A method for rapid analysis and calculation of magnetic field under transformer short-circuit fault and related device

Abstract

The present invention belongs to the field of rapid calculation of multi-physical fields of power equipment, and discloses a rapid analysis and calculation method for magnetic fields under transformer short-circuit faults and related devices: the method comprises the following steps: calculating the vector magnetic potential of the first several time steps through a full-order calculation model of the transformer short-circuit magnetic field in a high-dimensional space; constructing a snapshot matrix of a solution vector and a snapshot matrix of nonlinear terms; obtaining a set of orthogonal bases based on an intrinsic orthogonal decomposition method and in combination with the snapshot matrix of the solution vector; constructing a reduced-order subspace using the orthogonal bases; projecting the full-order calculation model of the transformer short-circuit magnetic field into the reduced-order subspace; obtaining an interpolation matrix of the nonlinear terms based on a discrete empirical interpolation method and in combination with the snapshot matrix of the nonlinear terms; updating the nonlinear terms in the reduced-order calculation model of the transformer short-circuit magnetic field using the interpolation matrix, and then calculating the vector magnetic potential in the reduced-order subspace; reconstructing the vector magnetic potential back into the high-dimensional space, and calculating the magnetic field under the transformer short-circuit fault using the reconstructed vector magnetic potential.

Description

Technical Field

[0001] The present invention belongs to the field of rapid calculation of multi-physical fields of power equipment, and particularly relates to a method for rapid analysis and calculation of magnetic fields under a transformer short-circuit fault and a related device. Background Art

[0002] Ultra-high voltage substations and converter stations are key nodes in ultra-high voltage direct current (UHVDC) transmission systems, carrying out crucial tasks such as signal processing, AC / DC conversion, and overvoltage protection. With the development of power systems primarily based on renewable energy, the number and capacity of in-station equipment has increased significantly. Transformers are crucial equipment in the transmission and application of electrical energy, and ensuring their safe and stable operation is crucial for improving power system reliability. When a transformer experiences a sudden short circuit, the surge in short-circuit current causes a sharp increase in the electromagnetic force on the windings, which can cause deformation or even damage, compromising the transformer's safe and stable operation. Therefore, accurately and in real time understanding the distribution of the transformer's leakage magnetic field and electromagnetic force during a short circuit, and developing rapid calculation and analysis techniques for these, are crucial to ensuring the transformer's safe and stable operation.

[0003] Physical field simulation analysis technology utilizes the finite element method to numerically solve field problems described by differential equations. With advances in simulation theory and computer technology, this technique has become a highly mature technology, with various commercial software packages now offering electromagnetic field finite element simulation capabilities. However, the complex structure of transformers and the large number of grid nodes create a significant computational burden. Furthermore, the transformer core is made of ferromagnetic material, and its relative permeability exhibits typical nonlinear characteristics. This requires multiple iterations for each time step, consuming significant time and severely limiting the computational efficiency of transformer short-circuit analysis. Therefore, to achieve real-time simulation of transformer short-circuit analysis, it is imperative to develop model reduction methods and rapidly calculate the transformer magnetic field, significantly reducing simulation time and improving efficiency. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a method and related device for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault. The present invention can meet the needs of rapid calculation of the transformer magnetic field, improve calculation efficiency, and ensure calculation accuracy; the short-circuit electromagnetic force of the transformer can be further quickly and accurately obtained through the obtained magnetic field under the transformer short-circuit fault.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] A method for quickly analyzing and calculating the magnetic field under a transformer short-circuit fault includes the following steps:

[0007] The vector magnetic potential of the first several time steps is iteratively calculated using a pre-established full-order calculation model of the transformer short-circuit magnetic field in a high-dimensional space.

[0008] Construct a snapshot matrix of the solution vector based on the vector magnetic potential;

[0009] A snapshot matrix of nonlinear terms is constructed according to the nonlinear terms in the process of iteratively calculating the vector magnetic potential of the first several time steps;

[0010] Based on the eigenorthogonal decomposition method and combined with the snapshot matrix of the solution vector, a set of orthogonal bases are obtained;

[0011] Using the orthogonal basis, constructing a reduced-order subspace;

[0012] The full-order calculation model of the transformer short-circuit magnetic field is projected into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field;

[0013] Based on the discrete empirical interpolation method and combined with the snapshot matrix of the nonlinear term, the interpolation matrix of the nonlinear term is obtained;

[0014] The nonlinear terms in the transformer short-circuit magnetic field reduction model are updated using the interpolation matrix of the nonlinear terms.

