Method for evaluating arc fault endurance capability of key structure of oil-immersed power equipment

Abstract

The invention discloses a method for evaluating the arc fault tolerance of key structures of oil-immersed power equipment, and the method comprises the steps: carrying out the impact load test and simulation calculation of each structure of the oil-immersed power equipment, determining the mapping relation between the test failure characterization quantity and the simulation failure characterization quantity of each structure, and constructing a structure failure curved surface; performing an equivalent impact test on the to-be-evaluated key structure of the oil-immersed power equipment to obtain a key structure test failure characterization quantity of the to-be-evaluated key structure; converting the key structure failure characterization quantity according to the mapping relation to obtain an effective failure characterization quantity of the to-be-evaluated key structure; and according to the structure failure curved surface, performing arc fault endurance capability evaluation on the effective failure characterization quantity of the key structure, and determining an endurance capability evaluation result of the to-be-evaluated key structure.

Description

Technical Field

[0001] The present invention relates to the technical field of oil-immersed power equipment, and more specifically, to a method for evaluating arc fault tolerance of key structures of oil-immersed power equipment. Background Art

[0002] Arc faults are inevitable in oil-immersed power equipment, such as transformers, tap changers, and risers. High-energy arc faults will cause damage to the equipment structure and uncontrolled release of the insulating oil inside, which can cause explosion accidents after contact with air. The leaked oil-gas mixture can further endanger the surrounding equipment, personnel, and the environment, causing great losses and adverse effects.

[0003] Existing oil-immersed power equipment is generally not subjected to explosion-proof verification, and only undergoes some factory tests with low static pressure values, such as positive and negative pressure tests. These tests are mainly used to detect the sealing performance of the oil tank and the oil carrying capacity during normal operation. Some transformer factories at home and abroad have put forward explosion-proof requirements and conduct explosion-proof verification and design for transformers, but they still use an iterative method based on static pressure. The verification criteria are mainly based on structural stress and strain, and the failure damage of impact loads under arc faults is ignored.

[0004] For general machinery and materials fields, material or structure-level quasi-static and dynamic impact test specifications and standards have been formed, such as uniaxial tension, three-point bending, Charpy test, pendulum and drop hammer test, etc. However, most of them require the processing of standard specimens, and the test conditions are different from the arc fault impact load conditions, and the stress state of the transformer structure during an arc fault is not considered.

[0005] As the voltage level increases, the higher the arc fault energy, the greater the impact load. If the existing static verification method is used, the verification standard is too strict and cannot effectively guide the design and verification of explosion-proof transformers. The explosion-proof capability assessment is directly based on the quasi-static and impact tests of existing materials and structures, which cannot well reflect the stress state of the transformer oil tank structure under the real arc fault, and cannot accurately correlate the test results with the arc fault tolerance of the key structure of the transformer. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for evaluating the arc fault tolerance capability of key structures of oil-immersed power equipment.

[0007] According to one aspect of the present invention, a method for evaluating arc fault tolerance of key structures of oil-immersed power equipment is provided, comprising: Conduct impact load tests and simulation calculations on various structures of oil-immersed power equipment, determine the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each structure, and construct the structural failure surface; Conduct an equivalent impact test on the key structure to be evaluated of the oil-immersed power equipment to obtain the key structure test failure characterization quantity of the key structure to be evaluated; The failure characterization quantity of the key structure is converted according to the mapping relationship to obtain the effective failure characterization quantity of the key structure to be evaluated; The arc fault tolerance capability is evaluated on the effective failure characterization quantity of the key structure according to the structural failure surface, and the tolerance capability evaluation result of the key structure to be evaluated is determined.

