Voltage transformer, design method and device thereof and storage medium

Abstract

The invention relates to the technical field of electrical engineering, and discloses a voltage transformer, a design method and device thereof and a storage medium, and the method comprises the steps: determining the size of an iron core, and the electrical parameters of a primary side winding and a secondary side winding according to the electrical performance parameters and space limitation conditions of a target voltage transformer; calculating no-load loss, no-load magnetization and no-load current of the target voltage transformer based on the ferromagnetic material attribute parameters and the iron core size; determining a leakage reactance value reduced to a secondary side and total resistance of the winding according to the winding structure parameters; establishing an initial three-dimensional finite element simulation model of the voltage transformer based on the iron core size information and the winding parameters; determining a no-load error and a load error of the voltage transformer based on the no-load loss, the no-load magnetization, the leakage reactance value, the total winding resistance and the winding structure parameters; and performing feedback optimization on the initial simulation model based on the no-load error and the load error to obtain a target three-dimensional finite element simulation model, and manufacturing a target voltage transformer based on the simulation model.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical engineering, and particularly relates to a voltage transformer, a design method, device and storage medium thereof. BACKGROUND

[0002] The low-voltage voltage transformer is a key device for realizing voltage transformation and measurement in a power system, and its measurement accuracy, operation reliability and environmental adaptability directly affect the accuracy of electric energy metering, the correctness of relay protection action and the stable operation of an automatic system. According to statistics, the contribution rate of transformer error to the statistical error of power grid line loss is up to 20%-30%, and its angle error is positively correlated with the misoperation rate of relay protection, so its performance directly affects the overall operation quality of the system.

[0003] However, the core design of the current low-voltage voltage transformer still faces three technical bottlenecks. First, the electromagnetic coupling mechanism is not well studied, and the existing design mostly relies on a simplified magnetic circuit model, without fully considering the frequency dependence of winding leakage inductance and distributed capacitance, resulting in excessive error prediction error under high-frequency working conditions. Second, it is difficult to model the multi-physical field coupling effect, and temperature changes will significantly affect the magnetic permeability of the core and the dielectric properties of the insulating material, and the lack of a unified modeling method limits the performance evaluation under extreme environments. Finally, the traditional design relies on experience and trial-and-error, with a long process cycle and high cost, and the optimization of material and structure parameters lacks theoretical guidance, affecting the design efficiency and resource utilization. SUMMARY

[0004] Therefore, the embodiments of the present application provide a voltage transformer and a design method, device and storage medium thereof to efficiently realize the design of a low-voltage voltage transformer.

[0005] In a first aspect, the embodiments of the present application provide a voltage transformer design method, comprising: According to the electrical performance parameters and spatial restriction conditions of a target voltage transformer, the core size information, the electrical parameters of the primary side winding and the electrical parameters of the secondary side winding are determined; based on the magnetic material attribute parameters and the core size information, the no-load loss, the no-load magnetization and the no-load current of the target voltage transformer are calculated; according to the winding structure parameters, the leakage reactance value and the total winding resistance reduced to the secondary side are determined; based on the core size information and the winding parameters, an initial three-dimensional finite element simulation model of the voltage transformer is established; wherein the winding parameters include the winding electrical parameters and the winding structure parameters; based on the no-load loss, the no-load magnetization, the leakage reactance value, the total winding resistance and the winding structure parameters, the no-load error and the load error of the voltage transformer are determined; the initial three-dimensional finite element simulation model is feedback optimized based on the no-load error and the load error to obtain a target three-dimensional finite element simulation model, and the target voltage transformer is manufactured based on the target three-dimensional finite element simulation model.

[0006] In a second aspect, the embodiments of the present application provide a voltage transformer design device, comprising: a calculation module configured to determine core size information, electrical parameters of a primary side winding, and electrical parameters of a secondary side winding according to electrical performance parameters and space limitation conditions of a target voltage transformer; the calculation module is further configured to calculate no-load loss, no-load magnetization, and no-load current of the target voltage transformer based on ferromagnetic material attribute parameters and the core size information; the calculation module is further configured to determine leakage reactance value and total winding resistance of the target voltage transformer according to winding structure parameters; a simulation module is configured to establish an initial three-dimensional finite element simulation model of the voltage transformer based on the core size information and winding parameters; the winding parameters comprise winding electrical parameters and the winding structure parameters; the calculation module is further configured to determine no-load error and load error of the voltage transformer based on the no-load loss, the no-load magnetization, the leakage reactance value, the total winding resistance, and the winding structure parameters; the simulation module is further configured to perform feedback optimization on the initial three-dimensional finite element simulation model based on the no-load error and the load error to obtain a target three-dimensional finite element simulation model, and to manufacture the target voltage transformer based on the target three-dimensional finite element simulation model.

[0007] In a third aspect, the embodiments of the present application provide a voltage transformer manufactured by the voltage transformer design method described above.

[0008] In a fourth aspect, the embodiments of the present application provide a computer readable storage medium storing a computer program, wherein the computer program is executed on a processor to implement the voltage transformer design method described in the foregoing embodiments.

[0009] The embodiments of the present application have the following beneficial effects: the present application systematically determines the core size information and electrical parameters of the primary side and secondary side winding according to the electrical performance parameters and space limitation conditions of the target voltage transformer, thereby realizing accurate design of the core structure of the transformer. Then, the no-load loss, no-load magnetization and no-load current are calculated in combination with the ferromagnetic material properties and core size information, and the magnetization state and energy loss of the core in operation are accurately evaluated, thereby providing basic support for error analysis. The leakage reactance value and total winding resistance of the secondary side are determined by the winding structure parameters, so that the influence of the magnetic leakage effect on the performance of the transformer can be quantitatively modeled, thereby improving the design accuracy. On this basis, an initial three-dimensional finite element simulation model of the voltage transformer is established, the theoretical design is converted into a visual and verifiable simulation structure, and effective analysis of the electromagnetic field distribution and voltage and current characteristics is realized. Further, based on the no-load loss, no-load magnetization, leakage reactance value, total winding resistance and winding structure parameters, the no-load error and load error of the transformer are calculated, so that the error evaluation has double support of theory and simulation, and the reliability of the design is enhanced. Finally, the initial three-dimensional finite element simulation model is optimized through error feedback, forming a closed-loop design process, ensuring that the transformer meets the error limit value requirement, and thereby improving the design efficiency and product consistency. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0011] Figure 1 A first flowchart of the voltage transformer design method of the embodiments of the present application is shown; Figure 2 A second flowchart of the voltage transformer design method of the embodiments of the present application is shown; Figure 3 A first winding structure diagram of the embodiments of the present application is shown; Figure 4 A third flowchart of the voltage transformer design method of the embodiments of the present application is shown; Figure 5 A fourth flowchart of the voltage transformer design method of the embodiments of the present application is shown; Figure 6 A second winding structure diagram of the embodiments of the present application is shown; Figure 7 A 1 / 4 simplified simulation model diagram of the voltage transformer of the embodiments of the present application is shown; Figure 8A schematic diagram showing the magnetization behavior of the core of the embodiment of the application under different magnetic flux densities is shown. Figure 9 A schematic diagram showing the mesh partitioning of the voltage transformer of the embodiment of the application is shown. Figure 10 A schematic diagram showing the simulation analysis of the voltage waveform of the primary side winding of the embodiment of the application is shown. Figure 11 A schematic diagram showing the simulation analysis of the voltage waveform of the secondary side winding of the embodiment of the application is shown. Figure 12 A schematic diagram showing the distribution of the modulus of the electric field strength of the voltage transformer under lightning impulse voltage of the embodiment of the application is shown. Figure 13 A schematic diagram showing one structure of the voltage transformer design device of the embodiment of the application is shown. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments of the application.

