Motor design method based on normalized cross-coupled magnetic circuit and application thereof

Abstract

The application discloses a motor design method based on normalized cross-coupling magnetic circuit, comprising: constructing a permanent magnet characteristic position magnetic circuit model containing symmetric magnetic circuit nodes according to the uniform division of permanent magnet magnetic pole space; equivalent mapping of magnetic motive force asymmetrically distributed on the d-axis to the permanent magnet characteristic position magnetic circuit model to realize the normalization processing of the magnetic motive force on the d-axis and the permanent magnet magnetic motive force; based on weight distribution, superimposing the magnetic motive force of each tooth on the d-axis to the symmetric magnetic circuit nodes of the permanent magnet characteristic magnetic circuit model to generate equivalent d-axis magnetic motive force; embedding the equivalent d-axis magnetic motive force and the permanent magnet magnetic motive force into the permanent magnet characteristic magnetic circuit model to form a cross-coupling magnetic circuit model; iteratively calculating the cross-coupling magnetic circuit model to solve the magnetic circuit equation until convergence is obtained to obtain motor design parameters. It can adapt to the multi-harmonic and high electromagnetic load characteristics of large-capacity low-speed motors and improve the accuracy of magnetic field calculation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor body design, and particularly relates to a motor design method and device based on normalized cross-coupling magnetic circuit, an electronic device and a computer readable storage medium. BACKGROUND

[0002] In a permanent magnet motor, the permanent magnet flux and the d-axis flux are interlinked. Based on the proposed unequal-width magnetic circuit model, the d-axis magnetic motive force is asymmetrically distributed, and the magnetic resistance characteristic in the d-axis magnetic circuit is in the form of "large and small poles". However, the magnetic motive force of the permanent magnet magnetic circuit does not have the "large and small pole" trend, and the magnetic circuit should be evenly divided according to the space of the permanent magnet magnetic pole. In the definition of magnetic induction lines in electromagnetic field theory, the magnetic induction lines must be closed, so when dividing the magnetic circuit, the characteristics of the magnetic induction lines should be considered to make them closed into complete loops for modeling and calculation. The size of the permanent magnet magnetic motive force is several times that of the stator magnetic motive force, so when the magnetic flux generated by the three different excitation sources of the permanent magnet, the d-axis and the q-axis of the stator shares the same magnetic resistance, the dominant one is the permanent magnet flux.

[0003] The current numerical calculation method of the permanent magnet motor is relatively mature, including the analytical method and the finite element method. Different from traditional motors, the megawatt direct-drive wind turbine has the characteristics of low speed and large capacity, and the electromagnetic load is generally designed to be very high, so the saturation and cross-coupling of the motor cannot be ignored during calculation. The analytical method usually uses the magnetic permeability saturation coefficient correction and only considers local saturation, and it is difficult to consider the influence of cross-coupling, while the finite element method has high accuracy, but it is time-consuming and requires large computer hardware. SUMMARY

[0004] In order to overcome the defects of the prior art, the embodiment of the present application provides a motor design method and application based on normalized cross-coupling magnetic circuit, based on the unequal-width magnetic circuit method, further researches the cross-coupling calculation method, to adapt to the multi-harmonic and high electromagnetic load characteristics of large-capacity low-speed motors, improve the accuracy of magnetic field calculation, and give it sufficient engineering application value.

[0005] In one aspect, the embodiment of the present application provides a motor design method based on normalized cross-coupling magnetic circuit, comprising: constructing a permanent magnet characteristic position magnetic circuit model containing symmetric magnetic circuit nodes according to the uniform division of the space of the permanent magnet magnetic pole; equivalently mapping the d-axis asymmetrically distributed magnetic motive force to the permanent magnet characteristic position magnetic circuit model to realize the normalization of the d-axis magnetic motive force and the permanent magnet magnetic motive force; based on weight distribution, superimposing the d-axis tooth magnetic motive force to the symmetric magnetic circuit nodes of the permanent magnet characteristic magnetic circuit model to generate equivalent d-axis magnetic motive force; embedding the equivalent d-axis magnetic motive force and the permanent magnet magnetic motive force into the permanent magnet characteristic magnetic circuit model to form a cross-coupling magnetic circuit model; iteratively calculating the cross-coupling magnetic circuit model to solve the magnetic circuit equation until convergence is obtained, and obtaining the motor design parameters.