[0008] Optionally, impact load tests and simulation calculations are performed on various structures of the oil-immersed power equipment to determine a mapping relationship between a test failure characterization quantity and a simulation failure characterization quantity of each structure and to construct a structural failure surface, including: Conduct mechanical property tests on various materials of oil-immersed power equipment and construct constitutive models and failure models of various materials; Construct a transformer arc fault simulation model based on the constitutive model of each material, perform arc fault simulation, and analyze the simulation results based on the failure model of each structure to determine the failure structures of the oil-immersed power equipment and the stress state and impact load of each failure structure; Perform equivalent impact tests on each failed structure according to the stress state and impact load to obtain the test failure characterization quantity of each failed structure; Establish the failure structure sub-model of each failure structure according to the boundary conditions and loads of each failure structure in the transformer arc fault simulation model; Perform simulation calculation on each failure structure sub-model to obtain the simulation failure characterization quantity of each failure structure; According to the experimental failure characterization quantity and the simulation failure characterization quantity of each failure structure, a mapping relationship between the experimental failure characterization quantity and the simulation failure characterization quantity of each failure structure and a structural failure surface are constructed.

[0009] Optionally, the constitutive model expression is: In the formula, A , B , n , C and m are constitutive model parameters obtained from experiments, is the equivalent plastic strain, is the equivalent strain rate, is the reference strain rate, , T is the current temperature, T room is the ambient temperature, T melt is the melting point, strain rate influence term C=5.94×10-6+0.019; is the equivalent stress; The failure model expression is: In the formula, D 1~ D 5 is the failure model parameter, is the stress triaxiality, is the plastic strain, is the relative strain rate.

[0010] Optionally, according to the test failure characterization quantity and the simulation failure characterization quantity of each failure structure, a structural failure surface of each failure structure is constructed, including: A sample data set is constructed according to the test failure characterization quantity and the simulation failure characterization quantity, wherein the test failure characterization quantity and the simulation failure characterization quantity both contain n characteristic quantities; The characteristic values ​​in the sample data set are subjected to infinite tempering and normalization to obtain m failure points; The m failure points are plotted in n-dimensional space for fitting to obtain an n-dimensional structural failure surface.

[0011] Optionally, the calculation formula for the tolerance assessment result is: In the formula, d critical is the vector modulus of the projection point of the effective failure characterization quantity of the key structure to be evaluated on the constructed structural failure surface, d It is the vector modulus of the effective failure characterization quantity of the key structure to be evaluated in the failure space.

[0012] According to another aspect of the present invention, there is provided a device for evaluating arc fault tolerance of key structures of oil-immersed power equipment, comprising: A determination module is used to perform impact load tests and simulation calculations on various structures of oil-immersed power equipment, determine the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each structure, and construct a structural failure surface; A test module, used to perform an equivalent impact test on the key structure to be evaluated of the oil-immersed power equipment, and obtain a key structure test failure characterization quantity of the key structure to be evaluated; A conversion module is used to convert the failure characterization quantity of the key structure according to the mapping relationship to obtain the effective failure characterization quantity of the key structure to be evaluated; The evaluation module is used to evaluate the arc fault tolerance capability of the key structure based on the structural failure surface and determine the tolerance capability evaluation result of the key structure to be evaluated.

[0013] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute the method described in any one of the above aspects of the present invention.

[0014] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of the above aspects of the present invention.

[0015] Therefore, the present invention calculates the impact loads acting on different structures of the transformer based on the display dynamics strong fluid-solid coupling algorithm; constructs failure criteria regarding strain rate and stress state, uses tests of different structural sizes to conduct mechanical property tests at different strain rates, and calculates the material failure surface. Based on the stress state of the transformer structure under an arc fault, an impact test fixture is designed to enable the test sample to reach the same stress state in the test. The time-varying arc fault impact load is equivalent based on the energy and impulse equivalence method. An impact test that is closer to the actual arc fault load condition is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings: Figure 1 It is a flow chart of a method for evaluating arc fault tolerance capability of a key structure of an oil-immersed power equipment provided by an exemplary embodiment of the present invention; Figure 2 It is another flow chart of a method for evaluating arc fault tolerance capability of a key structure of an oil-immersed power equipment provided by an exemplary embodiment of the present invention; Figure 3 is a schematic diagram of a spatial failure surface provided by an exemplary embodiment of the present invention; Figure 4 It is a structural schematic diagram of an arc fault tolerance capability evaluation device for a key structure of an oil-immersed power equipment provided by an exemplary embodiment of the present invention; Figure 5 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0017] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described here.

