Rapid leakage magnetic field calculation method and system for transformer anti-short-circuit capability evaluation

Abstract

The invention relates to the technical field of transformers, and discloses a leakage magnetic field rapid calculation method and system for transformer anti-short-circuit capability assessment, and the method comprises the steps: building a finite element model of a transformer, and loading a plurality of short-circuit current values under different short-circuit fault working conditions through the finite element model of the transformer, the leakage magnetic field intensity distribution of each coil in the transformer is obtained, and the leakage magnetic field electromagnetic force borne by each coil winding is determined based on the leakage magnetic field intensity distribution of each coil in the transformer, so that the accuracy and the calculation efficiency of leakage magnetic field analysis and calculation are improved, and the anti-short-circuit capability evaluation of the transformer is realized more accurately and efficiently.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a leakage magnetic field rapid calculation method and system for evaluating the short-circuit resistance capability of a transformer. Background Art

[0002] As the scale of power grids continues to expand, short-circuit faults of power transformers pose an increasingly serious threat to the stability and reliability of the entire power system. In actual operation, the damage to transformer windings caused by short-circuit electrodynamic shocks often accumulates gradually through multiple short-circuit shocks, and once this safety hazard breaks out, it will cause serious damage to the power grid. Therefore, further revealing the short-circuit resistance of power transformers has a positive guiding role in the structural optimization of power transformers and the improvement of short-circuit tolerance, and also helps to ensure the safe and stable operation of the power grid.

[0003] However, the key to evaluating the short-circuit resistance of power transformers is the calculation of the leakage magnetic field during the short-circuit process. Accurate and fast calculation of the leakage magnetic field can ensure the effective evaluation of the short-circuit resistance of power transformers. At present, the leakage magnetic field analysis and calculation methods include analytical method and finite element method, but the current leakage magnetic field analysis and calculation methods are difficult to accurately obtain leakage magnetic field results, and there are also problems such as complex calculation process and slow solution speed. Summary of the invention

[0004] The present invention provides a leakage magnetic field rapid calculation method and system for evaluating the short-circuit resistance of a transformer, which solves the technical problems that the current leakage magnetic field analysis and calculation method is difficult to accurately obtain leakage magnetic field results, and also has a complex calculation process and a slow solution speed.

[0005] In view of this, a first aspect of the present invention provides a method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance, comprising:

[0006] Finite element modeling is performed according to the geometric structure and electrical parameters of the transformer to obtain a finite element model of the transformer;

[0007] The short-circuit current values ​​under multiple different short-circuit fault conditions are loaded as excitations into the finite element model of the transformer to obtain leakage magnetic field intensity data corresponding to the multiple different short-circuit fault conditions;

[0008] Determine the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions;

[0009] The leakage magnetic field electromagnetic force borne by each coil winding is determined according to the leakage magnetic field intensity distribution of each coil.

[0010] Preferably, the short-circuit current value is determined according to the transformer capacity and impedance voltage corresponding to a plurality of different short-circuit fault conditions.

[0011] Preferably, the step of loading the short-circuit current values ​​under a plurality of different short-circuit fault conditions as excitations into the finite element model of the transformer to obtain leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions, respectively, comprises:

[0012] Using short-circuit current values ​​under multiple different short-circuit fault conditions as excitation, and loading the short-circuit current values ​​onto each coil winding in the finite element model of the transformer, and applying excitation to each coil winding in sequence from the lower coil to the upper coil;

[0013] The electromagnetic differential equations under various short-circuit fault conditions are numerically solved by finite element method to obtain the leakage magnetic field intensity data corresponding to multiple different short-circuit fault conditions.

[0014] Preferably, the step of determining the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions includes:

[0015] The leakage magnetic field intensity distribution of each coil in the transformer is visualized according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions, so as to obtain a leakage magnetic field intensity distribution cloud diagram of each coil in the transformer.

