Transformer core no-load performance analysis method, system, computer equipment and storage medium

Abstract

The present invention provides a method, system, computer device, and storage medium for analyzing the no-load performance of a transformer core, belonging to the technical field of transformer core design. The method comprises obtaining the hysteresis loss and eddy current loss of a single silicon steel sheet in the core; determining the loss of a single joint region of the core based on the hysteresis loss and eddy current loss of the single silicon steel sheet in the core; determining the total loss of the core based on the loss of the single joint region of the core; obtaining the average magnetic field strength of the silicon steel sheet cross section; determining the no-load current of the core based on the average magnetic field strength of the silicon steel sheet cross section; and analyzing the no-load performance of the transformer core based on the total loss and no-load current of the core. The present invention takes into account the effects of the step-lap joint method, paint film thickness, material sheet thickness, and gap size at the core joint on the no-load performance of the transformer, thereby avoiding the problem of exceeding the design standard for the no-load loss and no-load current of the core.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformer core design, and in particular relates to a transformer core no-load performance analysis method, system, computer equipment and storage medium. Background Art

[0002] The no-load performance of the transformer core mainly includes no-load loss and no-load current. By measuring the no-load current and loss, the efficiency, power factor and energy consumption of the transformer can be evaluated, which is crucial for the design and selection of the transformer.

[0003] Currently, the calculation of transformer core no-load losses primarily relies on a formula method, which uses the product of unit mass and specific total loss as the basis, supplemented by a process coefficient. The problem with this algorithm is that it treats the core as a homogeneous material, and the material's specific total loss is only related to the power supply excitation frequency and the core's magnetic flux density. However, silicon steel is not a homogeneous material, and the electromagnetic characteristics of the core joints are also very complex (this complexity is mainly due to the change in the main magnetic flux direction at the joints and the more complex structure of the joints compared to the core column area). The formula method cannot reflect the impact of the stepped overlap method, paint film thickness, material sheet thickness, and gap size at the core joints on no-load performance. As a result, the premise of the formula derivation no longer holds true in the joint area. Clearly, the formula method has large calculation errors when used for calculations of the entire core, and it cannot be used for research on joint structure optimization.

[0004] Engineering experts have traditionally estimated no-load current based on empirical evidence, using the material's unit magnetization capacity and the joint magnetization capacity, or using the finite element method to calculate no-load losses. However, these methods treat the core as a homogeneous entity, ignoring factors such as the step-lap joint pattern, paint film, and gap separation. This has led to excessive no-load current in production. Summary of the Invention

[0005] The present invention provides a transformer core no-load performance analysis method, system, computer equipment and storage medium to reduce the influence of the prior art on the transformer no-load performance analysis of the step-lap joint method, paint film thickness, material sheet thickness and gap size at the core joint.

[0006] In a first aspect, the present invention provides a method for analyzing no-load performance of a transformer core, comprising:

[0007] Obtain the hysteresis loss and eddy current loss of a single silicon steel sheet in the iron core;

[0008] Determine the loss of a single joint area of the core based on the hysteresis loss and eddy current loss of a single silicon steel sheet in the core;

[0009] Determine the total loss of the core based on the loss of a single seam area of the core;

[0010] Obtain the average magnetic field strength of the silicon steel sheet cross section;

[0011] The no-load current of the core is determined based on the average magnetic field strength of the silicon steel sheet cross section; the no-load performance of the transformer core is analyzed based on the total loss of the core and the no-load current.

[0012] Optionally, determining the loss of a single joint area of the core according to the hysteresis loss and eddy current loss of a single silicon steel sheet in the core includes:

[0013] The loss P1 of a single joint area of the core is calculated according to the following formula:

[0014]

[0015] Wherein, k is the core lamination coefficient; h1 is the core lamination height; n is the total number of silicon steel sheets in one step of the joint area; m is the number of silicon steel sheets in each stack; b1 is the number of steps in the step-by-step overlap method of the silicon steel sheets; h is the thickness of a single silicon steel sheet; P hi is the hysteresis loss of the i-th silicon steel sheet; P oi is the eddy current loss of the i-th silicon steel sheet.

