Diagnostic method and system for analyzing coordination among multiple physical fields in arc combustion process

Abstract

The invention relates to the technical field of electric arc finite element calculation, in particular to a diagnosis method and system for analyzing coordination among multiple physical fields in the electric arc combustion process, and the convergence of a finite element model under the condition of large-capacity breaking electric arc is improved by providing a more accurate convergence criterion; the finite element numerical calculation principle and the engineering practice are comprehensively considered, loopholes in traditional criteria are complemented, the criteria of four of temperature, pressure intensity, electric field intensity, magnetic field intensity and current density are introduced, coordination among multiple physical fields is comprehensively considered, and therefore the accuracy of a model result is improved; in addition, a reasonable field quantity distribution threshold value is determined according to actual engineering experience, actual engineering requirements are better met, and a large-capacity breaking circuit breaker is helped to be more accurately simulated.

Description

Technical Field

[0001] The present invention relates to the technical field of arc finite element calculation, and in particular to a diagnostic method and system for analyzing the coordination between multiple physical fields in an arc burning process. Background Art

[0002] In the power system, the circuit breaker is a key device used to cut off the current when the circuit is interrupted. When the circuit breaker breaks a large current, an arc is generated. The arc is a high-temperature plasma that has a great impact on power equipment and may cause damage to power equipment and instability in the power grid system. In order to gain a deeper understanding and optimize these processes, researchers generally use arc simulation technology to simulate the behavior of circuit breaker arc plasma. Through arc simulation, the formation, radiation and arc extinguishing processes of the arc can be simulated to help engineers design more efficient and safer circuit breakers. This simulation technology helps to improve the stability and reliability of the power system and reduce potential equipment damage.

[0003] Finite element arc simulation can help understand the behavior of arcs and optimize equipment design by numerically simulating the formation, radiation and dissipation of arcs. This simulation technology is based on the principles of finite element analysis and considers the thermodynamics, fluid dynamics and electromagnetic characteristics of arcs to predict the behavior of arcs under different conditions. Through finite element arc simulation, engineers can improve the design of switchgear equipment, improve equipment performance and system stability, and reduce potential failures and damage.

[0004] There are many existing finite element arc simulation platforms, all of which provide powerful functions and tools and are widely used by researchers. However, in the finite element calculation process, although the residuals are stably converged to a certain order of magnitude, it does not mean that the spatial distribution of the temperature field and the airflow field is reasonable. In the application scenario of arc plasma simulation of large-capacity interruption, the method of using only residuals to judge whether the results converge is flawed in traditional finite element software.

[0005] Therefore, in order to improve the reliability of convergence diagnosis in the arc plasma simulation process of large-capacity interruption, the present invention proposes a more stringent criterion, based on indicators such as grid size, thermodynamic parameter gradient, field intensity distribution, etc., to quantitatively analyze the coordination relationship between various physical fields and propose diagnostic indicators for reasonable distribution of various physical fields. Through this new diagnostic method, the convergence of simulation results can be diagnosed more accurately, and the overall accuracy of simulation can be improved. Summary of the invention

[0006] In view of the above problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the technical problem to be solved by the present invention is: the technical solution of the present invention focuses on how to more accurately judge whether the numerical solution tends to a stable analytical solution in the process of studying and predicting the behavior of the arc during large-capacity breaking through numerical simulation, and introduces a supplementary criterion for judging whether the solution of the arc simulation under large-capacity breaking conditions converges.

[0008] To solve the above technical problems, the present invention provides the following technical solutions, which are a diagnostic method for analyzing the coordination between multiple physical fields during arc burning, including: proposing convergence criteria to quantitatively analyze the coordination relationship between physical fields; determining diagnostic indicators for reasonable distribution of physical fields; and determining threshold settings for judging diagnostic indicators.

[0009] As a preferred solution of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process described in the present invention, the convergence criterion includes the convergence of finite element residuals, and the convergence behavior of the numerical solution is observed by gradually refining the grid, that is, increasing the number of units.

[0010] As a preferred solution of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process described in the present invention, the coordination relationship between the physical fields is quantitatively analyzed by calculating and realizing quantitative analysis by considering the influence of important indicators.

[0011] As a preferred scheme of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process described in the present invention, wherein: the diagnostic index is determined empirically based on key physical quantities as the judgment criteria, and if the judgment index satisfies greater than or equal to four key physical quantities, the result is considered to converge.

