Calculation method of magnetic density and loss of mixed silicon steel iron core and optimization method of mixing scheme

Abstract

The invention relates to the technical field of mixed silicon steel, and discloses a mixed silicon steel iron core magnetic density and loss calculation method and a mixed scheme optimization method, and the optimization method comprises the following steps: obtaining iron core information; calculating a unit loss required value according to the iron core information; the preset materials are divided into low-loss materials and high-loss materials according to the unit loss required value; enumerating all material mixing modes, and calculating the mixed iron core loss corresponding to each material mixing mode according to the calculation method; and screening out an optimal mixing scheme from all the mixing modes according to the mixed iron core loss. Under the condition that the design requirement is met, the material cost is controlled, high-loss materials are consumed, and the stock removing effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of hybrid silicon steel, and in particular to a method for calculating the magnetic density and loss of a hybrid silicon steel core and an optimization method for a hybrid solution. Background Art

[0002] In the design of electrical equipment such as transformers and motors, the selection of core materials is crucial to the performance and efficiency of the equipment. Traditional designs usually use a single grade of silicon steel material, ignoring the optimization effect that different material combinations may bring. Different grades of silicon steel materials have different magnetization and loss characteristics. Reasonable mixing can reduce costs and improve performance while meeting the magnetic density and loss requirements.

[0003] At present, there is a lack of theoretically supported algorithms for the calculation of magnetic flux density and loss of hybrid cores made of silicon-steel materials, and their accuracy remains to be verified. In addition, existing technologies mostly calculate the mixing ratio and design the core cross-section after determining the mixed materials, and lack systematic calculation and optimization methods for the optimal silicon-steel mixing solution for the core. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a method for calculating the magnetic density and loss of a hybrid silicon steel core and an optimization method for the hybrid solution, so as to solve one or more problems in the prior art.

[0005] To achieve the above object, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for calculating the magnetic density and loss of a hybrid silicon steel core.

[0006] A method for calculating magnetic flux density and loss of a hybrid silicon steel core comprises the following steps: Obtaining basic information of the mixed material, the basic information including the mixing ratio, weight ratio, magnetization curve and loss curve of the two materials, wherein the mixing ratio refers to the cross-sectional area ratio of the two materials in the iron core; Determine the equivalent magnetization curve according to the mixing ratio and magnetization curve of the two materials; Determine the equivalent magnetic field strength from the equivalent magnetization curve according to the preset core design magnetic density; Determine the magnetic flux density values ​​of the two materials from the two magnetization curves according to the equivalent magnetic field strength; The hybrid core loss is determined based on the magnetic density values, weight ratio and loss curves of the two materials.

[0007] Furthermore, the determination of the equivalent magnetization curve comprises the following steps: Determining corresponding magnetic density groups in the magnetization curves of the two materials respectively according to a preset magnetic field strength group, wherein the preset magnetic field strength group includes a plurality of magnetic field strengths with different values; The mixed magnetic density at the magnetic field strength is determined based on the mixing ratio and the magnetic density of the two materials at the same magnetic field strength. The equivalent magnetization curve is fitted according to the mixed magnetic flux density under multiple different magnetic field intensities.

[0008] Further, the mixed magnetic density under the magnetic field strength is determined according to the mixing ratio and the magnetic density of the two materials under the same magnetic field strength, comprising the following steps: The mixed magnetic flux density is calculated according to the following formula: B=kB1+(1-k)B2 Among them, k is the mixing ratio, B1 and B2 are the magnetic densities of the two materials respectively.

[0009] Further, the determination of the mixed core loss according to the magnetic density value, weight ratio and loss curve of the two materials comprises the following steps: Calculate the hybrid core loss according to the following formula: P mix =gP1+(1-g)P2 Among them, g is the weight ratio, P1 and P2 are the losses of the two materials at the corresponding magnetic density values ​​determined according to the loss curve.

[0010] In a second aspect, the present invention also provides a method for optimizing a hybrid silicon steel core mixing scheme.

[0011] A method for optimizing a hybrid silicon steel core mixing scheme comprises the following steps: Get core information; Calculate the required unit loss value based on the core information; Divide the preset materials into low-loss materials and high-loss materials according to the unit loss requirement value; Enumerate all mixing methods, including a low-loss material, a high-loss material, and a mixing ratio; According to the above calculation method, the mixed core loss corresponding to each mixing method is calculated; The optimal mixing scheme is selected from all mixing methods based on the mixed core loss.

