Two-dimensional power equipment high-fidelity high-efficiency transient flow field solving method under rectangular coordinates and related device

Abstract

The invention belongs to the field of power equipment simulation calculation, and discloses a two-dimensional power equipment high-fidelity efficient transient flow field solving method under rectangular coordinates and a related device, and the method comprises the steps: solving an established power equipment two-dimensional model through a flow field full-order model, obtaining flow field horizontal velocity components and vertical velocity components of the fluid in the power equipment at multiple moments; forming a sample matrix by the horizontal velocity components and the vertical velocity components of the flow field at the multiple moments; performing singular value decomposition on the sample matrix to obtain a velocity basis function and a velocity spectrum coefficient at an initial moment; calculating velocity spectrum coefficients at different moments by using an established two-dimensional power equipment flow field low-order transient calculation model, the velocity primary function and the velocity spectrum coefficients at the initial moment; and carrying out linear superposition on the velocity basis function and the velocity spectrum coefficients at different moments to obtain an approximate field of the flow field. According to the method, the transient flow field of the power equipment can be efficiently solved on the premise of ensuring the accuracy of a calculation result.

Description

Technical Field

[0001] The present invention belongs to the field of simulation calculation of electric power equipment, and specifically relates to a high-fidelity and high-efficiency transient flow field solution method and related device for two-dimensional electric power equipment under rectangular coordinates. The present invention is mainly used in flow and heat transfer simulation calculation of electric power equipment. Background Art

[0002] With the rapid construction of new power systems based on new energy sources, the number and capacity of equipment in converter stations will increase significantly. This requires power equipment to have low-carbon, safe and reliable characteristics under high energy flow density, strong coupling field and complex climate environment to ensure the long-term stable operation of the power system. As an important power transmission and transformation equipment in converter stations, transformers are subjected to the combined effects of complex electrical, thermal, mechanical and other multi-physical fields for a long time during their service life. The internal state is complex and changeable, and the risk of failure is high. At present, the non-isothermal flow of oil in power equipment such as transformers has an important influence on the heat transfer, heat dissipation performance and thermal field distribution of power equipment, and the calculation of transformer flow field and temperature field mostly relies on commercial software. However, due to the large size and complex internal structure of power equipment, a large number of grids need to be divided when solving. Therefore, the simulation iteration convergence speed is slow, which seriously restricts the online visualization of the characteristics of the multi-physical field of power equipment. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a high-fidelity and efficient transient flow field solution method and related devices for two-dimensional power equipment under rectangular coordinates. The present invention can achieve efficient solution of the transient flow field of power equipment while ensuring the accuracy of the calculation results.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates, comprising: The established two-dimensional model of power equipment is solved using the full-order flow field model to obtain the horizontal velocity component and vertical velocity component of the flow field of the fluid inside the power equipment at multiple times. The horizontal velocity components and vertical velocity components of the flow field at the multiple moments form a sample matrix; Performing singular value decomposition on the sample matrix to obtain velocity basis functions and velocity spectrum coefficients at an initial moment; The velocity spectrum coefficients at different times are calculated by using the established low-order transient calculation model of the flow field of the two-dimensional power equipment, the velocity basis function and the velocity spectrum coefficients at the initial time; The velocity basis function and the velocity spectrum coefficients at different times are linearly superimposed to obtain the approximate flow field.

[0005] Preferably, the low-order transient calculation model of the two-dimensional power equipment flow field is as follows:

[0006] in:

[0007]

[0008]

[0009]

[0010]

[0011] In the formula, is the velocity spectrum coefficient; is the horizontal velocity component of the flow field u The velocity basis function of is the vertical velocity component of the flow field v velocity basis function; M is the number of velocity basis functions used to describe the flow field, for pressure; for u Velocity source term; for v Velocity source term; is the transient term coefficient; is the convection term coefficient; is the diffusion term coefficient; is the boundary condition; is the source item.

[0012] Preferably, the horizontal velocity component of the flow field u and the vertical velocity component v The following continuity equation is satisfied:

[0013] In the formula, x is the horizontal coordinate of the rectangular coordinate system constructed in the flow field, y It is the ordinate of the rectangular coordinate system constructed in the flow field.

