Motor eddy current loss calculation method and related device

Abstract

The invention discloses a motor eddy current loss calculation method and a related device, and the method comprises the steps: calculating the initial magnetic induction of each part of a motor under the excitation of a sinusoidal magnetic field according to the size parameters of the parts in the motor, and adding the initial magnetic induction into a motor magnetic circuit model; wherein the component is an eddy current loss component; and according to the motor magnetic circuit model, obtaining the final magnetic induction of each component by adopting an iteration method, and calculating the eddy-current loss of each component according to the final magnetic induction of each component. According to the method, eddy current loss component magnetic induction under sinusoidal magnetic field excitation is added into the motor magnetic circuit model, characterization of a nonlinear coupling effect in the motor is realized, the influence of an eddy current effect on magnetic flux is considered into the motor magnetic circuit model, and the eddy current loss of each eddy current loss component can be obtained at the same time by adopting an iteration method; the method is a new technical means for efficiently and accurately analyzing the eddy-current loss of multiple components, and has high theoretical significance and application value.

Description

Technical Field

[0001] The present invention relates to a method for calculating motor eddy current loss and a related device, belonging to the technical field of motor eddy current loss calculation. Background Art

[0002] High-speed permanent magnet motors are core components in high-end applications such as air compressors, micro gas turbines, and electric turbochargers. Due to their high power density, fast dynamic response, and high efficiency, they are widely used in aerospace, electric vehicles, high-performance manufacturing, and other fields. However, as the speed increases, eddy current loss becomes a key factor restricting the efficiency and stability of the motor. Eddy current loss not only affects the thermal management of the motor, but also causes the degradation of motor performance. Therefore, accurately predicting and effectively suppressing eddy current loss is crucial to motor design and application. Currently, there are many methods for calculating eddy current loss, including loss separation method and Fourier decomposition method, but none of them can calculate the eddy current loss in multiple components at the same time. Therefore, there is an urgent need for a new method for calculating eddy current loss. Summary of the Invention

[0003] The present invention provides a method for calculating eddy current loss of a motor and a related device, which solve the problems disclosed in the background technology.

[0004] According to one aspect of the present application, a method for calculating eddy current loss of a motor is provided, comprising:

[0005] Based on the size parameters of the components in the motor, the initial magnetic induction of each component under the excitation of the sinusoidal magnetic field is calculated, and the initial magnetic induction is added to the motor magnetic circuit model; wherein the components are eddy current loss components;

[0006] According to the motor magnetic circuit model, an iterative method is used to obtain the final magnetic induction of each component, and the eddy current loss of each component is calculated based on the final magnetic induction of each component;

[0007] Among them, the iterative method includes:

[0008] 1) Based on the motor magnetic circuit model, calculate the air gap flux, as well as the magnetic flux density and magnetic field strength of each branch where the components in the motor magnetic circuit model are located;

[0009] 2) Calculate the new magnetic induction of each component based on the air gap flux, as well as the flux density and magnetic field strength of the branch where each component is located in the motor magnetic circuit model;

[0010] 3) If the magnetic induction errors obtained in two consecutive iterations for all components do not exceed the threshold, the new magnetic induction obtained in the current iteration is used as the final magnetic induction. Otherwise, the new magnetic induction is added to the motor magnetic circuit model and the process goes to step 1).

[0011] Furthermore, the components in the motor include stator teeth, a stator yoke, a rotor yoke, permanent magnets, a permanent magnet sheath and an armature winding.

[0012] Furthermore, the calculation formula for the initial magnetic induction of the stator teeth is:

[0013] ;

[0014] Where, is the initial magnetic induction of the stator teeth, n is the number of laminations of the core, a, b and h are the thickness, width and length of the core respectively, is the resistivity;

[0015] The calculation formula for the initial magnetic induction of the stator yoke and rotor yoke is:

[0016] ;

[0017] Where, is the initial magnetic induction of the stator yoke or rotor yoke, θ, R1 and R2 are the angle, inner radius and outer radius of the sector iron core of the stator yoke or rotor yoke respectively;

[0018] The calculation formula for the initial magnetic induction of the permanent magnet is:

[0019] ;

