Flat wire motor end winding loss calculation method and device

Abstract

The invention provides a flat wire motor end winding loss calculation method and device, and the method comprises the steps: carrying out the equivalent processing of a three-dimensional model of an end winding of a target flat wire motor: stretching a bent flat wire conductor, maintaining a winding gap, and obtaining a two-dimensional equivalent model of the end winding, the winding magnetic field is solved on the geometric basis of the two-dimensional equivalent model, after the magnetic field is solved, the eddy-current loss of the end winding is calculated according to the obtained magnetic field information, the direct-current loss of the end winding is calculated according to the skin effect resistance coefficient, and the eddy-current loss and the direct-current loss are added to obtain a two-dimensional equivalent model; and the end loss value of the target flat wire motor can be obtained. Thus, modeling is easy and convenient, time cost and calculation cost are effectively reduced, meanwhile, the magnetic field loss and the conductor loss are solved based on analysis, the complex finite element solving process is avoided, the calculation speed is effectively increased, and therefore the requirement for rapidly solving the winding loss of the flat wire motor under the complex working condition can be met.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a method, device, storage medium and equipment for calculating the end winding loss of a flat wire motor. Background Art

[0002] Flat wire winding permanent magnet synchronous motors are widely used in electric vehicles due to their outstanding advantages such as high efficiency and high power density. Compared with loose wires, flat wire windings can further improve the motor slot fill rate and reduce DC losses. However, with the increase of motor power density and speed, the high-frequency AC effect of the motor becomes more and more significant. At the same time, the flat wire conductor has a large cross-sectional size and the eddy current effect is more prominent, resulting in an increase in the AC copper loss of the winding, thereby reducing the motor efficiency. In addition, the conductor will produce local hot spots, causing serious hidden dangers to the motor insulation and operation safety. Therefore, it is of great significance to quickly and accurately calculate the winding loss of flat wire motors under complex and variable working conditions.

[0003] The end winding of the flat wire motor is an important part. The current solution for calculating the loss of the end winding of the flat wire motor is mainly achieved by finite element 3D modeling of the end winding. However, due to the complex structure of the end winding of the flat wire motor, this method is cumbersome to model and takes a long time to calculate, and cannot meet the needs of quickly solving the loss of the flat wire motor winding under complex working conditions. Summary of the invention

[0004] The purpose of this application is to provide a method, device, storage medium and equipment for calculating the end winding loss of a flat wire motor, aiming to solve the problem that the method for calculating the end winding loss of a flat wire motor in the related art has complicated modeling, long calculation time, and cannot meet the demand for quickly solving the winding loss of the flat wire motor under complex working conditions.

[0005] In a first aspect, the present application provides a method for calculating the end winding loss of a flat wire motor, comprising: performing equivalent processing on a three-dimensional model of the end winding of a target flat wire motor to obtain a two-dimensional equivalent model of the end winding; the equivalent processing includes stretching the bent flat wire conductor and maintaining the winding gap; analyzing the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model to obtain the magnetic field information of the end winding, and calculating the eddy current loss of the end winding according to the magnetic field information; calculating the DC loss of the end winding according to the skin effect resistivity, adding the eddy current loss and the DC loss to obtain the end loss value of the target flat wire motor.

[0006] In the above implementation process, the three-dimensional model of the end winding of the target flat wire motor is equivalently processed, including stretching the bent flat wire conductor and maintaining the winding gap to obtain a two-dimensional equivalent model of the end winding, and then the winding magnetic field is solved on the geometric basis of the two-dimensional equivalent model. After the magnetic field is solved, the eddy current loss of the end winding is calculated according to the obtained magnetic field information, and the DC loss of the end winding is calculated according to the skin effect resistivity. The eddy current loss and the DC loss are added to obtain the end loss value of the target flat wire motor. In this way, the complex three-dimensional end model is equivalent to a two-dimensional model, which is simple to model and effectively reduces the time cost and calculation cost. At the same time, the magnetic field and conductor loss are based on analytical solution, avoiding the complex finite element solution process, effectively improving the calculation speed, so as to meet the needs of quickly solving the winding loss of the flat wire motor under complex working conditions.

