Efficient modeling method for boosting effect of arc fault of transformer and related device

Abstract

The invention discloses an efficient modeling method and a related device for a boosting effect of an arc fault of a transformer, and belongs to the field of electromagnetic element transformers, and the method comprises the steps: constructing a coupling control equation set in the fault process of the transformer; obtaining transformer arc fault release energy, and determining a gas density condition and a gas speed condition in combination with an Euler grid gas injection model and a material state equation; the method comprises the following steps: determining a physical quantity and a basic dimension of a transformer arc fault, constructing a dimension matrix according to the physical quantity and the basic dimension, calculating to obtain a similarity index, and determining an arc fault related scaling coefficient according to the similarity index and a preset transformer oil tank scale; a transformer arc fault boost effect model is constructed through the above contents, and a pressure distribution result of the transformer arc fault boost effect is obtained through analysis of the transformer arc fault boost effect model. The problem of low production efficiency caused by too long calculation time during arc fault simulation in the prior art can be solved.

Description

Technical Field

[0001] The present invention belongs to the field of electromagnetic component transformers, and in particular relates to an efficient modeling method for boosting effect of transformer arc faults and a related device. Background Art

[0002] As the core equipment in the power system, the operating safety and stability of the power transformer directly affect the efficient operation and reliability of the entire power grid. However, arc faults caused by internal faults often cause deformation and rupture of the transformer box, and even cause serious accidents such as explosions or fires. These faults may not only cause local power outages and bring inconvenience to power supply, but also pose a serious threat to the safety of life and property in some cases. Therefore, in-depth research on transformer arc faults has important theoretical significance and practical application value for improving the operation and maintenance level of power equipment, ensuring the safe and stable operation of the power grid, and ensuring economic and social security.

[0003] At present, the real-size simulation test of arc discharge inside the transformer tank faces significant difficulties. The existing research method is to use software for numerical simulation. When the transformer tank capacity is huge, the modeling process is time-consuming and inefficient. In addition, the high-frequency impact process generated by the arc fault requires the use of very fine unit sizes in the simulation process, which increases the calculation complexity and accuracy requirements. Therefore, combined with the strong uncertainty of the arc fault, it is difficult for traditional simulation methods to accurately reproduce the actual fault phenomenon. Summary of the invention

[0004] The object of the present invention is to provide an efficient modeling method for the boost effect of transformer arc fault, so as to solve the problem of low production efficiency caused by long calculation time when simulating arc fault in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, an efficient modeling method for the voltage-boosting effect of an arc fault in a transformer comprises the following steps: Based on the conservation equations and material state equations of the transformer arc fault process, the coupled control equations of the transformer fault process are constructed; Obtaining the energy released by the transformer arc fault, and determining the gas density condition and the gas velocity condition of each time step of the arc fault by combining the Euler grid gas injection model and the material state equation; Determine the physical quantity and basic dimension of the transformer arc fault, construct a dimensional matrix according to the physical quantity and basic dimension, calculate a similarity index based on the dimensional matrix, and determine the arc fault related scaling factor according to the similarity index and a preset transformer tank scale; Based on the coupled control equations, gas density conditions, gas velocity conditions and arc fault related scaling coefficients, a transformer arc fault boosting effect model is constructed, and the pressure distribution result of the transformer arc fault boosting effect is obtained by analyzing the transformer arc fault boosting effect model.

[0006] In some embodiments, the conservation equations of the transformer arc fault process include: mass conservation equation, momentum conservation equation and energy conservation equation, and the material state equation includes: ideal gas state equation, liquid state equation and Johnson-Cook model.

[0007] In some embodiments, the gas density condition is based on the ideal gas state equation and is calculated by the unit pressure of the released gas in each time step of the arc fault; The constant gas mass inflow rate is obtained, and the gas velocity condition is calculated by combining the gas density condition and the total area of ​​the injected gas grid in the Euler grid gas injection model.