[0013] The components of the embodiments of the application generally described and illustrated in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the application.

[0014] In the following, the terms "comprise", "have", and their synonymous words used in various embodiments of the application are only intended to represent specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be understood as first excluding the presence or adding the possibility of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing. In addition, the terms "first", "second", "third", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0015] Unless specifically defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present application belong. The terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined in various embodiments of the present application.

[0016] Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments can be combined with each other in the case of no conflict.

[0017] The voltage transformer design method is described below in conjunction with some specific embodiments.

[0018] Figure 1 A flowchart of the voltage transformer design method of the embodiments of the present application is shown. Exemplarily, the voltage transformer design method includes the following steps: Step S100, determining the core size information and the electrical parameters of the primary side winding and the electrical parameters of the secondary side winding according to the electrical performance parameters and the space limitation conditions of the target voltage transformer.

[0019] The electrical performance parameters are determined in advance, and the determination of the electrical performance parameters is based on the electrical characteristic indicators required to be met by the voltage transformer in operation according to the user or the standard. In the present embodiment, the electrical performance parameters of the low-voltage voltage transformer include but are not limited to the rated voltage of the primary side, the rated voltage of the secondary side, the rated operating frequency, the measurement accuracy level, the rated capacity, the limit output capacity, the power factor and the temperature rise limit, the voltage per turn, the rated magnetic flux density, etc.

[0020] The space limitation conditions refer to the winding space, insulation space and installation space occupied by the primary and secondary winding coils in the annular or racetrack-shaped core. For the annular core, the space is determined by the inner diameter of the window; for the racetrack-shaped core, the space is determined by the inner length and the inner width of the window. The reasonable window size should meet the winding arrangement requirements, i.e. having sufficient inner diameter (for the annular core) or inner length and inner width (for the racetrack-shaped core) to ensure that the winding, insulation structure and installation components are reasonably arranged and the structure is compact.

[0021] In some embodiments, as shown in Figure 2 Step S100 includes steps S110-S130: Step S110, determining the cross-sectional area of the core of the target voltage transformer according to the voltage per turn, the rated magnetic flux density and the rated operating frequency of the target voltage transformer.

[0022] Exemplarily, the cross-sectional area of the iron core can be determined by a first formula, the first formula being: ; in the formula, is the cross-sectional area of the iron core, is a voltage per turn value (V / tum), the value range being 0.4V-0.5V, f is a rated working frequency (Hz), is a rated magnetic flux density (T), the value range being 0.8T-1.2T.

[0023] This step can control the iron core volume, no-load loss and winding arrangement space by reasonably setting the voltage per turn value and the rated magnetic flux density, so as to realize the design of a compact structure and stable performance of the transformer under the premise of meeting the measurement accuracy and magnetic performance.

[0024] In step S120, the diameter of the iron core column of the target voltage transformer is determined according to the iron core column space utilization coefficient and the voltage per turn value and the rated magnetic flux density of the target voltage transformer.

[0025] The iron core column space utilization coefficient is an empirical parameter, and the value thereof reflects the proportional relationship between the actual space available for winding arrangement in the iron core column and the theoretical geometric space. The parameter is affected by factors such as the arrangement density of the iron core material, the winding structure, the winding process and the insulation design, and in the design of low-voltage voltage transformers, the value thereof is generally 0.85-0.89. In actual design, the value of the parameter can be appropriately corrected according to historical experience data, feedback from prototype testing or electromagnetic simulation results, so as to ensure that the diameter of the iron core column is reasonably designed, the winding arrangement is feasible, and the electrical performance and compact structure requirements of the transformer are met.

[0026] Exemplarily, the diameter of the iron core column can be determined by a second formula, the second formula being: ; in the formula, is the iron core column space utilization coefficient, is the diameter of the iron core column.

[0027] In this step, the diameter of the iron core column is calculated, which can provide a size reference for the initial structural design of the iron core and guide the winding arrangement, error control and electromagnetic field simulation modeling. By reasonably setting the diameter of the iron core column, the subsequent winding arrangement space can be ensured to be reasonable, the magnetic flux density of the iron core can be controlled within a safe range, and the measurement accuracy, compact structure and manufacturing cost control of the transformer are also considered.

[0028] In step S130, the primary side winding number, the secondary side winding number, the primary side winding current, the secondary side winding current, the primary side winding wire diameter, the secondary side winding wire diameter, the primary side winding direct current resistance and the secondary side winding direct current resistance of the target voltage transformer are determined according to the rated primary side voltage, the rated secondary side voltage and the voltage per turn value.

[0029] As an example, the number of turns in the primary winding and the number of turns in the secondary winding can be determined according to the third formula and the fourth formula, respectively. The third formula is: The fourth formula is: In the formula, This refers to the number of turns in the primary winding. This refers to the number of turns in the secondary winding. The primary side rated voltage, This is the rated voltage of the secondary side. Voltage per turn.

[0030] When determining the wire diameter of the primary winding and the secondary winding, it is first necessary to determine the primary winding current and the secondary winding current based on the rated capacity of the target voltage transformer and the rated voltage of the primary and secondary windings.

[0031] The primary winding current and the secondary winding current can be determined using formula 5 and formula 6, respectively. Formula 5 is as follows: The sixth formula is: In the formula, The rated capacity of the target voltage transformer, The primary winding current (A) is... This represents the secondary winding current (A).

[0032] Furthermore, the wire diameters of the primary winding and the secondary winding can be determined using formula seven and formula eight, respectively. Formula seven is as follows: The eighth formula is: In the formula, The diameter of the primary winding wire (mm) is as follows. The secondary winding wire diameter (mm) The primary winding current density (A / ), Secondary winding current density (A / ).

[0033] The values ​​of the primary winding current density and the secondary winding current density are determined by comprehensively considering the winding temperature rise limit, heat dissipation conditions, winding process, conductor material characteristics, and the overall performance requirements of the transformer. In the low-voltage transformer design of this embodiment, the primary winding current density is typically set to... The secondary winding current density is taken as: .