[0015] The transformer short-circuit magnetic field reduced-order calculation model with updated nonlinear terms is used for iterative calculation to obtain the vector magnetic potential in the reduced-order subspace.

[0016] The vector magnetic potential in the reduced-order subspace is reconstructed back into the high-dimensional space, and the magnetic field under the transformer short-circuit fault is calculated from the reconstructed vector magnetic potential.

[0017] Preferably, the process of establishing the full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space includes:

[0018] Establish a two-dimensional axisymmetric geometric model of the transformer;

[0019] Set the material parameters and constraints required for calculating the magnetic field of the transformer's 2D axisymmetric geometry model;

[0020] Based on the two-dimensional axisymmetric geometric model of the transformer with set material parameters and constraints, the Galerkin finite element method is used to establish a full-order calculation model of the transformer short-circuit magnetic field in high-dimensional space.

[0021] Preferably, the material parameters include relative dielectric constant, electrical conductivity and magnetic permeability of the material;

[0022] The constraint conditions include the excitation of each winding, axisymmetric boundary conditions, external boundary conditions and the initial vector magnetic potential of each structure.

[0023] Preferably, the system characteristics represented by the orthogonal basis are at least greater than 99.99%.

[0024] Preferably, when the nonlinear terms in the transformer short-circuit magnetic field reduction calculation model are updated using the interpolation matrix of the nonlinear terms, each time the magnetic field distribution is iteratively calculated, the values ​​of the interpolation points in the nonlinear terms are calculated based on the distribution of the magnetic field in the previous time step, and the nonlinear term stiffness matrix is ​​updated in combination with the interpolation matrix of the nonlinear terms.

[0025] The present invention further provides a system for rapidly analyzing and calculating a magnetic field under a transformer short-circuit fault, which is used to implement the method for rapidly analyzing and calculating a magnetic field under a transformer short-circuit fault as described above, comprising:

[0026] Vector magnetic potential calculation unit: used to iteratively calculate the vector magnetic potential of the previous several time steps through a pre-established full-order calculation model of the transformer short-circuit magnetic field in a high-dimensional space;

[0027] Solution vector snapshot matrix construction unit: used to construct a snapshot matrix of the solution vector according to the vector magnetic potential;

[0028] Nonlinear item snapshot matrix construction unit: used to construct the snapshot matrix of nonlinear items according to the nonlinear items in the process of iteratively calculating the vector magnetic potential of the previous several time steps;

[0029] Orthogonal basis calculation unit: used to obtain a set of orthogonal bases based on the intrinsic orthogonal decomposition method and combined with the snapshot matrix of the solution vector;

[0030] A reduced-order subspace construction unit: configured to construct a reduced-order subspace using the orthogonal basis;

[0031] Reduced-order unit: used to project the full-order calculation model of the transformer short-circuit magnetic field into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field;

[0032] Interpolation matrix acquisition unit: used to obtain the interpolation matrix of nonlinear terms based on the discrete empirical interpolation method and combined with the snapshot matrix of nonlinear terms;

[0033] Nonlinear term update unit: used to update the nonlinear term in the transformer short-circuit magnetic field reduction calculation model using the interpolation matrix of the nonlinear term;

[0034] Reduced-order subspace magnetic field calculation unit: used to iteratively calculate the transformer short-circuit magnetic field reduced-order calculation model with updated nonlinear terms to obtain the vector magnetic potential in the reduced-order subspace;

[0035] Magnetic field reconstruction unit: used to reconstruct the vector magnetic potential in the reduced-order subspace back to the high-dimensional space, and calculate the magnetic field under the transformer short-circuit fault based on the reconstructed vector magnetic potential.

[0036] The present invention further provides an electronic device, characterized in that it includes:

[0037] one or more processors;

[0038] a storage device having one or more programs stored thereon;

[0039] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault of the present invention as described above.

[0040] The present invention also provides a storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault of the present invention as described above.

[0041] The present invention also provides a method for rapid analysis and calculation of electromagnetic force under transformer short-circuit fault, comprising:

[0042] Calculate the magnetic field under the transformer short-circuit fault by using the method for rapid analysis and calculation of the magnetic field under the transformer short-circuit fault of the present invention;

[0043] The transformer short-circuit electromagnetic force is calculated according to the magnetic field under the transformer short-circuit fault.