[0006] In an embodiment of the present application, the equivalent mapping of the d-axis asymmetrically distributed magnetomotive force to the permanent magnet feature position magnetic circuit model comprises: determining the geometric correspondence between the d-axis teeth and the permanent magnet magnetic circuit nodes through magnetic circuit topology analysis or finite element simulation; calculating the weight coefficient of each tooth magnetomotive force in the permanent magnet magnetic circuit based on the cross-sectional area and length of the magnetic flux path: ; wherein, is the cross-sectional area of the i-th tooth magnetic circuit, is the magnetic circuit length.

[0007] In an embodiment of the present application, the calculation formula of the equivalent d-axis magnetomotive force is: ; wherein, is the d-axis magnetomotive force of the i-th tooth, i is the number of teeth. N

[0008] In an embodiment of the present application, the cross-coupling magnetic circuit model contains the following magnetic resistance parameters: , is the permanent magnet, air magnetic barrier magnetic resistance, is the tooth leakage magnetic resistance, is the stator yoke magnetic resistance, is the stator tooth magnetic resistance, is the air gap magnetic resistance, is the magnetic bridge area magnetic resistance, is the rotor core magnetic resistance, is the permanent magnet magnetomotive force.

[0009] In an embodiment of the present application, the iterative calculation process comprises: initializing the magnetic flux density, setting the initial value of the stator tooth and air gap magnetic flux density; calculating the magnetic resistance of each part according to the magnetic flux conservation principle and the material magnetization curve; solving the magnetic circuit equation to obtain the new magnetic flux, updating the magnetic flux density; repeating the iteration with the error less than the preset error threshold as the convergence condition.

[0010] In an embodiment of the present application, the relative permeability of the stator tooth and the conducting part is dynamically updated according to the silicon steel sheet permeability curve in the iteration process.

[0011] In an embodiment of the present application, the permanent magnet feature position magnetic circuit model contains two feature position topologies of 4 teeth or 5 teeth, and the magnetic circuit division is consistent with the q-axis magnetic circuit tooth number.

[0012] ​On the other hand, this invention also proposes a motor design device based on a normalized cross-coupled magnetic circuit, comprising: a magnetic circuit model construction module, used to construct a permanent magnet characteristic position magnetic circuit model containing symmetrical magnetic circuit nodes according to the uniform division of the permanent magnet pole space; a normalization processing module, used to equivalently map the d-axis asymmetrically distributed magnetomotive force to the permanent magnet characteristic position magnetic circuit model, thereby achieving normalization processing of the d-axis magnetomotive force and the permanent magnet magnetomotive force; an equivalent magnetomotive force generation module, used to superimpose the magnetomotive force of each tooth on the d-axis onto the symmetrical magnetic circuit nodes of the permanent magnet characteristic magnetic circuit model based on weight allocation, thereby generating an equivalent d-axis magnetomotive force; a cross-coupled magnetic circuit module, used to embed the equivalent d-axis magnetomotive force and the permanent magnet magnetomotive force together into the permanent magnet characteristic magnetic circuit model, forming a cross-coupled magnetic circuit model; and an iterative solution module, used to perform iterative calculations on the cross-coupled magnetic circuit model, solve the magnetic circuit equations until convergence, and obtain the motor design parameters.

[0013] In another aspect, embodiments of the present invention also propose an electronic device, comprising: a memory and one or more processors connected to the memory, the memory storing a computer program, and the processors executing the computer program to implement the motor design method based on normalized cross-coupled magnetic circuits as described in any of the above embodiments.

[0014] In another aspect, embodiments of the present invention also propose a computer-readable storage medium storing computer-executable instructions for executing the motor design method based on normalized cross-coupled magnetic circuits as described in any of the above embodiments.