[0020] Where, is the initial magnetic induction of the permanent magnet, R 1PM and R 2PM are the inner and outer radii of the permanent magnet, θ PM is the circumferential arc value of a single permanent magnet, L PM is the axial length of the permanent magnet, h m is the length of the permanent magnet in the magnetizing direction;

[0021] The calculation formula for the initial magnetic induction of the permanent magnet sheath is:

[0022] ;

[0023] Where, is the initial magnetic induction of the permanent magnet sheath, R 1T and R 2T are the inner and outer radii of the sheath, h mT is the permanent magnet sheath thickness;

[0024] The formula for calculating the initial magnetic induction of the armature winding is:

[0025] ;

[0026] Where, is the initial magnetic induction of the armature winding, w is the number of pre-divided armature winding areas, l a is the average half-turn length of the conductor that makes up the armature winding, d c is the diameter of a single conductor that makes up the armature winding, is the magnetic flux leakage coefficient at the location of the conductor, is the preset initial air gap flux, is the magnetic flux density corresponding to the preset armature winding.

[0027] Furthermore, the new formula for calculating the magnetic induction of the stator teeth is:

[0028] ;

[0029] Where, is the new magnetic induction of the stator teeth, a, b and h are the thickness, width and length of the iron core respectively. is the resistivity, is the air gap flux, is the magnetic flux density of the branch where the stator teeth are located;

[0030] The new magnetic induction formula for calculating the stator yoke and rotor yoke is:

[0031] ;

[0032] Where, is the new magnetic induction of the stator yoke or rotor yoke, is the magnetic flux density of the branch where the stator yoke or rotor yoke is located;

[0033] The new formula for calculating the magnetic induction of a permanent magnet is:

[0034] ;

[0035] Where, The new magnetic induction of the permanent magnet, is the magnetic flux density of the branch where the permanent magnet is located, h m is the length of the permanent magnet in the magnetizing direction, L PM is the axial length of the permanent magnet, is the average resistivity corresponding to the permanent magnet, are the inner and outer radii of the permanent magnet respectively;

[0036] The new formula for calculating the magnetic induction of the permanent magnet sheath is:

[0037] ;

[0038] Where, The new magnetic induction for the permanent magnet sheath, R 1T and R 2Tare the inner and outer radii of the sheath, h mT is the permanent magnet sheath thickness, is the resistivity corresponding to the permanent magnet sheath;

[0039] The new formula for calculating the magnetic induction of the armature winding is:

[0040] ;

[0041] Where, is the new magnetic induction of the armature winding, w is the number of pre-divided armature winding areas, l a is the average half-turn length of the conductor that makes up the armature winding, d c is the diameter of a single conductor that makes up the armature winding, is the magnetic flux leakage coefficient at the location of the conductor, is the magnetic flux density of the armature winding branch.

[0042] Furthermore, adding the magnetic induction into the motor magnetic circuit model includes: converting the magnetic induction into magnetic reactance, and adding the magnetic reactance into the motor magnetic circuit model.

[0043] Furthermore, the formula for converting magnetic induction into magnetic reactance is:

[0044] ;

[0045] Where, is the magnetic induction, is the magnetic reactance, is the alternating angular frequency of the magnetic flux in the core.

[0046] Furthermore, the eddy current loss of each component is calculated based on the final magnetic induction of each component. The formula is:

[0047] ;

[0048] Where, is the final magnetic induction of the i-th component, is the eddy current loss of the i-th component, is the alternating angular frequency of the magnetic flux in the core, is the air gap flux.

[0049] According to another aspect of the present application, a device for calculating eddy current loss of a motor is provided, comprising:

[0050] The initial module calculates the initial magnetic induction of each component of the motor under sinusoidal magnetic field excitation based on the dimensional parameters of the components in the motor, and adds the initial magnetic induction to the motor magnetic circuit model; wherein the components are eddy current loss components;

[0051] The iterative module uses an iterative method to obtain the final magnetic induction of each component based on the motor magnetic circuit model, and calculates the eddy current loss of each component based on the final magnetic induction of each component;

[0052] Among them, the iterative method includes:

[0053] 1) Based on the motor magnetic circuit model, calculate the air gap flux, as well as the magnetic flux density and magnetic field strength of each branch where the components in the motor magnetic circuit model are located;

[0054] 2) Calculate the new magnetic induction of each component based on the air gap flux, as well as the flux density and magnetic field strength of the branch where each component is located in the motor magnetic circuit model;

[0055] 3) If the magnetic induction errors obtained in two consecutive iterations for all components do not exceed the threshold, the new magnetic induction obtained in the current iteration is used as the final magnetic induction. Otherwise, the new magnetic induction is added to the motor magnetic circuit model and the process goes to step 1).