[0034] Furthermore, the DC resistance of the primary winding and the DC resistance of the secondary winding can be determined using formulas nine and ten. Formula nine is as follows: The tenth formula is: In the formula, is a DC resistance of the primary side winding (Ω), is a DC resistance of the secondary side winding (Ω), is a resistivity of the wire (Ω•mm), is a length of the primary side winding (mm), is a length of the secondary side winding (mm).

[0035] wherein the wire resistivity is a material constant of the wire, which is determined according to the wire material adopted. The length of the primary side winding and the length of the secondary side winding can be calculated according to the core column diameter, the winding number of turns, and the wire diameter, etc. design parameters. Specifically, it can be obtained by multiplying the average circumference of the winding by the number of turns of the corresponding winding, for example, the length of the primary side winding = , and the length of the secondary side winding = .

[0036] In the above manner, the winding parameters are calculated systematically in the embodiment, ensuring that the transformer meets the electrical performance requirements while taking into account the compactness of the winding structure and the feasibility of the manufacturing process.

[0037] In step S200, the no-load loss, the no-load magnetization, and the no-load current of the target voltage transformer are calculated based on the ferromagnetic material attribute parameters and the core size information.

[0038] wherein the ferromagnetic material attributes include but are not limited to the specific excitation loss, the specific excitation volt-ampere, the material density, etc. In the embodiment, the core is made of high permeability silicon steel sheets (such as cold-rolled grain-oriented silicon steel sheets), and the thickness of the silicon steel sheets is generally 0.3mm or 0.35mm.

[0039] Exemplarily, the no-load loss and the no-load magnetization can be determined by the eleventh formula and the twelfth formula respectively, the eleventh formula being: , and the twelfth formula being: ; wherein, is the no-load loss of the core (W), is the no-load magnetization of the core (VA), m is the mass of the core (kg), is the specific excitation loss of the silicon steel (W / kg), is the specific excitation volt-ampere of the silicon steel (VA / kg), is the density of the silicon steel (kg / m3), is the volume of the transformer core (m3); wherein the volume of the transformer core can be calculated by the geometric parameters such as the cross-sectional area of the core and the height of the core.

[0040] After determining the no-load loss and no-load magnetization, the no-load current of the iron core can be calculated using Formula Thirteen, which is: In the formula This is the no-load current.

[0041] The no-load current is one of the important input parameters for transformer error analysis, and its magnitude directly affects the transformer's ratio error and phase angle error. In practical implementation, by reasonably selecting ferromagnetic materials and controlling the core volume, the no-load current can be effectively reduced, thereby improving the transformer's measurement accuracy.

[0042] Step S300: Determine the leakage reactance value referred to the secondary side and the total winding resistance based on the winding structure parameters.

[0043] Among them, such as Figure 3 As shown, the structural parameters of the winding include, but are not limited to, the axial height H of the primary winding and the axial height of the secondary winding. 1. Axial height difference ΔH between primary and secondary windings; 2. Radial width of secondary winding. Radial width of the primary winding Radial insulation gap between the primary winding and the secondary winding Radial distance from the outer edge of the primary winding to the center of the core column Radial distance from the outer edge of the primary winding to the center line of the winding Radial distance from the outer edge of the primary winding to the inner edge of the secondary winding .

[0044] In some implementations, such as Figure 4 As shown, the leakage reactance value referred to the secondary side is determined based on the winding structure parameters, including steps S310-S350. Step S310: Determine the Rockwell coefficient based on the radial width of the secondary winding, the radial width of the primary winding, the radial insulation gap between the primary and secondary windings, and the axial height of the primary winding.

[0045] Among them, the Lochte coefficient This parameter describes the proportion of leakage flux caused by structural asymmetry, insulation gaps, and uneven winding distribution between windings. It reflects the leakage flux effect resulting from incomplete magnetic coupling between windings and is crucial for subsequent leakage reactance modeling.

[0046] As an example, the Lochte coefficient can be determined according to formula fourteen. The fourteenth formula is: In the formula, .

[0047] Step S320, determining the transverse leakage magnetic coefficient according to the axial height of the primary side winding, the radial width of the secondary side winding, and the difference between the inner radius of the secondary side winding and the radius of the core column.

[0048] wherein the transverse leakage magnetic coefficient The transverse leakage magnetic coefficient characterizes the proportion of the transverse leakage magnetic flux in the main magnetic flux, and is one of the key factors affecting the nonlinear magnetic circuit distribution of the transformer. The introduction of the coefficient helps to more accurately evaluate the influence of winding asymmetry on the leakage magnetic flux path.

[0049] Exemplarily, the transverse leakage magnetic coefficient may be determined by a fifteenth formula, wherein the fifteenth formula is: ; in the formula, , wherein, is the difference between the inner radius of the secondary side winding and the radius of the core column.

[0050] Step S330, determining the equivalent magnetic circuit gap correction coefficient according to the radial width of the secondary side winding, the radial distance from the outer side of the primary side winding to the inner side of the secondary side winding, the radial distance from the outer side of the primary side winding to the center line of the winding, the radial insulation gap between the primary side winding and the secondary side winding, the radial width of the primary side winding, and the radial distance from the outer side of the primary side winding to the center of the core column.

[0051] wherein the equivalent magnetic circuit gap correction coefficient is used to equivalently convert the geometric asymmetry between the winding and the core, the insulation gap and other factors into a unified magnetic circuit gap, so as to simplify the modeling of the leakage magnetic flux path. The coefficient helps to improve the accuracy and efficiency of the leakage reactance modeling.

[0052] Exemplarily, the equivalent magnetic circuit gap correction coefficient may be determined by a sixteenth formula, wherein the sixteenth formula is: .

[0053] Step S340, determining the transverse leakage magnetic additional coefficient according to the Rockwell coefficient, the transverse leakage magnetic coefficient, the equivalent magnetic circuit gap correction coefficient, the radial width of the secondary side winding, and the axial height difference between the primary side winding and the secondary side winding.

[0054] wherein the transverse leakage magnetic additional coefficient is a secondary correction factor for the transverse leakage magnetic effect, which is used to further consider the influence of the winding height difference and structural asymmetry on the leakage magnetic distribution.

[0055] Exemplarily, the transverse leakage magnetic additional coefficient may be determined by a seventeenth formula, wherein the seventeenth formula is: .

[0056] Step S350, according to the secondary side rated voltage, the rated operating frequency, the Rockwell coefficient, the radial distance from the outer side of the primary side winding to the winding center line, the equivalent magnetic circuit gap correction coefficient, the transverse leakage magnetic additional coefficient and the axial height of the primary side winding, the leakage reactance value reduced to the secondary side is determined.