[0008] In some embodiments, the physical quantity includes: gas density , Arc fault energy , Gas Quality , Transformer oil tank pressure , gas pressure , gas velocity , Transformer oil tank length , Transformer oil tank width , Transformer oil tank height , Transformer oil tank thickness , Transformer oil tank density , Transformer tank stress , Transformer oil tank strain , elastic modulus and frequency ; The basic dimensions include: quality M ,length L and time T .

[0009] In some embodiments, the step of calculating the similarity index based on the dimensional matrix and determining the arc fault related scaling factor according to the similarity index and a preset transformer tank scale specifically includes: Through the dimensional matrix and the harmony principle, a similarity index is calculated after constructing a similarity standard, and all similarity constants of the transformer arc fault are obtained according to the similarity index and a preset transformer tank scale; When the gas density remains constant, a volume scaling factor and a mass scaling factor of the transformer arc fault are obtained according to the similarity constant; The similarity constants include an arc fault energy similarity constant, a gas velocity similarity constant and a gas density similarity constant, wherein the gas velocity similarity constant and the gas density similarity constant are 1; According to the arc fault energy similarity constant, the gas velocity similarity constant and the gas density similarity constant, in combination with the gas velocity condition, a scaling factor of the arc fault duration is obtained.

[0010] In some embodiments, the step of constructing a transformer arc fault boost effect model based on the coupled control equations, gas density conditions, gas velocity conditions and arc fault related scaling coefficients specifically includes: Constructing a mathematical model describing the physical process of transformer arc fault based on the coupled control equations; Based on the mathematical model, the gas generation and propagation process in the transformer tank is simulated by gas density conditions and gas velocity conditions, and the mathematical model is scaled by the arc fault related scaling factor to finally obtain the transformer arc fault boosting effect model.

[0011] In a second aspect, an efficient modeling system for transformer arc fault boosting effect includes: Arc fault physical process building module, which is used to build the coupled control equations of the transformer fault process based on the conservation equations and material state equations of the transformer arc fault process; A gas propagation condition determination module is used to obtain the energy released by the transformer arc fault, and determine the gas density condition and gas velocity condition of each time step of the arc fault in combination with the Euler grid gas injection model and the material state equation; A transformer scaling factor calculation module, used to determine the physical quantity and basic dimension of the transformer arc fault, construct a dimensional matrix according to the physical quantity and basic dimension, calculate a similarity index based on the dimensional matrix, and determine the arc fault related scaling factor according to the similarity index and a preset transformer tank scale; The arc fault boost effect model construction module is used to construct a transformer arc fault boost effect model based on the coupled control equation group, gas density conditions, gas velocity conditions and arc fault related scaling coefficients, and obtain the pressure distribution result of the transformer arc fault boost effect through the transformer arc fault boost effect model analysis.

[0012] In a third aspect, an electronic device comprises a memory, a processor and a computer program stored in the memory and executable in the processor, wherein when the processor executes the computer program, the steps of the method for efficiently modeling the voltage-boosting effect of an arc fault in a transformer are implemented.

[0013] In a fourth aspect, a computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for efficiently modeling the voltage-boosting effect of an arc fault in a transformer.

[0014] In a fifth aspect, a computer program product is provided, the computer program product comprising a computer program, wherein when the computer program is executed by a processor, the steps of the method for efficiently modeling the voltage-boosting effect of an arc fault in a transformer are implemented.