[0007] Furthermore, in some examples, the magnetic field generated by the flat wire conductor is analyzed based on the two-dimensional equivalent model to obtain the magnetic field information of the end winding, including: based on the two-dimensional equivalent model, obtaining the magnetic field generated by the flat wire conductor at any position at the remaining flat wire conductors when the target current is passed; the value of the target current is the effective value of the current; the effective value of the current is determined based on the actual operating data of the target flat wire motor; and vector superposition of the magnetic field generated by each flat wire conductor to obtain the magnetic field information of the end winding.

[0008] In the above implementation process, on the geometric basis of the two-dimensional equivalent model, the magnetic field interaction law between conductors is solved by magnetic field analysis, and the magnetic field changes at different conductors are obtained analytically, thereby improving the calculation efficiency of the eddy current loss of the end winding.

[0009] Furthermore, in some examples, the magnetic field generated by the flat wire conductor is calculated based on the following formula:

[0010]

[0011] Where B is the strength of the magnetic field generated by the current flat conductor at another flat conductor; d c is the spatial distance between the currently analyzed flat wire conductor and the other flat wire conductor, the spatial distance being measured based on the two-dimensional equivalent model; μ 0 is the vacuum magnetic permeability; I is the effective value of the current.

[0012] In the above implementation process, a specific method for solving the magnetic field generated by the flat wire conductor is provided. Through the above formula, the magnetic field generated by the end winding can be quickly solved, thereby improving the calculation efficiency.

[0013] Furthermore, in some examples, the eddy current loss of the end winding is calculated based on the magnetic field information, including: orthogonally decomposing the magnetic field information to obtain magnetic field information in a first direction and magnetic field information in a second direction; the first direction is perpendicular to the second direction; and calculating the eddy current loss of the end winding based on the geometric dimension information of the flat wire conductor, the magnetic field information in the first direction and the magnetic field information in the second direction.

[0014] In the above implementation process, the calculation process of eddy current loss is simplified by orthogonally decomposing the obtained magnetic field information, thereby more effectively improving the calculation efficiency of the end winding loss.

[0015] Further, in some examples, the geometric dimension information includes width, thickness and length; the eddy current loss of the end winding is calculated based on the following formula:

[0016]

[0017] Where P eddy is the eddy current loss of the end winding; a, b and l are the width, thickness and length of the flat wire conductor respectively; B m is the fundamental magnetic flux amplitude; η d is the magnetic field distortion coefficient; f is the magnetic field change frequency; ω is the magnetic field fundamental angular frequency; σ is the conductivity; t is the time for passing the target current.

[0018] In the above implementation process, an analytical formula for eddy current loss based on a two-dimensional equivalent model is provided, and the eddy current loss of the end winding can be quickly calculated through the above formula.

[0019] Further, in some examples, the skin effect resistivity is calculated based on the following formula:

[0020]

[0021] In the formula, k skin is the skin effect resistivity; δ is the skin depth.

[0022] In the above implementation process, a specific method for calculating the skin effect resistivity is provided.

[0023] Further, in some examples, the calculating the DC loss of the end winding according to the skin effect resistivity includes: calculating the initial DC loss of the end winding according to the effective value of the current and the DC resistance value of the end winding using Joule's law; and multiplying the initial DC loss by the skin effect resistivity to obtain the DC loss of the end winding.

[0024] In the above implementation process, the DC loss of the end winding is calculated by Joule's law combined with the skin effect resistivity. In this way, the influence of the skin effect and proximity effect of the motor end conductor on the eddy current loss is fully considered, and the calculation accuracy of the flat wire motor end winding loss is effectively improved.

