Inversion method and device of lightning return stroke current, electronic equipment and storage medium

Abstract

The invention discloses a lightning return stroke current inversion method and device, electronic equipment and a storage medium. The method comprises the steps of obtaining a lightning electromagnetic field waveform, position information of a lightning stroke point and position information of a detection station for positioning the lightning stroke point in a lightning stroke research area during a lightning occurrence period; extracting a plurality of sampling values from the lightning electromagnetic field waveform according to a preset sampling frequency; aiming at each sampling value, correcting the current sampling value according to the amplitude correction coefficient and the time delay correction coefficient, and generating each corrected sampling value; and performing inversion according to each corrected sampling value, the position information of the lightning stroke point and the position information of the detection station for positioning the lightning stroke point, and generating each lightning return stroke current. According to the invention, the accuracy of lightning return stroke current inversion can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning disaster monitoring and early warning, and particularly relates to a method, device, electronic device and storage medium for inverting lightning return stroke current. Background Art

[0002] With the frequent occurrence of large-scale severe convective weather and extreme weather, the impact of lightning on the power grid has become increasingly serious. Lightning strike faults show new characteristics and spatio-temporal differences in the power grid system. In particular, faults caused by lightning currents with large steepness and long wave tails often result in the lightning withstand capacity of line towers being lower than expected, and protective devices such as lightning arresters failing. The basic parameters of the lightning return stroke current, such as the wavefront time, wave tail time, and steepness, are closely related to the lightning electromagnetic field waveform and other lightning observation data. These parameters are crucial for the judgment and protection of lightning strike faults. However, due to the complexity of the lightning return stroke current waveform, it is particularly important to obtain the lightning return stroke current information of the lightning strike point in a timely and accurate manner. The full waveform of the lightning return stroke current can provide detailed information about lightning activities and provide an important basis for the lightning protection design and fault prediction of the power grid.

[0003] There are obvious deficiencies in the existing technology for the inversion calculation of lightning return stroke current. Due to a certain distance between the detection station and the lightning strike point, the lightning electromagnetic field signal inevitably changes during the propagation process, resulting in a deviation between the lightning electromagnetic field signal received by the detection station and the true lightning electromagnetic field signal at the lightning strike point. Especially during the propagation of the lightning electromagnetic field signal, the change in time delay will affect the time characteristics of the signal reaching the detection station, and the change in amplitude will affect the intensity characteristics of the signal. These changes generated during the propagation process exacerbate the difference between the lightning electromagnetic field signal at the detection station and the true lightning electromagnetic field signal at the lightning strike point, further reducing the accuracy of the inversion. Due to the accumulation of these deviations, it is difficult for the existing technology to achieve precise inversion of the lightning return stroke current, resulting in a large error in the calculation result and unable to meet the requirements of high-precision lightning return stroke current calculation in complex application scenarios. Summary of the Invention

[0004] Embodiments of the present invention provide a method, device, electronic device and storage medium for inverting lightning return stroke current. By implementing the present invention, the accuracy of lightning return stroke current inversion can be improved.

[0005] An embodiment of the present invention provides a method for inverting lightning return stroke current, including:

[0006] Obtaining the lightning electromagnetic field waveform during lightning occurrence in the lightning strike research area, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point;

[0007] Extract a number of sampling values from the lightning electromagnetic field waveform according to a preset sampling frequency; each sampling value includes magnetic field strength and time;

[0008] Generate a time delay correction coefficient and an amplitude correction coefficient according to a preset correction coefficient table, the position information of the lightning strike point, and the position information of the detection station that locates the lightning strike point;

[0009] For each sampling value, correct the current sampling value according to the amplitude correction coefficient and the time delay correction coefficient to generate each corrected sampling value;

[0010] Perform inversion according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station that locates the lightning strike point to generate each lightning return stroke current.

[0011] Further, the performing inversion according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station that locates the lightning strike point to generate each lightning return stroke current includes:

[0012] Generate each lightning return stroke current through the following formula:

[0013]

[0014] where, I p (t) is the lightning return stroke current at time t in the corrected sampling value; c is the speed of light; D is the distance between the lightning strike point and the detection station that locates the lightning strike point; μ 0 is the vacuum permeability; υ is the return stroke speed; H p is the magnetic field strength in the corrected sampling value.

[0015] Further, after performing inversion according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station that locates the lightning strike point to generate each lightning return stroke current, it further includes:

[0016] Draw a lightning current waveform according to the lightning return stroke currents.

