Rapid magnetic field analysis and calculation method under transformer short-circuit fault and related device

Abstract

The invention belongs to the field of power equipment multi-physical field rapid calculation, and discloses a magnetic field rapid analysis and calculation method under a transformer short-circuit fault and a related device. The method comprises the following steps: calculating vector magnetic potentials of a plurality of previous time steps through a full-order calculation model of a transformer short-circuit magnetic field in a high-dimensional space; constructing a snapshot matrix of a solution vector and a snapshot matrix of a nonlinear term; obtaining a group 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 by using an orthogonal basis; projecting the full-order calculation model of the short-circuit magnetic field of the transformer into the reduced-order subspace; based on a discrete experience interpolation method and in combination with the snapshot matrix of the non-linear term, obtaining an interpolation matrix of the non-linear term; updating a nonlinear term in the transformer short-circuit magnetic field reduced-order calculation model by using the interpolation matrix, and then calculating to obtain a vector magnetic potential in a reduced-order subspace; and reconstructing the vector magnetic potential back to the high-dimensional space, and calculating the magnetic field under the short-circuit fault of the transformer according to 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 specifically relates to a method for rapid analysis and calculation of magnetic fields under transformer short-circuit fault and related devices. Background Art

[0002] UHV substations and converter stations are key nodes in the UHV DC transmission system. They undertake important tasks such as signal processing, AC / DC conversion, and overvoltage protection. With the construction of power systems dominated by new energy, the number and capacity of equipment in the station have increased significantly. Among them, the transformer is a key equipment in the process of power transmission and application. Ensuring its safe and stable operation is of great significance to improving the reliability of the power system. When the transformer suddenly short-circuits, the surge in short-circuit current will cause the electromagnetic force on the winding to increase sharply, which will cause the winding to deform or even be damaged, affecting the safe and stable operation of the transformer. Therefore, it is crucial to accurately and in real time grasp the leakage magnetic field and electromagnetic force distribution of the transformer in the short-circuit state and develop its rapid calculation and analysis technology to ensure the safe and stable operation of the transformer.

[0003] Physical field simulation analysis technology is a numerical calculation method that uses the finite element method to solve field problems described by differential equations. With the advancement of simulation theory and computer technology, it has become a very mature technology. Many commercial software have the function of electromagnetic field finite element simulation calculation. However, the transformer has a complex structure and a large number of grid nodes, which results in a large amount of calculation. At the same time, the transformer core is made of ferromagnetic material, and its relative permeability has typical nonlinear characteristics. Multiple iterations are required in the calculation of each time step, which consumes a lot of time and seriously restricts the calculation efficiency of transformer short-circuit analysis. Therefore, in order to realize real-time simulation of transformer short-circuit analysis, it is urgent to develop model reduction methods, master the fast calculation method of transformer magnetic field, greatly reduce the time required for simulation calculation, and improve the efficiency of simulation calculation. 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 devices for quickly analyzing and calculating the magnetic field under a transformer short-circuit fault. The present invention can meet the needs of quickly calculating the transformer magnetic field, improve the calculation efficiency, and ensure the 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] In order to achieve the above object, the present invention is implemented by adopting the following technical solutions: A method for rapid analysis and calculation of magnetic field under transformer short-circuit fault includes the following process: The vector magnetic potential of the first several time steps is iteratively calculated through the pre-established full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space; Construct a snapshot matrix of solution vectors based on 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 previous several time steps; Based on the proper orthogonal 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 calculation 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.

[0006] Preferably, 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 full-order calculation model of the transformer short-circuit magnetic field in high-dimensional space is established using the Galerkin finite element method.

[0007] Preferably: 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.

[0008] Preferably, the system characteristics characterized by the orthogonal base are at least greater than 99.99%.

[0009] Preferably, when the nonlinear terms in the transformer short-circuit magnetic field reduction-order 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.

