High-speed permanent magnet motor rotor eddy current loss 2.5 D rapid calculation method

Abstract

The invention discloses a high-speed permanent magnet motor rotor eddy current loss 2.5 D rapid calculation method. Firstly, motor control parameters are obtained through a two-dimensional transient electromagnetic finite element model, and a magnetic field-circuit coupling model is constructed to obtain winding phase current containing harmonic waves. Secondly, the end effect axial lengths of magnetic field distribution and eddy current distribution are determined respectively, and an end three-dimensional model is constructed with the larger value of the end effect axial lengths; then, coupling the end part three-dimensional model with a middle two-dimensional model determined on the basis of the two-dimensional model through symmetrical boundary conditions to form a 2.5 D equivalent model; and finally, calculating the eddy-current loss of the end part and the middle part by using the model and summing to obtain the total eddy-current loss. According to the method, the calculation speed is greatly improved and the consumption of calculation resources is reduced while the calculation precision is ensured.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a rapid calculation method for 2.5D rotor eddy current loss of a high-speed permanent magnet motor. Background Technology

[0002] High-speed permanent magnet motors, as a type of special motor with high power density, high operating efficiency, and good dynamic response characteristics, have been increasingly widely used in many key fields such as traditional industrial production, new energy power generation, new green transportation, and aerospace in recent years, becoming core equipment for promoting technological upgrading and energy conservation in related industries. With the increasing demands for compact and efficient equipment in industrial production, high-speed rotors have become an important development trend for high-speed permanent magnet motors. While this trend significantly improves motor power density, it also brings a series of technical challenges that urgently need to be addressed, among which rotor eddy current losses are particularly prominent.

[0003] The high-speed rotation of the rotor makes the internal electromagnetic environment of the motor more complex. Not only does the rotor loss density increase significantly, but because the motor's fundamental frequency is much higher than that of ordinary motors, the carrier ratio of the matching power electronic controller is relatively low. This inevitably introduces a large number of winding current harmonics during control strategy execution. These harmonic components interact with the motor rotor's conductive components (including permanent magnets, rotor sleeves, and rotor core), generating significant eddy current losses, which become key factors affecting the motor's operational stability and service life. For high-speed permanent magnet motors, the temperature rise caused by rotor eddy current losses is particularly critical: excessively high temperatures can lead to irreversible decay of the permanent magnet's magnetic properties, even demagnetization; it can also damage the structural integrity of the rotor sleeve, causing safety risks under high-speed rotation; furthermore, increased temperature accelerates the aging of internal components, reducing the reliability and service life of the entire motor system.

[0004] Therefore, accurate calculation of rotor eddy current losses is one of the core aspects of the design phase of high-speed permanent magnet motors. The calculation results directly provide crucial information for motor temperature rise analysis, loss suppression measures formulation, and cooling system optimization design. If the calculated eddy current loss value is too low, it will lead to insufficient motor heat dissipation design, with the rotor temperature far exceeding the design threshold during actual operation, causing serious safety hazards such as permanent magnet demagnetization and rotor structural damage. If the calculated value is too conservative, it will result in a bulky cooling system, increased costs, and will also restrict further improvement in motor power density, failing to meet the design requirements of compact and lightweight equipment, thus violating the core development concept of high-speed permanent magnet motors.

[0005] In the current technological system, the 3D transient finite element method is the mainstream method for calculating rotor eddy current losses. This method can comprehensively simulate the three-dimensional electromagnetic field distribution inside the motor, considering complex physical phenomena such as rotor end effects and skin effects. Therefore, it has high computational accuracy and versatility and is widely used in various high-precision electromagnetic calculation scenarios. However, this method has significant drawbacks that are difficult to overcome: on the one hand, it requires the construction of a detailed three-dimensional electromagnetic model, which places extremely high demands on computer hardware resources (including processor performance, memory capacity, and graphics card computing power); on the other hand, the three-dimensional transient simulation process involves a large number of iterative calculations, which is extremely time-consuming. Even for a motor model of moderate complexity, a complete calculation may take several hours or even days. More importantly, when the impact of current harmonics on eddy current losses needs to be considered, the diversity and complexity of harmonic components will cause the computational load to increase exponentially, further increasing the computational burden and leading to a significant decrease in computational efficiency. This severely slows down the design cycle of high-speed permanent magnet motors and cannot meet the needs of rapid iterative design in engineering practice.