[0018] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0019] Those skilled in the art can understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, etc., and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0020] It should also be understood that, in the embodiments of the present invention, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0021] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0022] In addition, the term "and / or" in the present invention is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects before and after are in an "or" relationship.

[0023] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0024] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0025] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0026] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0027] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0028] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, servers, etc., which can operate with many other general or special computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, servers, etc. include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, small computer systems, large computer systems, and distributed cloud computing technology environments including any of the above systems, etc.

[0029] Electronic devices such as terminal devices, computer systems, servers, etc. can be described in the general context of computer system executable instructions (such as program modules) executed by computer systems. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in a distributed cloud computing environment, where tasks are performed by remote processing devices linked through a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media including storage devices.

[0030] Exemplary Methods Figure 1 1 is a flow chart of a method for evaluating arc fault tolerance of key structures of oil-immersed power equipment provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic equipment, such as Figure 1 As shown, the arc fault tolerance evaluation method 100 of the key structure of oil-immersed power equipment includes the following steps: Step 101, performing impact load tests and simulation calculations on various structures of the oil-immersed power equipment, determining a mapping relationship between a test failure characterization quantity and a simulation failure characterization quantity of each structure, and constructing a structural failure surface; Step 102, performing an equivalent impact test on the key structure to be evaluated of the oil-immersed power equipment to obtain a key structure test failure characterization quantity of the key structure to be evaluated; Step 103, converting the failure characterization quantity of the key structure according to the mapping relationship to obtain the effective failure characterization quantity of the key structure to be evaluated; Step 104 , performing arc fault tolerance assessment on the effective failure characterization quantity of the key structure according to the structural failure surface, and determining the tolerance assessment result of the key structure to be assessed.

[0031] Specifically, in view of the technical problems existing in the background technology, the present invention proposes a method for evaluating the arc fault tolerance capability of key structures of oil-immersed power equipment. Figure 2 As shown: Step 1: Material mechanical properties test. Different mechanical properties tests are carried out on the transformer tank material to calculate the material mechanical constitutive model and failure model. The construction of the constitutive model and failure model should consider the influence of strain rate effect and stress state, such as Johnson-cook (JC) constitutive model and Johnson-cook (JC) failure model. Therefore, different test methods / equipment are required for mechanical properties tests to achieve different strain rates, such as uniaxial tension for low-speed and quasi-static tension, and Hopkinson bar for medium- and high-speed tests. Modify the structure and parameters of the specimen to regulate the stress state in the effective deformation zone. Based on the test results, the standard constitutive model and failure model equations are fitted, and the equation parameters are solved to obtain the corresponding constitutive model and failure model. When the test results are difficult to fit the standard constitutive model and failure model well, the standard model can be appropriately modified. In addition to constructing the constitutive model and failure model for the tank material, the weld material and bolt material should also be tested and their constitutive and failure models should be constructed. (ps: Even if the same material is used, products from different manufacturers have different mechanical properties, especially plastic deformation and failure behavior. Therefore, in order to obtain a high-precision evaluation, it is necessary to build a model for the specific materials used by the transformer manufacturer. Similarly, the same is true for bolt materials. The performance of welding mechanism materials is affected by welding processes and other factors, and also has different properties, so model building is required.) Standard JC constitutive model: ; Standard JC failure model: .

[0032] Table 1 Constitutive model of fuel tank base material and weld A B n C m 25mm base material 420 858 0.627 0.04922 1.03872 40mm base material 352 646.7 0.5264 0.06 1.17989 Butt weld 429 667.3 0.5556 0.0416 0.7363 T-weld 589 547.6 0.467 0.02305 0.46367 Butt heat affected zone 454 444.1 0.3913 0.04336 0.9293 T-shaped heat affected zone 639 671.8 0.4882 0.03338 1.2059 Table 2 Failure model of fuel tank base material and weld <![CDATA[D1]]> <![CDATA[D2]]> <![CDATA[D3]]> <![CDATA[D4]]> <![CDATA[D5]]> 25mm base material 0.8152 1.99913 -3.77696 -0.05709 1.47103 40mm base material 0.84647 7.4121 -7.93835 -0.05751 0.10236 Butt weld 0.26265 2.7927 -3.03371 -0.05584 0.11399 T-weld 0.69487 2.2372 -5.7672 -0.054 7.38447 Butt heat affected zone 0.227705 0.27166 -2.9038 -0.02737 0.0674 T-shaped heat affected zone 0.17021 1.45239 -8.11624 -0.01557 12.85015 If the standard model does not agree well with the test results, the model can be modified. For example, the parameter C (strain rate influence term) in the JC constitutive model can be changed from a constant value to an expression such as C=5.94×10-6+0.019.