[0056] According to another aspect of the present application, a computer-readable storage medium is provided, which stores one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, enable the computing device to perform a method for calculating motor eddy current losses.

[0057] According to another aspect of the present application, a computer device is provided, comprising one or more processors and one or more memories, wherein one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for executing a method for calculating eddy current losses of a motor.

[0058] The beneficial effects achieved by the present invention are as follows: the present invention adds the magnetic induction of eddy current loss components under sinusoidal magnetic field excitation to the motor magnetic circuit model, realizes the characterization of the nonlinear coupling effect inside the motor, takes the influence of eddy current effect on magnetic flux into account in the motor magnetic circuit model, and adopts an iterative method to simultaneously obtain the eddy current loss of each eddy current loss component. It is a new technical means for efficiently and accurately analyzing the eddy current loss of multiple components, and has high theoretical significance and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a flow chart of the calculation method for motor eddy current loss;

[0060] Figure 2 It is the structural diagram of the motor;

[0061] Figure 3 This is a schematic diagram for calculating the magnetic induction of the stator tooth core laminations;

[0062] Figure 4 Schematic diagram for calculating the magnetic induction of the stator / rotor yoke core laminations;

[0063] Figure 5 Schematic diagram for calculating the corresponding magnetic induction in a permanent magnet;

[0064] Figure 6 Schematic diagram for calculating the corresponding magnetic induction in the permanent magnet sheath;

[0065] Figure 7 It is a schematic diagram of the motor magnetic circuit model;

[0066] Figure 8 This is a comparison chart of the eddy current losses of various components calculated by the method of the present invention and the finite element analysis (FEA) results. In the figure, FEA represents the finite element analysis results, and VMC-MEC represents the eddy current losses of various components calculated by the method of the present invention.

[0067] Figure 9 This is a comparison diagram of the d-axis flux calculated by the method of the present invention and the finite element analysis results. In the figure, MEC represents the equivalent magnetic circuit model, that is, the motor magnetic circuit model.

[0068] Figure 10 This is a block diagram of the motor eddy current loss calculation device. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. It is obvious that the embodiments described are only part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0070] Unless specifically stated otherwise, the relative arrangement of components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application.

[0071] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0072] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0073] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0074] It should be noted that like symbols and letters refer to like items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0075] In order to solve the problem that existing methods cannot calculate the eddy current losses in multiple components at the same time, the present application proposes a method for calculating the eddy current losses of a motor, which aims to put the magnetic induction representing the eddy current losses into the motor magnetic circuit model, and use iteration to achieve accurate analytical calculation of the eddy current losses of multiple components. The calculation method can be executed by a computing device, which can be a terminal device or a server. Among them, the terminal device can include but is not limited to mobile phones, computers, smart car devices, etc., and the embodiments of the present application are not limited thereto; the server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, big data and artificial intelligence platforms, etc., and the embodiments of the present application are not limited thereto. Optionally, the calculation method can also be collaboratively executed by multiple electronic devices with computing power. For the sake of convenience, the subsequent embodiments are described as being executed by a computing device.

[0076] See also Figure 1 , Figure 1 This is a flow chart of a method for calculating motor eddy current loss provided by an embodiment of the present application. The calculation method can be executed by a computing device and can include at least the following steps:

[0077] Step 1: Calculate the initial magnetic induction of each component of the motor under sinusoidal magnetic field excitation based on the size parameters of the components in the motor, and add the initial magnetic induction to the motor magnetic circuit model; wherein the components are eddy current loss components and the motor is a high-speed motor.

[0078] It should be noted that the main eddy current losses of high-speed motors include eddy current losses in the core losses of stator and rotor components under high-frequency power supply, eddy current losses of permanent magnets (generally ring-shaped) and permanent magnet sheaths, and eddy current losses of armature windings caused by skin effect and proximity effect. Therefore, the above-mentioned eddy current loss components mainly include stator teeth, stator yoke, rotor yoke, permanent magnets, permanent magnet sheaths and armature windings.

