Electric reactor equivalent scaling model construction method and device based on invariant winding vibration characteristics

Abstract

The invention belongs to the field of high-voltage shunt reactor detection, and particularly provides a reactor equivalent scaling model construction method and device based on winding vibration characteristic invariability, and the method comprises the steps: determining an equivalent scaling coefficient; determining that the mass, the rigidity and the stress have the same change according to the consistency of vibration characteristics before and after equivalence and a kinetic equation of the winding; adjusting current and winding turns according to a scaling principle; adjusting the number and the area of the winding cushion blocks according to a scaling principle; and establishing a simulation model of the high-voltage shunt reactor and the equivalent scaling model thereof in simulation software, comparing the prototype reactor with the equivalent scaling model, and if the deviation is large, repeating scaling model reconstruction until the deviation meets the requirement. The electric reactor scaling model with a typical iron core winding structure is designed by adopting the method, and the electric reactor scaling model is used for reflecting the electric characteristics of an original model electric reactor by measuring the test data of the scaling model.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage parallel reactor testing, specifically, it relates to a method and apparatus for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics. Background Technology

[0002] With the development of China's power industry and the formation of ultra-high voltage AC / DC interconnected power grids, high-voltage shunt reactors, as an important component, effectively compensate for capacitive reactive power and improve voltage distribution, playing a crucial role in ensuring the safe and stable operation of the power grid. The core of a high-voltage shunt reactor typically has gaps, leading to magnetostriction and leakage flux, resulting in more severe vibration and noise problems than transformers. Furthermore, it is subjected to electrical stress during operation, exhibiting high-order harmonic components and causing harmonic leakage magnetic fields. The complex vibrations can easily lead to mechanical defects in structural components, such as loosening of coils, cores, and fasteners, and may cause internal overheating and discharge faults. Current detection methods are insufficient for sensitive and accurate diagnosis of mechanical defects. Therefore, studying the mechanical vibration characteristics of reactors under operating conditions and proposing effective uninterrupted power-off detection techniques to achieve mechanical defect diagnosis and early warning is of great significance for avoiding sudden accidents and ensuring the safe and stable operation of the power grid.

[0003] For ultra-high voltage parallel reactors, it is difficult to obtain vibration data by measuring the actual operating conditions. However, using a scaled-down model of reactor vibration can solve the problem. Experiments can be conducted based on the scaled-down model to obtain experimental data and further theoretical research.

[0004] Similarity theory is a crucial theoretical foundation for establishing the relationship between the scaled-down model and the original model. Scaled-down formulas are derived based on similarity theory to design scaled-down reactor models. Whether the electrical and mechanical characteristics of the scaled-down model and the original model remain consistent is a key issue in scaled-down research. If the similarity relationship between the two is rigorously verified, experimental research can be conducted using the scaled-down model, provided that the electrical characteristics remain consistent. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and device for constructing an equivalent scaled-down model of a reactor based on the unchanged winding vibration characteristics, and to design a scaled-down model of a reactor with a typical iron core winding structure, so as to reflect the electrical characteristics of the original model reactor by measuring the test data of the scaled-down model.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics, comprising the following steps: S1. The materials used in the scaled-down reactor model are consistent with the structural materials of the UHV parallel reactor on site, and the equivalent scaling factor is determined accordingly. After scaling down, the core diameter of the scaled-down reactor model is calculated using an empirical formula: ; In the formula, C This is an empirical coefficient. For the capacity of the iron core column; Equivalent scaling factor This is the ratio of the core diameter of the scaled-down reactor model to the core diameter of the prototype reactor. S2. Based on the consistent vibration characteristics before and after the equivalent operation and the dynamic equation of the winding, it is determined that the mass, stiffness and force have changed in the same way. S3. Adjust the current or number of winding turns according to the scaling principle to ensure that the stress meets the requirements; S4. Adjust the number or size of the winding spacers according to the scaling principle to ensure that the stiffness meets the requirements; S5. Establish a simulation model of the high-voltage parallel reactor and its equivalent scaled-down model in the simulation software. Compare the prototype reactor with the equivalent scaled-down model to obtain the magnetic flux density distribution and winding natural frequency of the prototype reactor and the equivalent scaled-down model under normal operating conditions. If the maximum magnetic flux density or winding natural frequency deviation exceeds the set value, adjust the current or the number of winding turns, or adjust the number or size of the winding pads, and reconstruct the scaled-down model until the deviation meets the requirements.

