

[0072] Table 1

[0073] Frequency (MHz) Impedance (real part) Impedance (imaginary part) Conductivity(s / m) Dielectric constant 0.01 295.41032 -11.21856 0.0149576 1021.5279 0.02 293.44642 -13.31733 0.0150484 606.84971 0.05 284.43228 -18.54017 0.0154915 360.33209 0.1 278.57292 -25.26762 0.0157549 251.9657 0.2 266.64155 -34.37249 0.016324 191.09368 0.5 241.98802 -45.41103 0.017664 120.88287 1 218.2221 -51.18611 0.0192201 77.93477 2 196.40582 -57.89581 0.0207287 54.403056 5 157.9423 -69.89539 0.0234284 37.070108 10 118.46335 -73.60747 0.0269489 29.582579 40 45.871801 -40.05263 0.0547354 21.486738

[0074] According to the results in Table 1, the calculation is performed according to the method shown in step 2 to obtain the parameters of the soil and the Green's function values ​​in all directions of the soil.

[0075] Divide the line into small sections of 0.25 meters, and calculate according to the method in step 3 to obtain the frequency response results of the line to impact from 0 to 40 MHz.

[0076] Use 0.1 / 50 waveform (wave head 0.1us, half wave length 50us) as the impact source. Figure 4 The calculation results of the impulse response (such as Figure 5 The actual measurement results (as shown) are Figure 6 The fit is higher compared with that shown in Figure 2.

[0077] Provided is a device for evaluating an impulse response of a near-ground line, the device comprising:

[0078] A generation module is used to form a line model diagram according to the evaluation parameters of the near-ground line to be tested, wherein the near-ground line is divided into N segments, and the surrounding lines are divided into K segments, each of which includes a current unit and a potential unit, wherein the unit with inductance is called a current unit, and the unit with capacitance is called a potential unit; the evaluation parameters include the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth surface, and the wire diameter of the wire used in the line;

[0079] The acquisition module is used to obtain the conductivity σ and dielectric constant ε of the ground below the near-ground line corresponding to each measurement frequency from the power frequency to the high frequency range r ;

[0080] Determination module for the conductivity σ and the dielectric constant ε at each measuring frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

[0081] The description of the above-mentioned device has been explained in detail in the description of the above-mentioned method, and will not be repeated here.

[0082] Figure 7 1900 is a block diagram of an apparatus for evaluating an impulse response of a near-ground line according to an embodiment of the present disclosure. For example, apparatus 1900 may be provided as a server. Figure 7, the apparatus 1900 includes a processing component 1922, which further includes one or more processors, and a memory resource represented by a memory 1932 for storing instructions, such as an application, that can be executed by the processing component 1922. The application stored in the memory 1932 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 1922 is configured to execute instructions to perform the above method.

[0083] The device 1900 may also include a power supply component 1926 configured to perform power management of the device 1900, a wired or wireless network interface 1950 configured to connect the device 1900 to a network, and an input / output (I / O) interface 1958. The device 1900 may operate based on an operating system stored in the memory 1932, such as Windows Server™, MacOS X™, Unix™, Linux™, FreeBSD™, or the like.

[0084] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as a memory 1932 including computer program instructions, which can be executed by the processing component 1922 of the device 1900 to perform the above method.

[0085] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0086] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0087] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0088] The computer program instructions for performing the operation of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed completely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be customized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0089] Various aspects of the present disclosure are described herein with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer-readable program instructions.

[0090] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0091] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0092] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of the module, program segment or instruction includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of special hardware and computer instructions.