[0015] As can be seen from the above, the embodiments of the present invention, compared with the prior art, can have at least one or more of the following beneficial effects:

[0016] This invention proposes a motor design method based on a normalized cross-coupled magnetic circuit. Starting from the permanent magnet magnetic circuit, it proposes a cross-coupled calculation method based on a non-uniform width magnetic circuit model to represent the coupling relationship between the permanent magnet and the d-axis magnetic circuit. Since the permanent magnet and the d-axis magnetic flux have the same direction, there is a strong connection between them. Therefore, the magnetic circuit at the characteristic position of the permanent magnet and the d-axis "big and small poles" magnetic circuit are normalized, that is, the two magnetomotive forces are unified into one magnetic circuit, and then the same magnetic circuit is used for iterative calculation. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1A flow chart of a motor design method based on normalized cross-coupled magnetic circuit provided for an embodiment of the present application is shown in FIG. 1.

[0019] Figure 2 A permanent magnet magnetic circuit 5-tooth characteristic position magnetic circuit model diagram provided for an embodiment of the present application is shown in FIG. 2.

[0020] Figure 3 A permanent magnet magnetic circuit 4-tooth characteristic position magnetic circuit model diagram provided for an embodiment of the present application is shown in FIG. 3.

[0021] Figure 4 A permanent magnet magnetic circuit 5-tooth characteristic position equivalent magnetic circuit diagram provided for an embodiment of the present application is shown in FIG. 4.

[0022] Figure 5 A permanent magnet magnetic circuit 4-tooth characteristic position equivalent magnetic circuit diagram provided for an embodiment of the present application is shown in FIG. 5.

[0023] Figure 6 A permanent magnet characteristic magnetic circuit model with d-axis stator magnetic motive force-5-tooth characteristic position diagram provided for an embodiment of the present application is shown in FIG. 6.

[0024] Figure 7 A permanent magnet characteristic equivalent magnetic circuit with d-axis stator magnetic motive force-5-tooth characteristic position diagram provided for an embodiment of the present application is shown in FIG. 7.

[0025] Figure 8 A magnetic circuit iterative calculation flow chart provided for an embodiment of the present application is shown in FIG. 8.

[0026] Figure 9 A magnetic permeability change curve provided for an embodiment of the present application is shown in FIG. 9.

[0027] Figure 10 A structure schematic diagram of a motor design device based on normalized cross-coupled magnetic circuit provided for an embodiment of the present application is shown in FIG. 10.

[0028] Figure 11 A structure schematic diagram of an electronic device provided for an embodiment of the present application is shown in FIG. 11.

[0029] Figure 12 A structure schematic diagram of a computer readable storage medium provided for an embodiment of the present application is shown in FIG. 12. DETAILED DESCRIPTION

[0030] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described below with reference to the accompanying drawings and in combination with the embodiments.

[0031] In order to make ordinary skilled in the art better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments of the present application, which should all belong to the protection scope of the present application.

[0032] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are applicable to distinguish similar objects, and do not have to be used to describe a particular order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0033] It should also be noted that the division of the plurality of embodiments in the present application is only for the convenience of description, and should not constitute a special limitation. The features in various embodiments can be combined and mutually referenced without contradiction.

[0034] As shown in Figure 1 The first embodiment of the present application proposes a motor design method based on normalized cross-coupling magnetic circuit, for example, comprising: step S1, constructing a permanent magnet characteristic position magnetic circuit model containing symmetric magnetic circuit nodes according to uniform division of permanent magnet magnetic pole space; step S2, equivalent mapping of d-axis asymmetrically distributed magnetomotive force into the permanent magnet characteristic position magnetic circuit model, realizing the normalization processing of d-axis magnetomotive force and permanent magnet magnetomotive force; step S3, based on weight distribution, superimposing d-axis tooth magnetomotive force to the symmetric magnetic circuit nodes of the permanent magnet characteristic magnetic circuit model, generating equivalent d-axis magnetomotive force; step S4, embedding the equivalent d-axis magnetomotive force and the permanent magnet magnetomotive force into the permanent magnet characteristic magnetic circuit model together, forming a cross-coupling magnetic circuit model; step S5, iteratively calculating the cross-coupling magnetic circuit model, solving the magnetic circuit equation until convergence, obtaining the motor design parameters.