[0044] The present invention also provides a system for rapid analysis and calculation of electromagnetic force under transformer short-circuit fault, comprising:

[0045] High-dimensional space magnetic field calculation module: used to calculate the magnetic field under the transformer short-circuit fault by using the method for rapid analysis and calculation of the magnetic field under the transformer short-circuit fault of the present invention;

[0046] Electromagnetic force calculation module: used to calculate the transformer short-circuit electromagnetic force through the magnetic field under the transformer short-circuit fault.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault of the present invention adopts the intrinsic orthogonal decomposition method to construct a solution vector snapshot matrix. Through singular value decomposition, the eigenvectors representing more than 99.9% of the system characteristics are selected as the orthogonal basis to obtain a reduced-order subspace, and the original equation is projected into the reduced-order subspace to achieve the effect of model reduction. On the basis of the intrinsic orthogonal decomposition method, the present invention combines the discrete empirical interpolation method to construct an interpolation matrix for nonlinear terms, which reduces the update time of nonlinear terms and the overall solution time of the equation. Taking into account the calculation rate and accuracy of the transformer in the short-circuit state, the calculation time of the rapid analysis of the transformer short circuit is greatly reduced, while ensuring that the influence on the calculation accuracy is within a certain control range. It can provide an important reference for the transformer magnetic field and online anti-short-circuit analysis and evaluation, and support the digital transformation of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 Flowchart of electromagnetic force calculation based on POD-DEIM order reduction in an embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram of a two-dimensional axisymmetric geometric model of a transformer established using CAD software in an embodiment of the present invention.

[0052] FIG3 (a) is a diagram showing the overall magnetic field calculation results using the commercial simulation software COMSOL calculation method; FIG3 (b) is a diagram showing the overall magnetic field calculation results using the reduced-order calculation method proposed in the present invention.

[0053] Figure 4 This is the overall magnetic field error distribution diagram of the commercial simulation software COMSOL and the reduced-order calculation method proposed in this invention.

[0054] Figure 5 This is a comparison chart of the calculation results of the magnetic field change over time at the observation point of the transformer core using the commercial simulation software COMSOL and the reduced-order calculation method proposed in this invention.

[0055] Figure 6 (a) is a comparison diagram of the calculation results of the axial short-circuit electromagnetic force of the high-voltage winding using the commercial simulation software COMSOL and the reduced-order calculation method proposed in the present invention; Figure 6 (b) is a comparison diagram of the calculation results of the radial short-circuit electromagnetic force of the high-voltage winding using the commercial simulation software COMSOL and the reduced-order calculation method proposed in the present invention.

[0056] FIG7 (a) is a comparison diagram of the time-varying results of the axial short-circuit electromagnetic force of the winding coil using the commercial simulation software COMSOL and the reduced-order calculation method proposed in the present invention; FIG7 (b) is a comparison diagram of the time-varying results of the radial short-circuit electromagnetic force of the winding coil using the commercial simulation software COMSOL and the reduced-order calculation method proposed in the present invention. DETAILED DESCRIPTION

[0057] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0058] See also Figure 1 , a method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault includes the following steps:

[0059] 1) Use CAD software to establish a two-dimensional axisymmetric geometric model of the transformer. Set the material parameters and constraints required to calculate the magnetic field of the two-dimensional axisymmetric geometric model of the transformer. The material parameters include the relative dielectric constant, conductivity, and magnetic permeability of the material. The constraints include the excitation of each winding, axisymmetric boundary conditions, external boundary conditions, and the initial vector magnetic potential of each structure.

[0060] 2) Based on a two-dimensional axisymmetric geometric model of the transformer with set material parameters and constraints, the Galerkin finite element method is used to establish a full-order calculation model of the transformer short-circuit magnetic field in high-dimensional space;

[0061] 3) setting an iterative time step for transient short-circuit magnetic field calculation for the full-order calculation model;

[0062] 4) Iteratively calculating the vector magnetic potential of the first n time steps, constructing a snapshot matrix of the solution vector based on the vector magnetic potential, and constructing a snapshot matrix of nonlinear terms based on the nonlinear terms in the iterative calculation of the vector magnetic potential of the first n time steps; wherein the first n time steps should be sufficient to reflect the changing trend of the magnetic field, and those skilled in the art may select the number based on actual conditions, and the present invention does not impose any specific limitation thereto;

[0063] 5) Based on the proper orthogonal decomposition (POD) method and combined with the snapshot matrix of the solution vector, a set of orthogonal bases is obtained. The selected orthogonal bases must represent at least 99.99% of the system characteristics. Using the orthogonal bases, a reduced-order subspace is constructed. The full-order calculation model of the transformer short-circuit magnetic field is projected into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field.