[0016] Preferably, the step of determining the leakage magnetic field electromagnetic force borne by each coil winding according to the leakage magnetic field intensity distribution of each coil comprises:

[0017] Extracting the axial leakage magnetic field intensity and the radial leakage magnetic field intensity of each wire in the coil of each coil winding in the transformer according to the leakage magnetic field intensity distribution of each coil;

[0018] Determine the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor according to the axial leakage magnetic field strength and the radial leakage magnetic field strength of each conductor;

[0019] The leakage magnetic field electromagnetic force borne by each coil winding is determined by adding the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor of each coil winding.

[0020] Preferably, the method further comprises:

[0021] The short-circuit resistance of the transformer is evaluated according to the leakage magnetic field electromagnetic force borne by each coil winding.

[0022] In a second aspect, the present invention further provides a leakage magnetic field rapid calculation system for evaluating transformer short-circuit resistance capability, comprising:

[0023] A finite element modeling module is used to perform finite element modeling according to the geometric structure and electrical parameters of the transformer to obtain a finite element model of the transformer;

[0024] A loading module, used to load short-circuit current values ​​under multiple different short-circuit fault conditions as excitations into the finite element model of the transformer, and obtain leakage magnetic field intensity data corresponding to the multiple different short-circuit fault conditions;

[0025] A leakage magnetic field distribution module, used to determine the leakage magnetic field intensity distribution of each coil in the transformer according to leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions;

[0026] The electromagnetic force calculation module is used to determine the leakage magnetic field electromagnetic force borne by each coil winding according to the leakage magnetic field intensity distribution of each coil.

[0027] In a third aspect, the present invention further provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for quickly calculating the leakage magnetic field for evaluating the short-circuit resistance capability of a transformer as described in the first aspect.

[0028] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the steps of the method for quickly calculating leakage magnetic field for evaluating the short-circuit resistance capability of a transformer as described in the first aspect.

[0029] In a fifth aspect, the present invention further provides a computer program product, comprising a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program comprises program instructions, wherein when the program instructions are executed by a computer, the computer executes the steps of the method for quickly calculating leakage magnetic field for evaluating the short-circuit resistance capability of a transformer as described in the first aspect.

[0030] It can be seen from the above technical solutions that the present invention has the following advantages:

[0031] The present invention constructs a finite element model of the transformer, uses the finite element model of the transformer to load short-circuit current values ​​under multiple different short-circuit fault conditions, and obtains the leakage magnetic field intensity distribution of each coil in the transformer. Then, based on the leakage magnetic field intensity distribution of each coil in the transformer, the leakage magnetic field electromagnetic force borne by each coil winding is determined, thereby improving the accuracy and calculation efficiency of the leakage magnetic field analysis and calculation, thereby more accurately and efficiently realizing the transformer's anti-short-circuit capability evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flowchart of a method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance provided by an embodiment of the present invention;

[0033] Figure 2A simplified geometric model diagram of a transformer provided in an embodiment of the present invention;

[0034] Figure 3 A mesh division diagram of a finite element model of a transformer provided in an embodiment of the present invention;

[0035] Figure 4a A schematic diagram of the electromagnetic force of the radial leakage magnetic field borne by the coil provided in an embodiment of the present invention;

[0036] Figure 4b A schematic diagram of the electromagnetic force of the axial leakage magnetic field borne by the coil provided in an embodiment of the present invention;

[0037] Figure 5 A schematic diagram of the structure of a leakage magnetic field rapid calculation system for evaluating the short-circuit resistance capability of a transformer provided by an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, an embodiment of the present invention provides a method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance. The embodiment of the present invention is applicable to the case of quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance. The method can be performed by a device for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance. The device for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance can be implemented in the form of hardware and / or software. The device for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance can be configured in a computer device.

[0041] The embodiment of the present invention provides a method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance, comprising steps S1 to S4:

[0042] Step S1: Perform finite element modeling according to the geometric structure and electrical parameters of the transformer to obtain a finite element model of the transformer.