[0016] Optionally, determining the total loss of the core based on the loss of a single joint area of the core includes:

[0017] Obtain the unit iron loss P' under the average magnetic flux density of the silicon steel sheet cross section;

[0018] The total core loss P is calculated according to the following formula 总 :

[0019] P 总 =4P1+b·k·h1·d·P'·ρ;

[0020] Among them, P1 is the loss in a single seam area of the core; b is the width of a single silicon steel sheet; k is the core lamination coefficient; h1 is the core lamination height; d is the total length of the core and yoke in the core excluding the seam; ρ is the density of the silicon steel sheet.

[0021] Optionally, determining the no-load current of the core according to the average magnetic field strength of the silicon steel sheet cross section includes:

[0022] Obtain the excitation current I1 and the number of turns N of the excitation wire in a single joint area in the iron core;

[0023] Calculate the no-load current I of the core according to the following formula:

[0024]

[0025] Where H' is the average magnetic field intensity of the silicon steel sheet cross section; d is the total length of the core and yoke excluding the joints in the core.

[0026] In a second aspect, the present invention provides a transformer core no-load performance analysis system, comprising:

[0027] The first acquisition module is used to obtain the hysteresis loss and eddy current loss of a single silicon steel sheet in the iron core;

[0028] The first determination module is used to determine the loss of a single joint area of the core based on the hysteresis loss and eddy current loss of a single silicon steel sheet in the core;

[0029] The second determining module is used to determine the total loss of the core according to the loss of a single joint area of the core;

[0030] The second acquisition module is used to obtain the average magnetic field strength of the silicon steel sheet cross section;

[0031] The third determination module is used to determine the no-load current of the core based on the average magnetic field strength of the silicon steel sheet cross section; and analyze the no-load performance of the transformer core based on the total loss of the core and the no-load current.

[0032] Optionally, the first determining module includes:

[0033] The first calculation unit is used to calculate the loss P1 of a single joint area of the core according to the following formula:

[0034]

[0035] Wherein, k is the core lamination coefficient; h1 is the core lamination height; n is the total number of silicon steel sheets in one step of the joint area; m is the number of silicon steel sheets in each stack; b1 is the number of steps in the step-by-step overlap method of the silicon steel sheets; h is the thickness of a single silicon steel sheet; P hi is the hysteresis loss of the i-th silicon steel sheet; P oi is the eddy current loss of the i-th silicon steel sheet.

[0036] Optionally, the second determining module includes:

[0037] The first acquisition unit is used to obtain the unit iron loss P' under the average magnetic flux density of the silicon steel sheet cross section;

[0038] The second calculation unit is used to calculate the total loss P of the core according to the following formula 总 :

[0039] P 总 =4P1+b·k·h1·d·P'·ρ;

[0040] Among them, P1 is the loss in a single seam area of the core; b is the width of a single silicon steel sheet; k is the core lamination coefficient; h1 is the core lamination height; d is the total length of the core and yoke in the core excluding the seam; ρ is the density of the silicon steel sheet.

[0041] Optionally, the third determining module includes:

[0042] The second acquisition unit is used to obtain the excitation current I1 of a single joint area in the iron core and the number of turns N of the excitation wire;

[0043] The third calculation unit is used to calculate the no-load current I of the core according to the following formula:

[0044]

[0045] Where H' is the average magnetic field intensity of the silicon steel sheet cross section; d is the total length of the core and yoke excluding the joints in the core.

[0046] In a third aspect, the present invention provides a computer device comprising a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the transformer core no-load performance analysis method described in the first aspect are implemented.

[0047] In a fourth aspect, the present invention provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the transformer core no-load performance analysis method described in the first aspect are implemented.

[0048] The present invention provides a method, system, computer device, and storage medium for analyzing the no-load performance of a transformer core. The method comprises obtaining the hysteresis loss and eddy current loss of a single silicon steel sheet in the core; determining the loss of a single core joint region based on the hysteresis loss and eddy current loss of the single silicon steel sheet in the core; determining the total loss of the core based on the loss of the single core joint region; obtaining the average magnetic field strength of the silicon steel sheet cross section; determining the no-load current of the core based on the average magnetic field strength of the silicon steel sheet cross section; and analyzing the no-load performance of the transformer core based on the total loss and no-load current of the core. The present invention considers the effects of the step-lap joint method, paint film thickness, material sheet thickness, and gap size at the core joint on the no-load performance of the transformer, thereby avoiding the problem of exceeding the design standard for the no-load loss and no-load current of the core. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0050] Figure 1 A schematic flow chart of a method for analyzing no-load performance of a transformer core provided by an embodiment of the present invention;

[0051] Figure 2 A schematic structural diagram of a transformer core no-load performance analysis system provided by an embodiment of the present invention.