[0015] Compared with the prior art, the present invention has the following beneficial effects: Based on the similarity theory, the present invention determines the physical quantity and basic dimensions, constructs the dimensional matrix and calculates the similarity index, and then determines the arc fault related scaling coefficient according to the preset transformer tank scale. This process ensures that the model can maintain high accuracy in the simulation of the boost effect of the transformer arc fault under different sizes and different working conditions, which greatly enhances the applicability and versatility of the model. The present invention quickly calculates the boost effect through the dimensional analysis method, and the calculation time is greatly shortened by 97.0% compared with the traditional method. This high efficiency is not only reflected in the construction of a single model, but also in the ability to quickly respond to the pressure response research needs under various working conditions, providing a fast feedback mechanism for the design and optimization of transformers. By constructing an accurate transformer arc fault boost effect model, the present invention can replace these high-risk and high-cost test methods, reduce the risks and costs in the research process, and by accurately simulating the boost effect during the arc fault process, it can timely discover potential safety hazards, provide a scientific basis for preventive maintenance and troubleshooting of equipment, and thus ensure the stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a specific flow chart of an efficient modeling method for the voltage-boosting effect of an arc fault in a transformer provided in this embodiment; Figure 2 A schematic diagram of the gas transfer process caused by an arc fault provided in this embodiment; Figure 3 A model diagram of a transformer arc fault provided in this embodiment, wherein (a) is a three-dimensional geometric model of a transformer oil tank, and (b) is a fluid domain model; Figure 4Comparison diagram of the spatial distribution of the internal pressure of the model under different arc fault durations provided in this embodiment, wherein (a), (c), and (e) are the spatial distribution diagrams of the internal pressure of the scaled model under different arc fault durations, and (b), (d), and (f) are the spatial distribution diagrams of the internal pressure of the prototype model under different arc fault durations; Figure 5 A time course diagram of measurement points on the scaled model provided in this embodiment; Figure 6 A time course diagram of measurement points on the prototype model provided in this embodiment; Figure 7 A pressure time history comparison diagram of the measuring points on the model after filtering processing provided in this embodiment, wherein (a) is a pressure time history diagram of the measuring points of the scaled model after filtering processing, and (b) is a pressure time history diagram of the measuring points of the prototype model after filtering processing; Figure 8 A pressure time history diagram of a measuring point on the model after similarity transformation provided in this embodiment; Fig. 9 A flow chart of an efficient modeling method for the voltage-boosting effect of an arc fault in a transformer is provided for the present invention; Fig.10 A structural diagram of an efficient modeling system for the boosting effect of transformer arc faults provided by the present invention. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings, and the described content is intended to explain the present invention rather than to limit it.

[0018] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or are inherent to these processes, methods, systems, products or apparatus.

[0019] like Figure 1 and Fig. 9 As shown, this embodiment provides an efficient modeling method for the voltage boost effect of a transformer arc fault, comprising the following steps: S1, analyzing the control equations and material state equations in the transformer arc fault process, and constructing the coupled control equations of the transformer fault process based on the conservation equations and material state equations in the transformer arc fault process; During the transformer arc fault process, high-frequency fluctuations caused by the arc impact propagate in the insulating oil. Therefore, the mass conservation equation, momentum conservation equation, and energy conservation equation must be systematically solved to accurately describe the physical process caused by the arc fault: (1) (2) (3) In the formula, is the density, For speed, is the Hamiltonian equation, For time, is the spatial distribution density, For pressure, is the shear stress, For energy, is the thermal conductivity, is the temperature, Represents the radiation term.

[0020] The state equations involved in the transformer arc fault process mainly include the ideal gas state equation, the liquid state equation and the Johnson-Cook model.

[0021] (4) (5) (6) In the formula, is the adiabatic index, is the bulk modulus of the material, is the reference density, is the effective plastic strain, is the normalized effective plastic strain rate, A, B, C, n and m are five material constants, is the homologous temperature.

[0022] S2, studying the basic principles of arc fault simulation, first obtaining the energy released by the transformer arc fault, and combining the Euler grid gas injection model and the material state equation to determine the gas density condition and gas velocity condition for each time step of the arc fault; During the internal fault of the transformer, the kinetic energy of the pressure source mainly comes from the energy generated by the arc. The huge energy released by the arc fault causes the insulating oil in the tank to evaporate rapidly, thereby generating a significant pressure difference. The change in the pressure difference will trigger the propagation of the pressure wave, which will have an important impact on the structure and safety of the transformer. The energy released by the arc fault is: (7) In the formula, is the arc fault energy, is the arc duration, is the voltage on the arc, is the arc current.

