Method, system and device for calculating electromagnetic wave three-dimensional propagation path of multi-layer medium overlapping structure of power system external insulation equipment and medium

Abstract

The present application belongs to the technical field of electromagnetic wave propagation path calculation, and discloses a method, system, device and medium for calculating the three-dimensional propagation path of electromagnetic waves in the multi-layer medium overlapping structure of the external insulation equipment of a power system, to solve the problem of the calculation efficiency and accuracy of electromagnetic wave propagation paths. The method comprises: constructing an electromagnetic wave propagation model, and obtaining the relative dielectric constant of each layer of medium and the radius of each layer of circular interface; setting the positions of the transmitting antenna, receiving antenna and detection point; determining the angle range of the refraction point of each medium interface according to the radius relationship of the adjacent layer interface, and discretely selecting multiple candidate refraction points on each layer interface; calculating the total propagation time of each possible propagation path based on the relative dielectric constant through the traversal method; and determining the path with the shortest total propagation time among all possible propagation paths as the actual propagation path of the electromagnetic wave based on Fermat's principle.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic wave propagation path calculation technology, specifically relating to a method, system, equipment, and medium for calculating the three-dimensional propagation path of electromagnetic waves in the multi-layer dielectric overlapping structure of external insulation equipment in power systems. Background Technology

[0002] The accuracy of electromagnetic wave propagation path calculation is crucial to ensuring the accuracy of power system external insulation equipment detection. It directly determines the positioning accuracy of external insulation defects when using backward projection algorithm imaging.

[0003] In the application scenarios of ground penetrating radar and through-wall radar, the research of Wang Tingting (Wang Tingting, Li Yibing, Ye Fang. Inversion algorithm of layered medium parameters of ground penetrating radar based on hunter-prey optimization [J]. Applied Science and Technology, 2025, 52(01): 173-180+220.) and Xiao Jun (Xiao Jun, Liang Buge, Yang Degui, et al. Review of wall parameter estimation and compensation methods for through-wall radar [J]. Radio Engineering, 2022, 52(11): 2023-2034.) et al. shows that due to the difference in the propagation speed of electromagnetic waves in different media, their refractive indices are also different, which causes electromagnetic waves to undergo reflection and refraction at the interface between the earth and the wall. However, the interface in ground penetrating and through-wall radar scenarios is mostly planar. For such planar interface scenarios, F. A (FA, MGA, SAK. Synthetic aperture beamformer for imaging through adielectric wall[J]. IEEE Transactions on Aerospace and Electronic Systems, 2005, 41(1):271-283.) et al. proposed that the propagation path of electromagnetic waves can be calculated by solving a fourth-order polynomial; Liu (Liu, Jiangang, Kong, et al. Refraction Angle Approximation Algorithm for Wall Compensation in TWRI[J]. IEEE geoscience and remote sensing letters, 2016, 13(7):943-946.) et al. proposed using other approximate solution methods. However, these existing methods have obvious limitations, only applicable to planar interface scenarios, and cannot be directly applied to the detection of external insulation equipment in power systems.

[0004] External insulation equipment in power systems has unique structural characteristics, with curved dielectric interfaces and a generally axisymmetric structure. To meet functional requirements such as insulation and support, the external insulation is often layered radially. Taking an insulator as an example, its main body consists of sheds, sheaths, and core rods from the outside in, with at least three circular interfaces in cross-section. This complex curved surface and multi-layered structure makes existing electromagnetic wave propagation path calculation methods applicable to planar interfaces ineffective. This is because planar interface calculation methods, based on simple geometric assumptions and refraction models, cannot accurately handle the complex refraction and reflection of electromagnetic waves propagating on curved interfaces, as well as the superimposed effects of different layered media on electromagnetic wave propagation. Therefore, in the inspection of external insulation equipment in power systems, existing technologies cannot accurately calculate electromagnetic wave propagation paths, which severely affects the accuracy of locating external insulation defects and poses potential risks to the safe and stable operation of the power system.