[0006] Besides the 3D transient finite element method, there are other alternatives in the industry, such as the pure 2D finite element method or the simplified analytical method. While the pure 2D finite element method is fast and resource-efficient, it neglects the end effects of the motor and the differences in axial magnetic field distribution, leading to significant calculation errors, especially in high-speed motors where end effects are more pronounced. Its calculation results are insufficient to meet the accuracy requirements of engineering design. The simplified analytical method, through numerous idealized assumptions about the electromagnetic process, is extremely efficient, but it cannot accurately reflect the influence of complex factors such as current harmonics and the skin effect, resulting in limited calculation accuracy. It is only suitable for preliminary estimation scenarios.

[0007] In summary, the current field of high-speed permanent magnet motor rotor eddy current loss calculation faces a technical bottleneck where it is difficult to balance "computational accuracy" and "computational efficiency": the 3D transient finite element method has sufficient accuracy but low efficiency, while the 2D finite element method and analytical methods have higher efficiency but insufficient accuracy. Moreover, existing methods generally fail to fully consider the complex influence of current harmonics on eddy current losses. Therefore, in order to address these shortcomings, there is an urgent need for a high-speed permanent magnet motor rotor eddy current loss calculation method that balances computational accuracy and computational efficiency. This method should fully consider key influencing factors such as current harmonics, reduce computational resource consumption, and shorten computation time, thereby improving the design efficiency and reliability of high-speed permanent magnet motors. Summary of the Invention

[0008] In view of this, the purpose of this invention is to provide a fast 2.5D calculation method for rotor eddy current loss of high-speed permanent magnet motor. This method involves building a 2D transient finite element magnetic field-circuit direct coupling model to consider the influence of current harmonics introduced by the control strategy on rotor eddy current loss; and reducing the dimensionality of the rotor 3D eddy current loss calculation model to improve the calculation speed of rotor eddy current loss using the 2.5D model.

[0009] The technical solution adopted by this invention to solve its technical problem is:

[0010] A rapid calculation method for 2.5D rotor eddy current loss of a high-speed permanent magnet motor is provided, including the following steps:

[0011] S1. Construct a two-dimensional transient electromagnetic finite element calculation model of a high-speed permanent magnet motor, calculate the control parameters of the motor based on the two-dimensional transient electromagnetic finite element model, and construct a magnetic field-circuit direct coupling model to obtain the winding phase current containing current harmonics.

[0012] S2. Determine the first axial length of the end effect caused by the magnetic field distribution of the high-speed permanent magnet motor. And the second axial length of the end effect caused by eddy current distribution ;

[0013] S3, based on the first axial length With the second axial length The larger value in the equation is used to construct a three-dimensional end model to characterize the three-dimensional electromagnetic properties of the motor end.

[0014] S4. Construct a 2.5D equivalent model by coupling the end three-dimensional model and a middle two-dimensional model through symmetrical boundary conditions; wherein, the middle two-dimensional model is determined based on the two-dimensional transient electromagnetic finite element model of the high-speed permanent magnet motor;

[0015] S5. Using the winding phase current containing current harmonics as excitation, calculate the first eddy current loss of the rotor in the end region and the second eddy current loss in the middle region using the 2.5D equivalent model.

[0016] S6. Summing the first eddy current loss and the second eddy current loss, the total eddy current loss of the high-speed permanent magnet motor rotor is obtained.