[0033] Step 2: Transformer arc fault simulation. This simulation is used to obtain the stress state and load of the structure to be evaluated and the boundary conditions of the sub-model (step 3). The simulation model is based on the actual transformer structure, and the material properties of each structure are the constitutive model and failure model obtained in step 1. The constructed simulation model is used for transient simulation of transformer arc fault, which can simulate the dynamic development process of the arc fault pressure wave and its mutual influence with the transformer structure. Therefore, the simulation model needs to have the strong fluid-solid coupling calculation ability between the insulating oil and the transformer structure, and well show the plastic deformation and failure of the structure. The simulation model can be modeled and calculated on the LS-Dyna platform. The simulation can give the impact load curve on each structure to be evaluated, and the stress state of the structure (such as tension, compression, shear, bending or composite state, etc.). If the material failure criterion threshold is reached (JC failure model in step 1), the simulation can show the failure of the transformer, and then the potential failure structure can be known. Further, by simulating the impact effect of arc faults at different high-probability fault locations on the transformer structures, the maximum impact load on the structure under a given arc energy is found, and the impact load is used as the equivalent basis for the equivalent impact test load. Since the real tank structure is large in size, it is impossible to fully and accurately represent the details of the structure to be tested in the simulation, so the failure characteristics are relatively rough. Therefore, it is necessary to establish a fine sub-model of the structure to be evaluated to more accurately characterize the failure (step 3).

[0034] Step 3: The sub-model has a more detailed mesh division and structural detail expression, and can also characterize material heterogeneity (non-uniformity of material mechanical properties). The boundary conditions of the sub-model are obtained from the overall transformer model and are consistent with the corresponding parts in the overall model. The sub-model is mainly aimed at high-risk structures of transformer tanks such as welds and bolts. The sub-model can be modeled using a solid model and carefully set according to various contact and constraint conditions on the actual structure.

[0035] Step 4: Structural equivalent impact test. Perform an equivalent impact test on the high-risk failure structure obtained in the simulation of step 2. The equivalent application of the load in the equivalent test is based on the obtained impact pressure curve, and is equivalent from the perspective of energy and impulse equivalence, and the impact test parameters are set accordingly, such as the hammer weight and height in the drop hammer impact test. Further, according to the stress state of the structure to be tested obtained by simulation, the corresponding tooling fixture is designed so that the specimen has the same stress state in the impact test. Then, the failure characteristic quantity of the structural specimen is obtained for comparison with the failure characteristic quantity obtained by the simulation of the structural sub-model in step 3.

[0036] Step 5: Construct the structural failure surface. Based on the structural failure characteristic quantity calculated in step 3, construct the structural failure criterion. The failure criterion can be a single factor, such as the maximum deformation; it can also be a composite factor, such as the maximum deformation and bending angle, to construct a spatial failure surface / plane. The specific failure criterion selection is based on the actual structure. For example, the thin-walled box wall structure can use the maximum deformation, deflection, etc. as parameters, the welding structure can use the bending angle and relative displacement as the basis, and the threaded connection structure can use the screw elongation, bending angle, etc. as the basis. The selected basis is dimensionless and normalized to construct the failure point (failure characteristic value 1, failure characteristic value 2,..., failure characteristic value n). All m failure points obtained from simulation and experiment can be plotted in n-dimensional space, and further fitted to the n-dimensional failure surface based on these m failure points. When the failure characteristic quantity of the specimen obtained in the equivalent impact test falls on the failure surface or exceeds its range, it is considered to be a failure. If it is within the range, the ratio of the modulus of the characteristic quantity vector to the vector modulus of the point projected on the failure surface is calculated to calculate the failure probability. If Figure 3 As shown in the figure, taking 2 failure characteristic values ​​as an example, the construction and evaluation of the criterion are explained.