[0005] Existing technologies for calculating refraction points mainly approach the problem from two angles. Firstly, based on the law of refraction, if the position of a point on an interface allows the angles between the incident wave and the reflected wave and the normal to satisfy the law of refraction, then that point can be identified as the refraction location of the electromagnetic wave. However, in the complex curved surfaces and multi-layered structures of external insulation equipment in power systems, the application of the law of refraction is greatly limited due to the uneven distribution of the medium, making it difficult to accurately find refraction points that meet the conditions. On the other hand, based on Fermat's principle, Guolong Cui, Lingjiang Kong and Jianyu Yang, "A Back-projection algorithm to stepped-frequency synthetic aperture through-the-wallradar imaging," 2007 1st Asian and Pacific Conference on SyntheticApertureRadar,Huangshan,China,2007,pp.123-126,doi:10.1109 / APSAR.2007.4418570.) and H.-n.Wang (H.-n.Wang, B.-y. Lu, Z.-m. Zhou and Q. Song, "Through-the-wall imaging and correction based on the estimation of wallparameters," Proceedings of 2011 IEEE CIE International Conference on Radar,Chengdu, China, 2011, pp. 1327-1330, doi: Research by 10.1109 / CIE-Radar.2011.6159802. et al. indicates that if the relative permittivity is considered, and the sum of the propagation paths of each segment has an extremum (usually a minimum), then the location where the extremum is obtained is the refraction point. Although Fermat's principle can bypass the complex position and angle relationships of electromagnetic wave refraction between interfaces to some extent, in the scenario of external insulation equipment in power systems, due to the complexity of the dielectric interface and the diversity of layered structures, the process of calculating the sum of the propagation paths of each segment and finding the extremum becomes extremely complex. The calculation accuracy and time are difficult to control effectively, resulting in significant limitations of existing calculation methods based on Fermat's principle.

[0006] In summary, existing technologies have significant shortcomings in terms of applicable scenarios, calculation accuracy, and calculation efficiency when calculating electromagnetic wave propagation paths and refraction points of external insulation equipment in power systems, making it difficult to meet actual testing needs. Summary of the Invention

[0007] Based on the aforementioned shortcomings and deficiencies in the prior art, one of the objectives of this invention is to at least solve one or more of the aforementioned problems in the prior art. In other words, one of the objectives of this invention is to provide a method, system, device, and medium for calculating the three-dimensional propagation path of electromagnetic waves in the multilayer dielectric overlapping structure of the external insulation equipment of a power system that meets one or more of the aforementioned requirements, so as to improve the calculation efficiency and accuracy.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for calculating the three-dimensional propagation path of electromagnetic waves in a multilayer dielectric overlapping structure of an external insulation device in a power system, comprising the following steps: S1, constructing an electromagnetic wave propagation model of the external insulation device under test, wherein the electromagnetic wave propagation model is a multilayer axisymmetric dielectric structure with at least two circular interfaces, and obtaining the relative permittivity of each dielectric layer and the radius of each circular interface; S2, setting the positions of the transmitting antenna, the receiving antenna, and the detection point located within each dielectric layer; S3, for each dielectric interface, determining the angular range of the refraction point based on its radii relationship with adjacent dielectric interfaces; S4, within the angular range determined in step S3, discretely selecting multiple candidate refraction points on each dielectric interface; S5, traversing the refraction points on each dielectric interface that the electromagnetic wave may pass through from the transmitting antenna to the detection point, forming multiple possible propagation paths, and calculating the total propagation time of each possible propagation path based on the relative permittivity; S6, based on Fermat's law, determining the path with the shortest total propagation time among all possible propagation paths as the actual propagation path of the electromagnetic wave.

[0010] As a preferred embodiment, the angular range of the refraction point in step S3 is specifically as follows:

[0011] The minimum and maximum refraction angle positions of the refraction point are determined by the radius of the interface between adjacent layers, and the calculation formula is as follows:

[0012] ,

[0013] In the formula, This indicates that the possible refraction point location corresponds to half of the angular interval. Indicates the first i Possible refraction angles of the layer Indicates the first i The radius of the layer, Indicates the first i The radius of +1 layer, and They represent the first i The minimum and maximum refraction angle positions of the +1 layer.

[0014] As a preferred approach, step S4 involves discretely selecting multiple candidate refraction points, specifically as follows:

[0015] The first i +1 layer interface is divided into K -1 segment, obtained K The locations of discrete candidate refraction points, and the angle values ​​corresponding to the candidate refraction points. The expression is

[0016] .