[0025] In a second aspect, the present application provides a device for calculating the end winding loss of a flat wire motor, comprising: an equivalent module, used to perform equivalent processing on the three-dimensional model of the end winding of the target flat wire motor to obtain a two-dimensional equivalent model of the end winding; the equivalent processing includes stretching the bent flat wire conductor and maintaining the winding gap; an analysis module, used to analyze the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model to obtain the magnetic field information of the end winding, and calculate the eddy current loss of the end winding according to the magnetic field information; a calculation module, used to calculate the DC loss of the end winding according to the skin effect resistivity, and add the eddy current loss and the DC loss to obtain the end loss value of the target flat wire motor.

[0026] In a third aspect, the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in any one of the first aspects when executing the computer program.

[0027] In a fourth aspect, the present application provides a computer-readable storage medium, on which instructions are stored. When the instructions are executed on a computer, the computer executes the method as described in any one of the first aspects.

[0028] In a fifth aspect, the present application provides a computer program product, which, when running on a computer, enables the computer to execute the method as described in any one of the first aspects.

[0029] Other features and advantages disclosed in the present application will be described in the following description, or some features and advantages can be inferred or determined without doubt from the description, or can be learned by implementing the above-mentioned technology disclosed in the present application.

[0030] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A flowchart of a method for calculating the end winding loss of a flat wire motor provided in an embodiment of the present application;

[0033] Figure 2 A schematic diagram of a three-dimensional finite element model of a flat wire winding permanent magnet synchronous motor with ends provided in an embodiment of the present application;

[0034] Figure 3 A schematic diagram of a process of converting a three-dimensional model of a flat wire motor end winding into a two-dimensional model provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of eddy currents generated by a flat wire conductor under the action of an external magnetic field provided in an embodiment of the present application;

[0036] Figure 5 A block diagram of a device for calculating the end winding loss of a flat wire motor provided in an embodiment of the present application;

[0037] Figure 6 A structural block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0039] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0040] As described in the background technology, the method for calculating the end winding loss of the flat wire motor in the related art has the problems of cumbersome modeling, long calculation time, and failure to meet the demand for quickly solving the flat wire motor winding loss under complex working conditions. Based on this, the embodiment of the present application provides a new flat wire motor end winding loss calculation solution to solve the above problems.

[0041] Next, the embodiments of the present application are introduced:

[0042] like Figure 1 As shown, Figure 1 : is a flow chart of a method for calculating the end winding loss of a flat wire motor provided in an embodiment of the present application, the method comprising:

[0043] Step 101: performing equivalent processing on the three-dimensional model of the end winding of the target flat wire motor to obtain a two-dimensional equivalent model of the end winding; the equivalent processing includes stretching the bent flat wire conductor and maintaining the winding gap;

[0044] The target flat wire motor mentioned in this step is a flat wire motor whose winding loss needs to be calculated, which can be a flat wire winding permanent magnet synchronous motor or other types of flat wire motors. The core part of the flat wire motor is the flat wire conductor, which is usually composed of multiple flat wires. These flat wire conductors are arranged and connected in a specific way to form the winding of the motor, and the end winding is an important component. In the flat wire motor, the end winding is formed by the flat wire conductor according to a specific winding process and fixed at both ends of the stator core. The end winding structure of the flat wire motor is complex. Therefore, this embodiment proposes a two-dimensional equivalent method for the end of the flat wire conductor, which replaces the flat wire conductor with an approximate two-dimensional model. The modeling is simple, thereby effectively reducing the time cost and calculation cost.