[0043] The geometric structure of the transformer includes but is not limited to the relative position relationship of the internal structure of the transformer, transformer type, connection group, grounding method, high-voltage tap changer position, core size, oil tank size, magnetic shield size, magnetic shunt size, size and distribution of low-voltage, medium-voltage and high-voltage regulating windings, etc.

[0044] The electrical parameters of the transformer include but are not limited to impedance, the number of electrical turns of each coil of the low-voltage, medium-voltage and high-voltage regulating windings, rated capacity, rated voltage, high-voltage regulation range, impedance voltage value, short-circuit requirements (short-circuit duration, dynamic stability time, over-peak coefficient, over-excitation coefficient), tap rated parameters (high-voltage rated voltage), coil layout parameters (low, high and regulating coils, input coil spacing and distance from the upper yoke and lower yoke), core parameters (core diameter, window height, column center distance data), coil parameters (connection group, electrical parameters, rated phase voltage, electrical height, number of turns per coil, number of radial windings per coil).

[0045] In the process of finite element modeling of the transformer, it is necessary to geometrically model the geometric structure of the transformer, load the electrical parameters of the transformer, and obtain the finite element model of the transformer through meshing and setting boundary conditions.

[0046] During the meshing process, the internal structure of the transformer is finely meshed, including the coils and coils. The boundary conditions include parallel magnetic lines and perpendicular magnetic lines, and the analysis frequency is set.

[0047] In an embodiment of the present invention, the input dimensional parameters and electrical parameters are processed using the python script interface of Simdroid, and the automatic construction of the geometric model, material parameter assignment, mesh generation and boundary setting is realized to obtain a finite element model of the transformer taking into account material nonlinearity and detailed coil distribution.

[0048] In a possible implementation, the script program of the python script interface obtains a specific implementation of the finite element model of the transformer considering material nonlinearity and detailed coil distribution, including:

[0049] 1) Automatically draw the geometric model of the transformer

[0050] According to the transformer size data obtained, the simplified geometric drawing of the leakage magnetic field of the power transformer is realized. First, the core column rectangle is completed, then the air domain rectangle is completed, and finally each wire cake is drawn with a wire rectangle equivalently, such as Figure 2 shown.

[0051] 2) Add material parameters and assign corresponding geometry to material parameters

[0052] The materials of the power transformer include copper as coil conductor material, silicon steel as core and shielding material, and air as air geometry material. The magnetic permeability of silicon steel material is nonlinear, which is described by the BH curve, and the corresponding material is assigned the corresponding object geometry.

[0053] 3) Fine mesh generation

[0054] According to the detailed wire size and the minimum wire spacing, the meshing parameters are set as follows: the maximum mesh size is 100 mm, the minimum mesh size is 0 mm, the mesh accuracy is medium, and the wire mesh is set to 2.3 mm. The transformer model mesh considering the detailed wire and material nonlinearity is obtained, as shown in the figure. Figure 3 shown.

[0055] 4) Add time-harmonic analysis and complete the analysis settings

[0056] The time-harmonic field analysis type is used to calculate the distribution of the leakage magnetic field of the power transformer. The analysis frequency is set to 50 Hz, and the vertical boundary and parallel boundary of the magnetic field lines are set to obtain a complete finite element model of the transformer.

[0057] Step S2: Load the short-circuit current values ​​under multiple different short-circuit fault conditions as excitations into the finite element model of the transformer to obtain leakage magnetic field intensity data corresponding to the multiple different short-circuit fault conditions.

[0058] Short-circuit fault conditions include three-phase short-circuit conditions, single-phase short-circuit conditions and short-circuit conditions to ground. At the same time, in the specific implementation process, based on the determined impedance voltage and capacity, combined with the characteristics of three-phase short-circuit conditions and single-phase short-circuit conditions, each short-circuit fault condition includes rated, maximum and minimum short-circuit current conditions.