[0035] Specifically, the magnetic circuit of the permanent magnet is a magnetic circuit with the same number of teeth as the q-axis and the same direction of magnetic flux as the d-axis. Taking a 360-slot 84-pole permanent magnet motor as an example, the permanent magnet magnetic circuit has two different characteristic positions: 4-tooth characteristic position and 5-tooth characteristic position. The number of teeth contained in these two characteristic positions is consistent with the q-axis, and the magnetic circuit model diagram and the equivalent magnetic circuit diagram thereof are shown in Figures 2 to 5 .

[0036] Among them, 、 Permanent magnet, air gap reluctance, tooth leakage reluctance, stator yoke reluctance, stator tooth reluctance, air gap reluctance, flux barrier reluctance, rotor core reluctance, permanent magnet MMF.

[0037] There are three excitation sources in permanent magnet motor, including permanent magnet on rotor side, d-axis MMF on stator side, and q-axis MMF on stator side. Since the size of permanent magnet MMF is several times of stator MMF, when the magnetic flux generated by three different excitation sources share the same magnetic reluctance, the dominant one is the permanent magnet flux. Therefore, the coupling relationship between permanent magnet magnetic circuit and d-axis magnetic circuit should be considered first.

[0038] When discussing the calculation of cross-coupling between permanent magnet and d-axis, since the direction of permanent magnet flux and d-axis flux is the same, there is a strong relationship between them. Therefore, the most intuitive way to discuss the relationship between them is to normalize the permanent magnet characteristic position magnetic circuit and the d-axis "large pole" magnetic circuit, that is, to normalize the two MMFs into one magnetic circuit, and then use the same magnetic circuit for iterative calculation.

[0039] Therefore, the asymmetric MMF of each tooth on the d-axis can be equivalent to the magnetic circuit corresponding to the characteristic position of the permanent magnet, and the symmetric equivalent magnetic circuit can be established, and the specific process is as follows:

[0040] 1. Weight distribution: according to the magnetic circuit topology, determine the geometric correspondence between each tooth on the d-axis and the node of the permanent magnet magnetic circuit (such as through magnetic flux path analysis or finite element simulation), and calculate the weight coefficient of the MMF of each tooth in the permanent magnet magnetic circuit :

[0041] ;

[0042] Where, is the cross-sectional area of the i-th tooth magnetic circuit, is the length of the magnetic circuit.

[0043] 2. Equivalent MMF calculation: superimpose the MMF of each tooth on the d-axis on the symmetric nodes of the permanent magnet magnetic circuit according to the weight, and obtain the equivalent d-axis MMF :

[0044] ;

[0045] 3. Superimpose the equivalent d-axis MMF and the permanent magnet MMF The permanent magnet characteristic magnetic circuit model is embedded into the common magnetic circuit model, so that the permanent magnet characteristic magnetic circuit model with d-axis stator magnetomotive force as shown in FIG. 8 and the permanent magnet characteristic equivalent magnetic circuit with d-axis stator magnetomotive force as shown in FIG. 9 are obtained. Figure 6 Figure 7 Figure 6 Figure 7 Taking the 5-tooth characteristic position as an example, wherein, is the stator tooth magnetomotive force.

[0046] The iterative calculation of the obtained magnetic circuit follows the flow shown in FIG. 10, and the detailed calculation steps are as follows, taking the q-axis as an example: Figure 8

[0047] Step 1: Set the number of turns , the total current , and the magnetomotive force of each slot under different currents is obtained according to the foregoing. The following calculation is an example of the 5-tooth characteristic position, and the q-axis magnetomotive force of the four slots under No. 1 pole, i.e. , is given.

[0048] Before the iterative calculation starts, the initial value of the magnetic flux density of the stator tooth and the air gap is set to 0.01T. If the magnetic flux density of the magnetic bridge needs to be additionally set for the d-axis magnetic circuit, the initial condition is increased to meet the requirements of iterative solution.