[0064] 6) Obtain the interpolation matrix of the nonlinear term based on the discrete empirical interpolation method (DEIM) and the snapshot matrix of the nonlinear term;

[0065] 7) Using the interpolation matrix of the nonlinear terms, the nonlinear terms in the transformer short-circuit magnetic field reduced-order calculation model are updated. The transformer short-circuit magnetic field reduced-order calculation model is then used for iterative calculation to obtain the transformer short-circuit magnetic field in the reduced-order subspace. During each iterative calculation of the magnetic field distribution, the values ​​of the interpolation points in the nonlinear terms are calculated based on the distribution of the magnetic field at the previous time step. The nonlinear term stiffness matrix is ​​then updated in combination with the nonlinear term interpolation matrix.

[0066] 8) Reconstruct the transformer short-circuit magnetic field in the reduced-order subspace back to the high-dimensional space to obtain the magnetic field under the transformer short-circuit fault.

[0067] On the basis of the above solution, the transformer short-circuit electromagnetic force can be calculated through the magnetic field under the transformer short-circuit fault.

[0068] Example

[0069] The transformer short circuit rapid analysis and calculation method of this embodiment is specifically implemented in the following process. Figure 1 , including the following steps.

[0070] 1) Use CAD software to create Figure 2 The transformer is shown in the figure. The material parameters and constraints required for calculating the magnetic field of the transformer are set. The material parameters include the relative dielectric constant, conductivity, and magnetic permeability of the material. The constraints include the excitation of each winding, the axisymmetric boundary conditions, the external boundary conditions, and the initial vector magnetic potential of each structure.

[0071] 2) Based on the two-dimensional axisymmetric geometric model of the transformer with set material parameters and constraints, the Galerkin finite element method is used to establish a full-order calculation model of the transformer short-circuit magnetic field:

[0072]

[0073] Where: and is a nonlinear term, is the excitation term related to the winding current, is the vector magnetic potential, n Numbers the time steps in the calculation process.

[0074] 3) Setting the iterative time step of transient short-circuit magnetic field calculation for the full-order calculation model to 0.2 ms;

[0075] 4) Taking into account the changing characteristics of the transformer magnetic field under the short-circuit state, the vector magnetic potential of the first 20 time steps is iteratively calculated, and the snapshot matrix of the solution vector is constructed based on the vector magnetic potential. The snapshot matrix of the nonlinear term is constructed based on the nonlinear term in the iterative calculation of the vector magnetic potential of the first 20 time steps. Among them, each column of the snapshot matrix corresponds to the calculation results of the solution vector and the nonlinear term at different time steps. The snapshot matrix X =[ x 1, x 2, x 3,……, x 20 ], x i (1≤ i ≤20) is the solution vector or nonlinear term in the i The calculation results under time steps;

[0076] 5) Based on the eigenorthogonal decomposition method, the solution vector snapshot matrix Perform singular value decomposition:

[0077]

[0078] Where: , is a standard orthogonal matrix, is a semi-positive singular value matrix. Since the singular values ​​are arranged from large to small on the diagonal, it means that the original data can be approximately represented by the eigenvalue vectors corresponding to the first few larger singular values. U Column vector in u i This is the orthogonal basis vector that needs to be selected. U The column vectors whose first few representations of the system features exceed 99.9% u i , which is the orthogonal basis of the reduced-order subspace that meets the requirements: The orthogonal basis is used to construct a reduced-order subspace, and the full-order calculation model of the transformer short-circuit magnetic field is projected into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field:

[0079]

[0080]

[0081] Compared with the full-order computational model, the order of the reduced-order computational model equation is m Became d ,because d << m , the order of the equation is greatly reduced, which greatly improves the efficiency of solving the equation;

[0082] 6) Based on the discrete empirical interpolation method and combined with the nonlinear term snapshot matrix, the interpolation matrix of the nonlinear term is obtained D For the nonlinear term snapshot matrix , select the orthogonal basis through singular value decomposition. The principle of selecting the number of orthogonal bases is the same as that described in step 5). Use the orthogonal basis to express the nonlinear term:

[0083]

[0084] Where: W for m OK d Orthogonal basis of columns; c for d The coefficient matrix is ​​a 1-column matrix. c When the Boolean matrix is ​​introduced P Make a selection. Boolean matrix PThe expression is as follows:

[0085]

[0086] Where: , , for the i The Boolean matrix P Introduction In the equation, we get the coefficient matrix c The expression: . The coefficient matrix c Substitute the expression into the formula In the above equation, we can get: Where D This is the interpolation matrix of the nonlinear term.

[0087] 7) Using nonlinear terms to interpolate matrices D Update the nonlinear terms in the transformer short-circuit magnetic field reduction model: K , M The calculation results of the first 20 time steps form a snapshot matrix, and the discrete empirical interpolation method is used to obtain the corresponding Boolean matrix P K , P M and the interpolation matrix D K , D M . Interpolation matrix D and Boolean matrices P Only one calculation is required in the entire process. In the subsequent update of the nonlinear term, only the element values ​​at the 20 discrete point number positions need to be calculated and then multiplied by the interpolation matrix. D , the iterative update of the entire nonlinear term can be completed. The reduced-order calculation model combined with the discrete empirical interpolation method is as follows:

[0088]

[0089] The transformer short-circuit magnetic field reduction model is used for iterative calculation to obtain the vector magnetic potential results in the reduced-order subspace.

[0090] 8) The vector magnetic potential in the reduced-order subspace is reconstructed back to the high-dimensional space, and the magnetic field under the transformer short-circuit fault is calculated from the vector magnetic potential. The effectiveness of the proposed reduced-order algorithm is evaluated by comparing the calculation results between the reduced-order model and the commercial simulation software COMSOL. The overall leakage magnetic distribution inside the transformer is shown in Figure 3 (a) and Figure 3 (b). In the entire area, the flux density at the corner of the core is relatively large. The maximum value of the flux density obtained by the reduced-order algorithm and COMSOL is around 2.5T. The calculation results of the two methods are basically consistent, indicating that the calculation results of the reduced-order algorithm are in good agreement with the results of the COMSOL software. The relative percentage error cloud diagram between the calculation results of the reduced-order algorithm and COMSOL is shown in Figure 4 As shown. Figure 4 It can be seen that the error in the winding and insulating oil areas is relatively small, basically within 1%, while the error in the core area is relatively large. However, the relative percentage error between the reduced-order algorithm and the COSMOL software does not exceed 3.5% overall, which still has high accuracy. The data of the magnetic flux density change over time at the observation point of the core was extracted. The magnetic flux density change curve at the observation point is shown in the figure below. Figure 5 As shown in the figure, the change trend of the magnetic flux density of the reduced-order algorithm at the observation point is basically consistent with the COMSOL calculation result, with the absolute error not exceeding 0.03T and the relative error not exceeding 3.26%, which proves the accuracy of the reduced-order algorithm.

[0091] The transformer short-circuit electromagnetic force was further calculated using the magnetic field calculated in step 8) above under the transformer short-circuit fault. The axial and radial electromagnetic forces acting on each coil in the high-voltage winding were extracted using the reduced-order algorithm and compared with the COMSOL calculation results, as shown in Figures 6(a) and 6(b). Compared with the COMSOL calculation results, the error in the axial short-circuit electromagnetic force of the reduced-order algorithm was less than 1%, and the error in the radial short-circuit electromagnetic force of the reduced-order model was less than 3.2%, demonstrating high accuracy and the effectiveness of the reduced-order algorithm. Data on the temporal variation of the short-circuit electromagnetic force of winding No. 470 in the upper end region of the high-voltage winding were extracted, as shown in Figures 7(a) and 7(b). The transient variation of the reduced-order algorithm calculation results is essentially consistent with that of the COMSOL calculation results. The maximum relative error of the reduced-order algorithm compared to the COMSOL calculation results does not exceed 2.86%. To evaluate the computational efficiency of the reduced-order algorithm, the computational time of the reduced-order algorithm and COMSOL software was compared, as shown in Table 1.