[0023] During an arc fault, the generated gas will be generated in the Euler grid and will transfer fixed internal energy, variable density and velocity through the cell boundary where the arc fault occurs. The transfer form is as follows: Figure 2 According to the ideal gas state equation, the density of the gas can be calculated by the unit pressure of the released gas in each time step: (8) By using a constant gas mass inflow rate, the gas velocity can be calculated, thereby effectively simulating the arc behavior of a constant power during an arc fault, determining the gas density condition and the gas velocity condition, is the total area of ​​the Euler grid into which the gas is injected: (9) (10) S3, applying the dimensional analysis method based on similarity theory to the study of response similarity caused by transformer arc fault, determining the physical quantity and basic dimension of the transformer arc fault, constructing a dimensional matrix according to the physical quantity and basic dimension, calculating a similarity index based on the dimensional matrix, and determining an arc fault related scaling factor according to the similarity index and a preset transformer tank scale; When an arc fault occurs in the transformer tank, an extremely complex pressure rise phenomenon will occur inside. In the early stage of the arc fault, the insulating oil is rapidly evaporated by the huge energy released by the arc, causing the pressure in the tank to rise sharply. The pressure shock wave propagates and reflects inside the tank, accompanied by attenuation. As the arc fault continues, the volume of gas generated dominates the pressure change. In order to solve the problem of the influence of gas volume and impact on the pressure change inside the tank, this embodiment is based on similarity theory and combined with dimensional analysis method to systematically study the similarity relationship between various physical quantities during the arc fault process.

[0024] According to the above formula, a total of 15 physical quantities (n) are listed, among which mass M ,length L and time T It constitutes the three basic dimensions (k) of the quality system. Therefore, 12 (nk) similarity criteria can be defined to describe the similarity relationship of the system. Gas density, Arc fault energy and Gas mass is used as the basic physical quantity, while the remaining physical quantities Transformer tank pressure, Gas pressure, Gas velocity, Transformer tank length, Transformer tank width, Transformer oil tank height, Transformer tank thickness, Transformer tank density, Transformer tank stress, Transformer tank strain, Elastic modulus and Frequency is a physical quantity as a function.

[0025] (11) The similarity number of the system is obtained by using the dimensional analysis method, and the dimensional matrix is ​​shown in Table 1 below: Table 1 Dimensional matrix

[0026] According to the dimensional matrix and the harmony principle, 11 similarity criteria are obtained, and the π matrix is ​​as follows: (12) The similarity index can be obtained as follows: (13) Assume that the transformer tank size ratio is , which can be defined as At the same time, assuming that the scale model and the prototype model use the same material, we have , using formula (13) and the determined related parameters, we can further obtain all similarity constants: (14) Since the scale of the model is , the volume scaling factor is also , assuming that the density of the gas remains constant, the mass scaling factor of the gas can be obtained as , which can meet this condition. According to the above formula, we can get for ,at the same time and The values ​​of are all 1. Substituting these two conditions into the velocity formula (10), when the mesh size of the model is consistent and the area of ​​the explosion source remains unchanged, the scaling factor of the arc fault duration will be .

[0027] S4, constructing a mathematical model describing the physical process of transformer arc fault based on the coupled control equations; simulating the generation and propagation process of gas in the transformer tank through gas density conditions and gas velocity conditions based on the mathematical model, and scaling the mathematical model through arc fault related scaling coefficients to finally obtain a transformer arc fault boosting effect model.