[0045] Specifically, the three-dimensional model mentioned in this step can be a simple model created by three-dimensional modeling software, which represents the basic shape and structure of the end winding of the target flat wire motor in three-dimensional form. After obtaining the three-dimensional model, the three-dimensional model is equivalent to two dimensions, including stretching the bent flat wire conductor, and the winding gap is kept consistent with the previous one, so as to obtain a two-dimensional equivalent model of the end winding. In implementation, the computer can record the coordinate position and winding gap of each flat wire conductor for the three-dimensional model of the end winding, and then use a specific projection method to represent the three-dimensional model on a two-dimensional plane, and then in the two-dimensional view, identify the bent flat wire conductor according to the recorded information, stretch it, and adjust the winding gap. In this way, the complex three-dimensional model is equivalent to a two-dimensional model, which can avoid the cumbersome three-dimensional end structure interfering with the analytical solution of the end magnetic field, and effectively reduce the computational complexity.

[0046] Step 102: analyzing the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model to obtain magnetic field information of the end winding, and calculating the eddy current loss of the end winding according to the magnetic field information;

[0047] This step means: based on the geometry of the two-dimensional equivalent model, the magnetic field of the end winding is solved. After the magnetic field is solved, the eddy current loss of the end winding is calculated according to the magnetic field information of the end winding. In this way, the influence of the alternating magnetic field at the end conductor on the conductor loss is considered, and the complicated finite element solution process is avoided, thereby effectively improving the calculation speed.

[0048] In some embodiments, the step of analyzing the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model to obtain the magnetic field information of the end winding may include: based on the two-dimensional equivalent model, obtaining the magnetic field generated by the flat wire conductor at any position at the remaining flat wire conductors when the target current is passed; the value of the target current is the effective value of the current; the effective value of the current is determined based on the actual working condition data of the target flat wire motor; the magnetic field generated by each flat wire conductor is vector-superimposed to obtain the magnetic field information of the end winding. That is to say, when solving the winding magnetic field based on the two-dimensional equivalent model of the end winding, the conductor magnetic field at any position can be analyzed to analyze the size of the magnetic field generated by the flat wire conductor at the remaining flat wire conductors when the target current is passed. The target current here is alternating current, and its effective value can be determined based on the frequency, phase, waveform and other data of the current in the end winding of the target flat wire motor under actual working conditions. Based on this, the magnetic field generated by each flat wire conductor in the end winding can be obtained, and the magnetic field information of the end winding can be obtained by vector superposition of these magnetic fields. Since the effective value of the current is the winding current value at different working points of the motor, the magnetic field information at this time includes the magnetic field size corresponding to each coordinate point in the two-dimensional equivalent model at different working points. This is conducive to solving the end winding loss at any working point of the motor.

[0049] Furthermore, in some embodiments, the magnetic field generated by the flat wire conductor is calculated based on the following formula:

[0050]

[0051] Where B is the strength of the magnetic field generated by the current flat conductor at another flat conductor; d c is the spatial distance between the currently analyzed flat wire conductor and the other flat wire conductor, the spatial distance being measured based on the two-dimensional equivalent model; μ 0 is the vacuum magnetic permeability; I is the effective value of the current. That is to say, based on the geometry of the two-dimensional equivalent model, the spatial distance between different flat wire conductors can be quickly measured. Then, according to Ampere's loop law, the flat wire conductor with an effective current value of I at a spatial distance d c The magnitude B of the magnetic field generated at the other flat wire conductor can be calculated based on the above formula. In this way, the magnetic field generated by the end winding can be solved quickly, thereby improving the calculation efficiency.

[0052] Eddy current loss refers to the current generated inside the conductor under the action of the magnetic field, which forms a vortex flow, and this flow energy is converted into heat energy and lost. Therefore, after the magnetic field solution is completed, the obtained magnetic field information is substituted into the analytical calculation formula of the eddy current loss of the flat wire conductor to calculate the eddy current loss of the end winding. In some embodiments, the calculation of the eddy current loss of the end winding according to the magnetic field information mentioned in this step may include: orthogonally decomposing the magnetic field information to obtain the magnetic field information in the first direction and the magnetic field information in the second direction; the first direction and the second direction are perpendicular to each other; according to the geometric size information of the flat wire conductor, the magnetic field information in the first direction and the magnetic field information in the second direction, the eddy current loss of the end winding is calculated. That is to say, in the process of solving the eddy current loss of the end winding, the calculated magnetic field information can be orthogonally decomposed into the magnetic field in the x-axis direction and the y-axis direction, and the eddy current loss generated by the flat wire conductor can be calculated respectively in combination with the geometric size information of the flat wire conductor, and then added to obtain the eddy current loss of the end winding. In this way, the calculation process of the eddy current loss is simplified, thereby more effectively improving the calculation efficiency of the end winding loss.