[0010] The present invention also provides a system for quickly analyzing and calculating a magnetic field under a transformer short-circuit fault, which is used to implement the method for quickly analyzing and calculating a magnetic field under a transformer short-circuit fault as described above, comprising: Vector magnetic potential calculation unit: used to iteratively calculate the vector magnetic potential of the previous several time steps through the pre-established full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space; Solution vector snapshot matrix building unit: used to build 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: used 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 in combination with the snapshot matrix of nonlinear terms; Nonlinear term updating unit: used to update the nonlinear term in the transformer short-circuit magnetic field reduction order calculation model using the interpolation matrix of the nonlinear term; Reduced-order subspace magnetic field calculation unit: used for iterative calculation using 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 from the reconstructed vector magnetic potential.

[0011] The present invention also provides an electronic device, characterized in that it includes: 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 of the present invention as described above.

[0012] The present invention also provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method for rapid analysis and calculation of magnetic field under transformer short-circuit fault as described above in the present invention.

[0013] The present invention also provides a method for rapid analysis and calculation of electromagnetic force under transformer short-circuit fault, comprising: The magnetic field under the transformer short-circuit fault is calculated by the method for rapid analysis and calculation of the magnetic field under the transformer short-circuit fault of the present invention; The transformer short-circuit electromagnetic force is calculated through the magnetic field under the transformer short-circuit fault.

[0014] The present invention also provides a system for rapid analysis and calculation of electromagnetic force under transformer short-circuit fault, comprising: 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 of the present invention as described above; Electromagnetic force calculation module: used to calculate the transformer short-circuit electromagnetic force through the magnetic field under the transformer short-circuit fault.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The method for rapid analysis and calculation of the magnetic field under transformer short-circuit fault of the present invention adopts the intrinsic orthogonal decomposition method to construct a solution vector snapshot matrix, and through singular value decomposition, selects the eigenvectors representing more than 99.9% of the system characteristics as the orthogonal basis to obtain the reduced-order subspace, and projects the original equation 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 the interpolation matrix of the nonlinear terms, reduces the update time of the nonlinear terms, and reduces the overall solution time of the equation. Comprehensively considering the calculation rate and accuracy of the transformer in the short-circuit state, the calculation time of the transformer short-circuit rapid analysis is greatly reduced, while ensuring that the influence on the calculation accuracy is within a certain control range, which can provide an important reference for the transformer magnetic field and online short-circuit resistance analysis and evaluation, and support the digital transformation of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 creative work.

[0017] Figure 1 Flow chart of calculating electromagnetic force based on POD-DEIM order reduction in an embodiment of the present invention.

[0018] 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.

[0019] FIG. 3 (a) is a diagram showing the overall magnetic field calculation results using the commercial simulation software COMSOL calculation method; FIG. 3 (b) is a diagram showing the overall magnetic field calculation results using the reduced-order calculation method proposed in the present invention.

[0020] Figure 4 It is the overall magnetic field error distribution diagram of the commercial simulation software COMSOL and the reduced-order calculation method proposed in the present invention.

[0021] Figure 5 It is a comparison chart of the calculation results of the magnetic field variation over time at the observation point of the transformer core using the commercial simulation software COMSOL and the reduced-order calculation method proposed in the present invention.

[0022] FIG6 (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; FIG6 (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.