[0037] Step 6: By comparing the failure characteristics in the simulation and the failure characteristics obtained from the equivalent impact test, a mapping relationship between the structural failure characteristic quantities is constructed, such as the relative maximum deformation in the equivalent impact test and the deformation of the corresponding structure in the simulation. Subsequent equivalent impact tests can convert and calculate the structural failure characteristic quantities based on this mapping relationship and conduct explosion-proof capability evaluation. The boundary conditions of the deformation failure of the key structure of the real transformer oil tank arc fault and the structural deformation failure in the equivalent impact test cannot be completely consistent. For example, the boundary conditions of the top cover-side wall welding structure in the real oil tank also include the deformation and displacement of the top cover and side walls, but the deformation and position cannot be simulated in the equivalent impact test, and only fixed constraints can be used, so it is necessary to map the failure characteristic quantities.

[0038] Step 7: Structural arc fault tolerance assessment. Through the equivalent impact test and the mapping relationship established in step 6, the structural failure characteristic quantity is calculated. Compared with the failure surface established in step 5, the arc fault tolerance capability of the structure is assessed. The assessment algorithm is as follows: Therefore, the present invention calculates the impact loads acting on different structures of the transformer based on the display dynamics strong fluid-solid coupling algorithm; constructs failure criteria regarding strain rate and stress state, uses tests of different structural sizes to conduct mechanical property tests at different strain rates, and calculates the material failure surface. Based on the stress state of the transformer structure under an arc fault, an impact test fixture is designed to enable the test sample to reach the same stress state in the test. The time-varying arc fault impact load is equivalent based on the energy and impulse equivalence method. An impact test that is closer to the actual arc fault load condition is achieved.

[0039] Exemplary Devices Figure 4 FIG. 1 is a schematic diagram of a device for evaluating the arc fault tolerance capability of a key structure of an oil-immersed power equipment according to an exemplary embodiment of the present invention. Figure 4 As shown, the device 400 includes: A determination module 410 is used to perform impact load tests and simulation calculations on various structures of the oil-immersed power equipment, determine the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each structure, and construct a structural failure surface; The test module 420 is used to perform an equivalent impact test on the key structure to be evaluated of the oil-immersed power equipment to obtain a key structure test failure characterization quantity of the key structure to be evaluated; A conversion module 430 is used to convert the failure characterization quantity of the key structure according to the mapping relationship to obtain the effective failure characterization quantity of the key structure to be evaluated; The evaluation module 440 is used to evaluate the arc fault tolerance capability of the key structure based on the structural failure surface and determine the tolerance capability evaluation result of the key structure to be evaluated.

[0040] Optionally, the determination module 410 includes: The first construction submodule is used to perform mechanical property tests on various materials of oil-immersed power equipment and construct constitutive models and failure models of various materials; A determination submodule is used to construct a transformer arc fault simulation model based on the constitutive model of each material, and to perform arc fault simulation, and to analyze the simulation results according to the failure model of each structure, to determine each failure structure of the oil-immersed power equipment and the stress state and impact load of each failure structure; An acquisition submodule is used to perform an equivalent impact test on each failed structure according to the stress state and the impact load, and obtain the test failure characterization quantity of each failed structure; Establishing a submodule for establishing a failure structure submodel of each failure structure according to the boundary conditions and loads of each failure structure in the transformer arc fault simulation model; A calculation submodule is used to perform simulation calculations on each failure structure submodel to obtain a simulation failure characterization value of each failure structure; The second construction submodule is used to construct a mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each failure structure and a structural failure surface according to the test failure characterization quantity and the simulation failure characterization quantity of each failure structure.

[0041] Optionally, the constitutive model expression is: In the formula, A , B ,n , C and m are constitutive model parameters obtained from experiments, is the equivalent plastic strain, is the equivalent strain rate, is the reference strain rate, , T is the current temperature, T room is the ambient temperature, T melt is the melting point, strain rate influence term C =5.94×10-6+0.019; is the equivalent stress; The failure model expression is: In the formula, D 1~ D 5 is the failure model parameter, is the stress triaxiality, is the plastic strain, is the relative strain rate.