[0017] As a preferred option, in step S5:

[0018] When the detection point is located at the i When the layer is reached, the propagation path needs to pass through I The refraction point, the th I The refraction point at the th point i The position on the layer interface is determined by polar coordinates ( , )Sure;

[0019] Using the direction that passes through the circle and coincides with the polar coordinate axis as x The axis is defined by the direction perpendicular to the x-axis. y Axis, the first I The first refraction point i The position of the refraction point and the first i Layer and First i The expression for the refraction path segment between layers +1 is:

[0020] ,

[0021] In the formula, Indicates the first i The possible refraction point location of the layer x coordinate, Indicates the first i The possible refraction point location of the layer y coordinate, Indicates the first i Layer and First i Length of the refraction path segment between +1 layers;

[0022] When each layer interface is selected K When there are n candidate refraction points, the total number of possible paths is .

[0023] As a preferred option, in step S5:

[0024] By incorporating electromagnetic wave propagation time compensation, the total propagation time for each possible propagation path is calculated. The expression for the compensated propagation time of the refracted path is then given by:

[0025] ,

[0026] In the formula, This represents the total number of possible paths. Indicates the first i The relative permittivity of the -1 layer, and when i When =1, the corresponding air layer is... This represents the relative permittivity of air. This represents the speed of light in a vacuum. The propagation path from the transmitting antenna to the detection point is represented by the [number]th [unit]. i Segment length, The propagation path from the detection point to the receiving antenna is represented by the th... i Segment length.

[0027] Secondly, this invention provides a system for calculating the three-dimensional propagation path of electromagnetic waves in a multi-layer dielectric overlapping structure of an external insulation device in a power system. This system is used to implement the electromagnetic wave three-dimensional propagation path calculation method described in the first aspect. The system includes: a model construction module for constructing an electromagnetic wave propagation model of the external insulation device under test, wherein the electromagnetic wave propagation model is a multi-layer axisymmetric dielectric structure with at least two circular interfaces, and obtaining the relative permittivity of each dielectric layer and the radius of each circular interface; a parameter setting module for setting the positions of the transmitting antenna, the receiving antenna, and the detection point positions within each dielectric layer; a refraction point processing module for determining the angle range of the refraction point for each dielectric interface based on its radius relationship with adjacent interfaces, and discretely selecting multiple candidate refraction points on each interface within the determined angle range; and a path calculation module for traversing the refraction points on each interface that the electromagnetic wave may pass through from the transmitting antenna to the detection point, forming multiple possible propagation paths, calculating the total propagation time of each possible propagation path based on the relative permittivity, and determining the path with the shortest total propagation time among all possible propagation paths as the actual propagation path of the electromagnetic wave based on Fermat's Last Theorem.

[0028] As a preferred embodiment, the refraction point processing module includes: an angle range calculation unit, used to calculate the angle range of the refraction point on each layer interface based on the radius relationship between adjacent layers; and a discretization unit, used to discretize and select candidate refraction points within the angle range.

[0029] As a preferred embodiment, the path calculation module includes: a path traversal unit for generating all possible propagation path combinations; a time calculation unit for calculating the total propagation time of each path; and an optimal path selection unit for selecting the path with the shortest propagation time as the actual propagation path based on Fermat's Last Theorem.

[0030] Thirdly, the present invention provides an electronic device, the computer device including a memory, a processor and a computer program, wherein when the computer program is executed by the processor, it implements the electromagnetic wave three-dimensional propagation path calculation method as described in the first aspect.

[0031] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the electromagnetic wave three-dimensional propagation path calculation method as described in the first aspect.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. In terms of computational efficiency, this invention introduces Fermat's law to calculate the electromagnetic wave propagation path. This method focuses solely on the appropriate selection of refraction points within each medium layer, eliminating the need for complex and tedious angle calculations. This significantly simplifies the calculation process, reduces variables and computational steps, thereby substantially improving computational efficiency and enabling results to be obtained in a shorter time, meeting the timeliness requirements of practical applications.

[0034] 2. In terms of computational accuracy, the electromagnetic wave propagation path calculation method proposed in this invention has unique advantages. Unlike other algorithms that use approximations to simplify the calculation process, this invention does not use any approximations throughout the entire process. This means that during the calculation, the influence of various factors on the electromagnetic wave propagation path can be fully and accurately considered, avoiding the accumulation of errors that may be caused by approximations. This makes the calculation results more accurate and reliable, providing a solid data foundation for subsequent analysis and applications.