[0057] wherein the leakage reactance value reduced to the secondary side is a key parameter for reflecting the influence of the primary side leakage flux on the secondary side output voltage, which has a significant influence on the measurement error of the transformer, especially the ratio difference.

[0058] Exemplarily, the leakage reactance value reduced to the secondary side can be determined according to the eighteenth formula, which is: .

[0059] In some embodiments, the total resistance of the winding is the equivalent resistance of the primary side winding resistance reduced to the secondary side and the actual resistance of the secondary side winding , then ; wherein, is the equivalent resistance of the primary side winding resistance reduced to the secondary side, is the actual resistance of the secondary side winding.

[0060] In the design of the voltage transformer, in order to facilitate error analysis and modeling calculation, in the embodiment, the electrical parameters (such as resistance, leakage reactance) of the primary side are reduced to the secondary side to form a unified electrical model, the equivalent resistance of the primary side winding resistance reduced to the secondary side can be obtained by the nineteenth formula, which is ; wherein, is the actual resistance of the primary side winding.

[0061] Through this reduction method, the total resistance of the primary side and the secondary side winding can be unified under the same voltage level for analysis, which facilitates subsequent error modeling, impedance voltage calculation and error compensation strategy design.

[0062] Step S400, based on the core size information and the winding parameters, an initial three-dimensional finite element simulation model of the voltage transformer is established.

[0063] wherein the winding parameters include winding electrical parameters and structural parameters.

[0064] After the design and calculation of the core size, winding electrical parameters and structural parameters are completed, the initial three-dimensional finite element simulation model of the voltage transformer is established based on the above parameters, which is used for subsequent electromagnetic field simulation analysis, error verification and structural optimization design.

[0065] The three-dimensional finite element simulation model includes the following main components: The core is made of wound silicon steel sheet structure, the material is cold-rolled oriented silicon steel sheet, the thickness is generally 0.3mm or 0.35mm, and the core size is constructed according to the cross-sectional area of the core calculated in the foregoing steps, the core column diameter and other parameters.

[0066] The primary winding and the secondary winding are modeled according to electrical parameters such as winding turns ( 、 ), wire diameter ( 、 ), DC resistance ( 、 ), and other structural parameters such as axial height (H, 、 、 ).

[0067] The insulation structure takes into account the insulation gap between the primary winding and the secondary winding , the insulation layer between the winding and the core, etc., and the material includes epoxy resin, polyester film, etc.

[0068] The air domain is set to a certain range of external air domain to simulate the real electromagnetic environment, usually 3-5 times the size of the model to ensure reasonable boundary conditions.

[0069] After the three-dimensional modeling is completed, the following key parameters are imported into the finite element simulation software: Core material properties, including permeability, conductivity, B-H nonlinear curve, etc., among which the B-H curve is imported by interpolating the data provided by the manufacturer to accurately simulate the magnetization characteristics of the core under different magnetic flux densities.

[0070] Winding material properties, including the electrical conductivity and permeability of copper wire.

[0071] Insulation material properties, including relative permittivity, conductivity, etc., for electric field and insulation performance simulation.

[0072] Winding turns and winding method for constructing the geometric structure and excitation conditions of the winding coil.

[0073] In terms of meshing, a combination of manual encryption and adaptive meshing is used to ensure that the electromagnetic field gradient change area (such as the winding and the corner of the core) has a high enough grid density, usually the unit size is 1mm, and the corner of the core is encrypted to 0.5mm; For the gently changing area (such as the insulation layer, air domain), appropriate coarse grid (such as 5mm) can be used to improve the simulation efficiency.

[0074] For the mutual inductor with structural symmetry (such as a ring core or a symmetrical runway core), a 1 / 2 or 1 / 4 model can be used for simulation to reduce the amount of calculation and improve the simulation efficiency.

[0075] In the boundary condition setting, the outer boundary of the model is defined as a magnetic insulation boundary to simulate an infinite air domain; different material interfaces in the interior are set as natural boundaries to ensure the continuity of field quantities; and the winding end is set as a voltage excitation or current excitation source according to the actual connection mode.

[0076] The initial three-dimensional finite element simulation model can be used for subsequent simulation analysis of rated operating conditions, short-circuit operating conditions, impulse voltage operating conditions and the like, to evaluate the electromagnetic field distribution, voltage and current waveforms, core magnetic flux density, insulation structure breakdown risk and the like of the voltage transformer, and to provide data support for error analysis and feedback optimization design.

[0077] In step S500, the no-load error and the load error of the voltage transformer are determined based on the no-load loss, the no-load magnetization, the leakage reactance value, the total winding resistance and the winding structure parameters.

[0078] The no-load error refers to the ratio error (amplitude error) and the phase error (phase error) of the voltage transformer under no-load (no-load) conditions due to core magnetizing current, no-load loss and the like. The load error refers to the ratio error and the phase error of the voltage transformer under load operating conditions due to winding resistance, leakage reactance, load power factor and the like.

[0079] In some embodiments, the no-load error includes a no-load ratio error and a no-load phase error; the no-load ratio error is obtained based on the no-load loss, the no-load magnetization, the total calculated reactance of the primary side winding, the secondary side winding voltage and the secondary side rated voltage; and the no-load phase error is obtained based on the no-load loss, the no-load magnetization, the total calculated reactance of the primary side winding and the secondary side rated voltage.

[0080] The total calculated reactance of the primary side winding is determined based on the number of turns of the primary side winding, the number of turns of the secondary side winding, the primary side winding voltage, the no-load magnetization of the core and the actual leakage reactance of the primary side winding.

[0081] Exemplarily, ; in the formula, is the value of the leakage reactance of the primary side winding calculated to the secondary side, is the value of the core excitation reactance calculated to the secondary side.

[0082] The value of the leakage reactance of the primary side winding calculated to the secondary side can be obtained by the twentieth formula, and the twentieth formula is ; in the formula, is the actual leakage reactance of the primary side winding, is the number of turns of the secondary side winding, The number of turns of the primary winding.

[0083] The value of the core excitation reactance reduced to the secondary side The load error can be calculated by the twenty-first formula, which is: ; in the formula, is the voltage of the primary winding, is the no-load magnetization of the core.

[0084] The no-load ratio error is exemplary The load error can be calculated by the twenty-first formula, which is: .

[0085] The no-load angle error The load error can be calculated by the twenty-second formula, which is: .

[0086] In some embodiments, the load error includes a load ratio error and a load angle error; both the load ratio error and the load angle error are determined based on an active component of the impedance voltage, a reactive component of the impedance voltage, and a phase difference between the secondary winding output voltage and the load current.

[0087] The phase difference between the secondary winding output voltage and the load current represents the power factor angle of the load on the secondary side of the voltage transformer, which reflects the nature of the load and has a direct impact on the load error (ratio error and angle error). In three-dimensional finite element simulation, The load error can be calculated by setting the load impedance and extracting the voltage and current waveforms.