[0052] Figure 3 BH curve diagram of the silicon steel sheet provided in an embodiment of the present invention;

[0053] Figure 4 BP curve diagram of silicon steel sheet provided by an embodiment of the present invention;

[0054] Figure 5 The BP of the modified silicon steel sheet provided in the embodiment of the present invention is s curve chart;

[0055] Figure 6 A sketch of a seamless joint of a silicon steel sheet provided in an embodiment of the present invention;

[0056] Figure 7 A comparison chart of loss percentages under different stepping conditions provided by an embodiment of the present invention;

[0057] Figure 8 A comparison chart of current percentages under different stepping conditions provided by an embodiment of the present invention;

[0058] Figure 9 A comparison chart of the efficiency and accuracy of various multi-stack models provided in an embodiment of the present invention;

[0059] Figure 10 A diagram showing the positional relationship between the silicon steel sheet and the paint film layer provided in an embodiment of the present invention;

[0060] Figure 11 This is a cloud diagram of the magnetic flux density distribution of a 5-step 4mm step joint provided by an embodiment of the present invention;

[0061] Figure 12 This is a cloud diagram of the eddy current loss distribution of a 5-step 4mm step joint provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0062] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0063] Example 1

[0064] like Figure 1 As shown, this embodiment provides a method for analyzing no-load performance of a transformer core, including:

[0065] Step 101: Obtain the hysteresis loss and eddy current loss of a single silicon steel sheet in an iron core.

[0066] In this embodiment, the thickness h0 of a single silicon steel sheet with paint film on both sides is 0.18 mm, the iron core has a step size of 4 mm in 5 steps, the silicon steel sheets are stacked one by one, the sheet width of the silicon steel sheet is 100 mm, the sheet length of the silicon steel sheet is 500 mm, and the stack thickness is 40 mm.

[0067] In this step, the paint film thickness h' on one side of the single silicon steel sheet, the thickness h0 of the single silicon steel sheet, the electrical conductivity σ of the silicon steel sheet, and the density ρ of the silicon steel sheet are obtained.

[0068] like Figure 3 and Figure 4 As shown, a relationship curve between the magnetic flux density B and the loss P of the silicon steel sheet and a relationship curve between the magnetic flux density B and the magnetic field intensity H of the silicon steel sheet are obtained. Among them, the magnetic flux density is the magnetic induction intensity.

[0069] Calculate the thickness h of a single silicon steel sheet according to the following formula:

[0070] h=h0-2h'=0.173mm.

[0071] Calculate the eddy current loss coefficient K of a single silicon steel sheet according to the following formula e :

[0072]

[0073] Here, π is the ratio of the circumference of a circle to its circumference.

[0074] Calculate the classic eddy current loss P of the silicon steel sheet in the full magnetic flux density section at the test frequency f according to the following formula e :

[0075] P e =f 2 ·B 2 ·K e .

[0076] According to the calculation of silicon steel sheet residual loss P s , and get Figure 5 The magnetic flux density B and the residual loss P of the silicon steel sheet are shown s The BP curve obtained from the test shows that at any magnetic flux density B, P s =PP e .

[0077] Create a 3D model of the core in MAGNET software:

[0078] 1) Click on the new model material and input the obtained silicon steel sheet parameters according to the steps. It should be noted that the BP curve data that needs to be input needs to be modified to BP s Curve data.

[0079] 2) According to the required width of the silicon steel sheet, select about twice the width as the sheet length, such as Figure 6 Therefore, sketch the seam without any gaps.

[0080] 3) Use the stretch command to stretch each silicon steel sheet into a three-dimensional sheet according to the core thickness and the sketch outline.