[0059] Among them, the short-circuit current value is determined according to the transformer capacity and impedance voltage corresponding to multiple different short-circuit fault conditions, that is:

[0060]

[0061] Where Isc is the short-circuit current, IN is the transformer capacity, and UK is the impedance voltage.

[0062] In an embodiment of the present invention, current excitation is applied to the finite element model for leakage magnetic field analysis of the power transformer according to the short-circuit current of each coil obtained under each short-circuit fault condition. The low-voltage short-circuit current of the maximum three-phase short-circuit condition is used as the excitation of each coil of the low-voltage coil, and the high-voltage short-circuit current is used as the excitation of each coil of the high-voltage coil, to construct a finite element model of the transformer under the maximum three-phase short-circuit condition. Similarly, the short-circuit currents of the rated three-phase short-circuit condition, the minimum three-phase short-circuit condition, the maximum single-phase short-circuit condition, the rated single-phase short-circuit condition, and the minimum single-phase short-circuit condition are used as excitations to construct a finite element model of the transformer under the corresponding short-circuit fault condition.

[0063] Specifically, step S2 includes:

[0064] Step S201: taking short-circuit current values ​​under a plurality of different short-circuit fault conditions as excitation, and loading the short-circuit current values ​​onto each coil winding in the finite element model of the transformer, and applying excitation to each coil winding in sequence from the lower coil to the upper coil.

[0065] It can be understood that by loading the short-circuit current value onto each coil winding in the finite element model of the transformer and applying excitation to each coil winding in sequence from the lower coil to the upper coil, the actual short-circuit fault condition can be simulated.

[0066] Step S202: numerically solving the electromagnetic differential equations under various short-circuit fault conditions by finite element method to obtain leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions.

[0067] Among them, taking Maxwell equations as the basic theory, the electromagnetic differential equations under various short-circuit fault conditions are solved by finite element numerical solution method to obtain leakage magnetic field intensity data corresponding to multiple different short-circuit fault conditions. Among them, the electromagnetic differential equations are:

[0068]

[0069] In the formula, B represents the magnetic induction intensity vector; H represents the magnetic field intensity vector; J represents the current density vector; E represents the electric field intensity vector; D represents the electric displacement vector; represents the charge density; Represents the dielectric constant, and its unit is F / m; Represents magnetic permeability, its unit is H / m; Indicates electrical conductivity, its unit is S / m.

[0070] Step S3: determining the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions.

[0071] Specifically, the leakage magnetic field intensity distribution of each coil in the transformer is visualized according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions, so as to obtain a leakage magnetic field intensity distribution cloud map of each coil in the transformer.

[0072] Among them, VTK visualization technology is used to display the leakage magnetic field intensity data in the form of visual cloud maps and vector maps. Since the transformer is finely meshed during the finite element simulation process, the leakage magnetic field intensity distribution cloud map of each coil in the transformer can be obtained.

[0073] Step S4: determining the leakage magnetic field electromagnetic force borne by each coil winding according to the leakage magnetic field intensity distribution of each coil.

[0074] Specifically, step S4 includes:

[0075] Step S401: extracting the axial leakage magnetic field intensity and radial leakage magnetic field intensity of each wire in the coil of each coil winding in the transformer according to the leakage magnetic field intensity distribution of each coil.

[0076] Among them, in the specific implementation process, the leakage magnetic field intensity distribution cloud map of each coil in the transformer under each short-circuit fault condition is displayed, and the axial leakage magnetic field intensity and radial leakage magnetic field intensity of each conductor are extracted according to the coordinate position of each conductor in each coil.

[0077] Step S402: Determine the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor according to the axial leakage magnetic field strength and the radial leakage magnetic field strength of each conductor.

[0078] The axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor are calculated according to the axial leakage magnetic field strength and the radial leakage magnetic field strength of each conductor using the Lorentz force calculation formula F=BIL.