[0023] 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

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] See also Figure 1 , a method for rapid analysis and calculation of magnetic field under transformer short-circuit fault includes the following steps: 1) Use CAD software to establish a two-dimensional axisymmetric geometric model of the transformer, and set the material parameters and constraints required for calculating 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, and the constraints include the excitation of each winding, axisymmetric boundary conditions, external boundary conditions and the initial vector magnetic potential of each structure; 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 in high-dimensional space; 3) setting an iterative time step for transient short-circuit magnetic field calculation for the full-order calculation model; 4) Iteratively calculate the vector magnetic potential of the first n time steps, construct a snapshot matrix of the solution vector according to the vector magnetic potential, and construct a snapshot matrix of nonlinear terms according to the nonlinear terms in the process of iteratively calculating 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 can select them according to actual conditions, and the present invention does not make specific limitations; 5) Based on the proper orthogonal decomposition (POD) method and in combination with the snapshot matrix of the solution vector, a set of orthogonal bases are obtained, and the system characteristics represented by the selected orthogonal bases must be at least more than 99.99%; using the orthogonal bases, a reduced-order subspace is constructed, 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; 6) Based on the discrete empirical interpolation method (DEIM) and combined with the snapshot matrix of nonlinear terms, the interpolation matrix of nonlinear terms is obtained; 7) Use the interpolation matrix of the nonlinear term to update the nonlinear term in the transformer short-circuit magnetic field reduction calculation model, and then use the transformer short-circuit magnetic field reduction calculation model to iteratively calculate and obtain the transformer short-circuit magnetic field in the reduced-order subspace; wherein, each time the magnetic field distribution is iteratively calculated, the value of the interpolation point in the nonlinear term is 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 nonlinear term interpolation matrix; 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.

[0026] On the basis of the above scheme, the transformer short-circuit electromagnetic force can be calculated through the magnetic field under the transformer short-circuit fault.

[0027] Example The transformer short circuit rapid analysis and calculation method of this embodiment is specifically implemented in the following process. Figure 1 , comprising the following steps.

[0028] 1) Use CAD software to create Figure 2 The two-dimensional axisymmetric geometric model of the transformer is shown, and the material parameters and constraints required for calculating the magnetic field of the two-dimensional axisymmetric geometric model of the transformer are set, wherein the material parameters include the relative dielectric constant, conductivity and magnetic permeability of the material, and 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; 2) Based on the two-dimensional axisymmetric geometric model of the transformer with set material parameters and constraints, the full-order calculation model of the transformer short-circuit magnetic field is established using the Galerkin finite element method:

[0029] Where: and is a nonlinear term, is the excitation term related to the winding current, is the vector magnetic potential, nNumbers the time steps in the calculation process.

[0030] 3) Setting the iterative time step of transient short-circuit magnetic field calculation for the full-order calculation model to 0.2 ms; 4) Considering 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. Each column of the snapshot matrix corresponds to the calculation results of the solution vector and the nonlinear term at different time steps. 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 at time steps; 5) Based on the eigenorthogonal decomposition method, the solution vector snapshot matrix Perform singular value decomposition:

[0031] Where: , is a standard orthogonal matrix, is a semi-positive definite 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 The column vector in u i This is the orthogonal basis vector that needs to be selected. U The column vectors of the first few system features that represent more than 99.9% of the system features 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:

[0032]

[0033] Compared with the full-order computational model, the order of the reduced-order computational model equation is m Becamed ,because d << m , the order of the equation is greatly reduced, which greatly improves the efficiency of solving the equation; 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, and the principle of selecting the number of orthogonal bases is the same as that described in step 5). Use the orthogonal basis to represent the nonlinear term:

[0034] Where: W for m OK d Orthogonal basis of columns; c for d The coefficient matrix is ​​1 row and 1 column. c When the Boolean matrix is ​​introduced P Make a selection. Boolean Matrix P The expression is as follows:

[0035] Where: , , for i The Boolean matrix P Introduction In the equation, we get the coefficient matrix c The expression is: . The coefficient matrix c Substitute the expression into the formula In, we can get: Where D This is the interpolation matrix of the nonlinear term.