[0014] Preferably, the horizontal velocity component of the flow field u Velocity basis function and the vertical velocity component v Sudu basis function The following continuity equation is satisfied: .

[0016] Preferably, the established two-dimensional power equipment flow field low-order transient calculation model and the velocity basis function and the velocity spectrum coefficient at the initial moment are used to calculate the velocity spectrum coefficients at different moments: The low-order transient calculation model of the flow field of two-dimensional power equipment is discretized by using the finite volume method to obtain a discrete model; The velocity basis function and the velocity spectrum coefficients at the initial moment are substituted into the discrete model for calculation to obtain the velocity spectrum coefficients at different moments.

[0017] Preferably, after performing singular value decomposition on the sample matrix, based on the order of flow field pulsation according to energy size, the part whose contribution to the flow characteristics exceeds a first preset value is screened out to determine the velocity basis function and the velocity spectrum coefficient at the initial moment.

[0018] Preferably, the power equipment is a transformer, a bushing or a GIS having a fluid, and the fluid is an insulating fluid or a heat dissipation fluid.

[0019] The present invention also provides a high-fidelity and high-efficiency transient flow field solving system for two-dimensional power equipment under rectangular coordinates, comprising: The first calculation unit is used to solve the established two-dimensional model of the power equipment by using the full-order flow field model to obtain the horizontal velocity component and the vertical velocity component of the flow field of the oil inside the power equipment at multiple times; A sample matrix building unit: used for forming a sample matrix from the horizontal velocity components and the vertical velocity components of the flow field at the plurality of moments; Decomposition unit: used for performing singular value decomposition on the sample matrix to obtain velocity basis functions and velocity spectrum coefficients at an initial moment; The second calculation unit is used to calculate the velocity spectrum coefficients at different times by using the established two-dimensional power equipment flow field low-order transient calculation model and the velocity basis function and the velocity spectrum coefficients at the initial time; The third calculation unit is used to linearly superimpose the velocity basis function and the velocity spectrum coefficients at different times to obtain an approximate field of the flow field.

[0020] The present invention also provides an electronic device, comprising: 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 high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates as described above in the present invention.

[0021] Preferably, the present invention further provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates as described above in the present invention.

[0022] The present invention has the following beneficial effects: The present invention converts the variables in the flow field momentum equation into u and v It is transformed into the spectral coefficient a, because the number of spectral coefficients depends on the number of velocity basis functions when the sample matrix is ​​singularly decomposed. Usually, the contribution rate of the first few columns of basis functions to the overall flow field can reach more than 99%, so the number of spectral coefficients will be greatly reduced relative to the original variables u and v. The number of variables is greatly reduced, so the speed of solution is greatly improved, and the transient flow field of power equipment can be efficiently solved while ensuring the accuracy of the calculation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 It is a flow chart of a method for solving a high-fidelity and high-efficiency transient flow field of a two-dimensional power device under rectangular coordinates of the present invention; Figure 2 is a two-dimensional plane diagram of a transformer involved in an embodiment of the present invention; Figure 3 is a sample matrix of the flow field obtained in the embodiment of the present invention; FIG4 (a) is a diagram showing flow field simulation results using a full-order model (i.e., a two-dimensional transformer flow field full-order transient calculation model) in an embodiment of the present invention; FIG4( b ) is a diagram showing the flow field simulation results using a reduced-order model (ie, a two-dimensional transformer flow field low-order transient calculation model) in an embodiment of the present invention.

[0025] In the figure, 1-first outlet, 2-oil, 3-inlet, 4-insulation, 5-winding, 6-second winding. DETAILED DESCRIPTION

[0026] 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.

[0027] This method proposes a high-fidelity and efficient transient flow field solution method for two-dimensional power equipment under rectangular coordinates. This method uses the intrinsic orthogonal decomposition method combined with the Galerkin projection method to establish a method of a lower-dimensional model for a high-dimensional physical problem, thereby obtaining a low-order model of the flow field of the power equipment, and iteratively solving the low-order model to obtain the transient temperature field distribution, and finally restore the low-order model to obtain the flow field distribution at different times. The present invention can achieve efficient solution of physical problems under the premise of ensuring the accuracy of the calculation results, so as to obtain a high-fidelity transient model of the flow field of the power equipment.