[0017] Further, obtain the correction coefficient table in the following manner:

[0018] Obtain the elevation data, soil conductivity data, air conductivity data, soil dielectric constant data, air dielectric constant data of the lightning strike research area, and the position information of all detection stations in the lightning strike research area;

[0019] Perform rasterization processing on the lightning strike research area to generate a number of lightning strike research area grids;

[0020] Repeat the correction coefficient generation operation until the correction coefficient table is generated;

[0021] The correction coefficient generation operation includes:

[0022] For each detection station, according to the elevation data, soil conductivity data, air conductivity data, soil dielectric constant data, air dielectric constant data, and the position information of the current detection station, construct each first lightning electromagnetic field propagation model corresponding to the grid of the current lightning strike research area; wherein, each first lightning electromagnetic field propagation model corresponds to a grid of the lightning strike research area and a detection station; the initial grid of the lightning strike research area is any grid of the lightning strike research area that has not undergone the correction coefficient generation operation; the first lightning electromagnetic field waveform is a relationship curve of the magnetic field strength changing with time;

[0023] Solve each first lightning electromagnetic field propagation model to generate each first lightning electromagnetic field waveform corresponding to the grid of the current lightning strike research area;

[0024] For each detection station, according to the air conductivity data, air dielectric constant data, and the position information of the current detection station, construct each second lightning electromagnetic field propagation model corresponding to the grid of the current lightning strike research area; wherein, each second lightning electromagnetic field propagation model corresponds to a grid of the lightning strike research area and a detection station; the second lightning electromagnetic field waveform is a relationship curve of the magnetic field strength changing with time;

[0025] Solve each second lightning electromagnetic field propagation model to generate each second lightning electromagnetic field waveform corresponding to the grid of the current lightning strike research area;

[0026] Add the first lightning electromagnetic field waveforms to the first lightning electromagnetic field waveform set;

[0027] Add the second lightning electromagnetic field waveforms to the second lightning electromagnetic field waveform set;

[0028] Judge whether the correction coefficients of all grids of the lightning strike research area are generated. If not, select any grid of the lightning strike research area that has not generated the correction coefficient as the updated grid of the lightning strike research area;

[0029] If so, generate a correction coefficient table according to the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set.

[0030] Further, in the case of generating the correction coefficients of all grids of the lightning strike research area, the generating a correction coefficient table according to the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set includes:

[0031] Taking the grid of the lightning strike research area and the detection station as the matching criteria, screen the waveforms that meet the matching criteria from the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set, and combine the corresponding first lightning electromagnetic field waveforms and second lightning electromagnetic field waveforms into several electromagnetic field waveform groups;

[0032] For each electromagnetic field waveform group, the absolute difference between the maximum magnetic field strength in the current first lightning electromagnetic field waveform and the maximum magnetic field strength in the second lightning electromagnetic field waveform is used as the amplitude correction coefficient corresponding to the current electromagnetic field waveform group; the absolute difference between the time at which the maximum magnetic field strength in the current first lightning electromagnetic field waveform is located and the time at which the maximum magnetic field strength in the second lightning electromagnetic field waveform is located is used as the time delay correction coefficient corresponding to the current electromagnetic field waveform group; amplitude correction coefficients and time delay correction coefficients corresponding to each electromagnetic field waveform group are generated;

[0033] According to the amplitude correction coefficients and time delay correction coefficients corresponding to each electromagnetic field waveform group, a correction coefficient table is generated.

[0034] Furthermore, the first lightning electromagnetic field propagation model is specifically:

[0035]

[0036] where E r is the horizontal electric field; E z is the vertical electric field; is the horizontal magnetic field; ε is the permittivity; σ is the conductivity; r is the distance between the grid of the lightning strike study area and the detection station; μ is the permeability.

[0037] Based on the above method item embodiments, the present invention correspondingly provides device item embodiments.