[0012] Furthermore, the method of dividing the preset materials into low-loss materials and high-loss materials according to the unit loss requirement value includes the following steps: Determining a first loss interval according to a preset forward coefficient and a unit loss requirement value; Determining a second loss interval according to a preset negative coefficient and a unit loss requirement value; Determine the loss value corresponding to each material from the preset corresponding relationship; When the loss value is in the first loss interval, the corresponding material is a high-loss material; When the loss value is in the second loss range, the corresponding material is a low-loss material.

[0013] Furthermore, the core information includes a no-load loss requirement value, and the method of selecting the best mixing scheme from all mixing methods according to the mixed core loss includes the following steps: Select the mixed core loss with a value lower than or equal to the no-load loss requirement as the candidate loss. Select the mixed core loss that is closest to the no-load loss requirement from the alternative losses, and the mixing method corresponding to this loss is the optimal mixing solution.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows: By combining high-loss materials and low-loss materials and determining the optimal solution based on the losses corresponding to the combination, material costs are controlled while meeting design requirements, and high-loss materials are consumed, thereby reducing inventory. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A flowchart of a method for calculating magnetic flux density and loss of a hybrid silicon steel core provided by an embodiment of the present invention is shown.

[0016] Figure 2 A flowchart of an optimization method for a hybrid silicon steel core mixing solution provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] The invention provides a method for calculating the magnetic flux density and loss of a hybrid silicon steel core, so as to accurately calculate the magnetic flux density distribution and loss of a hybrid core made of two silicon steel materials.

[0018] A method for calculating the magnetic flux density and loss of a hybrid silicon steel core, see Figure 1 , including the following steps: S100. Obtain basic information of mixed materials.

[0019] The basic information includes the mixing ratio, weight ratio, magnetization curve and loss curve of the two materials. Among them, the mixing ratio refers to the cross-sectional area ratio of one material in the mixed core, and the weight ratio refers to the weight ratio of one material in the mixed core. For ease of understanding, in this embodiment, the two materials are defined as material A and material C, respectively, the mixing ratio refers to the cross-sectional area ratio of material A in the mixed core, and the weight ratio refers to the weight ratio of material A in the mixed core.

[0020] For example, the cross-sectional area of ​​the first, second and third stages of a three-stage core accounts for 0.723, 0.235 and 0.042 of the total cross-sectional area respectively, and the weight of each stage accounts for 0.727, 0.232 and 0.041 of the total weight of the core respectively. If the first and second stages use material A and the third stage uses material C, the mixing ratio of material A is 0.958 and the weight ratio is 0.959.

[0021] S200, determining an equivalent magnetization curve according to the mixing ratio of the two materials and the magnetization curves.

[0022] The equivalent magnetization curve refers to the magnetization curve of the mixed core. According to the Ampere loop theorem (Ni=HL), the two materials mixed in parallel in the thickness direction are under the same magnetomotive force (that is, the same Ni), and their magnetic field strength is also the same, so the magnetization curve of the mixed core can be determined according to the mixing ratio of the two materials and the corresponding magnetization curve.

[0023] S300, determining an equivalent magnetic field intensity from an equivalent magnetization curve according to a preset core design magnetic density.

[0024] According to the corresponding relationship between the magnetic flux density and the magnetic field strength in the equivalent magnetization curve, the corresponding equivalent magnetic field strength can be obtained when the core design magnetic flux density is known.

[0025] S400, determining magnetic density values ​​of two materials from two magnetization curves according to equivalent magnetic field strength.

[0026] Because the two materials are in the same magnetic field strength, when the magnetic field strength of the mixed core is determined, the magnetic density of each material can be determined based on the magnetization curves of the two materials.

[0027] S500, determining the mixed core loss according to the magnetic density values, weight ratio and loss curves of the two materials.

[0028] The unit iron loss values ​​of the two materials are obtained according to the magnetic density values ​​and loss curves determined by the two materials, and then the losses of the two materials are calculated separately and summed to obtain the total loss of the hybrid core.

[0029] In one embodiment, determining the equivalent magnetization curve comprises the following steps: S210, determining corresponding magnetic density groups in the magnetization curves of the two materials respectively according to the preset magnetic field intensity group.

[0030] The preset magnetic field strength group includes a plurality of magnetic field strengths of different values. Accordingly, the determined magnetic field density group includes a plurality of magnetic field densities corresponding one-to-one to each magnetic field strength in the preset magnetic field strength group.

[0031] S220, determining the mixed magnetic density at the magnetic field strength according to the mixing ratio and the magnetic densities of the two materials at the same magnetic field strength.

[0032] According to each magnetic field strength in the preset magnetic field strength group, the magnetic density of two materials under the same magnetic field strength is taken as a group in turn, and the two magnetic densities of the same group are combined with the mixing ratio to determine the mixed magnetic density under the corresponding magnetic field strength.