[0007] In a preferred embodiment, in step S1, the size equivalence scaling factor is determined. Then, the dimensions of each structural component in the scaled-down model are determined according to the following formula: ; In the formula, These are the dimensions of the prototype reactor structural components; The dimensions are for the scaled-down model.

[0008] In the preferred embodiment, in step S2, a system of second-order linear differential equations with n degrees of freedom is established to describe the axial dynamic behavior of the winding. The expression of the dynamic equations is as follows: ; In the formula: M For the winding mass matrix, K This is the stiffness coefficient matrix. F Here is the force matrix. x This is the winding displacement matrix; To ensure that the vibration characteristics of the scaled-down model winding are consistent with those of the original reactor winding, i.e., for the dynamic equations of the two models... Similarly, we need to find the equivalent mass matrix before and after the solution. M Stiffness coefficient matrix K Force matrix F The same changes occur.

[0009] In a preferred embodiment, in step S2, the length of each structural component in the scaled-down model is reduced to 1 / 3 the length of each structural component in the prototype reactor. k The mass of a single winding in the scaled-down model is 1 / 3 the mass of a single winding in the prototype reactor. k 3 Multiples, stiffness coefficient matrix K Force matrix F All are reduced to the stiffness coefficient matrix and force matrix corresponding to the prototype reactor 1 / k 3 times.

[0010] In a preferred embodiment, in step S3, the current I of the scaled-down model is scaled down to 1 / 3 of the prototype reactor current. k 3 The number of winding turns in the scaled-down model W The number of turns of the winding of the prototype reactor k times.

[0011] In a preferred embodiment, in step S4, the stiffness coefficient matrix of the winding in the equivalent scaled-down model is used. K Reduced to 1 / of the stiffness coefficient matrix corresponding to the prototype reactor k 3 The number of pads can be adjusted by multiplying the number of pads. m Alternatively, the contact area S between the pad and the coil can be adjusted to change the winding stiffness.

[0012] In a preferred embodiment, the number of pad blocks m Alternatively, the winding stiffness can be adjusted by changing the contact area S between the spacer and the coil, based on the following number of spacers. m Adjust the relationship between the contact area S between the pad and the coil and the winding stiffness: ; Where S is the contact area between the pad and the wire disc. m The number of pads, d The thickness of the pad after applying preload, The coefficient of the linear term reflects the stiffness of the material in its initial elastic stage. The coefficient of the cubic term characterizes the degree of nonlinear hardening of the material. This represents the strain magnitude of the pad block.

[0013] In a preferred embodiment, the winding stiffness and the number of spacers are... m The derivation of the expression relating the contact area S between the pad and the wire disc is as follows: The stress-strain fitting formula for the pad is: ; in, σ =( d 0-d ) / d 0, for strain. d 0 represents the original thickness of the pad without preload. d The thickness of the pad after applying preload; Therefore, the formula for calculating the elastic modulus is as follows: ; The equivalent stiffness has the following expression: .

[0014] In the preferred embodiment, in step S5, numerical simulation is performed using the finite element method to simulate the electromagnetic force characteristics of the reactor winding, establish a simulation model, and obtain the electric field distribution diagram, magnetic field distribution diagram, and vibration distribution diagram of the scaled-down model and the prototype reactor model. If the distribution of each part of the prototype reactor model and the scaled-down model is consistent, it proves that the scaled-down model meets the requirements; otherwise, the scaled-down model is reconstructed.