[0028] For power equipment, the governing equations for the unsteady convective heat transfer of the fluid inside it are as follows: (1) (2) (3) In the formula, u is the horizontal velocity component of the fluid flow field; v is the vertical velocity component of the fluid flow field; is the pressure of the fluid; for u Velocity source term; for v Velocity source term.

[0029] Specifically, the high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates of the present invention comprises the following steps: Step 1: Establish a two-dimensional model of the power equipment; Step 2: Use the full-order flow field model to solve the two-dimensional model of the power equipment and obtain the horizontal velocity components of the flow field of the fluid inside the power equipment at multiple times. u The vertical velocity component v , then the horizontal velocity component u The vertical velocity component v The sample matrix is ​​constructed, and the obtained sample matrix refers to Figure 3 ; Step 3: Perform singular value decomposition (SVD decomposition) on the sample matrix, sort the flow field pulsation by energy, screen out the flow features that contribute more to the flow field energy, select the part whose energy contribution accounts for more than a first preset value (such as 99%, which can be set by technicians in this field according to the specific situation, and the present invention does not make specific requirements), and obtain the velocity basis function and the velocity spectrum coefficient at the initial moment. The velocity basis function obtained by this method is a function of the spatial coordinates, and the velocity spectrum coefficient is a function of time.

[0030] Step 4, using the established two-dimensional power equipment flow field low-order transient calculation model and the velocity basis function and the velocity spectrum coefficient at the initial moment, calculate the velocity spectrum coefficients at different moments; linearly superimpose the velocity basis function and the velocity spectrum coefficients at different moments to obtain the approximate field of the flow field.

[0031] In the above solution of the present invention, the form of linearly superposing the basis function and the spectral coefficient is as follows: (4) (5) In the formula, is the velocity spectrum coefficient; for u Velocity basis functions; for v Velocity basis function; M is the number of velocity basis functions used to describe the flow field.

[0032] Due to the horizontal velocity component of the flow field u The vertical velocity component v The continuity equation (1) is satisfied, so each velocity basis function (i.e., the horizontal velocity component of the flow field) u Velocity basis function and the vertical velocity component v Sudu basis function ) also needs to satisfy the continuity equation (1), as follows: (6) Because the value of equation (6) is always 0, there is no need to consider the projection of the continuity equation when constructing a low-order model.

[0033] Substituting equations (4) and (5) into the flow field momentum equations (2) and (3), the flow field momentum equation of the two-dimensional power equipment can be transformed from the horizontal velocity component of the flow field u The vertical velocity component v The function is transformed into a function of velocity basis function and velocity spectrum coefficient to prepare for subsequent order reduction, as shown in the following formula: (7) (8) In order to reduce the order of the flow field of two-dimensional power equipment, the momentum equation composed of velocity basis function and spectral coefficient is converted to the horizontal velocity component of the flow field. u Velocity basis function and the vertical velocity component v Sudu basis function Projection on the subspace composed of , thus obtaining the low-order equation: (9) (10) To realize the horizontal velocity component of the water in the convection field u The vertical velocity component v Therefore, by summing up the two low-order equations (9) and (10), the low-order transient control equation of the two-dimensional power equipment flow field in the rectangular coordinate system as described above can be obtained: (11) (12) (13) (14) (15) (16) The above formula (11) is a low-order transient calculation model for the flow field of two-dimensional power equipment; When solving the velocity spectrum coefficients at different times, the low-order transient control equations of the two-dimensional power equipment flow field are first discretized using the finite volume method to obtain a discrete model; then the velocity basis function and the velocity spectrum coefficients at the initial moment are substituted into the discrete model, and the spectrum coefficients are iteratively solved to obtain the spectrum coefficients at different times; then the spectrum coefficients and the basis functions at different times are linearly superimposed to obtain the approximate field of the flow field.

[0034] In the above solution of the present invention, the power equipment may be a transformer, a bushing or a GIS, and the inside of the power equipment may be its insulating fluid or heat dissipation fluid.