[0038] An embodiment of the present invention provides an inversion device for lightning return stroke current, including: a lightning data acquisition module, a sampling value extraction module, a correction coefficient generation module, a sampling value correction module, and a current inversion module;

[0039] The lightning data acquisition module is used to acquire the lightning electromagnetic field waveform during the occurrence of lightning in the lightning strike study area, the position information of the lightning strike point, and the position information of the detection station for positioning the lightning strike point;

[0040] The sampling value extraction module is used to extract a number of sampling values from the lightning electromagnetic field waveform according to a preset sampling frequency; wherein each sampling value includes the magnetic field strength and time;

[0041] The correction coefficient generation module is used to generate a time delay correction coefficient and an amplitude correction coefficient according to a preset correction coefficient table, the position information of the lightning strike point, and the position information of the detection station for positioning the lightning strike point;

[0042] The sampling value correction module is used to correct the current sampling value according to the amplitude correction coefficient and the time delay correction coefficient for each sampling value, and generate each corrected sampling value;

[0043] The current inversion module is used to perform inversion based on the corrected sampling values, the position information of the lightning strike point, and the position information of the detection station that locates the lightning strike point, and generate the lightning return stroke currents.

[0044] Further, the lightning return stroke current inversion device further includes: a lightning current waveform module;

[0045] The lightning current waveform module is used to draw the lightning current waveform according to the lightning return stroke currents.

[0046] Based on the above method item embodiments, the present invention correspondingly provides an electronic device item embodiment.

[0047] An embodiment of the present invention provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it can implement the lightning return stroke current inversion method described in any one of the above method item embodiments.

[0048] Based on the above method item embodiments, the present invention correspondingly provides a storage medium item embodiment.

[0049] An embodiment of the present invention provides a storage medium, on which a computer program is stored. When the computer program is executed by a processor, it can implement the lightning return stroke current inversion method described in any one of the above method item embodiments.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The embodiment of the present invention provides a lightning return stroke current inversion method, device, electronic device, and storage medium. The method performs grid processing on the lightning strike research area, maps the positions of the lightning strike point and the detection station to the corresponding grids, and with the help of the grid-based spatial division, effectively simplifies the determination process of the lightning electromagnetic field signal propagation path, helps to uniformly describe the spatial relationship between the lightning strike point and the detection station, and provides a reliable basis for the accurate application of the subsequent time delay correction coefficient and amplitude correction coefficient. By using the correction coefficient to correct the lightning electromagnetic field intensity value, the deviation caused by the signal in the propagation path can be effectively eliminated, and the error in the lightning return stroke current inversion can be significantly reduced. By using the corrected lightning electromagnetic field intensity value and combining the position information of the lightning strike point and the detection station to calculate the lightning return stroke current, the characteristics of the lightning return stroke current at the lightning strike point can be accurately inverted, providing technical support for high-precision lightning return stroke current calculation in complex application scenarios, and improving the practicability and reliability of the lightning return stroke current inversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic flowchart of a lightning return stroke current inversion method provided by an embodiment of the present invention.

[0053] Figure 2 It is the elevation map of Guangdong Province provided by an embodiment of the present invention.

[0054] Figure 3 It is the distribution map of soil conductivity in Guangdong Province provided by an embodiment of the present invention.

[0055] Figure 4 It is the distribution map of lightning location stations in Guangdong Province provided by an embodiment of the present invention.

[0056] Figure 5 It is the elevation distribution map between the grid of the lightning strike research area and the detection station provided by an embodiment of the present invention.

[0057] Figure 6 It is the soil conductivity distribution map between the grid of the lightning strike research area and the detection station provided by an embodiment of the present invention.

[0058] Figure 7 It is the grid division map of Guangdong Province provided by an embodiment of the present invention.

[0059] Figure 8 It is the first lightning electromagnetic field waveform and the second lightning electromagnetic field waveform diagram provided by an embodiment of the present invention.

[0060] Figure 9 It is the structural schematic diagram of an inversion device for lightning return stroke current provided by an embodiment of the present invention. Detailed implementation manners

[0061] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0062] As Figure 1 shown, an embodiment of the present invention provides an inversion method for lightning return stroke current, which at least includes the following steps:

[0063] Step S1, obtain the lightning electromagnetic field waveform during the lightning occurrence in the lightning strike research area, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point;

[0064] Optionally, the longitude and latitude of the lightning strike point and the position information of the detection station for locating the lightning strike point can be obtained through a lightning location system, and the lightning electromagnetic field waveform during the lightning occurrence in the lightning strike research area can be obtained through a lightning location station.