[0017] Preferably, in step S2, the first axial length is determined. The specific method is as follows: A three-dimensional static electromagnetic finite element model containing the stator core, armature winding, rotor sheath, permanent magnet, and rotor core is constructed. Based on this model, the distribution data of the radial air gap magnetic flux density along the motor axis is obtained. The first axial length is determined based on the length of the transition zone where the magnetic field strength decreases from the end to a stable value in the middle of the axial direction. .

[0018] Preferably, in step S2, the second axial length is determined. The specific method is as follows: based on the formula for calculating the skin depth of a conductor. The calculation yielded, where The maximum skin depth of the rotor-induced eddy current. The resistivity of the rotor's conductive components. The lowest frequency of the asynchronous magnetic field acting on the rotor. denoted as ρ is the permeability of the rotor's conductive components.

[0019] Preferably, in step S3, the axial length of the end three-dimensional model Through formula It is determined that the three-dimensional model at the end is subject to symmetrical boundary conditions on the cross section away from the end of the motor winding.

[0020] Preferably, the effective axial length of the central two-dimensional model in step S4 Satisfy the formula ,in This refers to the effective axial length of the high-speed permanent magnet motor. The axial length of the end three-dimensional model, the stack height of the two-dimensional transient electromagnetic finite element calculation model and the aforementioned equal.

[0021] Preferably, in step S1, when constructing the direct coupling model of the magnetic field and the circuit, the simulation step size is... Based on the carrier frequency corresponding to the control strategy Set, and satisfy .

[0022] Preferably, step S4 further includes: applying a Fourier transform to the winding phase current containing current harmonics. Perform spectrum analysis, where The waveform of the winding phase current in the time domain is shown. Angular frequency, The imaginary unit; identifies the target harmonic frequency that plays a major role in rotor eddy current losses. According to the formula Calculate the skin depth of the corresponding rotor conductive component. A refined skin effect mesh is constructed in the corresponding rotor conductive component, wherein the mesh size is... satisfy .

[0023] Preferably, in step S5, the first eddy current loss is calculated using the three-dimensional transient finite element method based on the end three-dimensional model, and the second eddy current loss is calculated using the two-dimensional transient finite element method based on the middle two-dimensional model; the first eddy current loss With the second eddy current loss All are based on the integral formula of eddy current loss density. The calculation shows that, among which For electric field strength, For current density, To calculate the volume of the region.

[0024] Preferably, in step S6, the total eddy current loss The calculation formula is ,in This is the first eddy current loss. This is the second eddy current loss.

[0025] Preferably, the three-dimensional static electromagnetic finite element calculation model and the two-dimensional transient electromagnetic finite element calculation model use the same structural parameters, including stator core thickness, armature winding turns, rotor sheath thickness, permanent magnet dimensions, and rotor core diameter.

[0026] The beneficial effects of this invention are:

[0027] This invention provides a rapid 2.5D calculation method for rotor eddy current loss of a high-speed permanent magnet motor. It constructs a direct coupling model of the high-speed permanent magnet synchronous electromagnetic field and circuit, considering the influence of harmonic phase currents introduced by the control strategy on rotor eddy current loss. The 3D transient finite element model is reduced in dimension, and symmetrical boundary conditions are used to couple the end 3D model with the middle 2D model, constructing a 2.5D model for calculating rotor eddy current loss. The axial length of the end 3D model is determined based on the end effects of the magnetic field and eddy current distributions, ensuring calculation accuracy. Based on the harmonic distribution characteristics, a skin-like mesh for rotor eddy current loss is generated, ensuring calculation accuracy while avoiding mesh redundancy. Attached Figure Description

[0028] Figure 1 This is a 2D finite element model of a rapid 2.5D calculation method for rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0029] Figure 2 This is a flowchart illustrating the implementation of a rapid calculation method for 2.5D rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0030] Figure 3 This is a block diagram of the magnetic field-circuit direct coupling model under the SVPWM control strategy of the present invention, which is a fast calculation method for 2.5D rotor eddy current loss of a high-speed permanent magnet motor.