[0053] Further, in some embodiments, the aforementioned geometric dimension information may include width, thickness and length; the eddy current loss of the end winding is calculated based on the following formula:

[0054]

[0055] Where P eddy is the eddy current loss of the end winding; a, b and l are the width, thickness and length of the flat wire conductor respectively; B m is the fundamental magnetic flux amplitude; η dis the magnetic field distortion coefficient; f is the magnetic field change frequency; ω is the magnetic field fundamental frequency angular frequency; σ is the conductivity; t is the time for passing the target current. Among them, the geometric dimension information such as the width, thickness and length of the flat wire conductor can be obtained from the factory specification information of the target flat wire motor, or can be obtained by scanning and measuring during modeling. The fundamental magnetic flux density amplitude, magnetic field distortion coefficient, magnetic field change frequency and magnetic field fundamental frequency angular frequency can be obtained by Fourier transforming the magnetic field information, converting it from the time domain to the frequency domain and analyzing it. For example, the amplitude value corresponding to the fundamental frequency is extracted from the spectrum, that is, the fundamental magnetic flux density amplitude. According to the relationship between angular frequency and frequency, the magnetic field fundamental frequency angular frequency can be calculated; the proportion of other harmonic components in the spectrum except the fundamental wave to the total energy is analyzed to determine the magnetic field distortion coefficient; the magnetic field change frequency usually refers to the frequency corresponding to the main periodic change component in the magnetic field signal. In the spectrum diagram, this frequency component usually appears as an obvious peak, and its position corresponds to the magnetic field change frequency. The conductivity of the flat wire conductor can be measured by a conductivity tester. The time for passing the target current corresponds to the working point of the motor. The eddy current loss of the end winding can be quickly calculated using the above eddy current loss analytical calculation formula.

[0056] Step 103: Calculate the DC loss of the end winding according to the skin effect resistance coefficient, add the eddy current loss and the DC loss to obtain the end loss value of the target flat wire motor.

[0057] This step means: after calculating the eddy current loss of the end winding, the DC loss of the end winding is calculated, and the skin effect resistance coefficient is used to characterize the additional AC loss caused by the skin effect. In this way, the eddy current loss and the DC loss are added together to obtain the end winding loss value of the target flat wire motor at different working points. In this way, the influence of the skin effect and proximity effect of the motor end conductor on the eddy current loss is fully considered, and the calculation accuracy of the end winding loss of the flat wire motor is effectively improved.

[0058] In some embodiments, the skin effect resistivity mentioned in this step can be calculated based on the following formula:

[0059]

[0060] In the formula, k skin is the skin effect resistivity; δ is the skin depth. Among them, the parameter γ represents the ratio of the thickness of the flat wire conductor to the skin depth, and the skin depth refers to the depth at which the current density in the conductor decreases to 1 / e (e is the natural base) of the current density on the surface of the conductor cross section. The method for obtaining it can refer to the introduction of the skin depth in the relevant technology, and this application will not repeat it. Substituting the thickness and skin depth of the flat wire conductor into the above formula, the skin effect resistivity can be obtained.

[0061] Further, in some embodiments, the step of calculating the DC loss of the end winding according to the skin effect resistance coefficient mentioned in this step may include: calculating the initial DC loss of the end winding according to the effective value of the current and the DC resistance value of the end winding using Joule's law; and multiplying the initial DC loss by the skin effect resistance coefficient to obtain the DC loss of the end winding. In other words, the DC loss of the end winding can be calculated by Joule's law, which can be expressed based on the following formula:

[0062] P direct =I 2 R.k skin

[0063] Where R is the DC resistance of the end winding. The DC loss of the end winding can be calculated quickly and accurately through the above formula.