[0033] S230, fitting an equivalent magnetization curve according to the mixed magnetic flux density under multiple different magnetic field intensities.

[0034] In one embodiment, determining the mixed magnetic density at the magnetic field strength according to the mixing ratio and the magnetic densities of the two materials at the same magnetic field strength comprises the following steps: The equivalent magnetic field strength is calculated according to the following formula: B=kB1+(1-k)B2 Wherein, k is the mixing ratio, B1 and B2 are the magnetic density of the two materials respectively. In this embodiment, k is the mixing ratio corresponding to material A, B1 is the magnetic density of material A, and B2 is the magnetic density of material C.

[0035] In one embodiment, the method of determining the mixed core loss according to the magnetic density values, weight ratio and loss curve of the two materials comprises the following steps: Calculate the hybrid core loss according to the following formula: P mix =gP1+(1-g)P2 Wherein, g is the weight ratio, P1 and P2 are the losses of the two materials at the corresponding magnetic flux density values ​​determined according to the loss curve. In this embodiment, g is the weight ratio of material A, and P1 is the loss of material A at the corresponding magnetic flux density.

[0036] The invention also provides a method for optimizing a mixed silicon steel core mixing scheme.

[0037] An optimization method for a hybrid silicon steel core mixing scheme, see Figure 2 , including the following steps: D100, obtain core information.

[0038] The core information includes the core's geometric dimensions, design magnetic flux density, no-load loss requirement, process coefficient, etc. The core's geometric dimensions include the number of core stages, the width, length, thickness, cross-sectional area, and weight of each stage. The cross-sectional area ratio and weight ratio of each stage are calculated based on the core's geometric dimensions to facilitate the subsequent calculation of the material mixing ratio and weight ratio.

[0039] D200, calculate the unit loss requirement value based on the core information.

[0040] The calculation formula is P s=P / k / G, where P is the required no-load loss of the core, k is the process coefficient of the core, and G is the total weight of the core.

[0041] D300, divide the preset materials into low-loss materials and high-loss materials according to the unit loss requirement value.

[0042] The preset materials are stored in the material database, which stores the data corresponding to all materials used for silicon steel hybrid core calculations. The material data includes material model, corresponding magnetization curve and loss curve. The magnetization curve data is required to be in the form of magnetic field intensity as the horizontal axis and magnetic density as the vertical axis, and the data interval of magnetic field intensity must reach every 0.01A / m.

[0043] Low-loss material refers to material whose corresponding loss is lower than the required unit loss value; high-loss material refers to material whose corresponding loss is higher than the required unit loss value.

[0044] D400. Enumerate all the mixing methods.

[0045] The mixing method includes a low-loss material, a high-loss material and a mixing ratio.

[0046] All mixing methods need to consider both the combination of low-loss materials and high-loss materials, as well as all mixing ratios. Among them, all mixing ratios = C1 n+C2 n+…+Cn n, where n is the number of core stages. For example, when there are three low-loss materials with different properties and three high-loss materials with different properties, there are 9 combinations of the two materials, 7 mixing ratios for the three-stage core, and a total of 63 mixing methods.

[0047] D500, based on the calculation method of mixed silicon steel core magnetic density and loss, calculate the mixed core loss corresponding to each mixing method.

[0048] In this embodiment, the low-loss material is used as material A, and the high-loss material is used as material C. The mixed core loss of each material mixing method can be calculated by using the above-mentioned calculation method of mixed silicon steel core magnetic density and loss.

[0049] D600, select the best mixing scheme from all mixing methods based on the mixed core loss.

[0050] In one embodiment, the preset materials are divided into low-loss materials and high-loss materials according to the unit loss requirement value, including the following steps: D310. Determine a first loss interval according to a preset forward coefficient and a unit loss requirement value.

[0051] D320. Determine the second loss range according to the preset negative coefficient and the unit loss requirement value.

[0052] D330. Determine the loss value corresponding to each material from the preset corresponding relationship.

[0053] D340. When the loss value is in the first loss range, the corresponding material is a high-loss material.

[0054] D350. When the loss value is in the second loss range, the corresponding material is a low-loss material.

[0055] Considering that if the loss of high-loss materials and low-loss materials differ greatly, the magnetic flux density of the two materials will also differ greatly, which may introduce new problems such as core saturation, and the calculation may be inaccurate. Therefore, the range of materials is limited by setting positive and negative coefficients. In addition, the larger the positive and negative coefficients are, the more materials are covered in theory, and the number of combinations tends to increase exponentially, resulting in an increase in calculation time. Of course, in actual operation, the positive and negative coefficients can be changed according to needs.

