Electric transmission line unmanned aerial vehicle inspection safety distance electromagnetic field analysis method and system

Abstract

The invention relates to the technical field of electromagnetic field analysis and unmanned aerial vehicle inspection, in particular to a power transmission line unmanned aerial vehicle inspection safety distance electromagnetic field analysis method and system, and the method comprises the steps: building an electromagnetic field model of a power transmission line through a Maxwell equation set, and representing an electromagnetic field as a discretized finite element equation set; performing approximate processing on node potential and magnetic vector potential through energy functional of the electric field and the magnetic field in combination with a shape function, and solving electric field distribution and magnetic field intensity at the node; and in combination with simulation calculation, simulating the equivalent radius and charge distribution characteristics of a power transmission line conductor, and calculating the minimum safe flight distance of the unmanned aerial vehicle in the inspection task. The method has the advantages that accurate modeling and simulation analysis are conducted on the electromagnetic field of the power transmission line through the finite element method, and the safety and efficiency of unmanned aerial vehicle inspection operation are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical fields of electromagnetic field analysis and UAV inspection for transmission lines, and particularly to a method and system for analyzing the electromagnetic field of the safe distance of UAV inspection for transmission lines. Background Art

[0002] With the rapid development of the power system, the scale of transmission lines is expanding day by day, posing higher requirements for the safe operation and maintenance of the lines. Due to its high efficiency and flexibility, the UAV has gradually become an important tool for inspecting transmission lines. However, there is a complex electromagnetic field environment around the transmission lines, which may interfere with or even damage the normal operation of the UAV and its equipment. In addition, the electromagnetic field may also pose a potential threat to the health of the operators. Therefore, how to accurately evaluate the safe distance of the UAV during the inspection of transmission lines and provide a scientific basis for the inspection task is an urgent problem to be solved at present.

[0003] Traditional electromagnetic field analysis methods are mostly based on empirical formulas or simplified models, and it is difficult to comprehensively consider the influence of the geometric structure of the transmission line, the working voltage, and the surrounding environment on the electromagnetic field distribution. As a numerical calculation technology, the finite element method can accurately simulate the electromagnetic field distribution of complex geometric structures and material properties, providing a reliable tool for the electromagnetic environment assessment of transmission lines. In existing research, the finite element method has been widely used in the fields of electromagnetic compatibility analysis and field strength distribution calculation of power equipment, but there are still few application studies on the analysis of the safe distance of UAV inspection, lacking a systematic modeling method and accurate analysis results. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the specification of this application, to avoid obscuring the purpose of this part, the abstract, and the title, but such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a method and system for analyzing the electromagnetic field of the safe distance of UAV inspection for transmission lines, which can solve the problems mentioned in the background art.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] In the first aspect, the present invention provides a method for analyzing the electromagnetic field of the safe distance of UAV inspection for transmission lines, including establishing an electromagnetic field model of the transmission line by using Maxwell's equations and expressing the electromagnetic field as a discretized finite element equation set;

[0009] Approximate the node electric potential and magnetic vector potential by using the energy functionals of the electric field and magnetic field, combined with the shape function, and solve the electric field distribution and magnetic field intensity at the nodes;

[0010] Combined with simulation calculations, simulate the equivalent radius and charge distribution characteristics of the transmission line conductor, and calculate the minimum safe flight distance of the UAV during the inspection task.

[0011] As a preferred solution of the electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines of the present invention, wherein: Maxwell's equations include Ampere's law, Faraday's law of induction, Gauss's law, and Gauss's law of magnetism.

[0012] As a preferred solution of the electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines of the present invention, wherein: the energy functionals of the electric field and magnetic field are established by minimizing the total electrostatic energy and total magnetic energy of the electric field and magnetic field respectively.

[0013] As a preferred solution of the electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines of the present invention, wherein: the shape function is approximated by linearly or nonlinearly interpolating the node electric potential and magnetic vector potential.

[0014] As a preferred solution of the electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines of the present invention, wherein: the simulation calculations include defining geometric boundary conditions, physical properties, and mesh refinement.

[0015] As a preferred solution of the electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines of the present invention, wherein: the safe flight distance includes the safe flight altitude and the horizontal safe distance.

[0016] As a preferred solution of the electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines of the present invention, wherein: after calculating the minimum safe flight distance of the UAV during the inspection task, it further includes verifying the accuracy of the simulation results.