[0031] Figure 4 The phase current waveform containing harmonics is provided for the 2.5D rapid calculation method of rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0032] Figure 5 This is a schematic diagram of the construction of a 2.5D equivalent model for a fast 2.5D calculation method for rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0033] Figure 6This is a schematic diagram showing the radial air gap magnetic field distribution along the axial direction in the 2.5D rapid calculation method for rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0034] Figure 7 This is a schematic diagram of the skin mesh of the permanent magnet in the 2.5D fast calculation method for rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0035] Figure 8 This is a schematic diagram of the rotor sheath skin mesh for a 2.5D fast calculation method for rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0036] Figure 9 This is a schematic diagram of the rotor axial mesh for a 2.5D rapid calculation method for rotor eddy current loss of a high-speed permanent magnet motor according to the present invention.

[0037] In the diagram: 1. Permanent magnet; 2. Stator core; 3. Rotor sheath; 4. Armature winding.

[0038] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0039] The following will refer to the appendices in the embodiments of the present invention. Figure 1-9 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] This embodiment uses a high-speed permanent magnet motor with 2 poles, a fundamental frequency of 1500Hz, an effective axial length of le=105mm, and employing a cylindrical solid permanent magnet 1 and a nickel-based metal rotor sheath 3 as the subject of this description. Its 2D finite element model is as follows: Figure 1 As shown, the overall calculation process follows Figure 2 The implementation flowchart.

[0041] S1: Construct a two-dimensional transient electromagnetic finite element calculation model of a high-speed permanent magnet motor, calculate the control parameters of the motor based on the two-dimensional transient electromagnetic finite element model, and construct a magnetic field-circuit direct coupling model to obtain the winding phase current containing current harmonics.

[0042] Constructing a 2D transient electromagnetic finite element calculation model: The model adopts a 1 / 2 symmetrical structure along the circumference. The core components include stator core 2, armature winding 4, rotor sleeve 3, permanent magnet 1, and rotor core. The model stack height is equal to the effective axial length of the motor. Maintain consistency to ensure the model matches the actual motor structure.

[0043] Calculation of motor control parameters: Based on the above 2D model, considering the eddy current effect of the rotor conductive components (rotor sheath 3, permanent magnet 1, rotor core), the key control parameters of the motor are obtained through electromagnetic simulation: d-axis inductance. q-axis inductance Permanent magnet chain .

[0044] Constructing a direct coupling model between the magnetic field and the circuit: Based on the obtained control parameters, a direct coupling model between the magnetic field and the circuit under the space vector pulse width modulation (SVPWM) strategy is constructed, and its principle block diagram is shown below. Figure 3 As shown. To ensure the triangular carrier wave is not distorted, the simulation step size is... Based on the switching frequency of power devices Set, and satisfy In this embodiment .

[0045] Obtain and analyze phase currents containing harmonics: Simulate and output the winding phase current waveforms containing current harmonics through coupled model simulation (e.g. Figure 4 As shown), Fourier transform method is used. Spectral analysis of the current determined that the dominant frequency of the asynchronous magnetic field acting on the rotor is 36kHz. The harmonics corresponding to this frequency are the dominant harmonic orders affecting the rotor's eddy current losses. The waveform of the winding phase current in the time domain is shown. Angular frequency, It is the imaginary unit.

[0046] S2: Determine the first axial length of the end effect caused by the magnetic field distribution of the high-speed permanent magnet motor. And the second axial length of the end effect caused by eddy current distribution ;

[0047] Determine the first axial length Construct a 3D static electromagnetic finite element model that is completely identical to the radial cross-sectional structure of the 2D model. The model includes the stator core 2, armature winding 4, rotor sleeve 3, permanent magnet 1, and rotor core, with the axial length matching the effective axial length of the motor. The same; the radial air gap magnetic flux density distribution data along the axial direction is obtained through 3D static simulation (e.g., Figure 6 As shown in the figure, the first axial length of the end effect of the magnetic field distribution is determined based on the length of the transition zone where the magnetic field intensity decreases from the end to the stable value in the middle of the axis in the distribution curve. .