[0012] As a preferred solution of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process described in the present invention, the threshold setting includes an upper limit and a lower limit of the value obtained based on experience to ensure that a reasonable result is obtained in the time step.

[0013] As a preferred solution of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process described in the present invention, the important indicators include grid size, thermodynamic parameter gradient and rationality of field intensity distribution.

[0014] As a preferred solution of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process described in the present invention, the key physical quantities include temperature, pressure, electric field strength, magnetic field strength and current density.

[0015] Another object of the present invention is to provide a diagnostic system for analyzing the coordination between multiple physical fields during arc burning to enhance the effectiveness of arc simulation technology in practical applications. The system aims to ensure accurate prediction of arc plasma behavior by quantifying the relationship between various physical fields, thereby optimizing the design and performance evaluation of SF6 circuit breakers. By real-time monitoring and analysis of key thermodynamic and electromagnetic parameters, the system can help engineers identify potential problems in advance during the equipment design stage, improve the safety and reliability of power equipment, and ensure the stable operation of the power grid.

[0016] In order to solve the above technical problems, the present invention provides the following technical solutions: a diagnostic system for analyzing the coordination between multiple physical fields during arc burning, comprising: a criterion analysis module, a distribution diagnosis module and a threshold setting module;

[0017] The criterion analysis module proposes convergence criteria and quantitatively analyzes the coordination relationship between physical fields;

[0018] The distribution diagnosis module determines the diagnostic index of the reasonable distribution of the physical field;

[0019] The threshold setting module determines the threshold setting of the diagnostic indicator.

[0020] A computer device includes a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process as described above are implemented.

[0021] 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 diagnostic method for analyzing the coordination between multiple physical fields in an arc burning process as described above are implemented.

[0022] Beneficial effects of the present invention: Improve the convergence of the model: This method establishes a more accurate criterion that enables the finite element model to converge in the case of large-capacity arc breaking according to the principles of the finite element numerical calculation method and comprehensive consideration of engineering practice, which fills the loopholes of the traditional finite element convergence criterion in this case and enhances convergence. Comprehensive consideration of the coordination between multiple physical fields in arc simulation: This method introduces a criterion of selecting four out of five: temperature, pressure, electric field strength, magnetic field strength, and current density, considering a more comprehensive physical field and improving the accuracy of the model results. Better meet actual engineering needs: This method derives a reasonable threshold for field quantity distribution from actual engineering experience, which can help to more accurately simulate large-capacity circuit breakers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0024] Figure 1 A flow chart of a diagnostic method for analyzing the coordination between multiple physical fields during arc burning provided by one embodiment of the present invention.

[0025] Figure 2 A grid distribution diagram of a diagnostic method for analyzing the coordination between multiple physical fields during arc burning provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0027] Example 1, reference Figure 1 , is an embodiment of the present invention, which provides a diagnostic method for analyzing the coordination between multiple physical fields during arc burning, including:

[0028] This embodiment proposes a unique finite element arc simulation convergence criterion, which takes into account the rationality of the grid size, the gradient of thermodynamic parameters, and the distribution of electromagnetic field strength, quantitatively analyzes the coordination relationship between various physical fields, proposes diagnostic indicators for the reasonable distribution of various physical fields, and adds them to the finite element calculation;

[0029] Quantitative analysis of the coordination relationship between various physical fields, including grid size, thermodynamic gradient parameters, and field intensity distribution;

[0030] Among them, the grid size is a very important indicator in finite element electromagnetic simulation. Different grid sizes can affect the convergence of the results. Generally speaking, the smaller the grid size, the closer the simulation results are to the real physical phenomenon, but at the same time the calculation cost will increase. Using a smaller grid size will speed up the convergence of the results, that is, the simulation results will approach the stable value faster. However, too small a grid size may also lead to numerical instability or calculation errors. The initial grid size is set to 0.5mm*0.01mm. If the convergence criterion is still not met by reducing the time step or increasing the number of iterations, the grid can be encrypted by 10% to ensure the criterion is met.