[0088] The active component of the impedance voltage is obtained based on the voltage of the secondary winding , the rated capacity of the target voltage transformer , and the total resistance of the winding ; the reactive component of the impedance voltage is obtained based on the voltage of the secondary winding , the rated capacity of the target voltage transformer , and the leakage reactance value reduced to the secondary side .

[0089] The active component of the impedance voltage The load error can be calculated by the twenty-third formula, which is: .

[0090] The reactive component of the impedance voltage The load error can be calculated by the twenty-fourth formula, which is: .

[0091] Further, the load ratio difference The load angle difference can be calculated by a twenty-sixth formula, which is: .

[0092] The load angle difference can be calculated by a twenty-sixth formula, which is: .

[0093] The no-load error and the load error in the embodiment are key indicators for evaluating the measurement accuracy of the voltage transformer, and directly affect the error grade (such as 0.5 level, 0.2 level). By calculating the no-load ratio difference and the angle difference, the load ratio difference and the angle difference, it can be judged whether the measurement error of the voltage transformer under different operating states meets the design requirements. The no-load ratio difference and the no-load angle difference reflect the influence of the core magnetization characteristic and the primary winding voltage drop on the voltage transformation ratio, and are important basis for judging the measurement accuracy of the transformer under no-load state. The load ratio difference and the load angle difference reflect the influence of the winding resistance, leakage reactance and load power factor on the measurement error under load condition, and are key indicators for judging the performance of the transformer under actual operating conditions. Through the above error analysis, it can be judged whether the transformer meets the standard error limit value requirement; if the ratio difference exceeds the limit value, compensation can be made by reducing the turns of the primary winding; in addition, based on the error data, the winding structure, core size, material properties and other parameters can be adjusted, and used as reference indicators for error verification in three-dimensional finite element simulation, to provide input data for feedback optimization model in subsequent steps.

[0094] The voltage transformer design method proposed in the embodiment is based on Faraday's law of electromagnetic induction and transformer equivalent circuit model, starting from the principle of electromagnetic induction, combining the actual structure of the voltage transformer, and constructing the theoretical calculation model of core magnetization, winding leakage reactance, no-load and load error. Through Faraday's law of electromagnetic induction, the relationship between winding induced electromotive force and magnetic flux change rate is established, which provides a theoretical basis for the design of winding turns and core size; through the transformer equivalent circuit model, the electrical parameters of the primary side and the secondary side are modeled uniformly, and the system analysis and modeling of no-load loss, leakage reactance influence and measurement error are realized. The method breaks through the limitations of traditional experience design, and improves the theoretical depth and engineering applicability of low-voltage voltage transformer design.

[0095] In step S600, the initial three-dimensional finite element simulation model is feedback optimized based on the no-load error and the load error, a target three-dimensional finite element simulation model is obtained, and a target voltage transformer is manufactured based on the target three-dimensional finite element simulation model.

[0096] It is understandable that the feedback optimization process is a key step in the closed-loop design process of voltage transformers. Its purpose is to dynamically adjust the design parameters based on the error analysis results, so that the measurement error of the transformer converges within the standard limit range, ensuring that it meets the design requirements and accuracy level standards (such as 0.5 class, 0.2 class, etc.).

[0097] In some implementations, such as Figure 5 As shown, the initial three-dimensional finite element simulation model is optimized based on no-load error and load error to obtain the target three-dimensional finite element simulation model, including steps S610-S640: Step S610: Compare the no-load ratio difference, no-load angle difference, load ratio difference, and load angle difference with the corresponding standard error limits.

[0098] After calculating the no-load and load errors, the error values ​​are compared with the standard limits to determine whether the current design meets the measurement accuracy requirements. For example, for a 0.5-class voltage transformer, the standard error limits are as follows: no-load ratio difference limit: ±0.5%; no-load angle difference limit: ±20′; load ratio difference limit: ±0.5%; load angle difference limit: ±20′. If the error value exceeds the above limits, proceed to the next step for parameter adjustment.

[0099] In step S620, if the ratio difference exceeds the limit, the number of turns of the primary winding is adjusted by reducing the number of turns of the primary winding.

[0100] In this step, if the voltage ratio difference (especially the no-load voltage ratio difference) exceeds the limit, error compensation can be achieved by reducing the number of turns in the primary winding. The physical principle of this compensation mechanism is: reducing the number of turns in the primary winding reduces the induced electromotive force in the primary side, thereby improving the voltage ratio difference. Typically, the number of turns reduced in the primary winding is 1 to 7 turns, with the specific number determined based on the degree of error deviation. For example, in one embodiment, the original number of turns in the primary winding was 1787. Error analysis revealed a large voltage ratio deviation. After reducing 5 turns, the number became 1782 turns, and the voltage ratio was adjusted from 8 to 7.99, effectively improving the error performance.

[0101] In step S630, if the angle difference exceeds the limit, the winding structure or the core permeability distribution is adjusted.

[0102] In this step, when the angle difference (especially the no-load angle difference or the load angle difference) exceeds the limit, it can be optimized in the following ways: Adjust the winding structure: such as optimizing the winding height, winding method, insulation gap, etc., to change the leakage flux path and reduce the angle difference; Adjust the core permeability distribution: such as selecting ferromagnetic materials with higher permeability (such as cold-rolled grain-oriented silicon steel sheets), adjusting the core lamination direction, optimizing the core size, etc., to improve magnetization characteristics and improve the angle difference performance. This step can be based on simulation results to perform parameter sensitivity analysis and select the design variables that have the most significant impact on the angle difference for adjustment.

[0103] Step S640, based on the adjustment result, re-establish the three-dimensional finite element simulation model and perform error recalculation until the output error of the established three-dimensional finite element simulation model meets the error limit value, and then the target three-dimensional finite element simulation model is obtained.

[0104] Exemplarily, after completing the adjustment of the primary winding number of turns, winding structure or core parameters, the three-dimensional finite element simulation model of the voltage transformer is re-established, the updated core and winding parameters are imported, and error recalculation is performed. Through iterative optimization, the design parameters are continuously adjusted and re-simulated and verified until the output no-load and load errors meet the error limit value requirements. At this time, the established simulation model is the target three-dimensional finite element simulation model, which can be used for subsequent structure design, prototype trial production or error verification. The feedback optimization mechanism not only improves the design efficiency of the voltage transformer, but also ensures the measurement accuracy of the transformer under various operating conditions.

[0105] The low-voltage voltage transformer design method provided in this embodiment has strong universality and systematicness, can accurately determine the geometric size of the silicon steel core, the number of turns and the wire diameter of the primary and secondary windings and other key design parameters based on electrical performance parameters and spatial restriction conditions, and verify and optimize the design results through a three-dimensional finite element simulation model, realizing the organic unification of theoretical design and simulation verification.