[0035] 3. The method of this invention can be effectively applied to the calculation of the propagation distance of electromagnetic waves in the detection space when radar detects external insulation equipment in power systems. In power systems, accurately calculating the propagation distance of electromagnetic waves is crucial for imaging external insulation defects. Using the method of this invention, electromagnetic wave propagation path information can be obtained more accurately, thereby achieving accurate imaging of external insulation defects.

[0036] Further or more detailed beneficial effects will be described in conjunction with specific embodiments in the detailed implementation. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart illustrating the electromagnetic wave three-dimensional propagation path calculation method described in Embodiment 1 of the present invention.

[0039] Figure 2 This is a schematic diagram of the electromagnetic wave propagation model of the external insulation device under test as described in Embodiment 1 of the present invention.

[0040] Figure 3 This is the first embodiment of the present invention. i Layer and first i A schematic diagram of the refraction between the +1 layers.

[0041] Figure 4 This is a schematic diagram of selecting multiple candidate refraction points as described in Embodiment 1 of the present invention.

[0042] Figure 5 This is a schematic diagram of the electromagnetic wave three-dimensional propagation path calculation system described in Embodiment 2 of the present invention.

[0043] Figure 6 This is a structural diagram of the electronic device described in Embodiment 3 of the present invention.

[0044] Figure 7 This is a schematic diagram of the object under test in the simulation experiment described in Embodiment 5 of the present invention.

[0045] Figure 8 This is a schematic diagram of the configuration of the defect detection system in the simulation experiment described in Embodiment 5 of the present invention.

[0046] Figure 9 This is a schematic diagram of the imaging results without considering refraction and relative permittivity as described in Embodiment 5 of the present invention.

[0047] Figure 10 This is a schematic diagram of the imaging results based on Fermat's theorem as described in Embodiment 5 of the present invention.

[0048] Icon labels:

[0049] 600. Electronic equipment;

[0050] 601. Processor; 602. Communication bus; 603. User interface; 604. Network interface; 605. Memory. Detailed Implementation

[0051] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0052] In the following description, several embodiments of the present invention are provided. Different embodiments can be substituted or combined. Therefore, the present invention can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present invention should also be considered to include embodiments containing one or more other possible combinations of A, B, C, and D, even if such embodiments are not explicitly described in the following text.

[0053] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of the invention. Various processes or components may be appropriately omitted, substituted, or added to the various examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0054] To facilitate a better understanding of the embodiments of the present invention, its application scenarios will be explained before providing a detailed explanation of the specific implementation methods.

[0055] The electromagnetic wave three-dimensional propagation path calculation method described in the embodiments of this specification is applied to the detection, fault diagnosis, and radar detection of the surrounding environment of power equipment in power systems. In these scenarios, the application of the electromagnetic wave three-dimensional propagation path calculation method aims to accurately obtain the propagation path information of electromagnetic waves in complex multilayer dielectric overlapping structures, thereby providing a reliable basis for the accurate location and imaging of external insulation defects and the accurate assessment of the operating status of power equipment, ultimately ensuring the safe and stable operation of the power system. The following is a brief explanation of the electromagnetic wave propagation, relative permittivity, transmitting antenna, receiving antenna, detection point, refraction point, Fermat's principle, and electromagnetic wave propagation time compensation involved in the various embodiments of this specification:

[0056] Electromagnetic wave propagation: Electromagnetic waves are oscillating particle waves generated and emitted in space by in-phase and mutually perpendicular electric and magnetic fields. They are electromagnetic fields that propagate in wave form. In the multi-layered dielectric overlapping structure of external insulation equipment in power systems, electromagnetic waves will undergo reflection and refraction at the interfaces between different dielectrics, and their propagation characteristics are affected by dielectric parameters (such as relative permittivity and permeability). This invention calculates the three-dimensional propagation path of electromagnetic waves by studying the propagation laws of electromagnetic waves in these complex structures.

[0057] The relative permittivity is a physical quantity that reflects the degree of polarization of a dielectric. Different media have different relative permittivity, which affects the propagation speed and wavelength of electromagnetic waves within the medium. In this invention, obtaining the relative permittivity of each dielectric layer is a crucial parameter for constructing an electromagnetic wave propagation model and calculating the propagation path.