[0017] In a second aspect, the present invention provides an electromagnetic field analysis system for the safe distance of UAV inspection of transmission lines, including: a building module, configured to establish an electromagnetic field model of the transmission line by using Maxwell's equations, and represent the electromagnetic field as a discretized finite element equation system;

[0018] A solving module, configured to approximate the node electric potential and magnetic vector potential by using the energy functionals of the electric field and magnetic field, combined with the shape function, and solve the electric field distribution and magnetic field intensity at the nodes;

[0019] A calculation module, configured to simulate the equivalent radius and charge distribution characteristics of the transmission line conductor in combination with simulation calculations, and calculate the minimum safe flight distance of the UAV during the inspection task.

[0020] In a third aspect, the present invention provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the above method are implemented.

[0021] In a fourth aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: By accurately modeling and simulating the electromagnetic field of the transmission line using the finite element method, the safety and efficiency of the UAV inspection operation are significantly improved. Specifically, this method can accurately calculate the safe flight altitude and horizontal safety distance of the UAV during the inspection of the 220 kV three-phase transmission line, ensuring that the UAV maintains a sufficient safety interval from the transmission line and avoiding electromagnetic interference and potential equipment damage. In addition, by applying this method, not only can the reliability of the inspection work be improved, but it also helps to reduce the inspection cost and increase the inspection frequency, thereby enhancing the maintenance and monitoring capabilities of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0024] Figure 1 It is a flowchart of the electromagnetic field analysis method for the safety distance of UAV inspection of transmission lines.

[0025] Figure 2 It is a schematic internal structure diagram of a computer device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below with reference to the drawings in the specification.

[0027] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0028] Second, the "one embodiment" or "embodiment" referred to herein means a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that is mutually exclusive with other embodiments.

[0029] Embodiment 1

[0030] Referring to Figure 1 , which is the first embodiment of the present invention. This embodiment provides a method for analyzing the electromagnetic field of the safe distance for UAV inspection of transmission lines, which includes:

[0031] S1. Use Maxwell's equations to establish an electromagnetic field model of the transmission line, and represent the electromagnetic field as a discretized finite element equation system.

[0032] Furthermore, Maxwell's equations include Ampere's law, Faraday's law of induction, Gauss's law, and Gauss's law of magnetism.

[0033] It should be noted that based on Ampere's law, Faraday's law of induction, Gauss's law, and Gauss's law of magnetism, and through vector definitions, Maxwell's equations are used to describe the mutual relationship between the electric field and the magnetic field:

[0034]

[0035] In the formula, V and are the electric field and magnetic field vectors in the space coordinates (x, y), and ρ are the magnetic field strength, current density, dielectric flux density, magnetic flux density, and charge density respectively.

[0036] Furthermore, it should be noted that when applying the finite element method to electric field calculation, the region needs to be separated into finite sub-regions first. Each sub-region is represented by an equation, and the element combination is extracted. Among them, the energy equation representation of the sub-region under the finite element method is as follows:

[0037]

[0038] where D is the volume where the sub-region is located, ε is the dielectric constant of the material, ρ v is the volume charge density, is the electric potential gradient. Integrate D to calculate the total electrostatic energy and total electric power work in the sub-region. The energy equation can be balanced to the following fixed value:

[0039]

[0040] S2. Through the energy functionals of the electric field and the magnetic field, combined with the shape function, approximate the node electric potential and magnetic vector potential, and solve the electric field distribution and magnetic field strength at the nodes.

[0041] Furthermore, the energy functionals of the electric field and the magnetic field are established by minimizing the total electrostatic energy and the total magnetic energy of the electric field and the magnetic field, respectively.

[0042] Furthermore, the shape function is approximated by linearly or nonlinearly interpolating the nodal electric potential and the magnetic vector potential.

[0043] It should be noted that the energy functional expansion in the two-dimensional space of the electric field: In the context of the above equations, an electrostatic field in the spatial Cartesian coordinate system (x, y) is established and expressed as a function as follows:

[0044]

[0045] where M represents a nodal network formed by a plurality of discretized small elements.

[0046] Furthermore, the electric potential approximation of the electric field shape function: The electric potential function V can be approximately represented by the shape function s i (j) and each associated node i:

[0047]

[0048] where V i is the electric potential at the node, and j is an arbitrary point within the coordinate system. After substituting the approximation result into the equation and simplifying, the form S * is obtained and minimized under the following conditions:

[0049]

[0050] to obtain a system of equations for the electric potential in the electric field space.