[0064] In the embodiment of the present application, the three-dimensional model of the end winding of the target flat wire motor is equivalently processed, including stretching the bent flat wire conductor and maintaining the winding gap to obtain a two-dimensional equivalent model of the end winding, and then solving the winding magnetic field on the geometric basis of the two-dimensional equivalent model. After the magnetic field is solved, the eddy current loss of the end winding is calculated according to the obtained magnetic field information, and the DC loss of the end winding is calculated according to the skin effect resistivity. The eddy current loss and the DC loss are added to obtain the end loss value of the target flat wire motor. In this way, the complex three-dimensional end model is equivalent to a two-dimensional model, which is simple to model and effectively reduces the time cost and calculation cost. At the same time, the magnetic field and conductor loss are based on analytical solution, avoiding the complex finite element solution process, effectively improving the calculation speed, so as to meet the needs of quickly solving the winding loss of the flat wire motor under complex working conditions.

[0065] In order to explain the solution of this application in more detail, a specific embodiment is introduced below:

[0066] This embodiment provides a solution for calculating the end winding loss of a flat wire motor based on a two-dimensional equivalent model. The solution is for a flat wire winding permanent magnet synchronous motor and realizes fast calculation of the end winding loss of the flat wire motor in the full speed range.

[0067] This embodiment includes the following workflow:

[0068] S201, constructing a two-dimensional equivalent model of the end winding of the flat wire motor;

[0069] Specifically, Figure 2 It is a schematic diagram of a three-dimensional finite element model of a flat wire winding permanent magnet synchronous motor with ends. Figure 2It can be seen that the ends of the flat wire windings are twisted and arranged, and the spatial geometric structure is complex. In this embodiment, a three-dimensional model of the end windings of the flat wire motor can be obtained. The three-dimensional model can be a simple model that represents the basic shape and structure of the end windings of the target flat wire motor in three-dimensional form. Then, the three-dimensional model is two-dimensionally equivalent to obtain a two-dimensional equivalent model. The two-dimensional equivalent process is as follows Figure 3 As shown, the bent flat wire conductor is stretched, and the winding gap remains the same as before. Figure 3 In the figure, d represents the winding gap, d c Indicates the spatial distance between two flat wire conductors;

[0070] S202, solving the winding magnetic field based on the geometry of the two-dimensional equivalent model to obtain magnetic field information of the end winding;

[0071] Specifically, based on the geometry of the two-dimensional equivalent model, the magnetic field of the conductor at any position is analyzed, and the magnetic field generated by the conductor is solved. When implemented, the following Ampere's circuit law is used to calculate the current effective value of the flat wire conductor I at a spatial distance d. c The magnitude of the magnetic field B generated at the other flat wire conductor is:

[0072]

[0073] In the formula, μ 0 is the vacuum permeability;

[0074] Performing vector superposition of the magnetic field generated by each flat wire conductor to obtain magnetic field information of the end winding;

[0075] S203, substituting the obtained magnetic field information into the eddy current loss analytical formula to obtain the eddy current loss of the end winding;

[0076] Specifically, the eddy current generated by the flat wire conductor under the action of the external magnetic field is as follows: Figure 4 As shown, a, b and l represent the width, thickness and length of the flat wire conductor respectively; A and L represent the geometric information of the eddy current path;

[0077] The analytical formula for eddy current loss is as follows:

[0078]

[0079] Where P eddy is the eddy current loss of the end winding; B m is the fundamental magnetic flux amplitude; η d is the magnetic field distortion coefficient; f is the frequency of magnetic field change; ω is the fundamental angular frequency of the magnetic field; σ is the conductivity; t is the time of current flow;

[0080] S204, calculating the DC loss of the end winding according to the skin effect resistance coefficient;

[0081] Specifically, the skin effect resistivity k skin Calculated based on the following formula:

[0082]

[0083] Where δ is the skin depth;

[0084] Afterwards, the DC losses in the end windings are calculated using Joule's law:

[0085] P direct =I 2 R.k skin

[0086] Where P direct is the DC loss of the end winding; R is the DC resistance value of the end;

[0087] S205, adding the eddy current loss and the DC loss to obtain the end winding loss values ​​of the flat wire motor at different working points.