[0081] 4) Use the translation command to translate the silicon steel sheets in the vertical direction of the stacking by the total thickness of the silicon steel sheets. According to the relative position of the sheets, some sheets need to be moved several times. At this time, an air layer of the thickness of the paint film will appear between the silicon steel sheets, such as Figure 10 shown.

[0082] 5) Shift the silicon steel sheet as a whole to create a gap at the inclined joint.

[0083] 6) Draw the excitation wire and air bag, and make sure the edge of the air bag is flush with the end of the silicon steel sheet.

[0084] 7) Select the four copper conductors in the model one by one and use Model → Make Simple Coil to create the coils. Click the Circuit command to display the circuit diagram and click Voltage Source to add a voltage source. Set the Coil Type to Stranded and the Number of Turns and Strand Area according to the designed magnetic flux density. Set the voltage level and waveform as needed.

[0085] After the 3D model is established, the model needs to be simplified and corrected. The model simplification and correction includes the following steps:

[0086] 1) Select the surface of the silicon steel sheet that needs to be meshed. Right-click the sheet and under the Properties tab, select Mash Layers. Set a mesh layer in the center of the sheet. Within 10mm of the seam, set the maximum mesh size for the seam layer and the two layers above and below it to 1mm. Set the maximum mesh size for all other areas to 2-3mm. No special settings are required for areas outside the silicon steel sheet.

[0087] 2) Select the two surfaces flush with the air bag and the silicon steel section, and set them as FieldNormal Boundary boundary conditions.

[0088] 3) Select the bottom surface of the air bag parallel to the silicon steel sheet, click Even Periodic Boundary, and set the corresponding translation distance to the thickness of each stack.

[0089] After the model is simplified and corrected, simulation needs to be performed. The simulation calculation includes the following steps:

[0090] 1) Click Solve → Set Solver Option and set the Polynomial order to 2. Set other parameters as desired.

[0091] The post-processing calculation includes the following steps:

[0092] 1) Obtain the Hysteresis Loss (magnetic hysteresis loss) and Ohmic Loss (eddy current loss) of each silicon steel sheet in Results, and obtain the Current value, I' = 0.097956A.

[0093] 2) Obtain the RMS cloud diagram of the magnetic field intensity in Field, and obtain the average magnetic field intensity of the silicon steel sheet cross section at a certain point, which is calculated as H'; in this embodiment, H'=44.55 A / m.

[0094] 3) Obtain the magnetic flux density RMS cloud diagram in Field, and obtain the average magnetic flux density of the silicon steel sheet cross section at a point, which is calculated as B'; in this embodiment, B'=1.5T.

[0095] Step 102: Determine the loss of a single joint area of the core based on the hysteresis loss and eddy current loss of a single silicon steel sheet in the core.

[0096] For example, the loss P1 of a single joint region of the core is calculated according to the following formula:

[0097]

[0098] Wherein, k is the core lamination coefficient; h1 is the core lamination height; n is the total number of silicon steel sheets in one step of the joint area; m is the number of silicon steel sheets in each stack; b1 is the number of steps in the step-by-step overlap method of the silicon steel sheets; h is the thickness of a single silicon steel sheet; P hi is the hysteresis loss of the i-th silicon steel sheet; P oi is the eddy current loss of the i-th silicon steel sheet.

[0099] In this embodiment,

[0100] Step 103: Determine the total loss of the core based on the loss of a single joint area of the core.

[0101] Exemplarily, in this step, it is necessary to obtain the unit iron loss P' under the average magnetic flux density of the silicon steel sheet cross section.

[0102] The total core loss P is calculated according to the following formula 总 :

[0103] P 总 =4P1+b·k·h1·d·P'·ρ.

[0104] Among them, P1 is the loss in a single seam area of the core; b is the width of a single silicon steel sheet; k is the core lamination coefficient; h1 is the core lamination height; d is the total length of the core and yoke in the core excluding the seam; ρ is the density of the silicon steel sheet.

[0105] In this embodiment, d=4×(0.5-0.2×2)=0.4m; b·k·h1·d·P'·ρ=0.1×0.962×0.04×0.4×0.511×7650=6.01W; P 总 =4×4.650+6.01=24.61W.