[0031] Furthermore, in finite element simulation, the thermodynamic gradient parameters have an important influence on the convergence of the results. Thermodynamic parameter gradient refers to the degree of change of physical parameters (including temperature, pressure, etc.) appearing at different locations in the simulation area; these parameters affect the stability and accuracy of the simulation results, especially in the case of large-capacity arc breaking simulation involving physical processes such as heat conduction. It is necessary to consider whether the gradient distribution of temperature and pressure is reasonable, that is, whether the temperature and pressure gradients conform to the thermodynamic distribution, and the relevant parameters must be extracted in real time during the calculation process and saved in the database.

[0032] Furthermore, field intensity distribution refers to the distribution of electric field, magnetic field or other types of fields in the simulation area. In finite element simulation, field intensity distribution has an important influence on the convergence of the results, especially in simulations involving electromagnetic fields, thermal fields and other fields. Arc simulation is a system that couples multiple physical fields. It is necessary to consider whether the electric field intensity, magnetic field density and current density have a reasonable distribution. Only when the field intensity distribution is reasonable can the calculation result be converged.

[0033] Specifically, arc plasma simulation is a computational method that simulates the arc discharge process in electrical equipment. It studies and predicts the behavior of the arc through numerical simulation. The arc is a high-temperature, high-energy plasma system that usually occurs during faults or switching operations in electrical equipment, which may cause equipment damage and accidents.

[0034] Example 2, reference Figure 1-Figure 2 , is an embodiment of the present invention, which provides a diagnostic method for analyzing the coordination between multiple physical fields during arc burning, including:

[0035] This embodiment considers the physical field in the arc simulation in detail, and selects five physical quantities, namely temperature, pressure, electric field strength, magnetic field strength, and current density, as the evaluation criteria; through experience, it is established that the result can be considered convergent only if the number of judgment indicators is greater than or equal to 4.

[0036] Taking a simple grid distribution as an example, we explore what kind of convergence criteria should be set for temperature, pressure, electric field intensity, magnetic field intensity, and current density to further enhance the convergence and stability of the model results. Figure 2 As shown;

[0037] Among them, convergence refers to the convergence of finite element residuals. In finite element analysis, the convergence behavior of the numerical solution is observed by gradually refining the mesh (increasing the number of elements); the residual is the difference between the numerical solution and the analytical solution. The concept of residual convergence refers to the process in which the numerical solution gradually approaches the analytical solution as the mesh is refined;

[0038] Furthermore, for the central grid a, find all the grids that share the same edges or points with it and record them as b1~b n , for b1~b n , and then find all the grids that share the same edges or points with it, denoted as c1~c i , and get Figure 2 The graphics shown;

[0039] Then a method is proposed to test whether the distribution of various field quantities is reasonable:

[0040]

[0041] Among them, Z a represents the field value of grid a, Represents grid b1~b n The average value of all field quantities, Represents the grid c1~c i The average value of all field quantities, i represents the total number of grids of type C around the selected grid (i.e. Figure 2 The total number of pink grids in the middle), n represents the total number of grids of type B around the selected grid (i.e. Figure 2 The total number of yellow grids in the middle);

[0042] Furthermore, the field quantity Z in this method is the solution result data that needs to be paid attention to. When considering the convergence results of the following field quantities, the field quantity Z represents temperature, pressure, electric field intensity, magnetic field intensity, and current density.

[0043] Example 3, reference Figure 1-Figure 2 , which is an embodiment of the present invention, provides a diagnostic method for analyzing the coordination between multiple physical fields during arc burning, comprising:

[0044] Based on experience, this embodiment determines that the upper limit of the judgment index is 1.2 and the lower limit is 0.8. Such numerical settings can ensure that reasonable results can be obtained at each time step;

[0045] In the first step, the sum of the average values ​​of the innermost grid and the outermost grid is compared with twice the average value of the middle grid, and the ratio is set in the range of 0.8 to 1.2 as the convergence criterion;

[0046] The second step is to solve the values ​​of the five criteria of pressure, temperature, electric field strength, magnetic field strength, and current density, and determine whether four or more of the physical quantities meet the criteria;

[0047] In the third step, if the criterion is met, the converged result is output; if the criterion is not met, the time step is reduced or the iteration step is increased; if the criterion is still not met, the grid density is increased by 10% and the above judgment is performed again, and the process is repeated until the criterion is met.

[0048] Furthermore, for the finite element method, the quality of the mesh is crucial to the accuracy and convergence of the simulation results. By comparing the average values ​​of the innermost, outermost and middle layers of the mesh, the mesh resolution and sampling density in different areas can be evaluated to ensure that the physical phenomena in different areas are properly captured.