[0093] The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or improvements to the technology in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for evaluating the impulse response of a near-ground line, characterized in that: The method comprises: Step 1, for the near-ground line to be tested, determining the evaluation parameters of the near-ground line, the evaluation parameters including the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth's surface, and the wire diameter of the wire used in the line, placing the line in a spatial coordinate system according to the evaluation parameters, taking the earth's horizontal plane as the XY plane, obtaining the coordinates of each key point on the near-ground line and the surrounding lines in the spatial coordinate system, forming a line model diagram, dividing the near-ground line into N segments and the surrounding lines into K segments according to the line model diagram, each segment including a current unit and a potential unit, wherein the one with inductance is called a current unit, and the one with capacitance is called a potential unit; Step 2: Measure the conductivity σ and dielectric constant ε of the ground below the near-ground line at each measurement frequency from power frequency to high frequency. r ; Step 3: Based on the conductivity σ and dielectric constant ε at each measurement frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

2. The method according to claim 1, characterized in that Insert a monopole probe of a preset length into the soil as the positive electrode, and place a metal plate of a preset size flat on the ground as the negative electrode; Measure the impedance value R+j'X corresponding to the measurement frequency f within the preset frequency range between the positive and negative electrodes, where N is the number of measurement frequencies, R is the real part of the impedance, and X is the imaginary part of the impedance; measure the capacitance value C0 of the measurement subsystem in the air; use formula 1 and formula 2 to determine the conductivity σ and dielectric constant ε at the measurement frequency f r : Among them, ω=2πf, ε0 is the dielectric constant of vacuum.

3. The method according to claim 1, characterized in that: Set the upper frequency limit of the measurement to 10MHz.

4. The method according to claim 1, characterized in that: The current response of the current unit φ i As shown in formula 3 to formula 5: in, Among them, a i represents the length of the segment numbered i belonging to the near-ground line, a j represents the length of the segment with sequence number j belonging to the surrounding line, G(i,j) is the Green function of the segment with sequence number i reaching the segment with sequence number j in the line system of this calculation; The voltage response of the inductor unit φ i 'As shown in formula 6 and formula 7: in, According to equations 3 to 5, as well as the impact source and the final load of the line, the current I of each segment of the near-ground line is i ,I j As unknowns, according to Kirchhoff's current law, a system of simultaneous equations is established; among them, when there is an impulse source and the final load of the line is certain, for the number of line segments M (M = N + K), M equations can be listed, so the system of equations must have a solution. According to the system of equations, the current I on each segment is solved i ,I j , according to the determined I i ,I j And equations 6 and 7, determine φ i '; According to equations 1 to 6, the current response φ of any point in the system at different frequencies f can be determined i Or voltage response φ i '; Get the frequency response of the entire line system to be evaluated to all impacts.

5. A method for evaluating the impulse response of a near-ground line, characterized in that: The method comprises: Step 1, forming a line model diagram according to the evaluation parameters of the near-ground line to be tested, wherein the near-ground line is divided into N segments, and the surrounding lines are divided into K segments, each segment includes a current unit and a potential unit, wherein the unit with inductance is called a current unit, and the unit with capacitance is called a potential unit; the evaluation parameters include the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth surface, and the wire diameter of the wire used in the line; Step 2: Obtain the conductivity σ and dielectric constant ε of the ground below the near-ground line corresponding to each measurement frequency from the power frequency to the high frequency range r ; Step 3: Based on the conductivity σ and dielectric constant ε at each measurement frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

6. A device for evaluating the impulse response of a near-ground line, characterized in that: The device comprises: A generation module is used to form a line model diagram according to the evaluation parameters of the near-ground line to be tested, wherein the near-ground line is divided into N segments, and the surrounding lines are divided into K segments, each of which includes a current unit and a potential unit, wherein the unit with inductance is called a current unit, and the unit with capacitance is called a potential unit; the evaluation parameters include the horizontal line length and the vertical line length to be calculated in the near-ground line, the distance between the line and the earth surface, and the wire diameter of the wire used in the line; The acquisition module is used to obtain the conductivity σ and dielectric constant ε of the ground below the near-ground line corresponding to each measurement frequency from the power frequency to the high frequency range r ; Determination module for the conductivity σ and the dielectric constant ε at each measuring frequency r , determine the current response of each current unit and each inductance unit at each measurement frequency, thereby determining the frequency response of the entire line system to be evaluated to all impacts at different frequencies.

7. A device for evaluating the impulse response of a near-ground line, characterized in that: The device comprises: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to execute the method of claim 5.

8. A non-volatile computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the method of claim 5 is implemented.

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