[0015] The present invention also provides an electronic device, including a memory, a processor, and a program stored in the memory, wherein the processor executes the program to implement the above-described construction method.

[0016] The present invention provides a method and apparatus for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics, which has the following beneficial effects: 1. The enclosure of ultra-high voltage parallel reactors is large and has a complex internal structure. Disassembling and inspecting them is not only quite difficult, but also has a significant impact on the stability of local transmission lines. This patent constructs a scaled-down model of the reactor, which theoretically has the same vibration conditions and electromagnetic distribution as the prototype reactor, through formula derivation. Using the scaled-down model as the research object effectively avoids the influence of complex on-site environments during operation, and is conducive to clarifying and grasping the vibration characteristics and vibration laws of the reactor.

[0017] 2. A scaled-down model of a reactor with a typical iron core winding structure was designed to facilitate experimental research on the vibration and acoustic characteristics of the reactor. The measured vibration data can be used to reflect the electrical characteristics of the original model reactor with the same structure, which has great research significance and engineering application value. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0020] Example 1: A method for constructing an equivalent scaled-down model of a reactor based on invariant winding vibration characteristics, such as... Figure 1 As shown, it includes the following steps: S1. The materials used in the scaled-down reactor model are consistent with the structural materials of the UHV parallel reactor on site. The dimensional equivalence scaling factor is determined based on equipment parameters and experimental environment. Since the voltage rating and capacity of the scaled-down reactor model depend on the experimental environment, the equivalent scale-down factor for the reactor size is determined. To meet electrical parameter requirements, the core diameter can be calculated using empirical formulas: ; In the formula, C This is an empirical coefficient. The core column capacity is 6.7 Mvar in this embodiment.

[0021] Equivalent scaling factor This is the ratio of the core diameter of the scaled-down reactor model to the core diameter of the prototype reactor.

[0022] Table 1 shows the empirical coefficients for f=50Hz. Core column magnetic flux density limit The choice of values.

[0023]

[0024] The reactor body is assembled from various solid structural components, and the material properties of different parts determine the overall vibration level and distribution of the reactor. To simulate an on-site UHV parallel reactor, the materials used in the scaled-down model of the reactor should be consistent with the structural materials of the on-site UHV parallel reactor. The materials used in each group of the scaled-down model of the high-voltage parallel reactor must be consistent with those of the original reactor, mainly including core material, air gap pad, winding material, and tie rod clamp material, as detailed in Table 2.

[0025]

[0026] During the experiment, selecting a reasonable scaling factor requires comprehensive consideration of various factors, including experimental conditions, budget, and accuracy requirements. Considering the actual space limitations of the laboratory and the measurement range of the testing equipment, to ensure the accuracy of the experimental data, optimization can be achieved by appropriately increasing the scaling factor when experimental conditions are constrained. Only after the scaling factor k is determined can the remaining structural dimensions be determined sequentially.

[0027] Determine the dimensional equivalent scaling factor Then, the dimensions of each structural component in the scaled-down model are determined according to the following formula: ; In the formula, These are the dimensions of the prototype reactor structural components; The dimensions are for the scaled-down model.

[0028] S2. Based on the consistent vibration characteristics before and after the equivalent operation and the dynamic equation of the winding, it is determined that the mass, stiffness and force have changed in the same way.

[0029] While meeting certain electrical requirements, the scaled-down model of a reactor should also have a similar composition of structural components and vibration distribution as the original reactor. The axial vibration of the windings of a high-voltage shunt reactor during steady-state operation can be described using a mass-spring model.

[0030] A system of second-order linear differential equations with n degrees of freedom is established to describe the axial dynamic behavior of the winding. The expression for the dynamic equations is as follows: ; In the formula: M For the winding mass matrix, C Here is the damping coefficient matrix. K This is the stiffness coefficient matrix. F Here is the force matrix. x This is the winding displacement matrix; In practice, the damping coefficient matrix can be neglected; that is, the vibration intensity of the winding in the equation is determined by the mass matrix. M Stiffness coefficient matrix K and force matrix F The dynamic equation is determined to be: .