[0058] A transmitting antenna is a device that converts guided waves (such as electromagnetic waves in a transmission line) into free-space electromagnetic waves. In electromagnetic wave propagation path calculations, the transmitting antenna is the initial emission point of the electromagnetic wave, and its position, polarization, operating frequency, and other parameters affect the initial propagation direction and characteristics of the electromagnetic wave. This invention requires setting the position of the transmitting antenna to determine the starting point of electromagnetic wave propagation.

[0059] A receiving antenna is a device that converts electromagnetic waves in free space into guided waves. It corresponds to a transmitting antenna and is used to receive electromagnetic wave signals after they have traveled a propagation path. The location, performance, and other parameters of the receiving antenna affect the reception effect of the electromagnetic wave signals. In this invention, setting the location of the receiving antenna helps to determine the endpoint of electromagnetic wave propagation, thereby enabling a complete calculation of the propagation path.

[0060] Detection points are specific locations within each layer of the medium used to study the propagation characteristics of electromagnetic waves. By analyzing the parameters of electromagnetic waves (such as field strength and phase) at these points, the propagation of electromagnetic waves in the medium can be understood. The determination of detection point locations in this invention is to comprehensively consider the propagation path of electromagnetic waves in multilayered medium structures, ensuring the accuracy and completeness of the calculations.

[0061] Refraction point: When an electromagnetic wave propagates from one medium to another, refraction occurs at the interface between the two media. The refraction point is the point at which the electromagnetic wave changes its propagation direction at the interface between the different media. In this invention, determining the location of the refraction point is one of the key steps in calculating the propagation path of the electromagnetic wave, and it needs to be determined based on the geometry of the interface between the media and the propagation laws of electromagnetic waves.

[0062] Fermat's principle, also known as the principle of the shortest optical path, states that when light (and in a broader sense, electromagnetic waves) propagates between two points, its actual path is the one that minimizes the optical path length (the product of the geometric path length of light in a medium and the refractive index of the medium). This invention, based on Fermat's principle, compares the total propagation time (related to the optical path length) of all possible propagation paths and determines the path with the shortest total propagation time as the actual propagation path of the electromagnetic wave, thus achieving accurate calculation of the three-dimensional propagation path of electromagnetic waves.

[0063] Compensation for electromagnetic wave propagation time: In actual electromagnetic wave propagation, the time it takes for the electromagnetic wave to reach the receiving point varies due to factors such as different media and path lengths along different paths. Compensation for electromagnetic wave propagation time is the process of adjusting and correcting these time differences. While this invention primarily calculates the propagation path based on Fermat's principle, in some complex cases, it may be necessary to consider compensation for electromagnetic wave propagation time to further improve the accuracy of the calculation results, such as when considering multiple reflections and scattering of electromagnetic waves in the medium.

[0064] Example 1:

[0065] like Figure 1 As shown in the figure, this embodiment provides a method for calculating the three-dimensional propagation path of electromagnetic waves in a multi-layer dielectric overlapping structure of external insulation equipment in a power system. The specific steps are as follows:

[0066] Step S1 involves constructing an electromagnetic wave propagation model of the external insulation device under test and obtaining the relative permittivity of each dielectric layer and the radius of the circular interface between each layer. For example... Figure 2 As shown, the electromagnetic wave propagation model constructed in this embodiment is an n-layer axisymmetric medium structure with at least two circular interfaces.

[0067] Step S2 involves setting the positions of the transmitting antenna, the receiving antenna, and the detection points located within each layer of the medium.

[0068] Step S3 involves determining the angular range of the refraction point for each medium interface based on its radius relationship with the adjacent layer interface.

[0069] Specifically, for a such Figure 2 The n-layer circular medium shown in the figure, the traversal method needs to consider the first... i Layer and first i Refraction between +1 layers, such as Figure 3 As shown. Due to the radius limitation, the angle of the refraction point of each layer has a boundary, which is calculated as shown in formula (1):

[0070] (1)

[0071] In formula (1), This indicates that the possible refraction point location corresponds to half of the angular interval. Indicates the first i Possible refraction angles of the layer Indicates the first i The radius of the layer, Indicates the first i The radius of +1 layer, and They represent the first iThe minimum and maximum refraction angle positions of the +1 layer.

[0072] Dividing the (i+1)th layer into K-1 segments, the angles at these positions can be calculated as shown in formula (2):

[0073] (2)

[0074] Step S4 is within the angle range determined in step S3, see reference. Figure 4 Multiple candidate refraction points are discretely selected on each layer interface.