[0028] Then, the feasibility of this method in the arc fault problem of transformer oil tank was verified by simulation software. To verify the effectiveness of the proposed method, a simple cube model was used to simulate the arc fault of the transformer oil tank, and the multi-material fluid-solid coupling CEL algorithm was implemented using the finite element analysis software Ansys / Autodyn. By comparing with the test results in existing studies, the reliability and accuracy of the simulation method were verified. Subsequently, the pressure rise effect caused by the arc fault in the transformer oil tank was further studied, and the pressure change law was analyzed, as follows: 1. Construction of transformer oil tank arc fault model The arc fault process is simulated by constructing a three-dimensional geometric model of the transformer tank. The geometric structure of the model is as follows: Figure 3 (a), where the measurement location is indicated by the number in the figure, and the location where the fault arc occurs is marked with a gray box. The model of the fluid domain is shown in Figure 3 (b) is mainly used to describe the fluid behavior in the oil tank. Considering the significant influence of the grid size on the simulation accuracy, this embodiment refines the grid as much as possible while ensuring a reasonable calculation time to improve the accuracy of the simulation results. The multi-material fluid-solid coupling CEL algorithm is used for modeling and analysis. Specifically, the Lagrangian grid is used to represent the structural part, and the grid size is set to 0.05m; while the fluid part (including insulating oil, gas, and air around the transformer) is modeled by the Euler grid, and the size of the Euler grid is 0.025m. The bottom of the entire model is set to a fixed boundary condition.

[0029] In order to conduct numerical analysis of transformer tank arc fault, two simplified tank comparison models are selected. Considering the time limit and computing resource constraints, the side lengths of the two three-dimensional models are 0.25 m and 0.50 m respectively. In order to ensure the comparability and accuracy of the results and strictly control the variables, the simulation conditions of the two models are consistent except for the required similarity transformation parameters. The specific parameter settings are shown in Table 2. In the selection of model materials, the transformer tank is made of Q235 steel with the following physical properties: elastic modulus of 201 GPa, Poisson's ratio of 0.3, and density of 7850 kg / m³. In order to accurately simulate the dynamic response of the transformer tank, the Johnson-Cook dynamic model is used to describe the constitutive relationship of steel. For gas and air, it is assumed to be an ideal gas, while the insulating oil is modeled using a linear state equation. The relevant physical parameters are listed in Table 3.

[0030] Table 2 Parameters of scaled model and prototype model

[0031] Table 3 Material performance parameters

[0032] 2. Model calculation time In order to compare the computational performance of the scaled model and the prototype model, simulation calculations were performed on the same equipment, and the specific operating parameters are shown in Table 4. The table lists in detail the number of elements, number of nodes, natural frequency, and calculation time required for the two models. The results show that the average calculation time of the scaled model is 4 minutes, while the calculation time of the prototype model is 135 minutes. By reducing the model scale, the calculation time is reduced by about 97.0%, which significantly improves the calculation efficiency.

[0033] Table 4 Model calculation results

[0034] 3. Boost effect simulation results The pressure distribution cloud diagram of the scale model and prototype model of the transformer oil tank is shown in the figure Figure 4 As shown in the figure, an arc fault occurs at 0.1 ms, at which time the pressure inside the oil tank is low. As the fault arc continues to work, the pressure begins to rise sharply at the fault location. When the arc duration reaches 1 ms (corresponding to the arc duration of the prototype model of 8 ms), the maximum pressure exceeds 77 MPa; and when the arc duration is 2 ms (corresponding to the arc duration of the prototype model of 16 ms), the maximum pressure further increases to about 83 MPa. The internal pressure distribution of the two models shows similar spatial distribution characteristics, and the maximum pressure values ​​are basically the same.