[0065] It is understandable that due to the distance between the detection station and the lightning strike point, the lightning electromagnetic field signal inevitably changes during propagation, resulting in a deviation between the signal received by the detection station and the true signal at the lightning strike point. Soil conductivity and terrain elevation play a key role in the propagation path and intensity of the lightning electromagnetic field. Especially under complex terrain conditions, soil conductivity and terrain undulations will significantly change the propagation characteristics of electromagnetic waves. Ignoring these factors will lead to waveform distortion in space and time, affecting the time delay and amplitude characteristics of the signal, thereby exacerbating the difference between the signal and the true signal and reducing the accuracy of inversion.

[0066] Step S2: Extract a number of sampling values from the lightning electromagnetic field waveform according to a preset sampling frequency; wherein, each sampling value includes the magnetic field intensity and time;

[0067] It should be noted that a number of sampling values are uniformly extracted from the lightning electromagnetic field waveform according to the preset sampling frequency to accurately describe the change trend of the waveform. Among them, each sampling value consists of two key parameters, namely the magnetic field intensity and the corresponding time point. The selection of the sampling frequency is crucial for the reconstruction accuracy of the waveform. It is necessary to ensure that the extracted sampling values can fully reflect the dynamic characteristics of the lightning electromagnetic field, and at the same time avoid the loss of waveform information caused by too low sampling frequency. The acquisition of sampling values lays the foundation for the subsequent analysis and calculation of lightning return stroke current.

[0068] Step S3: Generate a time delay correction coefficient and an amplitude correction coefficient according to a preset correction coefficient table, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point;

[0069] In a preferred embodiment, the correction coefficient table is obtained in the following manner:

[0070] Obtain the elevation data, soil conductivity data, air conductivity data, soil dielectric constant data, air dielectric constant data of the lightning strike research area, and the position information of all detection stations in the lightning strike research area;

[0071] Perform rasterization processing on the lightning strike research area to generate a number of lightning strike research area grids;

[0072] Repeat the correction coefficient generation operation until the correction coefficient table is generated;

[0073] The correction coefficient generation operation includes:

[0074] For each detection station, based on the elevation data, soil conductivity data, air conductivity data, soil permittivity data, air permittivity data, and the location information of the current detection station, construct each first lightning electromagnetic field propagation model corresponding to the grid of the current lightning strike research area; wherein, each first lightning electromagnetic field propagation model corresponds to a grid of the lightning strike research area and a detection station; the initial grid of the lightning strike research area is any grid of the lightning strike research area that has not undergone the operation of generating correction factors; the first lightning electromagnetic field waveform is a relationship curve of the magnetic field strength changing with time;

[0075] Solve each first lightning electromagnetic field propagation model to generate each first lightning electromagnetic field waveform corresponding to the grid of the current lightning strike research area;

[0076] For each detection station, based on the air conductivity data, air permittivity data, and the location information of the current detection station, construct each second lightning electromagnetic field propagation model corresponding to the grid of the current lightning strike research area; wherein, each second lightning electromagnetic field propagation model corresponds to a grid of the lightning strike research area and a detection station; the second lightning electromagnetic field waveform is a relationship curve of the magnetic field strength changing with time;

[0077] Solve each second lightning electromagnetic field propagation model to generate each second lightning electromagnetic field waveform corresponding to the grid of the current lightning strike research area;

[0078] Add the first lightning electromagnetic field waveforms to the first lightning electromagnetic field waveform set;

[0079] Add the second lightning electromagnetic field waveforms to the second lightning electromagnetic field waveform set;

[0080] Judge whether the correction factors of all grids of the lightning strike research area are generated. If not, select any grid of the lightning strike research area that has not generated the correction factor as the updated grid of the lightning strike research area;

[0081] If so, generate a correction factor table according to the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set.

[0082] Exemplarily, taking Guangdong Province as the lightning research area, the DEM elevation data of Guangdong Province can be obtained from the Geospatial Data Cloud website, the soil conductivity data of Guangdong Province can be obtained from the World Soil Database, and the elevation and soil conductivity distribution of Guangdong Province can be drawn in the ArcGIS software. The elevation map of Guangdong Province is as Figure 2 shown, and the soil conductivity distribution map of Guangdong Province is as Figure 3 shown. Since there are 21 lightning location stations in Guangdong Province, their distribution is as Figure 4 shown. Arbitrarily select a grid of the lightning strike research area and a detection station, take the grid of the lightning strike research area as the lightning strike point, and the elevation distribution map between the grid of the lightning strike research area and the detection station is asFigure 5 As shown; the distribution map of soil conductivity between the lightning strike research area grid and the detection station is as Figure 6 shown.