[0075] Step S5 involves traversing the refraction points on each interface that the electromagnetic wave may pass through from the transmitting antenna to the detection point, forming multiple possible propagation paths, and calculating the total propagation time of each possible propagation path based on the relative permittivity.

[0076] Step S6 is to determine the path with the shortest total propagation time among all possible propagation paths, based on Fermat's principle, as the actual propagation path of the electromagnetic wave.

[0077] Specifically, when the detected point is located at the first i The layer has at least I refraction points along a unidirectional refraction path, and each... Both can determine the location of a refraction point and the refraction path segment between two layers. I The first refraction point i The position of the refraction point and the first i Layer and First i The expression for the refraction path segment between +1 layers is:

[0078] (3)

[0079] In formula (3), Indicates the first i The possible refraction point location of the layer x coordinate, Indicates the first i The possible refraction point location of the layer y coordinate, Indicates the first i Layer and First i Length of the refraction path segment between +1 layers;

[0080] When each layer interface is selected K When there are candidate refraction points, the total number of possible paths is:

[0081] (4)

[0082] This embodiment utilizes an electromagnetic wave refraction algorithm based on Fermat's theorem to calculate the refraction and propagation behavior of electromagnetic waves in a three-dimensional plane. Combined with electromagnetic wave propagation time compensation, an accurate electromagnetic wave propagation time can be obtained. The backward projection algorithm can then be used to image defects. Therefore, the expression for the compensated refraction path propagation time is:

[0083] (5)

[0084] In formula (5), This represents the total number of possible paths. Indicates the first i The relative permittivity of the -1 layer, and when i When =1, the corresponding air layer is... This represents the relative permittivity of air. This represents the speed of light in a vacuum. The propagation path from the transmitting antenna to the detection point is represented by the [number]th [unit]. i Segment length, The propagation path from the detection point to the receiving antenna is represented by the th... i Segment length.

[0085] Example 2:

[0086] like Figure 5 As shown, this embodiment provides a system for calculating the three-dimensional propagation path of electromagnetic waves in a multi-layer dielectric overlapping structure of an external insulation device in a power system. This system is used to implement the electromagnetic wave three-dimensional propagation path calculation method as described in Embodiment 1. The system includes: a model construction module for constructing an electromagnetic wave propagation model of the external insulation device under test. The electromagnetic wave propagation model is a multi-layer axisymmetric dielectric structure with at least two circular interfaces, obtaining the relative permittivity of each dielectric layer and the radius of each circular interface; a parameter setting module for setting the positions of the transmitting antenna, the receiving antenna, and the detection point positions within each dielectric layer; a refraction point processing module for determining the angle range of the refraction point for each dielectric interface based on its radius relationship with adjacent interfaces, and discretely selecting multiple candidate refraction points on each interface within the determined angle range; and a path calculation module for traversing the refraction points on each interface that the electromagnetic wave may pass through from the transmitting antenna to the detection point, forming multiple possible propagation paths, calculating the total propagation time of each possible propagation path based on the relative permittivity, and determining the path with the shortest total propagation time among all possible propagation paths as the actual propagation path of the electromagnetic wave based on Fermat's Last Theorem.

[0087] Specifically, the refraction point processing module includes: an angle range calculation unit, used to calculate the angle range of the refraction point on each layer interface according to the radius relationship between adjacent layers; and a discretization unit, used to discretize and select candidate refraction points within the angle range.

[0088] Specifically, the path calculation module includes: a path traversal unit for generating all possible propagation path combinations; a time calculation unit for calculating the total propagation time of each path; and an optimal path selection unit for selecting the path with the shortest propagation time as the actual propagation path based on Fermat's Last Theorem.

[0089] Example 3:

[0090] like Figure 6 As shown, this embodiment provides an electronic device, which may include: at least one processor, at least one network interface, a user interface, a memory, and at least one communication bus.

[0091] The communication bus can be used to enable communication between the various components mentioned above.

[0092] The user interface may include buttons, and optional user interfaces may also include standard wired interfaces and wireless interfaces.

[0093] The network interface may include, but is not limited to, Bluetooth modules, NFC modules, Wi-Fi modules, etc.