[0088] This embodiment scheme provides a two-dimensional equivalent method for the end of a flat wire conductor, avoiding the cumbersome finite element three-dimensional modeling process, replacing the flat wire conductor with an approximate two-dimensional model, and only requiring one equivalent modeling to complete the construction of the two-dimensional equivalent model. The modeling is simple and can effectively reduce the time cost and the calculation cost. A method for calculating the end winding loss based on the two-dimensional equivalent model is proposed. Both the magnetic field and the end winding loss are based on analytical solutions. It not only considers the influence of the alternating magnetic field at the end conductor on the conductor loss, but also avoids the complicated finite element solution process, thereby effectively improving the calculation speed and being able to meet the loss solution requirements for completing any working point of the motor.

[0089] Corresponding to the embodiments of the aforementioned method, the present application also provides embodiments of a device for calculating the end winding loss of a flat wire motor and a terminal for using the same:

[0090] like Figure 5 As shown, Figure 5 : is a block diagram of a device for calculating the end winding loss of a flat wire motor provided in an embodiment of the present application, the device comprising:

[0091] An equivalent module 51 is used to perform equivalent processing on the three-dimensional model of the end winding of the target flat wire motor to obtain a two-dimensional equivalent model of the end winding; the equivalent processing includes stretching the bent flat wire conductor and maintaining the winding gap;

[0092] An analysis module 52, configured to analyze the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model, obtain magnetic field information of the end winding, and calculate the eddy current loss of the end winding according to the magnetic field information;

[0093] The calculation module 53 is used to calculate the DC loss of the end winding according to the skin effect resistance coefficient, and add the eddy current loss and the DC loss to obtain the end loss value of the target flat wire motor.

[0094] The implementation process of the functions and effects of each module in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, which will not be repeated here.

[0095] This application also provides an electronic device, see Figure 6 , Figure 6 A block diagram of an electronic device provided in an embodiment of the present application. The electronic device may include a processor 610, a communication interface 620, a memory 630, and at least one communication bus 640. The communication bus 640 is used to realize direct connection and communication between these components. The communication interface 620 of the electronic device in the embodiment of the present application is used to communicate signaling or data with other node devices. The processor 610 may be an integrated circuit chip with signal processing capabilities.

[0096] The processor 610 mentioned above can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor 610 can also be any conventional processor, etc.

[0097] The memory 630 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electric erasable programmable read-only memory (EEPROM), etc. The memory 630 stores computer-readable instructions. When the computer-readable instructions are executed by the processor 610, the electronic device can execute the above-mentioned Figure 1 The method embodiment involves various steps.

[0098] Optionally, the electronic device may further include a storage controller and an input / output unit.

[0099] The memory 630, storage controller, processor 610, peripheral interface, input and output unit components are directly or indirectly electrically connected to each other to achieve data transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses 640. The processor 610 is used to execute executable modules stored in the memory 630, such as software function modules or computer programs included in the electronic device.

[0100] The input and output unit is used to provide users with the task creation and to create a start optional time period or preset execution time for the task to realize the interaction between the user and the server. The input and output unit can be, but is not limited to, a mouse and a keyboard.

[0101] Understandably, Figure 6 The structure shown is for illustration only, and the electronic device may also include Figure 6 More or fewer components as shown, or with Figure 6 Different configurations shown. Figure 6 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0102] An embodiment of the present application further provides a storage medium having instructions stored thereon. When the instructions are run on a computer, the computer program is executed by a processor to implement the method described in the method embodiment. To avoid repetition, the method will not be described here.