[0056] In this embodiment, the positive coefficient is +6%, and the negative coefficient is -6%, that is, the first loss interval is P s ~106%P s The second loss interval is 94%P s ~P s between.

[0057] In one embodiment, selecting the best mixing scheme from all mixing methods according to the mixed core loss includes the following steps: D610. Filter out the mixed core loss whose value is lower than or equal to the no-load loss requirement as the alternative loss.

[0058] D620. Select the mixed core loss that is closest to the no-load loss requirement from the alternative losses. The mixing method corresponding to this loss is the optimal mixing solution.

[0059] It can be seen that the obtained mixed core loss P m The results of ix that satisfy both Pmix-Ps≤0 and |Pmix-Ps|min are determined as the optimal mixed solution. The optimal solution can not only meet the design requirements, but also control the material cost, consume high-loss materials, and play a role in destocking.

[0060] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for calculating the magnetic flux density and loss of a hybrid silicon steel core, characterized in that , including the following steps: Obtaining basic information of the mixed material, the basic information including the mixing ratio, weight ratio, magnetization curve and loss curve of the two materials, wherein the mixing ratio refers to the cross-sectional area ratio of the two materials in the iron core; Determine the equivalent magnetization curve according to the mixing ratio and magnetization curve of the two materials; Determine the equivalent magnetic field strength from the equivalent magnetization curve according to the preset core design magnetic density; Determine the magnetic flux density values ​​of the two materials from the two magnetization curves according to the equivalent magnetic field strength; The hybrid core loss is determined based on the magnetic density values, weight ratio and loss curves of the two materials.

2. The method for optimizing a silicon steel core mixing scheme according to claim 1, characterized in that: Determining the equivalent magnetization curve comprises the following steps: Determining corresponding magnetic density groups in the magnetization curves of the two materials respectively according to a preset magnetic field strength group, wherein the preset magnetic field strength group includes a plurality of magnetic field strengths with different values; The mixed magnetic density at the magnetic field strength is determined based on the mixing ratio and the magnetic density of the two materials at the same magnetic field strength. The equivalent magnetization curve is fitted according to the mixed magnetic flux density under multiple different magnetic field intensities.

3. The method for optimizing a silicon steel core mixing scheme according to claim 2, characterized in that: The method of determining the mixed magnetic density under the magnetic field strength according to the mixing ratio and the magnetic density of the two materials under the same magnetic field strength comprises the following steps: The mixed magnetic flux density is calculated according to the following formula: B=kB1+(1-k)B2 Among them, k is the mixing ratio, B1 and B2 are the magnetic densities of the two materials respectively.

4. The method for optimizing a silicon steel core mixing scheme according to claim 2, characterized in that: The method of determining the mixed core loss according to the magnetic density values, weight ratio and loss curve of the two materials comprises the following steps: Calculate the hybrid core loss according to the following formula: P mix =gP1+(1-g)P2 Among them, g is the weight ratio, P1 and P2 are the losses of the two materials at the corresponding magnetic density values ​​determined according to the loss curve.

5. A method for optimizing a hybrid silicon steel core mixing scheme, characterized in that: The following steps are involved: Get core information; Calculate the required unit loss value based on the core information; Divide the preset materials into low-loss materials and high-loss materials according to the unit loss requirement value; Enumerate all mixing methods, including a low-loss material, a high-loss material, and a mixing ratio; Calculate the mixed core loss corresponding to each mixing method according to a calculation method as described in any one of claims 1 to 4; The optimal mixing scheme is selected from all mixing methods based on the mixed core loss.

6. The method for optimizing a silicon steel core mixing scheme according to claim 5, characterized in that: The method of dividing the preset materials into low-loss materials and high-loss materials according to the unit loss requirement value comprises the following steps: Determining a first loss interval according to a preset forward coefficient and a unit loss requirement value; Determining a second loss interval according to a preset negative coefficient and a unit loss requirement value; Determine the loss value corresponding to each material from the preset corresponding relationship; When the loss value is in the first loss interval, the corresponding material is a high-loss material; When the loss value is in the second loss range, the corresponding material is a low-loss material.

7. The method for optimizing a silicon steel core mixing scheme according to claim 5, characterized in that: The core information includes a no-load loss requirement value, and the method of selecting the best mixing scheme from all mixing methods according to the mixed core loss includes the following steps: Select the mixed core loss with a value lower than or equal to the no-load loss requirement as the candidate loss. Select the mixed core loss that is closest to the no-load loss requirement from the alternative losses, and the mixing method corresponding to this loss is the optimal mixing solution.

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