[0042] Optionally, in the second construction submodule, constructing a structural failure surface of each failure structure according to the test failure characterization value and the simulation failure characterization value of each failure structure includes: A construction unit, used to construct a sample data set according to the test failure characterization quantity and the simulation failure characterization quantity, wherein the test failure characterization quantity and the simulation failure characterization quantity both contain n characteristic quantities; A processing unit, used for performing a quantitative tempering and normalization process on the characteristic values ​​in the sample data set to obtain m failure points; The fitting unit is used to plot the m failure points in the n-dimensional space for fitting, so as to obtain the n-dimensional structural failure surface.

[0043] Optionally, the calculation formula for the tolerance assessment result is: In the formula, d critical is the vector modulus of the projection point of the effective failure characterization quantity of the key structure to be evaluated on the constructed structural failure surface, d It is the vector modulus of the effective failure characterization quantity of the key structure to be evaluated in the failure space.

[0044] Exemplary Electronic Devices Figure 5 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. Figure 5 As shown, the electronic device 50 includes one or more processors 51 and a memory 52 .

[0045] The processor 51 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0046] The memory 52 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 51 may run the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above and / or other desired functions. In one example, the electronic device may also include: an input device 53 and an output device 54, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0047] In addition, the input device 53 may also include, for example, a keyboard, a mouse, etc.

[0048] The output device 54 can output various information to the outside. The output device 54 can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0049] Of course, to simplify, Figure 5 Only some of the components related to the present invention in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application conditions.

[0050] Exemplary computer program products and computer-readable storage media In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above-mentioned "Exemplary Method" section of this specification.

[0051] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the embodiments of the present invention, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0052] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above “Exemplary Method” section of this specification.

[0053] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, system or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0054] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details disclosed above are only for the purpose of illustration and facilitation of understanding, rather than limitation, and the above details do not limit the present invention to being implemented by adopting the above specific details.

[0055] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0056] The block diagrams of the devices, systems, equipment, and systems involved in the present invention are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, systems, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0057] The method and system of the present invention may be implemented in many ways. For example, the method and system of the present invention may be implemented by software, hardware, firmware or any combination of software, hardware, firmware. The above order of steps for the method is only for illustration, and the steps of the method of the present invention are not limited to the order specifically described above, unless otherwise specifically stated. In addition, in some embodiments, the present invention may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present invention. Thus, the present invention also covers a recording medium storing a program for executing the method according to the present invention.

[0058] It should also be noted that in the system, device and method of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. The above description of the disclosed aspects is provided to enable any technician in the field to make or use the present invention. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined here can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown here, but in accordance with the widest range consistent with the principles and novel features disclosed here.

[0059] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for evaluating the arc fault tolerance capability of key structures of oil-immersed power equipment, characterized in that: include: Conduct impact load tests and simulation calculations on various structures of oil-immersed power equipment, determine the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each structure, and construct the structural failure surface; Performing an equivalent impact test on a key structure to be evaluated of an oil-immersed electric power device to obtain a key structure test failure characterization quantity of the key structure to be evaluated; Convert the failure characterization value of the key structure according to the mapping relationship to obtain the effective failure characterization value of the key structure to be evaluated; An arc fault tolerance capability assessment is performed on the effective failure characterization quantity of the key structure according to the structural failure surface to determine a tolerance capability assessment result of the key structure to be assessed.

2. The method according to claim 1, characterized in that Impact load tests and simulation calculations are performed on various structures of oil-immersed power equipment to determine the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each structure and to construct the structural failure surface, including: Conduct mechanical property tests on various materials of oil-immersed power equipment and construct constitutive models and failure models of various materials; Constructing a transformer arc fault simulation model based on the constitutive models of each material, and performing arc fault simulation, and analyzing the simulation results based on the failure models of each structure, to determine each failure structure of the oil-immersed power equipment and the stress state and impact load of each failure structure; Performing an equivalent impact test on each failed structure according to the stress state and the impact load to obtain a test failure characterization quantity of each failed structure; Establishing a failure structure sub-model of each failure structure according to the boundary conditions and loads of each failure structure in the transformer arc fault simulation model; Perform simulation calculation on each failure structure sub-model to obtain the simulation failure characterization quantity of each failure structure; According to the test failure characterization quantity of each failure structure and the simulation failure characterization quantity, the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each failure structure and the structural failure surface are constructed.