[0083] Exemplarily, taking Guangdong Province as the lightning research area, the square with a side length of 10 km is used to divide the grid of Guangdong Province, and the lightning strike research area is rasterized to generate several lightning strike research area grids. The grid division map of Guangdong Province is as Figure 7 shown.

[0084] In an optional embodiment, in the case of generating the correction coefficients of all lightning strike research area grids, generating a correction coefficient table according to the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set includes:

[0085] Taking the lightning strike research area grid and the detection station as the matching criteria, screening the waveforms that meet the matching criteria from the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set, and combining the corresponding first lightning electromagnetic field waveforms and second lightning electromagnetic field waveforms into several electromagnetic field waveform groups;

[0086] For each electromagnetic field waveform group, taking the ratio of the maximum value of the magnetic field strength in the current second lightning electromagnetic field waveform to the maximum value of the magnetic field strength in the first lightning electromagnetic field waveform as the amplitude correction coefficient corresponding to the current electromagnetic field waveform group; taking the absolute difference between the time when the maximum value of the magnetic field strength in the current first lightning electromagnetic field waveform is located and the time when the maximum value of the magnetic field strength in the second lightning electromagnetic field waveform is located as the time delay correction coefficient corresponding to the current electromagnetic field waveform group; generating the amplitude correction coefficient and time delay correction coefficient corresponding to each electromagnetic field waveform group;

[0087] Generating a correction coefficient table according to the amplitude correction coefficient and time delay correction coefficient corresponding to each electromagnetic field waveform group.

[0088] Optionally, draw the first lightning electromagnetic field waveform and the second lightning electromagnetic field waveform, as Figure 8 shown, and calculate the amplitude correction coefficient and time delay correction coefficient through the following formula:

[0089]

[0090] △t=|t a -t b |

[0091] where k is the amplitude correction coefficient; A a is the maximum value of the magnetic field strength in the second lightning electromagnetic field waveform; A b is the maximum value of the magnetic field strength in the first lightning electromagnetic field waveform; Δt is the time delay correction coefficient; t aThe time at which the maximum magnetic field strength in the second lightning electromagnetic field waveform occurs; t b The time at which the maximum magnetic field strength in the second lightning electromagnetic field waveform occurs.

[0092] Specifically, the first lightning electromagnetic field propagation model is specifically:

[0093]

[0094] where E r is the horizontal electric field; E z is the vertical electric field; is the horizontal magnetic field; ε is the permittivity; σ is the conductivity; r is the distance between the grid of the lightning strike research area and the detection station; μ is the permeability.

[0095] Preferably, since the first lightning electromagnetic field propagation model is a differential equation and it is relatively difficult to solve directly, the MTLE model and the finite-difference time-domain method (FDTD) are selected for solving.

[0096] In the first lightning electromagnetic field propagation model, the lightning return stroke channel current is regarded as the excitation source of the model. This channel is placed on the axis of symmetry of the two-dimensional cylindrical coordinate system. The MTLE engineering model is used as the return stroke current model, and its characteristic is that the base current shows an exponential decay during its upward development. The channel base current is constructed using the Heidler function and the double-exponential function.

[0097] The MTLE model formula is as follows:

[0098] I(z′, t) = e -z′ / 2 I(0, t - z′ / υ)

[0099] where I(z′, t) is the lightning return stroke channel current at height z′ and time t; υ is the return stroke speed, taking 1.5×10^8 m / s;

[0100] The channel base current formula is as follows:

[0101]

[0102] where I(0, t) is the instantaneous value of the channel base current at time t; I 01 is the lightning current amplitude, taking 200 kA; η is the amplitude correction coefficient, taking 0.845; τ 1 is the lightning current peak time, taking 1.2 μs; τ 2 is the half-peak time, taking 50 μs; v is the return stroke speed, taking 1.5×10 8 m / s;

[0103] The first lightning electromagnetic field propagation model is discretized using the finite-difference time-domain (FDTD) method, converting the continuous time and space distributions into a grid-based computational form. The computational domain is divided into multiple grids, and the numerical information of the electromagnetic field is stored at each grid point. The time step is determined according to the Courant stability condition to ensure computational stability. During the discretization process, medium parameters such as the permittivity, conductivity, and permeability are set according to the actual terrain and soil data to distinguish the physical properties of air and the ground, thereby reflecting the influence of the complex environment on the propagation of the electromagnetic field. Subsequently, using the time-stepping iteration method, the calculation is gradually advanced using the discretized equations, and the electric and magnetic field components at each grid point are updated iteratively to simulate the propagation process and spatio-temporal distribution of electromagnetic waves. During the entire solution process, the lightning return stroke current acts as a dynamic excitation source, continuously influencing the electromagnetic field distribution, enabling the calculation results to accurately reflect the generation and propagation characteristics of the lightning electromagnetic field.