[0106] The method introduces parameters such as Rockwell coefficient, transverse leakage magnetic coefficient, equivalent magnetic path gap correction coefficient and transverse leakage magnetic additional coefficient, establishes a leakage reactance model reduced to the secondary side, thereby more accurately reflecting the influence of leakage impedance on the measurement accuracy of the transformer, and combines parameters such as no-load loss, no-load magnetization and winding resistance to systematically model the no-load ratio difference, no-load angle difference, load ratio difference and load angle difference, making the error analysis more close to the actual operating condition.

[0107] Based on the error analysis, the embodiment also proposes a complete feedback optimization mechanism. By comparing the no-load and load errors with the standard limit value, the number of turns of the primary winding, the winding structure or the core permeability distribution can be dynamically adjusted, and based on the adjustment result, the three-dimensional finite element simulation model is re-established to perform error recalculation until the error converges within the limit value range, and the target three-dimensional finite element simulation model meeting the measurement accuracy requirements is obtained. Through this closed-loop design process, the scientificity and adaptability of the transformer design can be significantly improved.

[0108] Furthermore, this embodiment establishes a three-dimensional finite element model including the core, windings, and insulation structure. It imports the nonlinear BH curves of ferromagnetic materials and the medium properties of the windings and insulation materials. Combined with manual and adaptive mesh refinement, magnetic insulation boundary settings, and AC and impulse voltage excitation sources, it can simulate various operating conditions such as rated, short-circuit, and impulse voltage. This comprehensively evaluates the electromagnetic field distribution, voltage and current waveform characteristics, and insulation performance of the instrument transformer under different operating conditions, ensuring that the design model meets practical application requirements in terms of both electrical performance and structural safety. Moreover, the parameter calculation process in this embodiment is clear and logically rigorous. All key parameters are explicitly expressed through theoretical formulas, reducing reliance on empirical design and improving design efficiency and consistency.

[0109] To facilitate understanding of the method in this embodiment, a specific embodiment will be described below.

[0110] In this embodiment, the rated operating frequency f=50Hz and the primary side rated voltage are selected. =800V, secondary side rated voltage =100V, measurement accuracy of 0.5 class, rated capacity of the target voltage transformer This design will focus on a low-voltage voltage transformer with a capacity of 10VA, a maximum output capacity of 100VA, a power factor of 0.8 (lagging), and a temperature rise limit of 60K. The specific design steps are as follows: In the embodiment, firstly based on the voltage value per turn 0.45, rated operating frequency, rated magnetic flux density If the weight is 0.9T, then the calculated cross-sectional area of ​​the silicon steel core is: .

[0111] Then, based on the core column space utilization factor, the voltage per turn, and the rated magnetic flux density of the target voltage transformer, the core column diameter is calculated, i.e. .

[0112] Considering size limitations, the actual selection is as follows: Figure 6 The shown core is made of grain-oriented silicon steel strip with a double rectangular cross-section, wound together. Each core has a cross-sectional width of 2.8 cm and a thickness of 4.2 cm, with a cross-sectional area of ​​23.52 g / cm². The actual value is 23.52. Compared with theoretical value The two are not equal because, after completing the theoretical calculations, it was initially determined that the cross-sectional area of ​​the iron core should not be less than 22.52. , to ensure that the magnetic flux density does not exceed the set value (such as 0.9T). In the actual design, considering the winding arrangement space, insulation structure, manufacturing process and safety margin of magnetic flux density, the double-rectangular cross-section cold-rolled oriented silicon steel strip winding core is finally selected, the single core cross-section is 2.8cm wide and 4.2cm thick, and the cross-sectional area is 23.52 , slightly larger than the theoretical minimum value, to ensure that the magnetic flux density of the core is controlled within the safe range under the rated operating condition, while considering the winding arrangement and structural compactness. It can be understood that in the design of the core size in this embodiment, both the theoretical calculation of electromagnetic performance and the feasibility of actual structure arrangement and manufacturing process are considered. The theoretical calculation provides the design lower limit, and the actually selected core size leaves a proper margin on the basis of the theoretical value, which reflects the comprehensive consideration of safety, structural rationality and manufacturing realizability in engineering design.

[0113] According to the process of the above embodiment, the primary side winding turns and the secondary side winding turns are calculated as follows: ; the primary side winding current and the secondary side winding current are: . Then, the primary side winding wire diameter and the secondary side winding wire diameter are: ; and the primary side winding DC resistance and the secondary side winding DC resistance are calculated as: .

[0114] In this embodiment, the silicon steel grade 30Q140 is selected, which has a saturation magnetic density of 1.8T at 100℃ and a material density of 7.65g / cm3. According to the winding turns and wire diameter, considering the insulation allowance, the core is set to have an inner window length of 78mm, an inner window width of 48mm, an outer window length of 162mm and an outer window width of 132mm, and the average length of the magnetic circuit is 420mm. Then the core volume is 987.84cm3 and the mass is 7.56kg.

[0115] According to the above parameters, the no-load loss and no-load magnetization of the core can be calculated as: ; ; and the no-load current of the transformer is: .

[0116] In this embodiment, the winding structure parameters are defined as shown in Figure 3 and Table 1 as follows: Table 1:

[0117] Further, based on the above embodiment, the Rogowski coefficient, the transverse leakage magnetic coefficient, the equivalent magnetic gap correction coefficient, the transverse leakage magnetic additional coefficient, the leakage reactance reduced to the secondary side, the active component and the reactive component of the impedance voltage can be obtained in turn.

[0118] Then the Rogowski coefficient ; transverse leakage magnetic coefficient ; equivalent magnetic circuit gap correction coefficient ; transverse leakage magnetic additional coefficient ; leakage reactance reduced to secondary side ; active component of impedance voltage ; reactive component of impedance voltage .

[0119] Based on the above-mentioned calculation method of no-load error and load error, error analysis data of the transformer at different voltage levels (such as 5% to 200% rated voltage) can be obtained, as shown in Table 2.

[0120] Table 2:

[0121] In this embodiment, according to the error calculation results shown in Table 2, the total ratio error of the voltage transformer under the condition of 100% rated voltage is -0.506%, which has slightly exceeded the error limit value of 0.5 level (±0.5%), indicating that the measurement accuracy of the current design has not yet met the error requirements of the national standard for 0.5 level voltage transformer. According to the provisions of the national standard GB 1207-2016 "Electromagnetic Voltage Transformer", the ratio error limit value of 0.5 level voltage transformer is ±0.5%, and the angle error limit value is ±20'. Under this standard, if the calculated or simulated error exceeds the above limit value, error compensation measures need to be taken to improve the measurement accuracy.

[0122] In view of the fact that the ratio error is the main error item and exceeds the limit value, this embodiment adopts a primary winding turn reduction compensation method, reducing the number of turns of the primary winding from 1787 turns to 1782 turns, i.e. reducing 5 turns, to improve the ratio error performance. After turn reduction compensation, a three-dimensional finite element simulation model of the voltage transformer is re-established, and the measurement error after compensation is estimated, and the results are shown in Table 3.