[0079] Based on the geometric structure, the eddy current loss modeling of the motor's stator teeth, stator yoke, and rotor yoke can be performed one by one. The "magnetic induction" parameters of each part are calculated based on the geometry of the iron core (generally silicon steel sheets). Based on the principle of eddy current effect, the magnetic induction calculation formula for the core can be derived. However, due to the salient pole modulation of the stator in the motor, the magnetic flux density waveform in the core is not a standard sinusoidal, which greatly complicates the calculation of eddy current loss. To reduce the computational difficulty while ensuring accuracy, the magnetic induction value under sinusoidal magnetic flux excitation is used as the initial magnetic induction value. This means that the motor is set under sinusoidal magnetic field excitation to perform the initial magnetic induction calculation for each component.

[0080] by Figure 2 Take the motor in the figure as an example, t is the stator tooth pitch, b t Calculate the stator tooth width, h j is the stator yoke width, h c is the rotor yoke height, h m h is the length of the permanent magnet in the magnetizing direction, mT is the permanent magnet sheath thickness.

[0081] For the stator teeth, such as Figure 3 As shown in the figure, a coordinate system is established based on the center point O of the cross section to analyze the iron core. Assume that the thickness, width, and length of the iron core are a, b, and h respectively. The iron core is in a steady-state sinusoidal magnetic field excitation. According to Faraday's law of electromagnetic induction, the induced voltage e(t) on the eddy current ring loop shown in the figure is:

[0082] ;

[0083] Where x is the width of the eddy current loop along the X-axis, B(t) is the magnetic flux density corresponding to the eddy current loop, and B m is the magnetic flux density amplitude corresponding to the eddy current loop, E m is the induced electromotive force amplitude corresponding to the eddy current loop, is the alternating angular frequency of the magnetic flux in the core.

[0084] Assuming that the induced current in the loop is evenly distributed, the resistance Dr of the closed loop can be approximated by the resistance calculation formula:

[0085] ;

[0086] Where, is the resistivity, and Dx is the length corresponding to the resistance of the closed loop on the x-axis.

[0087] The amplitude of eddy current density J can be obtained from Ohm's law m for:

[0088] ;

[0089] Then the instantaneous eddy current power density p is:

[0090] .

[0091] By performing volume integration on the above equation for a single iron core, the eddy current loss in a single iron core can be obtained:

[0092] ;

[0093] Where, is the eddy current loss in a single iron core, and V is the volume of a single iron core.

[0094] In the vector magnetic circuit theory, the relationship between the magnetic induction and eddy current loss of the magnetic induction element is:

[0095] ;

[0096] Where, is the eddy current loss, is the magnetic induction, is the effective value of the magnetic flux flowing through the core.

[0097] Will and By combining the formulas, we can get the magnetic induction corresponding to a single iron core of the stator tooth:

[0098] ;

[0099] Where, is the magnetic induction corresponding to a single iron core of the stator tooth;

[0100] For the laminated core of the motor, the magnetic field of all laminations is almost the same. The magnetic induction of the corresponding part of the motor can be regarded as the parallel connection of the corresponding magnetic induction of each lamination. Assuming that the number of laminations is n, the initial magnetic induction of the stator teeth can be expressed as:

[0101] ;

[0102] Where, is the initial magnetic induction of the stator teeth.

[0103] Similar, such as Figure 4 As shown in the figure, the magnetic induction of a single sector iron core of the stator yoke or rotor yoke under sinusoidal excitation is:

[0104] ;

[0105] Where, is the magnetic induction of a single sector-shaped iron core of the stator yoke or rotor yoke under sinusoidal excitation, θ, R1 and R2 are the angle, inner radius and outer radius of the sector-shaped iron core of the stator yoke or rotor yoke respectively.

[0106] Assuming that the number of laminations of the core is n, the initial magnetic induction of the stator yoke and rotor yoke can be expressed as:

[0107] ;

[0108] Where, It is the initial magnetic induction of the stator yoke or rotor yoke.