[0079] Step S403: Determine the leakage magnetic field electromagnetic force borne by each coil winding by summing the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor of each coil winding.

[0080] It can be understood that, since the number of turns of each coil winding is fixed, the leakage magnetic field electromagnetic force borne by each coil winding is determined by adding the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each wire.

[0081] In order to evaluate the short-circuit resistance of the transformer, the embodiment of the present invention also evaluates the short-circuit resistance of the transformer according to the leakage magnetic field electromagnetic force borne by each coil winding.

[0082] It is understandable that when a transformer is subjected to a short circuit, the current flowing through the winding will increase sharply, which will lead to a significant increase in the leakage magnetic field. The increase in the leakage magnetic field will in turn cause greater electromagnetic forces, which will exert pressure on the windings and other components, possibly causing mechanical damage. When the transformer is short-circuited, the short-circuit current will generate electromagnetic forces between the windings. These forces can be decomposed into axial forces and radial forces. The electromagnetic force of the leakage magnetic field is proportional to the square of the short-circuit current. This means that even if the current increases only a little, the electromagnetic force will increase significantly. In order to improve the short-circuit resistance of the transformer, measures need to be taken during the design to reduce the strength of the leakage magnetic field and the electromagnetic force generated thereby. Therefore, the short-circuit resistance is inversely proportional to the electromagnetic force of the leakage magnetic field borne by each coil winding.

[0083] For example, taking the maximum three-phase short circuit condition as an example, the calculated radial leakage magnetic field electromagnetic force and axial leakage magnetic field electromagnetic force borne by the coil are as follows: Figure 4a ~b is shown, and can be used to evaluate the short-circuit resistance of the power transformer. The larger the electromagnetic force of the leakage radial leakage magnetic field and the electromagnetic force of the axial leakage magnetic field, the weaker the short-circuit resistance of the power transformer. Conversely, the smaller the electromagnetic force of the leakage radial leakage magnetic field and the electromagnetic force of the axial leakage magnetic field, the stronger the short-circuit resistance of the power transformer.

[0084] In some embodiments, post-processing of leakage magnetic field analysis results under different short-circuit conditions is achieved by writing a script program, including leakage magnetic field distribution cloud map, extraction of axial and radial magnetic induction intensity values ​​of each conductor position in each coil of low, medium, high and voltage regulating windings, and calculation of axial and radial forces of each conductor in each coil; Python language script codes of all processes are summarized to uniformly achieve rapid automated modeling, calculation and post-processing analysis of leakage magnetic field of power transformers under different short-circuit conditions. The present invention takes into account material nonlinearity and detailed coil structure, and achieves the effect of leakage magnetic field simulation under various short-circuit conditions through the finite element simulation method of the script program, which has the advantages of high precision and high automated calculation efficiency, and is convenient for carrying out more accurate evaluation of the short-circuit resistance of power transformers.

[0085] It should be noted that the present invention constructs a finite element model of the transformer, uses the finite element model of the transformer to load short-circuit current values ​​under multiple different short-circuit fault conditions, and obtains the leakage magnetic field intensity distribution of each coil in the transformer, and then determines the leakage magnetic field electromagnetic force borne by each coil winding based on the leakage magnetic field intensity distribution of each coil in the transformer, thereby improving the accuracy and calculation efficiency of the leakage magnetic field analysis and calculation, thereby more accurately and efficiently realizing the transformer's short-circuit resistance evaluation.

[0086] Based on the same inventive concept, an embodiment of the present application also provides a leakage magnetic field rapid calculation system for transformer short-circuit capability evaluation for implementing the leakage magnetic field rapid calculation method for transformer short-circuit capability evaluation involved above.