[0051] Furthermore, the calculation of the electric field distribution at the nodes:

[0052] By solving the above system of equations for the electric potential in the electric field space, the potentials of all nodes are obtained. Based on the electric potential gradient, the electric field distribution in space can be obtained:

[0053]

[0054] Furthermore, it should be noted that the establishment of the magnetic field energy functional: Similar to the electric field calculation, after stabilizing the magnetic field system, by solving the magnetic vector potential function within the region, the energy functional is minimized:

[0055]

[0056] where D is the volume of the sub-region, μ is the magnetic permeability of the material, represents the current density within the spatial region D, ∑ B represents the boundary surface under the Neumann condition, and f BThese conditional functions are defined. Based on the principle of minimum energy for magnetic field stability, the energy functional is varied to obtain the equilibrium conditions:

[0057]

[0058] Furthermore, the binary expression of the magnetic field functional:

[0059] In the two-dimensional Cartesian coordinate system (x, y), the energy functional is simplified to:

[0060]

[0061] where M represents the node network formed by multiple discretized small cells.

[0062] Furthermore, the discretized magnetic vector potential and approximate solution:

[0063] For the magnetic vector potential Discretization is performed, and it is expressed by the finite element method as:

[0064]

[0065] where A i is the magnetic vector potential at the node, j is an arbitrary point in the coordinate system, and t i (j) is the shape function. After substituting the approximate result into the equation representation, the form T * is obtained and minimized under the following conditions:

[0066]

[0067] To obtain a system of equations for the magnetic vector potential in the magnetic field space.

[0068] Furthermore, calculate the magnetic field strength;

[0069] Through the curl of the magnetic vector calculate the magnetic field strength B m in each cell:

[0070]

[0071] S3. Combine simulation calculations to simulate the equivalent radius and charge distribution characteristics of the transmission line conductor, and calculate the minimum safe flight distance of the UAV during the inspection mission.

[0072] Furthermore, the simulation calculations include defining geometric boundary conditions, physical properties, and mesh refinement.

[0073] Furthermore, the safe flight distance includes the safe flight altitude and the horizontal safe distance.

[0074] Further, after calculating the minimum safe flight distance of the drone during the inspection mission, it also includes verifying the accuracy of the simulation results.

[0075] It should be noted that, according to the equations in S1 and combined with simulation calculations, the finite element equations near the transmission line are calculated. In the model of the equations, it is assumed that each sub-conductor of the transmission line is modeled by replacing each conductor bundle with a conductor of equal radius, and the equivalent conductor radius:

[0076]

[0077] where n is the number of sub-conductors and r is the radius of the sub-conductor, is the radius of the conductor bundle

[0078] By replacing with an equivalent conductor and assuming that the charge distribution of the conductor bundle remains symmetric, the same charge distribution effect as the original conductor is simulated. In this simulation process, the model is discretized into finite element cells, and by defining geometric boundary conditions, physical properties, and mesh refinement operations, the electromagnetic field problem is solved.

[0079] Further, it should be noted that during the solution process, the wire parameters are added: the wires are arranged horizontally with a wire spacing of 5 meters and a height of 15 meters. According to the anti-electromagnetic interference ability of the drone equipment (the electric field strength is lower than 5 kV / m), the safe flight height of the drone is calculated to be 20 meters and the horizontal safe distance is 10 meters.

[0080] Furthermore, it should be noted that the simulation results are compared with the on-site test data, and the error is within 10%. Therefore, it is proved that the present invention has high accuracy and practicability and is applicable to the analysis of the safe distance and electromagnetic field evaluation of the drone transmission line inspection.

[0081] In summary, the beneficial effect of the method for analyzing the safe distance electromagnetic field of the transmission line drone inspection in the present invention is that by using the finite element method to accurately model and simulate the electromagnetic field of the transmission line, the safety and efficiency of the drone inspection operation are significantly improved. Specifically, this method can accurately calculate the safe flight height and horizontal safe distance of the drone during the inspection of the 220 kV three-phase transmission line, ensure that the drone maintains a sufficient safety interval from the transmission line, and avoid electromagnetic interference and potential equipment damage. In addition, by applying this method, not only can the reliability of the inspection work be improved, but also it helps to reduce the inspection cost and increase the inspection frequency, thereby enhancing the maintenance and monitoring capabilities of the power system.