[0031] To ensure that the vibration characteristics of the scaled-down model winding are consistent with those of the original reactor winding, i.e., for the dynamic equations of the two models... Similarly, we need to find the equivalent mass matrix before and after the solution. M Stiffness coefficient matrix K Force matrix F The same changes occur.

[0032] The length dimensions of each structural component in the scaled-down model are reduced to 1 / 3 of the length dimensions of each structural component in the prototype reactor.k The volume size is 1 / 3 of the volume size of each structural component of the prototype reactor. k 3 The mass of a single winding in the scaled-down model is 1 / 3 the mass of a single winding in the prototype reactor. k 3 Multiples, stiffness coefficient matrix K Force matrix F All are reduced to the stiffness coefficient matrix and force matrix corresponding to the prototype reactor 1 / k 3 times.

[0033] S3. Adjust the current and number of winding turns according to the scaling principle to ensure that the stress meets the requirements.

[0034] The equivalence principle considered in this invention is the vibration characteristics and leakage flux before and after equivalence. The current density J remains constant, and this is considered in conjunction with the winding stress and leakage flux. The formula for calculating current density J derives the parameters that need to be adjusted, including: I The scaling ratio is 1 / of the original current. k 3 The number of turns W is the original. k times.

[0035] The derivation process is as follows: When the winding is subjected to an alternating magnetic field generated by alternating current, it will be subjected to axial and radial electromotive forces generated by axial and radial leakage flux. Fz and Fx .

[0036] ; ; In the formula, This represents the axial component of the leakage flux. Here, r is the radial component of the leakage flux, and r is the winding radius. This represents the current flowing through the winding.

[0037] The formula for calculating leakage flux is as follows: ; In the formula, Permeability, For leakage flux, W The number of turns in the winding. Lochtein coefficient, The height of the winding pad. The outer radius of the winding, The radius of the circumcircle of the iron core is 1. I It represents electric current.

[0038] The structural components of the scaled-down model are arranged proportionally. k After reduction, the coefficient The values ​​remain unchanged. Therefore, to ensure that the magnitude of the leakage flux remains unchanged before and after the equivalent operation, the values ​​of W and I should be adjusted.

[0039] Let the equivalent current density J remain unchanged before and after, since: ; Combining the above formula, let I be scaled down to 1 / of the original current. k 3 The number of turns W is the original. k This doubles the force matrix F, thus satisfying the above equivalence principle, meaning the force matrix F becomes 1 / 2 of the original. k 3 Leakage flux The current density J remains constant.

[0040] S4. Adjust the number and area of ​​the winding pads according to the scaling principle to ensure that the stiffness meets the requirements.

[0041] Based on the stiffness coefficient matrix of the winding in the equivalent scaled-down model K Reduced to 1 / of the stiffness coefficient matrix corresponding to the prototype reactor k 3 The number of pads can be adjusted by multiplying the number of pads. m Alternatively, the contact area S between the pad and the coil can be adjusted to change the winding stiffness.

[0042] Stiffness coefficient matrix of equivalent scaled-down model winding K It should be reduced to 1 / k 3 The winding stiffness can be adjusted by changing the number of spacers (m) or the contact area (S) between the spacers and the coil.

[0043] The stress-strain fitting formula for the pad is: ; in, σ =( d 0- d ) / d 0, for strain. d 0 represents the original thickness of the pad without preload. d The thickness of the pad after applying preload, The coefficient of the linear term reflects the stiffness of the material in its initial elastic stage. The coefficient of the cubic term characterizes the degree of nonlinear hardening of the material. This represents the strain magnitude of the pad block.

[0044] Therefore, the formula for calculating the elastic modulus is as follows: ; The equivalent stiffness has the following expression: .

[0045] Where S is the contact area between the pad and the wire disc. m The number of pads, d The thickness of the pad after applying preload, The coefficient of the linear term reflects the stiffness of the material in its initial elastic stage. The coefficient of the cubic term characterizes the degree of nonlinear hardening of the material. This represents the strain magnitude of the pad block.