[0104] Exemplarily, the computational domain is as Figure 7 shown. In the figure, H is the height of the lightning channel, taken as 5 km; v is the return stroke velocity, taken as 1.5×10 8 m / s; r is the horizontal distance from the lightning strike point to the lightning detection station, ε 1 and ε 0 are the permittivities of the ground and air respectively, and σ 1 and σ 0 are the conductivities of the ground and air respectively.

[0105] The computational domain is divided into grids of 100 m * 100 m, and the above equations are differenced in time and space. The time step is taken as 0.16 μs, and the FDTD calculation iteration formula is obtained as follows:

[0106]

[0107]

[0108] In the formula, i and j represent the coordinates of the spatial grid, and n represents the coordinate on the time axis. ε(i, j), σ(i, j), and μ(i, j) are the values of the permittivity, conductivity, and permeability at the grid point (i, j) respectively. For ε(i, j), the permittivity of the underground grid ( Figure 7 region ②) can be set to ε 1 using the actual elevation data, and the permittivity of the above-ground grid ( Figure 7 region ①) can be set to ε 0 to distinguish air and the ground; for σ(i, j), the actual soil conductivity data is imported into the Figure 7 grids in region ②, and the conductivity of air is set to σ 0Since both the earth and the air are non-magnetic media, μ(i, j) = μ 0 . The above formula can be used to gradually calculate the spatial electromagnetic field distribution at each moment.

[0109] Step S4: For each sampling value, correct the current sampling value according to the amplitude correction coefficient and the time delay correction coefficient to generate each corrected sampling value;

[0110] The corrected sampling value is calculated and generated through the following formula:

[0111] t = t′ - Δt

[0112] H p = kH′ p

[0113] where t is the peak time of the corrected waveform; H p is the peak value of the magnetic field intensity waveform after correction.

[0114] Step S5: Invert according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point to generate each lightning return stroke current.

[0115] In a preferred embodiment, the inverting according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point to generate each lightning return stroke current includes:

[0116] Calculate the distance between the lightning strike point and the detection station for locating the lightning strike point according to the position information of the lightning strike point and the position information of the detection station for locating the lightning strike point;

[0117] Generate each lightning return stroke current through the following formula:

[0118]

[0119] where I p (t) is the lightning return stroke current at time t in the corrected sampling value; c is the speed of light; D is the distance between the lightning strike point and the detection station for locating the lightning strike point; μ 0 is the vacuum permeability; υ is the return stroke speed; H p is the magnetic field intensity in the corrected sampling value.

[0120] In an alternative embodiment, after the inverting according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point to generate each lightning return stroke current, it further includes:

[0121] Draw the lightning current waveform according to the lightning return stroke currents.

[0122] Based on the above method embodiments, the present invention correspondingly provides apparatus embodiments.

[0123] As Figure 9 shown, an embodiment of the present invention provides an apparatus for inverting lightning return stroke current, including: a lightning data acquisition module, a sampling value extraction module, a correction coefficient generation module, a sampling value correction module, and a current inversion module;

[0124] The lightning data acquisition module is configured to acquire the lightning electromagnetic field waveform during lightning occurrence in the lightning strike research area, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point;

[0125] The sampling value extraction module is configured to extract a plurality of sampling values from the lightning electromagnetic field waveform according to a preset sampling frequency; wherein each sampling value includes magnetic field strength and time;

[0126] The correction coefficient generation module is configured to generate a time delay correction coefficient and an amplitude correction coefficient according to a preset correction coefficient table, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point;

[0127] The sampling value correction module is configured to correct each current sampling value according to the amplitude correction coefficient and the time delay correction coefficient to generate each corrected sampling value;

[0128] The current inversion module is configured to perform inversion according to each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station for locating the lightning strike point to generate each lightning return stroke current.

[0129] In an optional embodiment, the apparatus for inverting lightning return stroke current further includes: a lightning current waveform module;

[0130] The lightning current waveform module is configured to draw a lightning current waveform according to the lightning return stroke currents.