[0092] Table 1

[0093]

[0094] Table 1 shows that the COMSOL software computation time is 1299 seconds. For the reduced-order model, the preprocessing time includes the time to form the orthogonal basis and construct the interpolation matrix. The reduced-order algorithm computation time is 132.6 seconds. Compared to COMSOL, the reduced-order algorithm's computational efficiency is improved by a factor of 9.8, fully demonstrating the effectiveness of the proposed reduced-order algorithm in calculating transformer short-circuit magnetic fields.

[0095] An embodiment of the present invention further provides a system for rapidly analyzing and calculating a magnetic field under a transformer short-circuit fault, which is used to implement the method for rapidly analyzing and calculating a magnetic field under a transformer short-circuit fault as described above, comprising:

[0096] Vector magnetic potential calculation unit: used to iteratively calculate the vector magnetic potential of the previous several time steps through a pre-established full-order calculation model of the transformer short-circuit magnetic field in a high-dimensional space;

[0097] Solution vector snapshot matrix construction unit: used to construct a snapshot matrix of the solution vector according to the vector magnetic potential;

[0098] Nonlinear item snapshot matrix construction unit: used to construct the snapshot matrix of nonlinear items according to the nonlinear items in the process of iteratively calculating the vector magnetic potential of the previous several time steps;

[0099] Orthogonal basis calculation unit: used to obtain a set of orthogonal bases based on the intrinsic orthogonal decomposition method and combined with the snapshot matrix of the solution vector;

[0100] A reduced-order subspace construction unit: configured to construct a reduced-order subspace using the orthogonal basis;

[0101] Reduced-order unit: used to project the full-order calculation model of the transformer short-circuit magnetic field into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field;

[0102] Interpolation matrix acquisition unit: used to obtain the interpolation matrix of nonlinear terms based on the discrete empirical interpolation method and combined with the snapshot matrix of nonlinear terms;

[0103] Nonlinear term update unit: used to update the nonlinear term in the transformer short-circuit magnetic field reduction calculation model using the interpolation matrix of the nonlinear term;

[0104] Reduced-order subspace magnetic field calculation unit: used to iteratively calculate the transformer short-circuit magnetic field reduced-order calculation model with updated nonlinear terms to obtain the vector magnetic potential in the reduced-order subspace;

[0105] Magnetic field reconstruction unit: used to reconstruct the vector magnetic potential in the reduced-order subspace back to the high-dimensional space, and calculate the magnetic field under the transformer short-circuit fault based on the reconstructed vector magnetic potential.

[0106] The embodiments of the present invention also provide corresponding electronic devices and computer-readable storage media for implementing the solutions provided by the embodiments of the present invention.

[0107] The electronic device includes a storage device and a processor, the storage device is used to store instructions or codes, and the processor is used to execute the instructions or codes so that the electronic device executes the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault as described in any embodiment of the present application.

[0108] In practical applications, the computer-readable storage medium may be any combination of one or more computer-readable media, which may be a computer-readable signal medium or a computer-readable storage medium.

[0109] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for rapid analysis and calculation of magnetic field under transformer short-circuit fault, characterized in that: The process includes the following: The vector magnetic potential of the first several time steps is iteratively calculated using a pre-established full-order calculation model of the transformer short-circuit magnetic field in a high-dimensional space. Construct a snapshot matrix of the solution vector based on the vector magnetic potential; A snapshot matrix of nonlinear terms is constructed according to the nonlinear terms in the process of iteratively calculating the vector magnetic potential of the first several time steps; Based on the eigenorthogonal decomposition method and combined with the snapshot matrix of the solution vector, a set of orthogonal bases are obtained; Using the orthogonal basis, constructing a reduced-order subspace; The full-order calculation model of the transformer short-circuit magnetic field is projected into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field; Based on the discrete empirical interpolation method and combined with the snapshot matrix of the nonlinear term, the interpolation matrix of the nonlinear term is obtained; The nonlinear terms in the transformer short-circuit magnetic field reduction model are updated using the interpolation matrix of the nonlinear terms. The transformer short-circuit magnetic field reduced-order calculation model with updated nonlinear terms is used for iterative calculation to obtain the vector magnetic potential in the reduced-order subspace. The vector magnetic potential in the reduced-order subspace is reconstructed back into the high-dimensional space, and the magnetic field under the transformer short-circuit fault is calculated from the reconstructed vector magnetic potential.