3. The method according to claim 2, characterized in that The constitutive model expression is: In the formula, A , B , n , C and m are constitutive model parameters obtained from experiments, is the equivalent plastic strain, is the equivalent strain rate, is the reference strain rate, , T is the current temperature, T room is the ambient temperature, T melt is the melting point, strain rate influence term C =5.94×10-6+0.019; is the equivalent stress; The failure model expression is: In the formula, D 1~ D 5 is the failure model parameter, is the stress triaxiality, is the plastic strain, is the relative strain rate.

4. The method according to claim 2, characterized in that: According to the test failure characterization quantity of each failure structure and the simulation failure characterization quantity, the structural failure surface of each failure structure is constructed, including: Constructing a sample data set according to the test failure characterization quantity and the simulation failure characterization quantity, wherein the test failure characterization quantity and the simulation failure characterization quantity both contain n feature quantities; Performing a quantitative tempering and normalization process on the characteristic values ​​in the sample data set to obtain m failure points; The m failure points are plotted in an n-dimensional space for fitting, and an n-dimensional failure surface of the structure is obtained.

5. The method according to claim 1, characterized in that The calculation formula of the tolerance evaluation result is: In the formula, d critical is the vector modulus of the projection point of the effective failure characterization quantity of the key structure to be evaluated on the constructed structural failure surface, d It is the vector modulus of the effective failure characterization quantity of the key structure to be evaluated in the failure space.

6. A device for evaluating the arc fault tolerance capability of key structures of oil-immersed power equipment, characterized in that: include: A determination module is used to perform impact load tests and simulation calculations on various structures of oil-immersed power equipment, determine the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each structure, and construct a structural failure surface; A test module, used for performing an equivalent impact test on a key structure to be evaluated of an oil-immersed electric equipment, and obtaining a key structure test failure characterization quantity of the key structure to be evaluated; A conversion module, used to convert the failure characterization quantity of the key structure according to the mapping relationship to obtain the effective failure characterization quantity of the key structure to be evaluated; An evaluation module is used to evaluate the arc fault tolerance capability of the key structure based on the structural failure surface and determine the tolerance capability evaluation result of the key structure to be evaluated.

7. The device according to claim 6, characterized in that Identify modules, including: The first construction submodule is used to perform mechanical property tests on various materials of oil-immersed power equipment and construct constitutive models and failure models of various materials; A determination submodule is used to construct a transformer arc fault simulation model according to the constitutive model of each material, and perform arc fault simulation, and analyze the simulation results according to the failure model of each structure to determine each failure structure of the oil-immersed power equipment and the stress state and impact load of each failure structure; An acquisition submodule, used for performing an equivalent impact test on each failed structure according to the stress state and the impact load, and obtaining a test failure characterization quantity of each failed structure; Establishing a submodule, for establishing a failure structure submodel of each failure structure according to the boundary conditions and loads of each failure structure in the transformer arc fault simulation model; A calculation submodule is used to perform simulation calculations on each failure structure submodel to obtain a simulation failure characterization value of each failure structure; The second construction submodule is used to construct the mapping relationship between the test failure characterization quantity and the simulation failure characterization quantity of each failure structure and the structural failure surface according to the test failure characterization quantity of each failure structure and the simulation failure characterization quantity.

8. The device according to claim 7, characterized in that The second construction submodule constructs the structural failure surface of each failure structure according to the test failure characterization value of each failure structure and the simulation failure characterization value, including: A construction unit, configured to construct a sample data set according to the test failure characterization quantity and the simulation failure characterization quantity, wherein the test failure characterization quantity and the simulation failure characterization quantity both include n feature quantities; A processing unit, used for performing a non-quantitative tempering and normalization process on the characteristic values ​​in the sample data set to obtain m failure points; The fitting unit is used to plot the m failure points in the n-dimensional space for fitting, so as to obtain the n-dimensional failure surface of the structure.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 5.

10. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is used to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1 to 5.

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