[0109] To protect the permanent magnets and their sheaths from damage caused by centrifugal forces during high-speed rotation, a sheath is typically installed on the rotor. While the sheath is made of a conductive, non-magnetic alloy to ensure good thermal conductivity, it generates eddy current losses during motor operation. Similar to the derivation method for the core, the eddy current losses of the permanent magnets and sheaths can also be modeled using magnetic induction elements.

[0110] like Figure 5 and Figure 6 As shown, similar to the derivation method of the core magnetic induction (i.e. the stator teeth and stator / rotor yokes mentioned above), the initial magnetic induction of the permanent magnet can be expressed as:

[0111] ;

[0112] Where, is the initial magnetic induction of the permanent magnet, R 1PM and R 2PM are the inner and outer radii of the permanent magnet, θ PM is the circumferential arc value of a single permanent magnet, L PM is the axial length of the permanent magnet, h m is the length of the permanent magnet in the magnetizing direction.

[0113] The initial magnetic induction calculation of the permanent magnet sheath can be expressed as:

[0114] ;

[0115] Where, is the initial magnetic induction of the permanent magnet sheath, R 1T and R 2T are the inner and outer radii of the sheath, h mT is the permanent magnet sheath thickness.

[0116] In the AC windings of the motor, the AC copper loss caused by magnetic flux leakage through the armature winding also requires modeling using magnetic induction elements. This loss is the result of the combined eddy current density caused by the skin effect and the proximity effect. The magnitude of this loss is closely related to the winding size and magnetic flux density. The greater the magnetic induction intensity of the leakage field, the more severe the current distortion within the conductor, resulting in greater AC copper loss.

[0117] To simplify the calculation during modeling, the AC winding is divided into several winding regions based on the principle of similar leakage coefficients. For example, one armature coil is considered as one region. The average leakage coefficient of the region is used to calculate the corresponding magnetic induction value of the whole. Finally, the magnetic induction of each region in the stator slot is connected in series. The initial magnetic induction of the armature winding can be expressed as:

[0118] ;

[0119] Where, is the initial magnetic induction of the armature winding, w is the number of pre-divided armature winding areas, such as 12, l a is the average half-turn length of the conductor that makes up the armature winding, d c is the diameter of a single conductor that makes up the armature winding, is the magnetic flux leakage coefficient at the location of the conductor, is the preset initial air gap flux, For the magnetic flux density corresponding to the preset armature winding, the initial bm value of the permanent magnet working point can be set to 0.8, which can be calculated based on the assumed permanent magnet working point and motor size parameters. and .

[0120] It should be noted that the purpose of adding magnetic induction to the motor magnetic circuit model is to convert magnetic induction into magnetic reactance, which can be expressed as follows:

[0121] ;

[0122] Where, is the magnetic induction, is the magnetic reactance, is the alternating angular frequency of the magnetic flux in the core;

[0123] Then the magnetic reactance is further added to the motor magnetic circuit model; the specific model can be found in Figure 7 , only the magnetic induction element is drawn in the figure, but the magnetic induction needs to be converted into magnetic reactance when calculating. is the magnetic flux corresponding to the permanent magnet, R PM is the internal resistance of the permanent magnet, is the magnetic induction of the permanent magnet, is the total magnetic flux of the motor, is the leakage magnetic resistance, is the magnetic induction of the armature winding, is the magnetic induction of the permanent magnet sheath, R δ is the air gap reluctance, R t is the stator tooth reluctance, is the magnetic induction of the stator teeth, R j is the stator yoke reluctance, is the stator yoke magnetic induction, R c is the rotor yoke reluctance, is the magnetic induction of the rotor yoke.

[0124] Step 2: Based on the motor magnetic circuit model, an iterative method is used to obtain the final magnetic induction of each component, and the eddy current loss of each component is calculated based on the final magnetic induction of each component.

[0125] Among them, the iterative method includes:

[0126] 1) Based on the motor magnetic circuit model, calculate the air gap flux and the magnetic flux density of each branch where the components in the motor magnetic circuit model are located.

[0127] 2) Calculate the new magnetic induction of each component based on the air gap flux and the magnetic flux density of the branch where each component is located in the motor magnetic circuit model.