[0123] The three-dimensional finite element simulation model includes the primary winding, the secondary winding, the winding core and the insulation structure, and ignores the mechanical structures such as bolts and perforations that have no effect on the magnetic field distribution, so as to improve the modeling efficiency. As shown in Figure 6 , it is a complete three-dimensional model of the voltage transformer; as shown in Figure 7 , it is a 1 / 4 simplified simulation model established based on the structural symmetry, which is used to improve the simulation efficiency and ensure the accuracy of the results.

[0124] In the simulation modeling process, the medium properties of the core, winding and insulation material are imported, as shown in Table 4. Among them, the nonlinear magnetization characteristics of the core material are interpolated according to the B-H curve provided by the manufacturer, so as to accurately simulate the magnetization behavior of the core under different magnetic flux densities, as shown in Figure 8 .

[0125] Table 3:

[0126] Table 4:

[0127] In terms of mesh generation, a combination of manual and adaptive meshing was used. Regions with significant electromagnetic field gradient changes (such as core corners and areas near windings) were meshed with tetrahedral meshes of 1mm element size, further refined to 0.5mm at core corners, totaling 350,000 meshes. The insulation layer and air domain regions used 5mm meshes, totaling 150,000 meshes, for a total of 500,000 meshes. This met the simulation requirements for nonlinear hysteresis characteristics and electromagnetic field distribution accuracy. Figure 9 As shown.

[0128] Regarding the boundary conditions and excitation source settings, the outer boundary of the model is set as a magnetically insulated boundary to simulate an infinite air domain; the excitation source is set as an AC voltage source or a pulse voltage source according to the simulation conditions. The simulation conditions include typical operating conditions such as rated voltage, short circuit, and impulse voltage, which are used to verify the electrical performance and structural safety of the instrument transformer under different operating conditions.

[0129] Under rated operating conditions, the magnetic flux density distribution of the iron core and the voltage waveforms of the primary and secondary windings are simulated and analyzed, such as... Figure 10 and Figure 11 As shown in the figure. Simulation results show that the magnetic flux density of the iron core is less than its saturation magnetic flux density value, the secondary voltage waveform matches the primary voltage waveform well, and both the ratio difference and angle difference are significantly improved.

[0130] In addition, a 1.2 / 50μs lightning impulse voltage with a peak value of 2.5kV was applied in the simulation to evaluate the insulation safety margin of the transformer under overvoltage conditions. An insulation breakdown criterion was set in the simulation: insulation breakdown was considered to have occurred when the electric field strength exceeded 25kV / mm. Figure 12 As shown in Table 5, the electric field strength modulus distribution of a voltage transformer under lightning impulse voltage is presented. Based on the simulation results, an optimized insulation structure scheme is proposed to improve insulation performance and overvoltage withstand capability.

[0131] Table 5:

[0132] Through Tables 2 to 5, Figures 9 to 11 The simulation and error analysis results show that after the turn reduction compensation, the voltage amplitude and phase error of the secondary side of the low-voltage transformer designed in this embodiment are significantly improved, the core magnetic flux density is controlled within a safe range, fully meets the error limit requirements of 0.5-class voltage transformers, and has good measurement accuracy and operational stability.

[0133] Figure 13 A structural schematic diagram of a voltage transformer design device of an embodiment of the present application is shown. Exemplarily, the voltage transformer design device comprises: The calculation module 100 is configured to determine core size information, electrical parameters of the primary side winding, and electrical parameters of the secondary side winding according to electrical performance parameters and spatial restriction conditions of the target voltage transformer.

[0134] The calculation module 100 is further configured to calculate no-load loss, no-load magnetization, and no-load current of the target voltage transformer based on the ferromagnetic material attribute parameters and the core size information.

[0135] The calculation module 100 is further configured to determine leakage reactance value and total winding resistance of the secondary side according to the winding structure parameters.

[0136] The simulation module 200 is configured to establish an initial three-dimensional finite element simulation model of the voltage transformer based on the core size information and the winding parameters, wherein the winding parameters comprise winding electrical parameters and winding structure parameters.

[0137] The calculation module 100 is further configured to determine no-load error and load error of the voltage transformer based on the no-load loss, the no-load magnetization, the leakage reactance value, the total winding resistance, and the winding structure parameters.

[0138] The simulation module 200 is further configured to perform feedback optimization on the initial three-dimensional finite element simulation model based on the no-load error and the load error to obtain a target three-dimensional finite element simulation model, and to manufacture the target voltage transformer based on the target three-dimensional finite element simulation model.

[0139] It can be understood that the device of the embodiment corresponds to the voltage transformer design method of the above-mentioned embodiment, and the optional items in the above-mentioned embodiment are also applicable to the present embodiment, and thus will not be described again here.

[0140] An embodiment of the present application provides a voltage transformer manufactured by the above-mentioned voltage transformer design method.

[0141] The present application further provides a terminal device, which exemplarily comprises a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program to enable the terminal device to perform the functions of the voltage transformer design method or each module of the voltage transformer design device.

[0142] The processor can be an integrated circuit chip with a processing capability of signals. The processor can be a general processor, including a central processing unit (CPU), a graphics processing unit (GPU), and a network processor (NP), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, a discrete gate or transistor logic device, a discrete hardware component, at least one of the above. The general processor can be a microprocessor or the processor can be any conventional processor or the like, which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application.

[0143] The memory can be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM) and the like. The memory is used to store a computer program. After receiving an execution instruction, the processor can execute the computer program accordingly.

[0144] The present application also provides a computer readable storage medium for storing the computer program used in the terminal device. For example, the computer readable storage medium can include, but is not limited to, a U disk, a mobile hard disk, a read only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk and various program code storage media.

[0145] It should be understood that all the functional units and steps in the embodiments disclosed in the present application can be implemented by using a dedicated hardware, or a combination of software and hardware. In general, any device unit or step in the embodiments disclosed in the present application can be implemented by using a dedicated hardware, or a combination of software and hardware. Software can be stored in a readable storage medium, such as a floppy disk, a USB flash disk, a ROM, a RAM, or a removable program storage medium of the computer. The functional units and steps in the embodiments disclosed in the present application can be implemented by using a computer. The computer can include a processor and a memory for storing program code of the computer program. When the program code is executed by the processor, the processor performs the functions of the embodiments disclosed in the present application.

[0146] In addition, each functional module or unit in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0147] The above describes only the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application.