[0106] Step 104: Obtain the average magnetic field strength of the silicon steel sheet cross section.

[0107] Step 105: Determine the no-load current of the core based on the average magnetic field strength of the silicon steel sheet cross section; and analyze the no-load performance of the transformer core based on the total loss of the core and the no-load current.

[0108] For example, the number of turns N of the excitation wire in the three-dimensional model is obtained; the Current value of the silicon steel sheet obtained in Results is used as the excitation current I1 of a single joint area in the iron core.

[0109] Calculate the no-load current I of the core according to the following formula:

[0110]

[0111] Where H' is the average magnetic field intensity of the silicon steel sheet cross section; d is the total length of the core and yoke excluding the joints in the core.

[0112] In this embodiment,

[0113] Obtain the required flux density cloud map and loss cloud map in Field, and observe the core loss distribution, such as Figure 11 and Figure 12 As shown, the magnetic flux density distribution and eddy current loss distribution of the joint with 5 steps and 4mm step size are respectively shown.

[0114] To solve the problem that the classical eddy current loss formula is not applicable to calculating the loss at the joint, this embodiment adopts a loss separation calculation method, which divides the iron loss into two parts: classical eddy current loss and other iron loss, and calculates them separately. The characteristics are:

[0115] 1) Correct the BP curve to BP before simulation calculation s Curve, used to calculate the part of the joint other than the classical eddy current loss.

[0116] 2) The induced current caused by the magnetic flux penetrating the joint is calculated through refined finite element simulation, and the ohmic loss of the induced current in the silicon steel matrix is calculated. This value is the actual eddy current loss at the joint, which is significantly different from the classic eddy current loss value.

[0117] In general models, eddy current loss is calculated using the classic eddy current loss formula. The classic eddy current loss formula is an approximate calculation based on the magnetic flux density but has nothing to do with the induced current in the silicon steel sheet. It is only applicable to locations in the core or yoke where the magnetic flux density is uniform and there is no through-sheet magnetic flux. The error is large when used for seam calculations because eddy current loss is actually caused by induced current rather than magnetic flux density.

[0118] To reduce calculation errors, this embodiment adopts a single-piece modeling method, and the paint film thickness is modeled according to a full 1:1 ratio, and the gap size can be adjusted. The no-load performance of different joint forms can be accurately calculated, including multiple parameters such as piece width, number of steps, step amount, film thickness, gap size, etc., with the following characteristics:

[0119] 1) Only one stack of silicon steel sheets is selected as the simulation object, and the number of layers of silicon steel sheets is used as the step number, and each layer contains 2 sheets (side column seams) to 3 sheets (broken yoke middle column seams) of silicon steel sheets (if there are multiple sheets in a stack, the number of sheets will be doubled accordingly).

[0120] like Figure 7 and Figure 8 The figure shows the no-load performance of different joint stepping methods, with high accuracy enough to identify small differences, which is superior to existing finite element simulation calculations. This example clearly defines the optimal stepping method for a small-capacity core with a magnetic flux density of 1.5T, namely 5 steps of 3mm, with a step size of 4mm being the optimal (4mm is optional for structural strength considerations).

[0121] 2) The thickness of the silicon steel sheet mentioned above is the actual iron base thickness of the silicon steel sheet, not the nominal thickness.

[0122] 3) The air gap between each layer of silicon steel sheets must include the paint film and the stacking gap. The gap cannot be ignored. The existence of the air gap eliminates the need to use an approximate magnetic permeability setting in the stacking direction, thus avoiding errors caused by equivalent settings.

[0123] 4) The above-mentioned gap can be adjusted within a certain range according to the process and research requirements, and the gap cannot be ignored otherwise it will affect the calculation accuracy.

[0124] To avoid the problem of extremely low computational efficiency caused by the complexity of multi-stack single-piece modeling, this invention introduces the even-symmetric Even Periodic Boundary condition. This allows the characteristics of the entire core joint to be accurately characterized using only a single stack of silicon steel. The characteristics are:

[0125] 1) The even symmetric boundary is a parallel symmetric boundary condition rather than a rotational symmetric boundary in motor simulation.

[0126] 2) The translation distance Shift Vector of the symmetry boundary is the height of one cycle (the thickness of a stack of silicon steel sheets).