[0128] The new formula for calculating the magnetic induction of the stator teeth is:

[0129] ;

[0130] Where, is the new magnetic induction of the stator teeth, a, b and h are the thickness, width and length of the iron core respectively. is the resistivity, is the air gap flux, is the magnetic flux density of the branch where the stator teeth are located.

[0131] The new magnetic induction formula for calculating the stator yoke and rotor yoke is:

[0132] ;

[0133] Where, is the new magnetic induction of the stator yoke or rotor yoke, It is the magnetic flux density of the branch where the stator yoke or rotor yoke is located.

[0134] The new formula for calculating the magnetic induction of a permanent magnet is:

[0135] ;

[0136] Where, The new magnetic induction of the permanent magnet, is the magnetic flux density of the branch where the permanent magnet is located, h m is the length of the permanent magnet in the magnetizing direction, LPM is the axial length of the permanent magnet, is the average resistivity corresponding to the permanent magnet, are the inner and outer radii of the permanent magnet, respectively.

[0137] The new formula for calculating the magnetic induction of the permanent magnet sheath is:

[0138] ;

[0139] Where, The new magnetic induction for the permanent magnet sheath, R 1T and R 2T are the inner and outer radii of the sheath, h mT is the permanent magnet sheath thickness, is the resistivity corresponding to the permanent magnet sheath.

[0140] The new formula for calculating the magnetic induction of the armature winding is:

[0141] ;

[0142] Where, is the new magnetic induction of the armature winding, w is the number of pre-divided armature winding areas, l a is the average half-turn length of the conductor that makes up the armature winding, d c is the diameter of a single conductor that makes up the armature winding, is the magnetic flux leakage coefficient at the location of the conductor, is the magnetic flux density of the armature winding branch.

[0143] 3) If the magnetic induction errors obtained in two consecutive iterations for all components do not exceed the threshold, the new magnetic induction obtained in the current iteration is used as the final magnetic induction. Otherwise, the new magnetic induction is added to the motor magnetic circuit model and the process is turned to step 1). The threshold is generally set to 1×10 -6 .

[0144] It should be noted that the eddy current loss of each component is calculated based on the final magnetic induction of each component. The formula can be expressed as:

[0145] ;

[0146] Where, is the final magnetic induction of the i-th component, is the eddy current loss of the i-th component, is the alternating angular frequency of the magnetic flux in the core.

[0147] Using the above eddy current loss calculation method, the eddy current loss of each component can be calculated, and the total eddy current loss of the motor under rated operating conditions can be obtained by adding them up.

[0148] In order to verify the above method, a comparative experiment was conducted. Figure 8 A comparison between the magnetic circuit model calculation results (i.e., the above-mentioned method) and the finite element simulation results is presented. Experimental data show that the two are highly consistent in the prediction of core losses (i.e., stator teeth and stator / rotor yoke losses), permanent magnet eddy current losses, and winding AC losses, with a maximum relative error of only 2%.

[0149] Figure 9 It is shown that when the motor is running under load, when the load current remains at rated conditions, the continuous increase in motor speed will lead to a significant increase in eddy current losses. Specifically, as the speed increases, the nonlinear growth of eddy current losses directly leads to the attenuation of d-axis magnetic flux. This proves that the magnetic circuit analysis and calculation of this phenomenon is realized through the iterative process of adding magnetic induction to magnetic flux. At the same time, it further verifies the above-mentioned accurate simulation of eddy current effects under the action of high-frequency harmonic magnetic fields.

[0150] The above method adds the magnetic induction of eddy current loss components under sinusoidal magnetic field excitation to the motor magnetic circuit model, that is, constructs the eddy current effect action model through the magnetic resistance-magnetic induction coupling model, realizes the characterization of the nonlinear coupling effect inside the motor, and takes the influence of the eddy current effect on the magnetic flux into account in the motor magnetic circuit model. By using an iterative method, the eddy current loss of each eddy current loss component can be obtained at the same time. It is a new technical means for efficient and accurate analysis of the eddy current loss of multiple components, and has high theoretical significance and application value.

[0151] See also Figure 10 , Figure 10 is a block diagram of a motor eddy current loss calculation device provided in an embodiment of the present application, Figure 10 The embodiment is a virtual device that can be loaded and executed by a computer device, which may include the above-mentioned computing device, Figure 10 The device may include an initial module and an iterative module, which, when used to execute the above-mentioned motor eddy current loss calculation method, may:

[0152] The initial module calculates the initial magnetic induction of each component of the motor under sinusoidal magnetic field excitation based on the dimensional parameters of the components in the motor, and adds the initial magnetic induction to the motor magnetic circuit model; among them, the components are eddy current loss components.