[0036] 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 corresponding Boolean matrix is ​​obtained using the discrete empirical interpolation method. P K , P M And the interpolation matrix D K , D M The interpolation matrix D and the Boolean matrix POnly one calculation is required in the entire process. In the subsequent update of the nonlinear term, only the element values ​​at the positions of the 20 discrete point numbers 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:

[0037] The transformer short-circuit magnetic field reduction model is used for iterative calculation to obtain the vector magnetic potential result in the reduced-order subspace. 8) 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 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 value 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, and the calculation results of the two methods are basically consistent, indicating that the calculation results of the reduced-order algorithm are consistent 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 area is small, basically within 1%; the error in the core area is 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 change of magnetic flux density over time at the observation point of the core is extracted. The change curve of magnetic flux density at the observation point is shown in 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, the absolute error does not exceed 0.03T, and the relative error does not exceed 3.26%, which proves the accuracy of the reduced-order algorithm.

[0038] The magnetic field under the transformer short-circuit fault calculated by the above step 8) is used to further calculate the transformer short-circuit electromagnetic force. The axial and radial electromagnetic forces on each coil in the high-voltage winding of the reduced-order algorithm are extracted and compared with the calculation results of COMSOL, as shown in Figures 6 (a) and 6 (b). Compared with the COMSOL calculation results, the error of the axial short-circuit electromagnetic force of the reduced-order algorithm is less than 1%, and the error of the radial short-circuit electromagnetic force of the reduced-order model is less than 3.2%, which has high accuracy, indicating the effectiveness of the reduced-order algorithm. The data of the short-circuit electromagnetic force of the 470th winding in the upper end area of ​​the high-voltage winding over time are extracted, as shown in Figures 7 (a) and 7 (b). The transient change process of the reduced-order algorithm calculation results is basically consistent with that of the COMSOL calculation results. Among them, compared with the COMSOL calculation results, the maximum relative error of the reduced-order algorithm does not exceed 2.86%. In order to evaluate the computational efficiency of the reduced-order algorithm, the calculation time of the reduced-order algorithm and COMSOL software is compared, and the results are shown in Table 1: Table 1

[0039] From Table 1, it can be seen that the calculation time of COMSOL software is 1299s. For the reduced-order model, its preprocessing time includes the time to form the orthogonal basis and the time to construct the interpolation matrix. The calculation time of the reduced-order algorithm is 132.6s. Compared with COSMOL software, the calculation efficiency of the reduced-order algorithm is improved by 9.8 times, which fully demonstrates the efficiency of the proposed reduced-order algorithm in calculating the transformer short-circuit magnetic field problem.

[0040] The embodiment of the present invention further provides a system for quickly analyzing and calculating a magnetic field under a transformer short-circuit fault, which is used to implement the method for quickly analyzing and calculating a magnetic field under a transformer short-circuit fault as described above, comprising: Vector magnetic potential calculation unit: used to iteratively calculate the vector magnetic potential of the previous several time steps through the pre-established full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space; Solution vector snapshot matrix building unit: used to build 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: used 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 in combination with the snapshot matrix of nonlinear terms; Nonlinear term updating unit: used to update the nonlinear term in the transformer short-circuit magnetic field reduction order calculation model using the interpolation matrix of the nonlinear term; Reduced-order subspace magnetic field calculation unit: used for iterative calculation using 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 from the reconstructed vector magnetic potential.

[0041] 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.

[0042] Among them, 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.

[0043] 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.

[0044] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope 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 through the pre-established full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space; Construct a snapshot matrix of solution vectors based on 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 previous several time steps; Based on the proper orthogonal 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 calculation 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 two-dimensional 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 characterized 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 the pre-established full-order calculation model of the transformer short-circuit magnetic field in the high-dimensional space; Solution vector snapshot matrix building unit: used to build 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: used 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 in combination with the snapshot matrix of nonlinear terms; Nonlinear term updating unit: used to update the nonlinear term in the transformer short-circuit magnetic field reduction order calculation model using the interpolation matrix of the nonlinear term; Reduced-order subspace magnetic field calculation unit: used for iterative calculation using 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 from 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 as described in 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 as claimed in 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: 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 as claimed in any one of claims 1 to 5; The transformer short-circuit electromagnetic force is calculated through 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 as claimed in 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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