[0049] Step 2: The cross-sectional area of the corresponding part of the magnetic resistance has been obtained in the magnetic resistance calculation. According to the initial setting of the magnetic flux density, the magnetic flux of the stator teeth 1-3 and the air gaps 1-2 can be obtained. Considering the conservation of magnetic flux, the magnetic flux density of the stator teeth 4 and the conduction part 1-2 of the silicon steel sheet can be further obtained. Based on this, in addition to the constant air gap permeability, the relative permeability of the stator teeth 1-4 and the silicon steel sheet conduction part 1-2 can be obtained according to Figure 9 . Then, combined with the magnetic resistance calculation method, the magnetic resistance of each part can be obtained.

[0050] Step 3: Substitute the magnetic resistance of the stator tooth, the stator yoke, the air gap, the silicon steel sheet and the leakage resistance into the magnetic circuit equation. Through one calculation, the magnetic flux corresponding to the magnetic resistance of each part is solved. Combined with the known magnetic resistance cross-sectional area of the corresponding part in the magnetic resistance calculation, the new magnetic flux density of each part can be calculated. Compare the error with the initial set magnetic flux density.

[0051] Step 4: The iteration convergence condition takes the preset error threshold (as a preferred embodiment, the preset error threshold in the present application is set to 0.1%), that is: if the error is greater than the preset error threshold, replace the magnetic flux density with ​​​​and repeat the process of step 2 and 3. Until the error is less than the preset error threshold, it is considered that the magnetic flux meets the magnetic flux solved by the magnetic circuit equation, thereby realizing self-consistency. In the case of allowing the computing power, the convergence condition of iteration can be taken smaller, and the corresponding solution result is more accurate.

[0052] Step 5: According to the final solved magnetic flux, the q-axis inductance can be further calculated as Wherein and are the magnetic fluxes of the stator teeth 1 and 2 respectively.

[0053] In summary, the first embodiment of the present application proposes a motor design method based on normalized cross-coupling magnetic circuit. By starting from the permanent magnet magnetic circuit, a cross-coupling calculation method based on unequal-width magnetic circuit model is proposed to represent the coupling relationship between the permanent magnet and the d-axis magnetic circuit. Since the directions of the permanent magnet and the d-axis magnetic flux are the same, there is a strong relationship between them. Therefore, the permanent magnet feature position magnetic circuit and the d-axis "large pole" magnetic circuit are normalized, that is, the two kinds of magnetic motive forces are normalized to one magnetic circuit, and then the same magnetic circuit is used for iterative calculation.

[0054] In addition, as shown in Figure 10 , the second embodiment of the present application also proposes a motor design device based on normalized cross-coupling magnetic circuit, for example, comprising: a magnetic circuit model construction module 201, a normalization processing module 202, an equivalent magnetic motive force generation module 203, a cross-coupling magnetic circuit module 204 and an iterative solving module 205.

[0055] Wherein, the magnetic circuit model construction module 201 is used to construct a permanent magnet feature position magnetic circuit model containing symmetric magnetic circuit nodes according to uniform division of permanent magnet pole space; the normalization processing module 202 is used to equivalent map the d-axis asymmetric distributed magnetic motive force to the permanent magnet feature position magnetic circuit model, realizing the normalization processing of the d-axis magnetic motive force and the permanent magnet magnetic motive force; the equivalent magnetic motive force generation module 203 is used to superimpose the d-axis tooth magnetic motive force to the symmetric magnetic circuit node of the permanent magnet feature magnetic circuit model based on weight distribution, generating an equivalent d-axis magnetic motive force; the cross-coupling magnetic circuit module 204 is used to embed the equivalent d-axis magnetic motive force and the permanent magnet magnetic motive force into the permanent magnet feature magnetic circuit model, forming a cross-coupling magnetic circuit model; the iterative solving module 205 is used to iteratively calculate the cross-coupling magnetic circuit model, solve the magnetic circuit equation until convergence, and obtain the motor design parameters.