[0153] The iterative module uses an iterative method to obtain the final magnetic induction of each component based on the motor magnetic circuit model, and calculates the eddy current loss of each component based on the final magnetic induction of each component;

[0154] Among them, the iterative method includes:

[0155] 1) Based on the motor magnetic circuit model, calculate the air gap flux, as well as the magnetic flux density and magnetic field strength of each branch where the components in the motor magnetic circuit model are located;

[0156] 2) Calculate the new magnetic induction of each component based on the air gap flux, as well as the flux density and magnetic field strength of the branch where each component is located in the motor magnetic circuit model;

[0157] 3) If the magnetic induction errors obtained in two consecutive iterations for all components do not exceed the threshold, the new magnetic induction obtained in the current iteration is used as the final magnetic induction. Otherwise, the new magnetic induction is added to the motor magnetic circuit model and the process goes to step 1).

[0158] The above-mentioned device adds the magnetic induction of eddy current loss components under sinusoidal magnetic field excitation to the motor magnetic circuit model, realizes the characterization of the nonlinear coupling effect inside the motor, and takes into account the influence of eddy current effect on magnetic flux into the motor magnetic circuit model. By using an iterative method, the eddy current loss of each eddy current loss component can be obtained at the same time. It is a new technical means for efficiently and accurately analyzing the eddy current loss of multiple components, and has high theoretical significance and application value.

[0159] The present application also relates to a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions. When the instructions are executed by a computing device, the computing device executes a method for calculating eddy current losses of a motor.

[0160] The present application also relates to a computer device comprising one or more processors and one or more memories, wherein one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for executing a method for calculating eddy current losses of a motor.

[0161] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0162] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0163] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0164] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0165] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A method for calculating eddy current loss of a motor, characterized in that: include: Based on the size parameters of the components in the motor, the initial magnetic induction of each component under the excitation of the sinusoidal magnetic field is calculated, and the initial magnetic induction is added to the motor magnetic circuit model; wherein the components are eddy current loss components; According to the motor magnetic circuit model, an iterative method is used to obtain the final magnetic induction of each component, and the eddy current loss of each component is calculated based on the final magnetic induction of each component; Among them, the iterative method includes: 1) Calculate the air gap flux and the magnetic flux density of each branch of the motor magnetic circuit model based on the motor magnetic circuit model; 2) Calculate the new magnetic induction of each component based on the air gap flux and the magnetic flux density of the branch where each component is located in the motor magnetic circuit model; 3) If the magnetic induction errors obtained in two consecutive iterations for all components do not exceed the threshold, the new magnetic induction obtained in the current iteration is used as the final magnetic induction. Otherwise, the new magnetic induction is added to the motor magnetic circuit model and the process goes to step 1).

2. The method according to claim 1, characterized in that The components of the motor include stator teeth, stator yoke, rotor yoke, permanent magnets, permanent magnet sheaths and armature windings.

3. The method according to claim 2, characterized in that The calculation formula of the initial magnetic induction of the stator teeth is: ； Where, is the initial magnetic induction of the stator teeth, n is the number of laminations of the core, a, b and h are the thickness, width and length of the core respectively, is the resistivity; The calculation formula for the initial magnetic induction of the stator yoke and rotor yoke is: ； Where, is the initial magnetic induction of the stator yoke or rotor yoke, θ, R1 and R2 are the angle, inner radius and outer radius of the sector iron core of the stator yoke or rotor yoke respectively; The calculation formula for the initial magnetic induction of the permanent magnet is: ； Where, is the initial magnetic induction of the permanent magnet, R 1PM and R 2PM are the inner and outer radii of the permanent magnet, θ PM is the circumferential arc value of a single permanent magnet, L PM is the axial length of the permanent magnet, h m is the length of the permanent magnet in the magnetizing direction; The calculation formula of the initial magnetic induction of the permanent magnet sheath is: ； Where, is the initial magnetic induction of the permanent magnet sheath, R 1T and R 2T are the inner and outer radii of the sheath, h mT is the permanent magnet sheath thickness; The formula for calculating the initial magnetic induction of the armature winding is: ； Where, is the initial magnetic induction of the armature winding, w is the number of pre-divided armature winding areas, l a is the average half-turn length of the conductor that makes up the armature winding, d c is the diameter of a single conductor that makes up the armature winding, is the magnetic flux leakage coefficient at the location of the conductor, is the preset initial air gap flux, is the magnetic flux density corresponding to the preset armature winding.