[0127] 3) The starting and ending positions of this boundary can be any position in the iron core parallel to the silicon steel surface, either in the air or inside the silicon steel sheet.

[0128] 4) This boundary must cover the upper and lower surfaces of the entire model (i.e. the upper and lower surfaces of the air bag).

[0129] To maintain the integrity of the joint magnetic circuit, a normal symmetric FieldNormal Boundary boundary condition is set at the model boundary. The characteristics are:

[0130] 1) The rolling direction is perpendicular to the boundary conditions.

[0131] 2) Normal boundary conditions exist in pairs.

[0132] 3) Pairs of normal boundaries intersect and are at 90° to each other.

[0133] 4) The normal boundary condition is set on the surface of the air bag and completely covers the air bag surface.

[0134] To avoid the influence of high magnetic fields near the coils on the silicon steel sheets in the single-stack model, the excitation coils in this embodiment use straight wires instead of traditional toroidal coils. The features are:

[0135] 1) Straight conductors appear in pairs on both sides of the silicon steel sheet and do not contact the silicon steel.

[0136] 2) The length of the straight wire is consistent with the stack thickness and is equal to the translation distance of the even symmetric boundary condition.

[0137] 3) The end face of the straight conductor coincides with the surface where the boundary of the pair is located.

[0138] To further simplify the calculation, this embodiment adopts a grid partitioning method with the following characteristics:

[0139] 1) Taking a certain length from the seam as the boundary (generally between 5-10mm), the silicon steel sheet where the seam is located and its upper and lower layers are divided into fine grid areas, and the silicon steel in other areas is coarse grid areas.

[0140] 2) The fine mesh area in 1) above needs to have an intermediate layer, which can be done using the Mash Layers command.

[0141] 3) In the above 1), the maximum mesh size of the fine mesh area is set smaller than that of the coarse mesh area. Generally, the maximum mesh size of the fine mesh area is 1mm, and that of the coarse mesh area is 2-3mm.

[0142] like Figure 9As shown, the larger the number of stacks, the more accurate the calculation, but the number of grids increases linearly. The single-stack periodic model provided by this embodiment has the best calculation accuracy and efficiency (the fewer the number of grids, the higher the efficiency; in finite element simulation, as the calculation becomes more and more accurate, the calculation results gradually tend to a stable value.).

[0143] In this embodiment, the silicon steel sheet can be set to anisotropic or isotropic properties, which can be selected according to the researcher's own needs and hardware equipment conditions. The characteristics are:

[0144] 1) When setting to anisotropy, two BH curves along the rolling direction and perpendicular to the rolling direction must be given when setting the material.

[0145] 2) When set to anisotropy, the calculation accuracy is further improved, while the equipment requirements are higher.

[0146] 3) When set to anisotropy, when the silicon steel sheet is applied to the material, the material direction must be set according to the actual magnetic circuit direction to ensure that the magnetic circuit is always consistent with the direction of high magnetic permeability of the material.

[0147] In summary, the transformer core no-load performance analysis method provided in this embodiment takes into account the influence of the step-by-step overlap method, paint film thickness, material sheet thickness and gap size at the core joints on the no-load performance of the transformer, avoiding the problems of core no-load loss and no-load current design exceeding the standard.

[0148] Example 2

[0149] Based on the same inventive concept as Example 1, this embodiment also provides a transformer core no-load performance analysis system. Since the principle of solving the problem by this system is similar to the aforementioned transformer core no-load performance analysis method, the implementation of this system can refer to the implementation of the transformer core no-load performance analysis method.

[0150] like Figure 2 As shown, the transformer core no-load performance analysis system includes:

[0151] The first acquisition module 10 is used to obtain the hysteresis loss and eddy current loss of a single silicon steel sheet in the iron core.

[0152] The first determining module 20 is configured to determine the loss of a single joint region of the core according to the hysteresis loss and eddy current loss of a single silicon steel sheet in the core.

[0153] The second determining module 30 is configured to determine the total loss of the core according to the loss of a single joint area of the core.

[0154] The second acquisition module 40 is used to obtain the average magnetic field strength of the silicon steel sheet cross section.