[0056] The motor design method based on the normalized cross-coupled magnetic circuit realized by the motor design device based on the normalized cross-coupled magnetic circuit disclosed in the second embodiment of the present application is as described in the first embodiment, and thus will not be described in detail here. Alternatively, each module in the second embodiment and the other operations or functions described above are respectively arranged to realize the method described in the first embodiment, and the beneficial effects of the motor design device based on the normalized cross-coupled magnetic circuit provided in the present embodiment are the same as the beneficial effects of the motor design method based on the normalized cross-coupled magnetic circuit provided in the first embodiment. For the sake of brevity, the description will not be repeated here.

[0057] As shown in Figure 11 the third embodiment of the present application further provides an electronic device 30, for example, comprising at least one processing unit 31 and at least one storage unit 32, wherein the storage unit 32 stores a computer program, and when the computer program is executed by the processing unit 31, the processing unit 31 executes the method as described in the first embodiment, and the beneficial effects of the electronic device 30 provided in the present embodiment are the same as the beneficial effects of the motor design method based on the normalized cross-coupled magnetic circuit provided in the first embodiment.

[0058] As shown in Figure 12 the fourth embodiment of the present application further provides a computer readable storage medium 40, which stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented, and the beneficial effects of the computer readable storage medium 40 provided in the present embodiment are the same as the beneficial effects of the motor design method based on the normalized cross-coupled magnetic circuit provided in the first embodiment.

[0059] The computer readable storage medium can include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, micro-drives, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0060] It should be noted that for the above-mentioned method embodiments, in order to simply describe, they are all described as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0061] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0062] In several embodiments provided in the present application, it should be understood that the disclosed apparatus can be implemented in other manners. For example, the division of the apparatus embodiments described above is merely illustrative, and the division of the units can be changed according to actual needs. For example, the units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0063] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments.

[0064] In addition, each functional unit in the various embodiments of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0065] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that makes a contribution to the prior art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0066] A person of ordinary skill in the art can understand that all or part of the steps of the various methods in the above embodiments can be completed by a program instructing relevant hardware, and the program can be stored in a computer readable storage medium, which can include a flash disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, etc.

[0067] The above-described examples are merely illustrative of the present disclosure, and do not limit the scope of the disclosure. Any equivalent variation, modification, and / or substitution of the above-described examples are possible within the scope of the present disclosure. Embodiments of the present disclosure will be readily apparent to those skilled in the art in view of the disclosure herein. The present application is intended to embrace any and all variations, uses, or adaptations of the present disclosure that are within the scope of the present disclosure. The specification and drawings should be regarded as illustrative only and should not be considered restrictive in any sense. The scope of the present disclosure should be determined by the appended claims and their legal equivalents.

[0068] Any of the technical features of the above examples can be combined, and for brevity, not all possible combinations of the various technical features described above are repeated, however, any combination of the technical features should be considered as within the scope of the present disclosure, as long as the combination does not result in a contradiction.

[0069] Those skilled in the art easily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A motor design method based on a normalized cross-coupled magnetic circuit, characterized in that, include: A magnetic circuit model of the characteristic positions of a permanent magnet, containing symmetrical magnetic circuit nodes, is constructed by uniformly dividing the magnetic pole space of the permanent magnet. The d-axis asymmetric distribution of magnetomotive force is equivalently mapped to the magnetic circuit model of the characteristic position of the permanent magnet, thereby achieving normalization of the d-axis magnetomotive force and the permanent magnet magnetomotive force. Based on weight allocation, the magnetomotive force of each tooth on the d-axis is superimposed onto the symmetrical magnetic circuit node of the magnetic circuit model at the characteristic position of the permanent magnet to generate an equivalent d-axis magnetomotive force. The equivalent d-axis magnetomotive force and the permanent magnet magnetomotive force are jointly embedded into the magnetic circuit model of the characteristic position of the permanent magnet to form a cross-coupled magnetic circuit model. The cross-coupled magnetic circuit model is iteratively calculated to solve the magnetic circuit equations until convergence, thereby obtaining the motor design parameters.