[0087] The implementation solution to the problem provided by the device is similar to the implementation solution recorded in the above method. Therefore, the specific limitations in the embodiments of the leakage magnetic field rapid calculation system for evaluating the short-circuit capability of the transformer provided below can be referred to the limitations of the leakage magnetic field rapid calculation method for evaluating the short-circuit capability of the transformer above, and will not be repeated here.

[0088] like Figure 5 As shown, a leakage magnetic field rapid calculation system for transformer short-circuit resistance evaluation provided by an embodiment of the present invention includes:

[0089] The finite element modeling module 100 is used to perform finite element modeling according to the geometric structure and electrical parameters of the transformer to obtain a finite element model of the transformer.

[0090] The loading module 200 is used to load the short-circuit current values ​​under multiple different short-circuit fault conditions as excitations into the finite element model of the transformer, and obtain leakage magnetic field intensity data corresponding to the multiple different short-circuit fault conditions.

[0091] The short-circuit current value is determined according to the transformer capacity and impedance voltage corresponding to a plurality of different short-circuit fault conditions.

[0092] In some embodiments, the loading module 200 is specifically used to use the short-circuit current values ​​under multiple different short-circuit fault conditions as excitation, and load the short-circuit current values ​​to each coil winding in the finite element model of the transformer, and apply excitation to each coil winding from the lower coil to the upper coil in sequence; it is also used to numerically solve the electromagnetic differential equations under each short-circuit fault condition through finite element method to obtain leakage magnetic field strength data corresponding to multiple different short-circuit fault conditions.

[0093] The leakage magnetic field distribution module 300 is used to determine the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions.

[0094] Among them, the leakage magnetic field distribution module 300 is specifically used to visualize the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to multiple different short-circuit fault conditions, and obtain the leakage magnetic field intensity distribution cloud map of each coil in the transformer.

[0095] The electromagnetic force calculation module 400 is used to determine the leakage magnetic field electromagnetic force borne by each coil winding according to the leakage magnetic field intensity distribution of each coil.

[0096] In some embodiments, the electromagnetic force calculation module 400 is specifically used to extract the axial leakage magnetic field strength and radial leakage magnetic field strength of each conductor in the coil of each coil winding in the transformer according to the leakage magnetic field strength distribution of each coil; determine the axial leakage magnetic field electromagnetic force and radial leakage magnetic field electromagnetic force of each conductor according to the axial leakage magnetic field strength and radial leakage magnetic field strength of each conductor; and determine the leakage magnetic field electromagnetic force borne by each coil winding by adding the axial leakage magnetic field electromagnetic force and radial leakage magnetic field electromagnetic force of each conductor of each coil winding.

[0097] In some embodiments, the system further includes an evaluation module for evaluating the short-circuit resistance of the transformer according to the leakage magnetic field electromagnetic force borne by each coil winding.

[0098] like Figure 6 As shown, an embodiment of the present invention further provides an electronic device, the electronic device 10 includes a memory 20 and a processor 30, the memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 executes the steps of the leakage magnetic field rapid calculation method for evaluating the short-circuit resistance capability of the transformer as in any of the above embodiments.

[0099] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the steps of the method for quickly calculating leakage magnetic field for evaluating the short-circuit resistance capability of a transformer as described in any of the above embodiments.

[0100] The embodiment of the present invention further provides a computer program product, the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the steps of the method for quickly calculating the leakage magnetic field for evaluating the short-circuit resistance of a transformer in any of the above embodiments.

[0101] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, electronic devices, computer storage media and computer program products can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0102] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings 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 clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0103] In several embodiments provided by the present invention, it is understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and a part of a module, a program segment or a code includes one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved.

[0104] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, electronic devices, computer storage media, computer program products and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0105] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0106] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0107] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for executing all or part of the steps of the method described in each embodiment of the present invention through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fast calculation method for leakage magnetic field for short-circuit protection capability evaluation of transformers. It is characterized in that include: Finite element modeling is performed according to the geometric structure and electrical parameters of the transformer to obtain a finite element model of the transformer; The short-circuit current values ​​under multiple different short-circuit fault conditions are loaded as excitations into the finite element model of the transformer to obtain leakage magnetic field intensity data corresponding to the multiple different short-circuit fault conditions; Determine the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions; The leakage magnetic field electromagnetic force borne by each coil winding is determined according to the leakage magnetic field intensity distribution of each coil.