2. The method for rapid analysis and calculation of magnetic field under transformer short-circuit fault according to claim 1 is characterized in that: The process of establishing the full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space includes: Establish a two-dimensional axisymmetric geometric model of the transformer; Set the material parameters and constraints required for calculating the magnetic field of the transformer's 2D axisymmetric geometry model; Based on the two-dimensional axisymmetric geometric model of the transformer with set material parameters and constraints, the Galerkin finite element method is used to establish a full-order calculation model of the transformer short-circuit magnetic field in high-dimensional space.

3. The method for rapid analysis and calculation of magnetic field under transformer short-circuit fault according to claim 2 is characterized in that: The material parameters include relative dielectric constant, electrical conductivity and magnetic permeability of the material; The constraint conditions include the excitation of each winding, axisymmetric boundary conditions, external boundary conditions and the initial vector magnetic potential of each structure.

4. The method for rapid analysis and calculation of magnetic field under transformer short-circuit fault according to claim 1 is characterized in that: The system characteristics represented by the orthogonal basis must be at least greater than 99.99%.

5. The method for rapid analysis and calculation of magnetic field under transformer short-circuit fault according to claim 1 is characterized in that: When the nonlinear terms in the transformer short-circuit magnetic field reduction calculation model are updated using the interpolation matrix of the nonlinear terms, each time the magnetic field distribution is iteratively calculated, the values ​​of the interpolation points in the nonlinear terms are calculated according to the distribution of the magnetic field in the previous time step, and the nonlinear term stiffness matrix is ​​updated in combination with the interpolation matrix of the nonlinear terms.

6. A system for rapid analysis and calculation of magnetic field under transformer short-circuit fault, characterized in that: include: Vector magnetic potential calculation unit: used to iteratively calculate the vector magnetic potential of the previous several time steps through a pre-established full-order calculation model of the transformer short-circuit magnetic field in a high-dimensional space; Solution vector snapshot matrix construction unit: used to construct a snapshot matrix of the solution vector according to the vector magnetic potential; Nonlinear item snapshot matrix construction unit: used to construct the snapshot matrix of nonlinear items according to the nonlinear items in the process of iteratively calculating the vector magnetic potential of the previous several time steps; Orthogonal basis calculation unit: used to obtain a set of orthogonal bases based on the intrinsic orthogonal decomposition method and combined with the snapshot matrix of the solution vector; A reduced-order subspace construction unit: configured to construct a reduced-order subspace using the orthogonal basis; Reduced-order unit: used to project the full-order calculation model of the transformer short-circuit magnetic field into the reduced-order subspace to obtain the reduced-order calculation model of the transformer short-circuit magnetic field; Interpolation matrix acquisition unit: used to obtain the interpolation matrix of nonlinear terms based on the discrete empirical interpolation method and combined with the snapshot matrix of nonlinear terms; Nonlinear term update unit: used to update the nonlinear term in the transformer short-circuit magnetic field reduction calculation model using the interpolation matrix of the nonlinear term; Reduced-order subspace magnetic field calculation unit: used to iteratively calculate the transformer short-circuit magnetic field reduced-order calculation model with updated nonlinear terms to obtain the vector magnetic potential in the reduced-order subspace; Magnetic field reconstruction unit: used to reconstruct the vector magnetic potential in the reduced-order subspace back to the high-dimensional space, and calculate the magnetic field under the transformer short-circuit fault based on the reconstructed vector magnetic potential.

7. An electronic device, characterized in that: include: one or more processors; a storage device having one or more programs stored thereon; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault according to any one of claims 1 to 5.

8. A storage medium, characterized in that: A computer program is stored thereon, wherein when the computer program is executed by a processor, the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault according to any one of claims 1 to 5 is implemented.

9. A method for rapid analysis and calculation of electromagnetic force under transformer short-circuit fault, characterized in that: include: Calculating the magnetic field under a transformer short-circuit fault by using the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault according to any one of claims 1 to 5; The transformer short-circuit electromagnetic force is calculated according to the magnetic field under the transformer short-circuit fault.

10. A system for rapid analysis and calculation of electromagnetic force under transformer short-circuit fault, characterized in that: include: A high-dimensional space magnetic field calculation module: used to calculate the magnetic field under a transformer short-circuit fault by using the method for rapid analysis and calculation of the magnetic field under a transformer short-circuit fault according to any one of claims 1 to 5; Electromagnetic force calculation module: used to calculate the transformer short-circuit electromagnetic force through the magnetic field under the transformer short-circuit fault.

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