2. The motor design method based on normalized cross-coupled magnetic circuits according to claim 1, characterized in that, The step of equivalently mapping the d-axis asymmetric magnetomotive force to the magnetic circuit model of the characteristic position of the permanent magnet includes: The geometric correspondence between each tooth on the d-axis and the magnetic circuit node of the permanent magnet is determined by magnetic circuit topology analysis or finite element simulation. Based on the cross-sectional area and length of the magnetic flux path, calculate the weighting coefficient of each tooth's magnetomotive force in the permanent magnet's magnetic circuit: ;in, Let i be the cross-sectional area of ​​the magnetic circuit of the i-th tooth. This represents the length of the magnetic circuit.

3. The motor design method based on normalized cross-coupled magnetic circuits according to claim 2, characterized in that, The formula for calculating the equivalent d-axis magnetomotive force is as follows: ； in, Let N be the d-axis magnetomotive force of the i-th tooth, and N be the number of teeth.

4. The motor design method based on normalized cross-coupled magnetic circuits according to claim 1, characterized in that, The reluctance parameters included in the cross-coupled magnetic circuit model are: For permanent magnet reluctance, It is the magnetic barrier and magnetic reluctance of air. For tooth leakage magnetic resistance, For the stator yoke reluctance, For stator tooth reluctance, For air gap reluctance, For the magnetic reluctance of the magnetic bridge region, For the rotor core magnetic reluctance, It is the magnetomotive force of the permanent magnet.

5. The motor design method based on normalized cross-coupled magnetic circuits according to claim 1, characterized in that, The iterative calculation process includes: Initialize the magnetic flux density by setting the initial values ​​for the stator teeth and air gap magnetic flux density; Calculate the magnetic reluctance of each part based on the principle of magnetic flux conservation and the magnetization curve of the material; Solving the magnetic circuit equations yields a new magnetic flux, which in turn updates the magnetic flux density. The iteration is repeated with the convergence condition that the error is less than a preset error threshold.

6. The motor design method based on normalized cross-coupled magnetic circuits according to claim 5, characterized in that, During the iteration process, the relative permeability of the stator teeth and the conducting part is dynamically updated based on the permeability curve of the silicon steel sheet.

7. The motor design method based on normalized cross-coupled magnetic circuits according to claim 6, characterized in that, The permanent magnet feature position magnetic circuit model includes two feature position topologies: 4 teeth or 5 teeth, and the magnetic circuit division is consistent with the number of teeth in the q-axis magnetic circuit.

8. A motor design device based on a normalized cross-coupled magnetic circuit, characterized in that, include: The magnetic circuit model construction module is used to construct a magnetic circuit model of the characteristic position of a permanent magnet, which includes symmetrical magnetic circuit nodes, by uniformly dividing the magnetic pole space of the permanent magnet. The normalization module is used to equivalently map the d-axis asymmetric distribution of magnetomotive force to the magnetic circuit model of the characteristic position of the permanent magnet, thereby realizing the normalization of the d-axis magnetomotive force and the permanent magnet magnetomotive force. The equivalent magnetomotive force generation module is used to superimpose the magnetomotive force of each tooth on the d-axis onto the symmetrical magnetic circuit node of the magnetic circuit model at the characteristic position of the permanent magnet based on weight allocation, thereby generating an equivalent d-axis magnetomotive force. A cross-coupled magnetic circuit module is used to embed the equivalent d-axis magnetomotive force and the permanent magnet magnetomotive force into the magnetic circuit model of the characteristic position of the permanent magnet to form a cross-coupled magnetic circuit model. The iterative solution module is used to perform iterative calculations on the cross-coupled magnetic circuit model, solve the magnetic circuit equations until convergence, and obtain the motor design parameters.

9. An electronic device, characterized in that, include: A memory and one or more processors connected to the memory, the memory storing a computer program, the processors executing the computer program to implement the motor design method based on a normalized cross-coupled magnetic circuit as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable commands for performing the motor design method based on normalized cross-coupled magnetic circuits as described in any one of claims 1-7.

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