[0035] This process is described below by means of the following examples.

[0036] Example 1 The two-dimensional transformer model provided in this embodiment is as follows Figure 2 As shown, the height of the transformer two-dimensional model is 1.68m, the radial radius is 0.48m, the inlet flow velocity is 0.3m / s, and the winding power is 55000W / m 3 , the external temperature is 50℃, and the external convection heat transfer coefficient is 15W / (m 2 ·K).

[0037] The full-order solution program of the two-dimensional transformer (i.e., the full-order transient calculation model of the two-dimensional transformer flow field) is written using equations (1), (2), and (3). For this non-steady-state problem, in order to comprehensively and economically capture the essential information of the physical problem, sampling is performed during the time period when the physical field changes drastically, and the following is obtained: Figure 3 The flow field distribution matrix (i.e., sample matrix) is shown.

[0038] Then the horizontal velocity component uThe vertical velocity component v The constructed sample matrix is ​​subjected to singular value decomposition to obtain the fifth-order velocity basis function matrix and velocity spectrum coefficients.

[0039] Then, the velocity spectrum coefficients at different times are calculated by using the two-dimensional transformer flow field low-order transient calculation model and the velocity basis function and the velocity spectrum coefficients at the initial time; specifically, the two-dimensional power equipment flow field low-order transient control equation is discretized by using the finite volume method to obtain a discrete model; then, the velocity basis function and the velocity spectrum coefficients at the initial time are substituted into the discrete model, the spectrum coefficients are iteratively solved, and the velocity spectrum coefficients at different times are calculated; Finally, the velocity basis function and the velocity spectrum coefficients at different times are linearly superimposed to obtain the approximate field of the flow field.

[0040] The approximate fields of the flow field obtained by using the full-order transient calculation model of the two-dimensional transformer flow field and the reduced-order model of the present invention (i.e., the above-mentioned two-dimensional transformer flow field low-order transient calculation model) are shown in Figure 4 (a) and Figure 4 (b), respectively. By comparison, the maximum flow velocity error of the flow velocity calculated by the above-mentioned two-dimensional transformer flow field low-order transient calculation model relative to the two-dimensional transformer flow field full-order transient calculation model is 2%, but the calculation speed of the above-mentioned two-dimensional transformer flow field low-order transient calculation model is much faster than that of the full-order model. To calculate the flow field results at the same time, the two-dimensional transformer flow field full-order transient calculation model takes 3 hours, while the above-mentioned two-dimensional transformer flow field low-order transient calculation model only takes two minutes.

[0041] The present invention also provides a system based on the high-fidelity and high-efficiency transient flow field solution method of two-dimensional power equipment under rectangular coordinates as described above, the system comprising: The first calculation unit is used to solve the established two-dimensional model of the power equipment by using the full-order flow field model to obtain the horizontal velocity component and the vertical velocity component of the flow field of the oil inside the power equipment at multiple times; A sample matrix building unit: used for forming a sample matrix from the horizontal velocity components and the vertical velocity components of the flow field at the plurality of moments; Decomposition unit: used for performing singular value decomposition on the sample matrix to obtain velocity basis functions and velocity spectrum coefficients at an initial moment; The second calculation unit is used to calculate the velocity spectrum coefficients at different times by using the established two-dimensional power equipment flow field low-order transient calculation model and the velocity basis function and the velocity spectrum coefficients at the initial time; The third calculation unit is used to linearly superimpose the velocity basis function and the velocity spectrum coefficients at different times to obtain an approximate field of the flow field.

[0042] 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.

[0043] Among them, the device includes a memory and a processor, the memory is used to store instructions or codes, and the processor is used to execute the instructions or codes so that the device executes the high-fidelity and efficient transient flow field solution method for two-dimensional power equipment under rectangular coordinates described in any embodiment of the present application.

[0044] The storage medium stores a computer program, wherein the computer program, when executed by the processor, implements the high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates as described in any embodiment of the present application.

[0045] The specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection of the claims of the present invention.