2. The method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance according to claim 1, It is characterized in that The short-circuit current value is determined according to the transformer capacity and impedance voltage corresponding to a plurality of different short-circuit fault conditions.

3. The method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance according to claim 1, It is characterized in that The step of loading the short-circuit current values ​​under a plurality of different short-circuit fault conditions as excitations into the finite element model of the transformer to obtain leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions, respectively, comprises: Using short-circuit current values ​​under multiple different short-circuit fault conditions as excitation, and loading the short-circuit current values ​​onto each coil winding in the finite element model of the transformer, and applying excitation to each coil winding in sequence from the lower coil to the upper coil; The electromagnetic differential equations under various short-circuit fault conditions are numerically solved by finite element method to obtain the leakage magnetic field intensity data corresponding to multiple different short-circuit fault conditions.

4. The method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance according to claim 1, It is characterized in that The step of determining the leakage magnetic field intensity distribution of each coil in the transformer according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions includes: The leakage magnetic field intensity distribution of each coil in the transformer is visualized according to the leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions, so as to obtain a leakage magnetic field intensity distribution cloud diagram of each coil in the transformer.

5. The method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance according to claim 1, It is characterized in that The step of determining the leakage magnetic field electromagnetic force borne by each coil winding according to the leakage magnetic field intensity distribution of each coil comprises: Extracting the axial leakage magnetic field intensity and the radial leakage magnetic field intensity of each wire in the coil of each coil winding in the transformer according to the leakage magnetic field intensity distribution of each coil; Determine the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor according to the axial leakage magnetic field strength and the radial leakage magnetic field strength of each conductor; The leakage magnetic field electromagnetic force borne by each coil winding is determined by adding the axial leakage magnetic field electromagnetic force and the radial leakage magnetic field electromagnetic force of each conductor of each coil winding.

6. The method for quickly calculating leakage magnetic field for evaluating transformer short-circuit resistance according to claim 1, It is characterized in that Also includes: The short-circuit resistance of the transformer is evaluated according to the leakage magnetic field electromagnetic force borne by each coil winding.

7. A leakage magnetic field rapid calculation system for transformer short-circuit resistance assessment, It is characterized in that include: A finite element modeling module is used to perform finite element modeling according to the geometric structure and electrical parameters of the transformer to obtain a finite element model of the transformer; A loading module, used to load short-circuit current values ​​under multiple different short-circuit fault conditions as excitations into the finite element model of the transformer, and obtain leakage magnetic field intensity data corresponding to the multiple different short-circuit fault conditions; A leakage magnetic field distribution module, used to determine the leakage magnetic field intensity distribution of each coil in the transformer according to leakage magnetic field intensity data corresponding to a plurality of different short-circuit fault conditions; The electromagnetic force calculation module is used to determine the leakage magnetic field electromagnetic force borne by each coil winding according to the leakage magnetic field intensity distribution of each coil.

8. An electronic device, It is characterized in that The electronic device includes a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the leakage magnetic field rapid calculation method for evaluating the short-circuit resistance capability of a transformer as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed, the steps of the method for quickly calculating leakage magnetic field for evaluating the short-circuit resistance capability of a transformer as claimed in any one of claims 1 to 6 are implemented.

10. A computer program product, It is characterized in that The computer program product comprises a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program comprises program instructions, wherein when the program instructions are executed by a computer, the computer is caused to execute the steps of the method for quickly calculating leakage magnetic field for evaluating the short-circuit resistance capability of a transformer as claimed in any one of claims 1 to 6.

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