[0094] The processor may include one or more processing cores. It connects various parts of the electronic device via various interfaces and lines, executing instructions, programs, code sets, or instruction sets stored in memory, and accessing data stored in memory to perform various functions and process data. Optionally, the processor can be implemented using at least one hardware form of DSP, FPGA, or PLA. The processor may integrate one or more of the following: CPU, GPU, and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also be implemented as a separate chip without being integrated into the processor.

[0095] The memory may include RAM or ROM. Optionally, the memory may include a non-transitory computer-readable medium. The memory can be used to store instructions, programs, code, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor. The memory, as a computer storage medium, may include an operating system, a network communication module, a user interface module, and computing applications. The processor can be used to call the computing applications stored in the memory and execute the steps of the electromagnetic wave three-dimensional propagation path calculation method mentioned in the foregoing embodiments.

[0096] Example 4:

[0097] This embodiment provides a computer-readable storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform the above-described instructions. Figure 1 One or more steps in the illustrated embodiment. If the constituent modules of the above-described electronic device are implemented as software functional units and sold or used as independent products, they can be stored in the computer-readable storage medium.

[0098] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this specification are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., Solid State Disks (SSDs)).

[0099] Those skilled in the art will understand that all or part of the processes in the method of Embodiment 1 described above can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and the implementation scheme can be combined arbitrarily.

[0100] Example 5:

[0101] To verify the effectiveness of the electromagnetic wave three-dimensional propagation path calculation method for a multilayer dielectric overlapping structure of external insulation equipment in a power system described in this specification, this embodiment uses CST software (CST Studio Suite) for simulation experiments.

[0102] In the experiment, the object being tested was a ceramic cylinder with a diameter of 160 mm. It contained an internal defect: a circular cavity 48 mm from its axis and with a radius of 5 mm. The specific structure is as follows: Figure 7 As shown. Both the transmitting and receiving antennas are ultra-wideband antennas, with an available bandwidth consistent with the pulse source, both being 0.3 - 3 GHz. The configuration of the defect detection system is as follows. Figure 8 As shown.

[0103] In this simulation, the object under test was placed in a single-layer medium, and a single-layer refraction algorithm was used for imaging. The imaging results are compared below: Without considering refraction and relative permittivity, the imaging results obtained using the back projection algorithm are as follows: Figure 9 As shown, the energy convergence point is relatively scattered, making it impossible to accurately represent the actual location of the defect; however, considering refraction and relative permittivity, and using the back projection algorithm based on Fermat's theorem, the imaging result is as follows: Figure 10 As shown, the imaging results reveal a distinct area of ​​enhanced energy, which is the location of the defect. Measurements indicate that the defect is 44.7 mm from the axis and has a radius of 5 mm, consistent with the actual situation.

[0104] Therefore, the electromagnetic wave three-dimensional propagation path calculation method can accurately calculate the electromagnetic wave propagation path, thus contributing to precise defect imaging. Based on the above experimental process and results, this embodiment verifies the effectiveness of the electromagnetic wave three-dimensional propagation path calculation method for a multi-layer dielectric overlapping structure of external insulation equipment in a power system, as described in this specification.

[0105] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0106] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0107] The above description is merely an exemplary embodiment of the present invention and should not be construed as limiting the scope of the invention. Any equivalent changes and modifications made in accordance with the teachings of this invention are still within the scope of this invention. Those skilled in the art will readily conceive of embodiments of the invention upon considering the specification and practicing the disclosure herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of the invention are defined by the claims.

Claims

1. A method for calculating electromagnetic wave three-dimensional propagation paths in a multi-layer dielectric overlapping structure of an electric power system external insulation device, characterized by, The method comprises the steps of: S1, constructing an electromagnetic wave propagation model of the external insulation device under test, the electromagnetic wave propagation model being applied to a multi-layer axisymmetric medium structure, and obtaining relative dielectric constants of each layer of medium and radii of each layer of circular interface; S2, setting a transmitting antenna position, a receiving antenna position, and a probe point position located in each layer of medium; S3, for each medium interface, determining an angle range of a refraction point according to a radius relationship between the medium interface and an adjacent layer interface; The angle range of the refraction point in step S3 is specifically: The minimum refraction angle position and the maximum refraction angle position of the refraction point are determined by the radii of the adjacent layer interfaces, and a calculation formula is ， wherein represents half of the interval of the corresponding angle of the possible refraction point position, represents the minimum refraction angle position of the first i layer, represents the radius of the first i layer, represents the radius of the first i +1 layer, and respectively represent the minimum refraction angle position and the maximum refraction angle position of the first i +1 layer; S4, within the angle range determined in step S3, a plurality of candidate refraction points are discretely selected on each layer interface; S5, each layer interface on which the electromagnetic wave can pass through is traversed to form a plurality of possible propagation paths, and a total propagation time of each possible propagation path is calculated based on the relative dielectric constants; S6, based on Fermat's principle, a path with the shortest total propagation time among all possible propagation paths is determined as an actual propagation path of the electromagnetic wave.