[0082] Embodiment 2

[0083] This embodiment provides an electromagnetic field analysis system for the safe distance of UAV inspection of transmission lines, which includes a building module for building an electromagnetic field model of the transmission line using Maxwell's equations and representing the electromagnetic field as a discretized finite element equation set;

[0084] a solving module for approximately processing the node electric potential and magnetic vector potential through the energy functionals of the electric field and magnetic field and combining the shape function to solve the electric field distribution and magnetic field strength at the nodes;

[0085] a calculation module for combining simulation calculations, simulating the equivalent radius and charge distribution characteristics of the transmission line conductor, and calculating the minimum safe flight distance of the UAV during the inspection task.

[0086] The above-mentioned unit modules can be embedded in the processor of the computer device in hardware form or be independent of it, or be stored in the memory of the computer device in software form, so as to facilitate the processor to call and execute the operations corresponding to the above respective modules.

[0087] Embodiment 3

[0088] This embodiment provides a computer device, which can be a terminal, and its internal structure diagram can be as Figure 2 shown. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a carrier network, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it realizes an electromagnetic field analysis method for the safe distance of UAV inspection of transmission lines. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the shell of the computer device, or an external keyboard, a touchpad, or a mouse, etc.

[0089] This embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by the processor, it realizes: building an electromagnetic field model of the transmission line using Maxwell's equations and representing the electromagnetic field as a discretized finite element equation set;

[0090] approximately processing the node electric potential and magnetic vector potential through the energy functionals of the electric field and magnetic field and combining the shape function to solve the electric field distribution and magnetic field strength at the nodes;

[0091] Combined with simulation calculations, the equivalent radius and charge distribution characteristics of the transmission line conductors are simulated, and the minimum safe flight distance of the UAV during the inspection mission is calculated.

[0092] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for analyzing electromagnetic fields at safe distances for unmanned aerial vehicle inspection of power transmission lines, characterized by: include, Maxwell equations are used to establish the electromagnetic field model of the transmission line, and the electromagnetic field is expressed as a discretized finite element equation set; The energy functionals of the electric and magnetic fields are combined with shape functions to approximate the node electric potential and magnetic vector potential, and the electric field distribution and magnetic field intensity at the node are solved. Combined with simulation calculations, the equivalent radius and charge distribution characteristics of the transmission line conductor are simulated, and the minimum safe flight distance of the UAV in the inspection mission is calculated.

2. The electromagnetic field analysis method for safe distance inspection of power transmission lines by drones according to claim 1, characterized in that: The Maxwell equations include Ampere's law, Faraday's law of induction, Gauss's law and Gauss's law of magnetism.

3. The electromagnetic field analysis method for safe distance inspection of power transmission lines by drones according to claim 2, characterized in that: The energy functionals for the electric and magnetic fields are established by minimizing the total electrostatic energy and the total magnetic energy of the electric and magnetic fields, respectively.

4. The electromagnetic field analysis method for safe distance of transmission line inspection by unmanned aerial vehicle according to claim 3, characterized in that: The shape function is approximated by linear or nonlinear interpolation of the node electric potentials and magnetic vector potentials.

5. The electromagnetic field analysis method for safe distance of transmission line inspection by unmanned aerial vehicle according to claim 4, characterized in that: The simulation calculation includes defining geometric boundary conditions, physical properties and mesh refinement.

6. The electromagnetic field analysis method for safe distance of transmission line inspection by unmanned aerial vehicle according to claim 5, characterized in that: The safe flight distance includes a safe flight altitude and a horizontal safe distance.

7. The electromagnetic field analysis method for safe distance of transmission line inspection by unmanned aerial vehicle according to claim 6, characterized in that: After calculating the minimum safe flight distance of the UAV in the inspection mission, the method also includes verifying the accuracy of the simulation results.

8. A transmission line UAV inspection safety distance electromagnetic field analysis system, characterized in that: include: Establishing a module for establishing an electromagnetic field model of a transmission line using Maxwell equations and expressing the electromagnetic field as a discretized finite element equation system; The solution module is used to approximate the node electric potential and magnetic vector potential through the energy functional of the electric field and magnetic field combined with the shape function to solve the electric field distribution and magnetic field intensity at the node; The calculation module is used to combine simulation calculations to simulate the equivalent radius and charge distribution characteristics of the transmission line conductor and calculate the minimum safe flight distance of the UAV in the inspection mission.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images