[0131] It should be noted that the embodiments of the device described above correspond to the above embodiments of the present invention and can implement the method for inverting the lightning return stroke current described in any one of the above of the present invention. In addition, the embodiments of the above device are merely illustrative. The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between modules indicates that they have a communication connection, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement without creative work.

[0132] Based on the above method embodiment of the present invention, a corresponding embodiment of an electronic device is provided.

[0133] An embodiment of the present invention provides an electronic device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the method for inverting the lightning return stroke current described in any one of the present invention is implemented, or when the processor executes the computer program, the functions of each module in the above device embodiments are implemented.

[0134] Exemplarily, the computer program can be divided into one or more modules. The one or more modules are stored in the memory and executed by the processor to complete the present invention. The one or more modules can be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0135] The terminal device can be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory.

[0136] The so-called processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the terminal device and connects various parts of the entire terminal device through various interfaces and lines.

[0137] The memory can be used to store the computer program and / or module. The processor realizes various functions of the terminal device by running or executing the computer program and / or module stored in the memory, and by calling the data stored in the memory. The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store the operating system, application programs required for at least one function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include high-speed random access memory, and can also include non-volatile memory, such as a hard disk, memory, plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, at least one magnetic disk storage device, flash device, or other volatile solid-state storage devices.

[0138] Based on the above method item embodiments, the present invention correspondingly provides storage medium item embodiments;

[0139] Another embodiment of the present invention provides a storage medium, which includes a stored computer program. When the computer program runs, it controls the device where the storage medium is located to execute any one of the above lightning return stroke current inversion methods of the present invention.

[0140] Among them, the above storage medium is a computer-readable storage medium, and the computer program includes computer program code, which can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0141] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example" or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0142] The above is the preferred implementation manner of the present invention. It should be pointed out that for those of ordinary skill in the art in the technical field of the present invention, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A method for inverting lightning return current, characterized in that: include: Obtaining the lightning electromagnetic field waveform during the period of lightning occurrence in the lightning strike study area, the location information of the lightning strike point, and the location information of the detection station locating the lightning strike point; According to a preset sampling frequency, a number of sampling values ​​are extracted from the lightning electromagnetic field waveform; wherein each sampling value includes magnetic field intensity and time; Generate a time delay correction coefficient and an amplitude correction coefficient according to a preset correction coefficient table, location information of a lightning strike point, and location information of a detection station for locating the lightning strike point; For each sampling value, the current sampling value is corrected according to the amplitude correction coefficient and the delay correction coefficient to generate each corrected sampling value; Inversion is performed based on each corrected sampling value, the position information of the lightning strike point, and the position information of the detection station locating the lightning strike point to generate each lightning return stroke current.

2. The method for inverting lightning return current according to claim 1, characterized in that: The inversion is performed according to each corrected sampling value, the position information of the lightning strike point and the position information of the detection station locating the lightning strike point to generate each lightning return stroke current, including: Calculate the distance between the lightning strike point and the detection station that locates the lightning strike point according to the location information of the lightning strike point and the location information of the detection station that locates the lightning strike point; Each lightning return stroke current is generated by the following formula: Among them, I p (t) is the lightning return stroke current at time t in the corrected sampling value; c is the speed of light; D is the distance between the lightning strike point and the detection station locating the lightning strike point; μ0 is the vacuum magnetic permeability; v is the return stroke speed; H p is the magnetic field strength in the corrected sampling value.

3. The method for inverting lightning return current according to claim 2, characterized in that: After performing inversion according to the corrected sampling values, the location information of the lightning strike point and the location information of the detection station locating the lightning strike point to generate each lightning return stroke current, the method further includes: According to each lightning return stroke current, a lightning current waveform is drawn.