[0035] The pressure change process inside the fuel tank can be divided into three obvious stages: initial pressure fluctuation stage, transient pressure wave stage and steady-state pressure fluctuation oscillation stage. The relevant pressure change trends are as follows: Figure 5 and Figure 6 As shown in the figure, it is consistent with the existing research results of transformer oil tank arc explosion. In order to further explore the frequency components of the pressure waveform at the model measurement point, the fast Fourier transform technology is used to perform frequency domain analysis on the pressure waveform. Through the inverse Fourier transform, the processed pressure waveform is obtained, as shown in Figure 7 The analysis results show that since the natural frequencies of the two models are much lower than the impact frequency on the high-frequency side, the tank is more sensitive to low-frequency vibration. Therefore, we further focus on the waveform on the low-frequency side for detailed analysis.

[0036] According to the above similarity formula, the numerical results obtained from the scaled model are processed and compared with the numerical results of the prototype model. Figure 8 The comparison of the pressure change process at the measuring point of the scaled model and the prototype model is shown. The results show that as the arc fault duration increases, the pressure at the measuring point on both the prototype model and the scaled model shows an upward trend. For the measuring points at the same position, the overall change trend of the pressure curve is highly consistent, and the maximum pressure value is similar. This shows that the method proposed based on similarity theory can effectively simulate the boost effect generated by the transformer tank during the arc fault process.

[0037] like Fig.10 As shown, the present invention also provides an efficient modeling system for the voltage-boosting effect of transformer arc fault, comprising: Arc fault physical process building module, which is used to build the coupled control equations of the transformer fault process based on the conservation equations and material state equations of the transformer arc fault process; A gas propagation condition determination module is used to obtain the energy released by the transformer arc fault, and determine the gas density condition and gas velocity condition of each time step of the arc fault in combination with the Euler grid gas injection model and the material state equation; A transformer scaling factor calculation module, used to determine the physical quantity and basic dimension of the transformer arc fault, construct a dimensional matrix according to the physical quantity and basic dimension, calculate a similarity index based on the dimensional matrix, and determine the arc fault related scaling factor according to the similarity index and a preset transformer tank scale; The arc fault boost effect model construction module is used to construct a transformer arc fault boost effect model based on the coupled control equation group, gas density conditions, gas velocity conditions and arc fault related scaling coefficients, and obtain the pressure distribution result of the transformer arc fault boost effect through the transformer arc fault boost effect model analysis.

[0038] The division of modules in the embodiments of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present invention may be integrated into one processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0039] In this embodiment, a computer device is also provided, which includes a processor and a memory, the memory is used to store a computer program (in this embodiment, the computer program includes a computing component and an iterative component, which can perform model calculation and model update), the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of an efficient modeling method for the boosting effect of a transformer arc fault.

[0040] This embodiment also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of an efficient modeling method for the boost effect of a transformer arc fault in the above embodiment.

[0041] This embodiment further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the corresponding steps of the efficient modeling method for the boosting effect of an arc fault on a transformer in the above embodiment are implemented.

[0042] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0043] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0044] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0045] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0046] Finally, 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 above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An efficient modeling method for the voltage-boosting effect of transformer arc faults, characterized in that: The following steps are involved: Based on the conservation equations and material state equations of the transformer arc fault process, the coupled control equations of the transformer fault process are constructed; Obtaining the energy released by the transformer arc fault, and determining the gas density condition and the gas velocity condition of each time step of the arc fault by combining the Euler grid gas injection model and the material state equation; Determine the physical quantity and basic dimension of the transformer arc fault, construct a dimensional matrix according to the physical quantity and basic dimension, calculate a similarity index based on the dimensional matrix, and determine the arc fault related scaling factor according to the similarity index and a preset transformer tank scale; Based on the coupled control equations, gas density conditions, gas velocity conditions and arc fault related scaling coefficients, a transformer arc fault boosting effect model is constructed, and the pressure distribution result of the transformer arc fault boosting effect is obtained by analyzing the transformer arc fault boosting effect model.

2. The efficient modeling method for the voltage-boosting effect of transformer arc fault according to claim 1, characterized in that: The conservation equations of the transformer arc fault process include: mass conservation equation, momentum conservation equation and energy conservation equation, and the material state equation includes: ideal gas state equation, liquid state equation and Johnson-Cook model.