[0155] The third determination module 50 is used to determine the no-load current of the core according to the average magnetic field strength of the silicon steel sheet cross section; and analyze the no-load performance of the transformer core based on the total loss of the core and the no-load current.

[0156] Exemplarily, the first determining module includes:

[0157] The first calculation unit is used to calculate the loss P1 of a single joint area of the core according to the following formula:

[0158]

[0159] Wherein, k is the core lamination coefficient; h1 is the core lamination height; n is the total number of silicon steel sheets in one step of the joint area; m is the number of silicon steel sheets in each stack; b1 is the number of steps in the step-by-step overlap method of the silicon steel sheets; h is the thickness of a single silicon steel sheet; P hi is the hysteresis loss of the i-th silicon steel sheet; P oi is the eddy current loss of the i-th silicon steel sheet.

[0160] Exemplarily, the second determining module includes:

[0161] The first acquisition unit is used to acquire the unit iron loss P' under the average magnetic flux density of the silicon steel sheet cross section.

[0162] The second calculation unit is used to calculate the total loss P of the core according to the following formula 总 :

[0163] P 总 =4P1+b·k·h1·d·P'·ρ.

[0164] Among them, P1 is the loss in a single seam area of the core; b is the width of a single silicon steel sheet; k is the core lamination coefficient; h1 is the core lamination height; d is the total length of the core and yoke in the core excluding the seam; ρ is the density of the silicon steel sheet.

[0165] Exemplarily, the third determining module includes:

[0166] The second acquisition unit is used to obtain the excitation current I1 of a single joint area in the iron core and the number of turns N of the excitation wire.

[0167] The third calculation unit is used to calculate the no-load current I of the core according to the following formula:

[0168]

[0169] Where H' is the average magnetic field intensity of the silicon steel sheet cross section; d is the total length of the core and yoke excluding the joints in the core.

[0170] For more specific working processes of the above modules, please refer to the corresponding content disclosed in Example 1, which will not be repeated here.

[0171] Example 3

[0172] This embodiment provides a computer device, including a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the transformer core no-load performance analysis method described in Example 1 are implemented.

[0173] For more specific details about the above method, please refer to the corresponding content disclosed in Example 1, which will not be repeated here.

[0174] Example 4

[0175] This embodiment provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the transformer core no-load performance analysis method described in Example 1 are implemented.

[0176] For more specific details about the above method, please refer to the corresponding content disclosed in Example 1, which will not be repeated here.

[0177] Example 5

[0178] This embodiment provides a computer program product, including computer executable instructions or a computer program. When the computer executable instructions or the computer program are executed by a processor, the steps of the transformer core no-load performance analysis method described in Example 1 are implemented.

[0179] For more specific details about the above method, please refer to the corresponding content disclosed in Example 1, which will not be repeated here.

[0180] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. References to the same or similar parts between the various embodiments will be sufficient. The systems, devices, storage media, and computer program products disclosed in the embodiments correspond to the methods disclosed in the embodiments, so their descriptions are relatively simplified. For relevant details, refer to the method descriptions.

[0181] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software plus a necessary general-purpose hardware platform. Based on this understanding, the technical solutions in the embodiments of the present invention, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention or certain portions of the embodiments.

[0182] In some embodiments, computer-executable instructions may be in the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0183] As an example, computer-executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file that stores other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinating files (e.g., files storing one or more modules, subroutines, or code portions).

[0184] By way of example, computer-executable instructions may be deployed to be executed on one electronic device, or on multiple electronic devices located at one site, or on multiple electronic devices distributed across multiple sites and interconnected by a communication network.

[0185] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for analyzing the no-load performance of a transformer core, characterized in that: include: Obtain the hysteresis loss and eddy current loss of a single silicon steel sheet in the iron core; Determine the loss of a single joint area of the core based on the hysteresis loss and eddy current loss of a single silicon steel sheet in the core; Determine the total loss of the core based on the loss of a single seam area of the core; Obtain the average magnetic field strength of the silicon steel sheet cross section; Determine the no-load current of the core based on the average magnetic field strength of the silicon steel sheet cross section; analyze the no-load performance of the transformer core based on the total core loss and no-load current; Determining the loss of a single joint area of the core based on the hysteresis loss and eddy current loss of a single silicon steel sheet in the core includes: The loss P1 of a single joint area of the core is calculated according to the following formula: Wherein, k is the core lamination coefficient; h1 is the core lamination height; n is the total number of silicon steel sheets in one step of the joint area; m is the number of silicon steel sheets in each stack; b1 is the number of steps in the step-by-step overlap method of the silicon steel sheets; h is the thickness of a single silicon steel sheet; P hi is the hysteresis loss of the i-th silicon steel sheet; P oi is the eddy current loss of the i-th silicon steel sheet.