[0046] S5. Establish a simulation model of the high-voltage parallel reactor and its equivalent scaled-down model in the simulation software. Compare the prototype reactor with the equivalent scaled-down model to obtain the magnetic flux density distribution and winding natural frequency of the prototype reactor and the equivalent scaled-down model under normal operating conditions. If the deviation of the maximum magnetic flux density or winding natural frequency exceeds 10%, adjust the current or the number of winding turns, or adjust the number or size of the winding pads, and reconstruct the scaled-down model until the deviation meets the requirements.

[0047] Specifically, if there is a deviation in the magnetic field, repeat step S3 to adjust the current or number of turns; if there is a deviation in the stiffness, repeat step S4 to adjust the number or size of the pads, and adjust the size of the pads accordingly to adjust the contact area S between the pads and the wire disc.

[0048] A simplified reactor structure was used to design an equivalent scaled-down model, and its electrical characteristics were simulated and compared. To verify the effectiveness of the scaled-down model design, simulation models of the scaled-down model and the original model were established. Numerical simulations were performed using the finite element method to simulate the electromagnetic force characteristics of the reactor windings. Simulation models were built to obtain the electric field distribution, magnetic field distribution, and vibration distribution diagrams of the scaled-down and original models. If the distributions of the original and scaled-down models are basically consistent, the effectiveness of the scaled-down model design method is verified. For a clearer comparison, specific paths corresponding to the two models were selected to obtain the magnetic field distribution of the original and scaled-down models at different frequencies. Furthermore, the natural frequencies of the reactor and its scaled-down model can also be simulated; consistent natural frequencies are a necessary condition for consistent vibration characteristics.

[0049] Specifically, Ansys software was used to establish a simulation model of the high-voltage shunt reactor and its equivalent scaled-down model. Material parameters, boundary conditions, and excitation were reasonably set. Finite element numerical simulation was used to obtain the electric field distribution, magnetic field distribution, and vibration distribution of the scaled-down model and the original model. The distributions of the original model and the scaled-down model were basically consistent, thus verifying the effectiveness of the scaled-down model design method. If the deviation is large, further optimization is needed. Furthermore, based on the designed scaled-down model, experiments were conducted on the scaled-down model and the original model under rated operating conditions to measure the vibration characteristics. If the results are within a certain error range, the effectiveness of the scaled-down model design method is demonstrated.

[0050] In addition to simulation, it can also be verified experimentally by measuring and comparing the vibration of the high-voltage shunt reactor and its scaled-down model under rated operating conditions.

[0051] Example 2: The present invention also provides an electronic device, including a memory, a processor, and a program stored in the memory, wherein when the processor executes the program, it implements the method for constructing an equivalent scaled model of a reactor based on unchanged winding vibration characteristics as described in Embodiment 1.

[0052] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing an equivalent scaled-down model of a reactor based on invariant winding vibration characteristics, characterized in that, Includes the following steps: S1. The materials used in the scaled-down reactor model are consistent with the structural materials of the UHV parallel reactor on site, and the equivalent scaling factor is determined accordingly. After scaling down, the core diameter of the scaled-down reactor model is calculated using an empirical formula: ； In the formula, C This is an empirical coefficient. For the capacity of the iron core column; Equivalent scaling factor This is the ratio of the core diameter of the scaled-down reactor model to the core diameter of the prototype reactor. S2. Based on the consistent vibration characteristics before and after the equivalent operation and the dynamic equation of the winding, it is determined that the mass, stiffness and force have changed in the same way. S3. Adjust the current or number of winding turns according to the scaling principle to ensure that the stress meets the requirements; S4. Adjust the number or size of the winding spacers according to the scaling principle to ensure that the stiffness meets the requirements; S5. Establish a simulation model of the high-voltage parallel reactor and its equivalent scaled-down model in the simulation software. Compare the prototype reactor with the equivalent scaled-down model to obtain the magnetic flux density distribution and winding natural frequency of the prototype reactor and the equivalent scaled-down model under normal operating conditions. If the maximum magnetic flux density or winding natural frequency deviation exceeds the set value, adjust the current or the number of winding turns, or adjust the number or size of the winding pads, and reconstruct the scaled-down model until the deviation meets the requirements.

2. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 1, characterized in that, In step S1, the size equivalent scaling factor is determined. Then, the dimensions of each structural component in the scaled-down model are determined according to the following formula: ； In the formula, These are the dimensions of the prototype reactor structural components; The dimensions are for the scaled-down model.

3. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 1, characterized in that, In step S2, a system of second-order linear differential equations with n degrees of freedom is established to describe the axial dynamic behavior of the winding. The expression of the dynamic equations is as follows: ； In the formula: M For the winding mass matrix, K This is the stiffness coefficient matrix. F Here is the force matrix. x This is the winding displacement matrix; To ensure that the vibration characteristics of the scaled-down model winding are consistent with those of the original reactor winding, i.e., for the dynamic equations of the two models... Similarly, we need to find the equivalent mass matrix before and after the solution. M Stiffness coefficient matrix K Force matrix F The same changes occur.

4. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 3, characterized in that, In step S2, the length of each structural component in the scaled-down model is reduced to 1 / 3 of the length of each structural component in the prototype reactor. k The mass of a single winding in the scaled-down model is 1 / 3 the mass of a single winding in the prototype reactor. k 3 Multiples, stiffness coefficient matrix K Force matrix F All are reduced to the stiffness coefficient matrix and force matrix corresponding to the prototype reactor 1 / k 3 times.

5. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 1, characterized in that, In step S3, the scaled-down model's current I is 1 / 3 of the prototype reactor's current. k 3 The number of winding turns in the scaled-down model W The number of turns of the winding of the prototype reactor k times.

6. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 4, characterized in that, In step S4, the stiffness coefficient matrix of the equivalent scaled-down model winding is used. K Reduced to 1 / of the stiffness coefficient matrix corresponding to the prototype reactor k 3 The number of pads can be adjusted by multiplying the number of pads. m Alternatively, the contact area S between the pad and the coil can be adjusted to change the winding stiffness.

7. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 6, characterized in that, The number of pads m Alternatively, the winding stiffness can be adjusted by changing the contact area S between the spacer and the coil, based on the following number of spacers. m Adjust the relationship between the contact area S between the pad and the coil and the winding stiffness: ； Where S is the contact area between the pad and the wire disc. m The number of pads, d The thickness of the pad after applying preload, The coefficient of the linear term reflects the stiffness of the material in its initial elastic stage. The coefficient of the cubic term characterizes the degree of nonlinear hardening of the material. This represents the strain magnitude of the pad block.

8. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 7, characterized in that, The winding stiffness and the number of pads m The derivation of the expression relating the contact area S between the pad and the wire disc is as follows: The stress-strain fitting formula for the pad is: ； in, σ =( d 0- d ) / d 0, for strain. d 0 represents the original thickness of the pad without preload. d The thickness of the pad after applying preload; Therefore, the formula for calculating the elastic modulus is as follows: ； The equivalent stiffness has the following expression: 。 9. The method for constructing an equivalent scaled-down model of a reactor based on unchanged winding vibration characteristics according to claim 1, characterized in that, In step S5, numerical simulation is performed using the finite element method to simulate the electromagnetic force characteristics of the reactor winding, establish a simulation model, and obtain the electric field distribution diagram, magnetic field distribution diagram, and vibration distribution diagram of the scaled-down model and the prototype reactor model. If the distribution of each part of the prototype reactor model and the scaled-down model is consistent, it proves that the scaled-down model meets the requirements; otherwise, the scaled-down model is reconstructed.

10. An electronic device comprising a memory, a processor, and a program stored in the memory, characterized in that, When the processor executes the program, it implements the construction method as described in any one of claims 1-9.

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