2. The method of claim 1, wherein the method is characterized by: The plurality of candidate refraction points are discretely selected in step S4, and specifically: The first i +1 layer interface is divided into K -1 segments, obtaining K discrete candidate refraction point positions, the angle value corresponding to the candidate refraction point is expressed as 。 3. The method of claim 2, wherein the method is characterized by: In step S5: When the probe point is located at the i layer, the propagation path needs to pass through I refraction points, the position of the I refraction point on the interface of the i layer is determined by the polar coordinates ( , ). Using the direction that passes through the circle and coincides with the polar coordinate axis as x The axis is defined by the direction perpendicular to the x-axis. y Axis, as the first I The first refraction point i The position of the refraction point and the first i Layer and First i The expression for the refraction path segment between layers +1 is: ， wherein represents the i layer possible refraction point position x coordinate, represents the i layer possible refraction point position y coordinate, represents the i layer and the i +1 layer; When each layer interface selects K candidate refraction points, the total number of possible paths is .

4. The method of claim 3, wherein the method is characterized by: In step S5: In combination with compensation of electromagnetic wave propagation time, the total propagation time of each possible propagation path is calculated, and an expression of the propagation time of the compensated refraction path is ， wherein denotes the total number of possible paths, denotes the first i -1 layer, and when i = 1 corresponds to an air layer, i.e. denotes the relative dielectric constant of air, denotes the speed of light in vacuum, denotes the length of the first i segment of the propagation path from the transmitting antenna to the detection point, denotes the length of the first i segment of the propagation path from the detection point to the receiving antenna.

5. A system for calculating electromagnetic wave three-dimensional propagation paths in a multi-layer dielectric overlapping structure of an electric power system external insulation device, characterized by The method for implementing the electromagnetic wave three-dimensional propagation path calculation method of claim 4 comprises: A model construction module is configured to construct an electromagnetic wave propagation model of the external insulation device under test, the electromagnetic wave propagation model being applied to a multi-layer axisymmetric medium structure, and obtaining relative dielectric constants of each layer of medium and radii of each layer of circular interface; A parameter setting module is configured to set a transmitting antenna position, a receiving antenna position, and a probe point position located in each layer of medium; A refraction point processing module is configured to, for each medium interface, determine an angle range of a refraction point according to a radius relationship between the medium interface and an adjacent layer interface, and discretely select a plurality of candidate refraction points on each layer interface within the determined angle range; A path calculation module is configured to traverse each layer interface on which the electromagnetic wave can pass through to form a plurality of possible propagation paths, and calculate a total propagation time of each possible propagation path based on the relative dielectric constants, and based on Fermat's principle, determine a path with the shortest total propagation time among all possible propagation paths as an actual propagation path of the electromagnetic wave.

6. The electromagnetic wave three-dimensional propagation path calculation system for a multi-layer medium overlapping structure of a power system external insulation device according to claim 5, characterized by The refraction point processing module comprises: An angle range calculation unit is configured to calculate an angle range of a refraction point on each layer interface according to a radius relationship between adjacent layers; A discretization unit is configured to discretely select candidate refraction points within the angle range.

7. The electromagnetic wave three-dimensional propagation path calculation system for a multi-layer medium overlapping structure of a power system external insulation device according to claim 5, characterized by, The path calculation module comprises: A path traversal unit is configured to generate all possible propagation path combinations; A time calculation unit is configured to calculate a total propagation time of each path; An optimal path selection unit is configured to select a path with the shortest propagation time as an actual propagation path based on Fermat's principle.

8. A computer device comprising a memory, a processor and a computer program, characterized in that The computer program, when executed by a processor, implements the electromagnetic wave three-dimensional propagation path calculation method according to any one of claims 1 to 4.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by a processor, implements the electromagnetic wave three-dimensional propagation path calculation method according to any one of claims 1 to 4.

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