4. The method according to claim 2, characterized in that The new formula for calculating the magnetic induction of the stator teeth is: ； Where, is the new magnetic induction of the stator teeth, a, b and h are the thickness, width and length of the iron core respectively. is the resistivity, is the air gap flux, is the magnetic flux density of the branch where the stator teeth are located; The new magnetic induction formula for calculating the stator yoke and rotor yoke is: ； Where, is the new magnetic induction of the stator yoke or rotor yoke, is the magnetic flux density of the branch where the stator yoke or rotor yoke is located; The new formula for calculating the magnetic induction of a permanent magnet is: ； Where, The new magnetic induction of the permanent magnet, is the magnetic flux density of the branch where the permanent magnet is located, h m is the length of the permanent magnet in the magnetizing direction, L PM is the axial length of the permanent magnet, is the average resistivity corresponding to the permanent magnet, are the inner and outer radii of the permanent magnet respectively; The new formula for calculating the magnetic induction of the permanent magnet sheath is: ； Where, The new magnetic induction for the permanent magnet sheath, R 1T and R 2T are the inner and outer radii of the sheath, h mT is the permanent magnet sheath thickness, is the resistivity corresponding to the permanent magnet sheath; The new formula for calculating the magnetic induction of the armature winding is: ； Where, is the new magnetic induction of the armature winding, w is the number of pre-divided armature winding areas, l a is the average half-turn length of the conductor that makes up the armature winding, d c is the diameter of a single conductor that makes up the armature winding, is the magnetic flux leakage coefficient at the location of the conductor, is the magnetic flux density of the armature winding branch.

5. The method according to claim 1, wherein Adding magnetic induction to the motor magnetic circuit model includes: converting magnetic induction into magnetic reactance, and adding magnetic reactance to the motor magnetic circuit model.

6. The method according to claim 5, characterized in that The formula for converting magnetic induction into magnetic reactance is: ； Where, is the magnetic induction, is the magnetic reactance, is the alternating angular frequency of the magnetic flux in the core.

7. The method according to claim 1, characterized in that According to the final magnetic induction of each component, the eddy current loss of each component is calculated using the following formula: ； Where, is the final magnetic induction of the i-th component, is the eddy current loss of the i-th component, is the alternating angular frequency of the magnetic flux in the core, is the air gap flux.

8. A device for calculating eddy current loss of a motor, characterized in that: include: The initial module calculates the initial magnetic induction of each component of the motor under sinusoidal magnetic field excitation based on the dimensional parameters of the components in the motor, and adds the initial magnetic induction to the motor magnetic circuit model; wherein the components are eddy current loss components; The iterative module uses an iterative method to obtain the final magnetic induction of each component based on the motor magnetic circuit model, and calculates the eddy current loss of each component based on the final magnetic induction of each component; Among them, the iterative method includes: 1) Based on the motor magnetic circuit model, calculate the air gap flux, as well as the magnetic flux density and magnetic field strength of each branch where the components in the motor magnetic circuit model are located; 2) Calculate the new magnetic induction of each component based on the air gap flux, as well as the flux density and magnetic field strength of the branch where each component is located in the motor magnetic circuit model; 3) If the magnetic induction errors obtained in two consecutive iterations for all components do not exceed the threshold, the new magnetic induction obtained in the current iteration is used as the final magnetic induction. Otherwise, the new magnetic induction is added to the motor magnetic circuit model and the process goes to step 1).

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores one or more programs, and the one or more programs include instructions. When the instructions are executed by a computing device, the computing device executes the method according to any one of claims 1 to 7.

10. A computer device, characterized in that: include: One or more processors, and one or more memories, one or more programs stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for executing any one of the methods of claims 1 to 7.

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