Claims

1. A high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates, characterized in that: include: The established two-dimensional model of power equipment is solved using the full-order flow field model to obtain the horizontal velocity component and vertical velocity component of the flow field of the fluid inside the power equipment at multiple times. The horizontal velocity components and vertical velocity components of the flow field at the multiple moments form a sample matrix; Performing singular value decomposition on the sample matrix to obtain velocity basis functions and velocity spectrum coefficients at an initial moment; The velocity spectrum coefficients at different times are calculated by using the established low-order transient calculation model of the flow field of the two-dimensional power equipment, the velocity basis function and the velocity spectrum coefficients at the initial time; The velocity basis function and the velocity spectrum coefficients at different times are linearly superimposed to obtain the approximate flow field.

2. According to the method for solving the high-fidelity and high-efficiency transient flow field of two-dimensional power equipment in rectangular coordinates in claim 1, it is characterized in that: The low-order transient calculation model of the two-dimensional power equipment flow field is as follows: in: In the formula, is the velocity spectrum coefficient; is the horizontal velocity component of the flow field u The velocity basis function of is the vertical velocity component of the flow field v velocity basis function; M is the number of velocity basis functions used to describe the flow field, for pressure; for u Velocity source term; for v Velocity source term; is the transient term coefficient; is the convection term coefficient; is the diffusion term coefficient; is the boundary condition; is the source item.

3. According to the method for solving the high-fidelity and high-efficiency transient flow field of two-dimensional power equipment in rectangular coordinates in claim 2, it is characterized in that: Horizontal velocity component of flow field u and the vertical velocity component v The following continuity equation is satisfied: In the formula, x is the horizontal coordinate of the rectangular coordinate system constructed in the flow field, y It is the ordinate of the rectangular coordinate system constructed in the flow field.

4. The high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates according to claim 3 is characterized in that: Horizontal velocity component of flow field u Velocity basis function and the vertical velocity component v Sudu basis function The following continuity equation is satisfied: 。 5. The high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates according to claim 1 is characterized in that: By using the established low-order transient calculation model of the flow field of two-dimensional power equipment and the velocity basis function and the velocity spectrum coefficient at the initial moment, the velocity spectrum coefficients at different moments are calculated: The low-order transient calculation model of the flow field of two-dimensional power equipment is discretized by using the finite volume method to obtain a discrete model; The velocity basis function and the velocity spectrum coefficients at the initial moment are substituted into the discrete model for calculation to obtain the velocity spectrum coefficients at different moments.

6. The high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates according to claim 1 is characterized in that: After performing singular value decomposition on the sample matrix, based on the order of flow field pulsation according to energy size, the part whose contribution to flow characteristics exceeds a first preset value is screened out to determine the velocity basis function and the velocity spectrum coefficient at the initial moment.

7. The high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates according to claim 1 is characterized in that: The power equipment is a transformer, a bushing or a GIS having a fluid, and the fluid is an insulating fluid or a heat dissipation fluid.

8. A high-fidelity and high-efficiency transient flow field solution system for two-dimensional power equipment under rectangular coordinates, characterized in that: include: The first calculation unit is used to solve the established two-dimensional model of the power equipment by using the full-order flow field model to obtain the horizontal velocity component and the vertical velocity component of the flow field of the oil inside the power equipment at multiple times; A sample matrix building unit: used for forming a sample matrix from the horizontal velocity components and the vertical velocity components of the flow field at the plurality of moments; Decomposition unit: used for performing singular value decomposition on the sample matrix to obtain velocity basis functions and velocity spectrum coefficients at an initial moment; The second calculation unit is used to calculate the velocity spectrum coefficients at different times by using the established two-dimensional power equipment flow field low-order transient calculation model and the velocity basis function and the velocity spectrum coefficients at the initial time; The third calculation unit is used to linearly superimpose the velocity basis function and the velocity spectrum coefficients at different times to obtain an approximate field of the flow field.

9. 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 high-fidelity and high-efficiency transient flow field solution method for two-dimensional power equipment under rectangular coordinates as described in any one of claims 1 to 7.

10. 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 solving the high-fidelity and high-efficiency transient flow field of two-dimensional power equipment under rectangular coordinates as described in any one of claims 1 to 7 is implemented.

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