2. The transformer core no-load performance analysis method according to claim 1, characterized in that: Determining the total loss of the core based on the loss of a single joint area of the core includes: Obtain the unit iron loss P' under the average magnetic flux density of the silicon steel sheet cross section; The total core loss P is calculated according to the following formula 总 : P 总 =4P1+b·k·h1·d·P'·ρ; Among them, P1 is the loss in a single seam area of the core; b is the width of a single silicon steel sheet; k is the core lamination coefficient; h1 is the core lamination height; d is the total length of the core and yoke in the core excluding the seam; ρ is the density of the silicon steel sheet.

3. The transformer core no-load performance analysis method according to claim 1, characterized in that: Determining the no-load current of the core according to the average magnetic field strength of the silicon steel sheet cross section includes: Obtain the excitation current I1 and the number of turns N of the excitation wire in a single joint area in the iron core; Calculate the no-load current I of the core according to the following formula: Where H' is the average magnetic field intensity of the silicon steel sheet cross section; d is the total length of the core and yoke excluding the joints in the core.

4. A transformer core no-load performance analysis system, characterized in that: include: The first acquisition module is used to obtain the hysteresis loss and eddy current loss of a single silicon steel sheet in the iron core; The first determination module is used to determine the loss of a single joint area of the core based on the hysteresis loss and eddy current loss of a single silicon steel sheet in the core; The second determining module is used to determine the total loss of the core according to the loss of a single joint area of the core; The second acquisition module is used to obtain the average magnetic field strength of the silicon steel sheet cross section; A third determination module is used to determine the no-load current of the iron core according to the average magnetic field strength of the silicon steel sheet cross section; Analyze the no-load performance of transformer core by the total core loss and no-load current; The first determining module includes: The first calculation unit is used to calculate the loss P1 of a single joint area of the core according to the following formula: Wherein, k is the core lamination coefficient; h1 is the core lamination height; n is the total number of silicon steel sheets in one step of the joint area; m is the number of silicon steel sheets in each stack; b1 is the number of steps in the step-by-step overlap method of the silicon steel sheets; h is the thickness of a single silicon steel sheet; P hi is the hysteresis loss of the i-th silicon steel sheet; P oi is the eddy current loss of the i-th silicon steel sheet.

5. The transformer core no-load performance analysis system according to claim 4, characterized in that: The second determining module includes: The first acquisition unit is used to obtain the unit iron loss P' under the average magnetic flux density of the silicon steel sheet cross section; The second calculation unit is used to calculate the total loss P of the core according to the following formula 总 : P 总 =4P1+b·k·h1·d·P'·ρ; Among them, P1 is the loss in a single seam area of the core; b is the width of a single silicon steel sheet; k is the core lamination coefficient; h1 is the core lamination height; d is the total length of the core and yoke in the core excluding the seam; ρ is the density of the silicon steel sheet.

6. The transformer core no-load performance analysis system according to claim 4, characterized in that: The third determining module includes: The second acquisition unit is used to obtain the excitation current I1 of a single joint area in the iron core and the number of turns N of the excitation wire; The third calculation unit is used to calculate the no-load current I of the core according to the following formula: Where H' is the average magnetic field intensity of the silicon steel sheet cross section; d is the total length of the core and yoke excluding the joints in the core.

7. A computer device, characterized in that: The method comprises a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the transformer core no-load performance analysis method according to any one of claims 1 to 3 are implemented.

8. A computer-readable storage medium, characterized in that Used to store computer programs; when the computer programs are executed by the processor, the steps of the transformer core no-load performance analysis method according to any one of claims 1 to 3 are implemented.

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