4. The method for inverting lightning return current according to claim 3, characterized in that: Obtain the correction factor table by: Obtain elevation data, soil conductivity data, air conductivity data, soil dielectric constant data, air dielectric constant data and location information of all detection stations in the lightning strike study area; Repeat the correction coefficient generation operation until a correction coefficient table is generated; The correction coefficient generation operation includes: For each detection station, each first lightning electromagnetic field propagation model corresponding to the current lightning strike study area grid is constructed according to the elevation data, soil conductivity data, air conductivity data, soil dielectric constant data, air dielectric constant data and the location information of the current detection station; wherein each first lightning electromagnetic field propagation model corresponds to a lightning strike study area grid and a detection station; the initial lightning strike study area grid is any lightning strike study area grid that has not been subjected to the correction coefficient generation operation; the first lightning electromagnetic field waveform is a curve of the relationship between the magnetic field intensity and time; Solve each first lightning electromagnetic field propagation model to generate each first lightning electromagnetic field waveform corresponding to the grid of the current lightning strike research area; For each detection station, according to the air conductivity data, the air dielectric constant data and the location information of the current detection station, the second lightning electromagnetic field propagation models corresponding to the current lightning study area grid are constructed; wherein each second lightning electromagnetic field propagation model corresponds to a lightning study area grid and a detection station; the second lightning electromagnetic field waveform is a curve of the relationship between the magnetic field intensity and time; Solve each second lightning electromagnetic field propagation model to generate each second lightning electromagnetic field waveform corresponding to the grid of the current lightning strike research area; Adding each of the first lightning electromagnetic field waveforms to the first lightning electromagnetic field waveform set; Adding each of the second lightning electromagnetic field waveforms to the second lightning electromagnetic field waveform set; Determine whether to generate correction coefficients for all lightning strike study area grids, and if not, select any lightning strike study area grid for which no correction coefficient has been generated as an updated lightning strike study area grid; If yes, a correction coefficient table is generated according to the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set.

5. The method for inverting lightning return current according to claim 4, characterized in that: In the case of generating correction coefficients for all lightning study area grids, generating a correction coefficient table according to the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set includes: Taking the lightning research area grid and the detection station as matching criteria, selecting waveforms that meet the matching criteria from the first lightning electromagnetic field waveform set and the second lightning electromagnetic field waveform set, and combining the corresponding first lightning electromagnetic field waveform and the second lightning electromagnetic field waveform into a plurality of electromagnetic field waveform groups; For each electromagnetic field waveform group, the ratio of the maximum value of the magnetic field intensity in the current second lightning electromagnetic field waveform to the maximum value of the magnetic field intensity in the first lightning electromagnetic field waveform is used as the amplitude correction coefficient corresponding to the current electromagnetic field waveform group; the absolute difference between the time at which the maximum value of the magnetic field intensity in the current first lightning electromagnetic field waveform is located and the time at which the maximum value of the magnetic field intensity in the second lightning electromagnetic field waveform is located is used as the delay correction coefficient corresponding to the current electromagnetic field waveform group; the amplitude correction coefficient and the delay correction coefficient corresponding to each electromagnetic field waveform group are generated; A correction coefficient table is generated according to the amplitude correction coefficient and the time delay correction coefficient corresponding to each electromagnetic field waveform group.

6. The method for inverting lightning return current according to claim 5, characterized in that: The first lightning electromagnetic field propagation model is specifically: Among them, E r is the horizontal electric field; E z is the vertical electric field; is the horizontal magnetic field; ε is the dielectric constant; σ is the conductivity; r is the distance between the lightning strike research area grid and the detection station; μ is the magnetic permeability.

7. A lightning return current inversion device, characterized in that: include: Lightning data acquisition module, sampling value extraction module, correction coefficient generation module, sampling value correction module and current inversion module; The lightning data acquisition module is used to obtain the lightning electromagnetic field waveform during the period of lightning occurrence in the lightning study area, the location information of the lightning strike point, and the location information of the detection station locating the lightning strike point; The sampling value extraction module is used to extract a number of sampling values ​​from the lightning electromagnetic field waveform according to a preset sampling frequency; wherein each sampling value includes magnetic field intensity and time; The correction coefficient generation module is used to generate a time delay correction coefficient and an amplitude correction coefficient according to a preset correction coefficient table, location information of a lightning strike point, and location information of a detection station for locating the lightning strike point; The sampling value correction module is used to correct the current sampling value for each sampling value according to the amplitude correction coefficient and the delay correction coefficient to generate each corrected sampling value; The current inversion module is used to perform inversion according to each corrected sampling value, the position information of the lightning strike point and the position information of the detection station locating the lightning strike point, so as to generate each lightning return stroke current.

8. The lightning return current inversion device according to claim 7, characterized in that: Also includes: Lightning current waveform module; The lightning current waveform module is used to draw a lightning current waveform according to each lightning return stroke current.

9. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for inverting the lightning return stroke current as claimed in any one of claims 1 to 6 can be implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for inverting the lightning return stroke current described in any one of claims 1 to 6 can be implemented.

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