[0049] Furthermore, the ratio range is set to 0.8–1.2 to consider the stability of the results. If the ratio deviates from this range, it may indicate that there are large differences in the results between different grid layers, and further adjustments to the model or grid settings are needed to obtain more reliable results.

[0050] The above is a schematic scheme of a diagnostic method for analyzing the coordination between multiple physical fields during arc burning in this embodiment. It should be noted that the technical scheme of the system of the diagnostic method for analyzing the coordination between multiple physical fields during arc burning is the same as the technical scheme of the diagnostic method for analyzing the coordination between multiple physical fields during arc burning described above. For details not described in detail in the technical scheme of the diagnostic system for analyzing the coordination between multiple physical fields during arc burning in this embodiment, please refer to the description of the technical scheme of the above method.

[0051] Embodiment 4 is an embodiment of the present invention, which provides a diagnostic system for analyzing the coordination between multiple physical fields in an arc burning process, including: a criterion analysis module, a distribution diagnosis module and a threshold setting module;

[0052] The criterion analysis module proposes convergence criteria and quantitatively analyzes the coordination relationship between physical fields;

[0053] The distribution diagnosis module determines the diagnostic index of the reasonable distribution of the physical field;

[0054] The threshold setting module determines the threshold setting of the diagnostic indicator.

[0055] This embodiment also provides a computing device, which is suitable for analyzing the diagnostic method of the coordination between multiple physical fields in the arc burning process, including:

[0056] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process as proposed in the above embodiment.

[0057] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the diagnostic method for analyzing the coordination between multiple physical fields in the arc burning process proposed in the above embodiment is implemented.

[0058] The storage medium proposed in this embodiment and the diagnostic method for analyzing the coordination between multiple physical fields during arc burning proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0059] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0060] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0061] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0062] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A diagnostic method for analyzing the coordination between multiple physical fields during arc burning, characterized by: include: Propose convergence criteria and quantitatively analyze the coordination relationship between physical fields; Determine diagnostic indicators for reasonable distribution of physical fields; Threshold setting for judging diagnostic indicators.

2. The diagnostic method for analyzing the coordination between multiple physical fields during arc burning according to claim 1, characterized in that: The convergence criterion includes the convergence of the finite element residual, and the convergence behavior of the numerical solution is observed by gradually refining the grid, that is, increasing the number of elements.

3. The diagnostic method for analyzing the coordination between multiple physical fields during arc burning according to claim 2, characterized in that: The coordination relationship between the physical fields is quantitatively analyzed by taking into account the influence of important indicators and performing calculations to achieve quantitative analysis.

4. The diagnostic method for analyzing the coordination between multiple physical fields during arc burning according to claim 3, characterized in that: The diagnostic index is determined empirically based on key physical quantities as a judging criterion, and if the judging index satisfies or is greater than or equal to four key physical quantities, the result is considered to be converged.

5. The diagnostic method for analyzing the coordination between multiple physical fields during arc burning according to claim 4, characterized in that: The threshold setting includes an upper limit and a lower limit of a value derived from experience to ensure that a reasonable result is obtained for the time step.

6. The diagnostic method for analyzing the coordination between multiple physical fields during arc burning according to claim 5, characterized in that: The important indicators include grid size, thermodynamic parameter gradient and rationality of field intensity distribution.

7. The diagnostic method for analyzing the coordination between multiple physical fields during arc burning according to claim 6, characterized in that: The key physical quantities include temperature, pressure, electric field strength, magnetic field strength and current density.

8. A diagnostic system for analyzing the coordination between multiple physical fields in an arc burning process according to any one of claims 1 to 7, characterized in that: include: Criteria analysis module, distribution diagnosis module and threshold setting module; The criterion analysis module proposes convergence criteria and quantitatively analyzes the coordination relationship between physical fields; The distribution diagnosis module determines the diagnostic index of the reasonable distribution of the physical field; The threshold setting module determines the threshold setting of the diagnostic indicator.

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 diagnostic method for analyzing the coordination between multiple physical fields in an arc burning process 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 diagnostic method for analyzing the coordination between multiple physical fields in an arc burning process according to any one of claims 1 to 7 are implemented.

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