Claims

1. A voltage transformer design method, characterized in that, include: Based on the electrical performance parameters and space constraints of the target voltage transformer, determine the core size information, the electrical parameters of the primary winding, and the electrical parameters of the secondary winding; Based on the ferromagnetic material property parameters and the core size information, the no-load loss, no-load magnetization and no-load current of the target voltage transformer are calculated. Based on the winding structure parameters, determine the leakage reactance value referred to the secondary side and the total winding resistance; An initial three-dimensional finite element simulation model of the voltage transformer is established based on the core size information and winding parameters; wherein, the winding parameters include winding electrical parameters and winding structural parameters; Based on the no-load loss, no-load magnetization, leakage reactance, total winding resistance, and winding structure parameters, the no-load error and load error of the voltage transformer are determined. The initial three-dimensional finite element simulation model is optimized based on the no-load error and the load error to obtain the target three-dimensional finite element simulation model, and the target voltage transformer is fabricated based on the target three-dimensional finite element simulation model.

2. The voltage transformer design method according to claim 1, characterized in that, The electrical performance parameters include primary side rated voltage, secondary side rated voltage, rated operating frequency, voltage per turn, and rated magnetic flux density; The process of determining the core size information and the electrical parameters of the primary and secondary windings based on the electrical performance parameters and space constraints of the target voltage transformer includes: Calculate the cross-sectional area of ​​the core of the target voltage transformer based on the voltage per turn, the rated magnetic flux density, and the rated operating frequency. The core column diameter of the target voltage transformer is calculated based on the core column space utilization coefficient, the voltage per turn, and the rated magnetic flux density. Based on the primary side rated voltage, the secondary side rated voltage, and the voltage per turn value of the target voltage transformer, determine the number of turns in the primary winding, the number of turns in the secondary winding, the primary winding current, the secondary winding current, the primary winding wire diameter, the secondary winding wire diameter, the primary winding DC resistance, and the secondary winding DC resistance.

3. The voltage transformer design method according to claim 2, characterized in that, The winding structure parameters include the axial height of the primary winding, the axial height of the secondary winding, the difference in axial height between the primary and secondary windings, the radial width of the secondary winding, the radial width of the primary winding, the radial insulation gap between the primary and secondary windings, the radial distance from the outer edge of the primary winding to the center of the core column, the radial distance from the outer edge of the primary winding to the winding centerline, and the radial distance from the outer edge of the primary winding to the inner edge of the secondary winding.

4. The voltage transformer design method according to claim 3, characterized in that, Based on the winding structure parameters, determine the leakage reactance value referred to the secondary side, including: The Rockwell coefficient is determined based on the radial width of the secondary winding, the radial width of the primary winding, the radial insulation gap between the primary and secondary windings, and the axial height of the primary winding. The transverse leakage coefficient is determined based on the axial height of the primary winding, the radial width of the secondary winding, and the difference between the inner radius of the secondary winding and the radius of the core column. The equivalent magnetic circuit gap correction coefficient is determined based on the radial width of the secondary winding, the radial distance from the outer side of the primary winding to the inner side of the secondary winding, the radial distance from the outer side of the primary winding to the winding centerline, the radial insulation gap between the primary winding and the secondary winding, the radial width of the primary winding, and the radial distance from the outer side of the primary winding to the center of the core column. The additional coefficient of transverse leakage flux is determined based on the Rockwell coefficient, the transverse leakage flux coefficient, the equivalent magnetic circuit gap correction coefficient, the radial width of the secondary winding, and the axial height difference between the primary winding and the secondary winding. The leakage reactance value referred to the secondary side is determined based on the rated voltage of the secondary side, the rated operating frequency, the Rockwell coefficient, the radial distance from the outer edge of the primary winding to the center line of the winding, the equivalent magnetic circuit gap correction coefficient, the lateral leakage flux additional coefficient, and the axial height of the primary winding.

5. The voltage transformer design method according to claim 2, characterized in that, The no-load error includes no-load ratio difference and no-load angle difference; The no-load ratio difference is obtained based on the no-load loss, the no-load magnetization, the total reduced reactance of the primary winding, the voltage of the secondary winding, and the rated voltage of the secondary winding. The no-load angle difference is obtained based on the no-load loss, the no-load magnetization, the total reduced reactance of the primary winding, and the rated voltage of the secondary winding; wherein, the total reduced reactance of the primary winding is determined based on the number of turns of the primary winding, the number of turns of the secondary winding, the voltage of the primary winding, the no-load magnetization, and the actual leakage reactance of the primary winding.

6. The voltage transformer design method according to claim 5, characterized in that, The load error includes load ratio difference and load angle difference; both the load ratio difference and the load angle difference are determined based on the active component of the impedance voltage, the reactive component of the impedance voltage, and the phase difference between the secondary winding output voltage and the load current. The active component of the impedance voltage is obtained based on the voltage of the secondary winding, the rated capacity of the target voltage transformer, and the total resistance of the winding; the reactive component of the impedance voltage is obtained based on the voltage of the secondary winding, the rated capacity of the target voltage transformer, and the leakage reactance value referred to the secondary side.

7. The voltage transformer design method according to claim 6, characterized in that, The step of performing feedback optimization on the initial three-dimensional finite element simulation model based on the no-load error and the load error to obtain the target three-dimensional finite element simulation model includes: The no-load ratio difference, the no-load angle difference, the load ratio difference, and the load angle difference are compared with the corresponding standard error limits; If the ratio difference exceeds the limit, the number of turns of the primary winding is adjusted by reducing the number of turns of the primary winding. If the angle difference exceeds the limit, adjust the winding structure or adjust the core permeability distribution. Based on the adjustment results, a new three-dimensional finite element simulation model is established and the error is recalculated until the output error of the established three-dimensional finite element simulation model meets the error limit. Then the target three-dimensional finite element simulation model is obtained.

8. A voltage transformer design device, characterized in that, include: The calculation module is used to determine the core size information, the electrical parameters of the primary winding, and the electrical parameters of the secondary winding based on the electrical performance parameters and space constraints of the target voltage transformer. The calculation module also calculates the no-load loss, no-load magnetization, and no-load current of the target voltage transformer based on the ferromagnetic material property parameters and the core size information. The calculation module is also used to determine the leakage reactance value referred to the secondary side and the total winding resistance based on the winding structure parameters; The simulation module is used to establish an initial three-dimensional finite element simulation model of the voltage transformer based on the core size information and winding parameters; wherein, the winding parameters include winding electrical parameters and winding structural parameters; The calculation module is also used to determine the no-load error and load error of the voltage transformer based on the no-load loss, the no-load magnetization, the leakage reactance, the total winding resistance and the winding structure parameters; The simulation module is also used to perform feedback optimization on the initial three-dimensional finite element simulation model based on the no-load error and the load error to obtain the target three-dimensional finite element simulation model, and to fabricate the target voltage transformer based on the target three-dimensional finite element simulation model.

9. A voltage transformer, characterized in that, The voltage transformer is manufactured using the voltage transformer design method described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed on a processor, implements the voltage transformer design method according to any one of claims 1-7.

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