[0103] The present application also provides a computer program product, which, when executed on a computer, enables the computer to execute the method described in the method embodiment.

[0104] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0105] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0106] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0107] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0108] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0109] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for calculating the end winding loss of a flat wire motor, characterized in that: include: Performing equivalent processing on the three-dimensional model of the end winding of the target flat wire motor to obtain a two-dimensional equivalent model of the end winding; the equivalent processing includes stretching the bent flat wire conductor and maintaining the winding gap; Analyzing the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model to obtain magnetic field information of the end winding, and calculating the eddy current loss of the end winding according to the magnetic field information; The DC loss of the end winding is calculated according to the skin effect resistance coefficient, and the eddy current loss and the DC loss are added to obtain the end loss value of the target flat wire motor.

2. The method according to claim 1, characterized in that The step of analyzing the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model to obtain magnetic field information of the end winding includes: Based on the two-dimensional equivalent model, the magnetic field generated by the flat wire conductor at any position at the other flat wire conductors when the target current is passed is obtained; the value of the target current is the effective value of the current; the effective value of the current is determined based on the actual operating condition data of the target flat wire motor; The magnetic field generated by each flat wire conductor is vector-superimposed to obtain the magnetic field information of the end winding.

3. The method according to claim 2, characterized in that The magnetic field generated by the flat wire conductor is calculated based on the following formula: Where B is the strength of the magnetic field generated by the current flat conductor at another flat conductor; d c is the spatial distance between the currently analyzed flat wire conductor and the other flat wire conductor, and the spatial distance is measured based on the two-dimensional equivalent model; μ0 is the vacuum permeability; I is the effective value of the current.

4. The method according to claim 2, characterized in that: The calculating the eddy current loss of the end winding according to the magnetic field information comprises: orthogonally decomposing the magnetic field information to obtain magnetic field information in a first direction and magnetic field information in a second direction; the first direction and the second direction are perpendicular to each other; The eddy current loss of the end winding is calculated according to the geometric dimension information of the flat wire conductor, the magnetic field information in the first direction and the magnetic field information in the second direction.

5. The method according to claim 4, characterized in that The geometric dimension information includes width, thickness and length; the eddy current loss of the end winding is calculated based on the following formula: Where P eddy is the eddy current loss of the end winding; a, b and l are the width, thickness and length of the flat wire conductor respectively; B m is the fundamental magnetic flux amplitude; η d is the magnetic field distortion coefficient; f is the magnetic field change frequency; ω is the magnetic field fundamental angular frequency; σ is the conductivity; t is the time for passing the target current.

6. The method according to claim 5, characterized in that The skin effect resistivity is calculated based on the following formula: In the formula, k skin is the skin effect resistivity; δ is the skin depth.

7. The method according to claim 6, characterized in that The calculating the DC loss of the end winding according to the skin effect resistivity comprises: Calculating the initial DC loss of the end winding using Joule's law according to the effective value of the current and the DC resistance value of the end winding; The initial DC loss and the skin effect resistance coefficient are multiplied to obtain the DC loss of the end winding.

8. A device for calculating the end winding loss of a flat wire motor, characterized in that: include: An equivalent module, used for performing equivalent processing on the three-dimensional model of the end winding of the target flat wire motor to obtain a two-dimensional equivalent model of the end winding; the equivalent processing includes stretching the bent flat wire conductor and maintaining the winding gap; An analysis module, used for analyzing the magnetic field generated by the flat wire conductor based on the two-dimensional equivalent model, obtaining the magnetic field information of the end winding, and calculating the eddy current loss of the end winding according to the magnetic field information; A calculation module is used to calculate the DC loss of the end winding according to the skin effect resistivity, and add the eddy current loss and the DC loss to obtain the end loss value of the target flat wire motor.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. An electronic device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

Images