3. The efficient modeling method for the voltage-boosting effect of transformer arc fault according to claim 2, characterized in that: The gas density condition is based on the ideal gas state equation and is calculated by the unit pressure of the released gas in each time step of the arc fault; The constant gas mass inflow rate is obtained, and the gas velocity condition is calculated by combining the gas density condition and the total area of ​​the injected gas grid in the Euler grid gas injection model.

4. The efficient modeling method for the voltage-boosting effect of an arc fault in a transformer according to claim 1, characterized in that: The physical quantities include: gas density , Arc fault energy , Gas Quality , Transformer oil tank pressure , gas pressure , gas velocity , Transformer oil tank length , Transformer oil tank width , Transformer oil tank height , Transformer oil tank thickness , Transformer oil tank density , Transformer oil tank stress , Transformer oil tank strain , elastic modulus and frequency ; The basic dimensions include: quality M ,length L and time T .

5. The efficient modeling method for the voltage-boosting effect of transformer arc fault according to claim 1, characterized in that: The step of calculating a similarity index based on the dimensional matrix and determining an arc fault related scaling factor according to the similarity index and a preset transformer tank scale specifically includes: Through the dimensional matrix and the harmony principle, a similarity index is calculated after constructing a similarity standard, and all similarity constants of the transformer arc fault are obtained according to the similarity index and a preset transformer tank scale; When the gas density remains constant, a volume scaling factor and a mass scaling factor of the transformer arc fault are obtained according to the similarity constant; The similarity constants include an arc fault energy similarity constant, a gas velocity similarity constant and a gas density similarity constant, wherein the gas velocity similarity constant and the gas density similarity constant are 1; According to the arc fault energy similarity constant, the gas velocity similarity constant and the gas density similarity constant, in combination with the gas velocity condition, a scaling factor of the arc fault duration is obtained.

6. The efficient modeling method for the voltage-boosting effect of transformer arc fault according to claim 1, characterized in that: The step of constructing a transformer arc fault boost effect model based on the coupled control equations, gas density conditions, gas velocity conditions and arc fault related scaling coefficients specifically includes: Constructing a mathematical model describing the physical process of transformer arc fault based on the coupled control equations; Based on the mathematical model, the gas generation and propagation process in the transformer tank is simulated by gas density conditions and gas velocity conditions, and the mathematical model is scaled by the arc fault related scaling factor to finally obtain the transformer arc fault boosting effect model.

7. An efficient modeling system for the voltage-boosting effect of transformer arc faults, characterized in that: include: Arc fault physical process building module, which is used to build the coupled control equations of the transformer fault process based on the conservation equations and material state equations of the transformer arc fault process; A gas propagation condition determination module is used to obtain the energy released by the transformer arc fault, and determine the gas density condition and gas velocity condition of each time step of the arc fault in combination with the Euler grid gas injection model and the material state equation; A transformer scaling factor calculation module, used to determine the physical quantity and basic dimension of the transformer arc fault, construct a dimensional matrix according to the physical quantity and basic dimension, calculate a similarity index based on the dimensional matrix, and determine the arc fault related scaling factor according to the similarity index and a preset transformer tank scale; The arc fault boost effect model construction module is used to construct a transformer arc fault boost effect model based on the coupled control equation group, gas density conditions, gas velocity conditions and arc fault related scaling coefficients, and obtain the pressure distribution result of the transformer arc fault boost effect through the transformer arc fault boost effect model analysis.

8. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable in the processor, wherein when the processor executes the computer program, the steps of the efficient modeling method for the voltage-boosting effect of an arc fault on a transformer as claimed in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the efficient modeling method of the transformer arc fault boosting effect as described in any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that: When the computer program is executed by a processor, the steps of the efficient modeling method of the transformer arc fault boosting effect as described in any one of claims 1 to 6 are implemented.

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