[0048] Determine the second axial length Based on the formula for calculating the skin depth of a conductor The resistivity of rotor sheath 3 magnetic permeability The lowest frequency of the asynchronous magnetic field acting on the rotor Substituting the values ​​into the calculation, the maximum skin depth of the rotor-induced eddy current is found to be 14.22 mm, which is the second axial length of the end effect of the eddy current distribution. .

[0049] S3: Based on the larger value between the first axial length l1 and the second axial length l2, construct an end three-dimensional model to characterize the three-dimensional electromagnetic properties of the motor end;

[0050] According to the formula Substitute , Determine the axial length of the end three-dimensional model. Symmetrical boundary conditions are applied to the section of the 3D model at the end far from the winding end, laying the foundation for subsequent coupling with the middle 2D model.

[0051] S4: Construct a 2.5D equivalent model by coupling the end three-dimensional model and a middle two-dimensional model through symmetrical boundary conditions; wherein, the middle two-dimensional model is determined based on the two-dimensional transient electromagnetic finite element model of the high-speed permanent magnet motor;

[0052] The parameters of the central two-dimensional model are determined: the central two-dimensional model is determined based on the 2D transient electromagnetic finite element model constructed in step S1, and its effective axial length is determined. According to the formula Calculate, substitute , ,get .

[0053] 2.5D Model Coupling: A 2.5D equivalent model is constructed by coupling the end 3D model and the middle 2D model through symmetrical boundary conditions. A schematic diagram of the overall model structure is shown below. Figure 5 As shown, symmetrical boundary conditions are used to ensure the continuity of the magnetic field and eddy current distribution at the ends and in the middle, thus ensuring the accuracy of loss calculation.

[0054] Refined skin-like mesh generation: Based on the dominant harmonic frequency of 36kHz identified in step S1, according to the formula... Calculate the skin depth of the key conductive components of the rotor separately: resistivity of permanent magnet 1 Corresponding to skin depth Rotor sheath resistivity 3 Corresponding to skin depth A refined skin mesh is constructed based on skin depth, with the mesh size... satisfy The skin mesh of permanent magnet 1 is as follows: Figure 7 As shown, the skin-like mesh of the rotor sheath 3 is as follows: Figure 8 As shown, the axially stretched mesh is as follows Figure 9 As shown, this approach avoids mesh redundancy while ensuring the accuracy of eddy current distribution simulation.

[0055] S5: Using the winding phase current containing current harmonics as excitation, the first eddy current loss of the rotor in the end region and the second eddy current loss in the middle region are calculated using the 2.5D equivalent model.

[0056] Using the phase current of the winding containing harmonics obtained in step S1 as excitation, eddy current losses are calculated at the ends and middle of the 2.5D equivalent model, respectively:

[0057] The end region was analyzed using the 3D transient finite element method, and the first eddy current loss was calculated based on the 3D end model. The second eddy current loss in the central region was calculated using the 2D transient finite element method based on the central 2D model. Both calculation methods are based on the integral formula for eddy current loss density. The calculation shows that, among which For electric field strength, For current density, To calculate the volume of the region and ensure the theoretical consistency of the loss calculation.

[0058] S6: Summing the first eddy current loss and the second eddy current loss yields the total eddy current loss of the high-speed permanent magnet motor rotor.

[0059] According to the formula is The end and middle eddy current losses calculated in step S5 are added together to obtain the total rotor eddy current loss. In this embodiment, the end eddy current losses are: permanent magnet 1 loss 75.4478W, rotor sleeve 3 loss 406.604W; the middle eddy current losses and end losses are superimposed according to the same component type to obtain the final total rotor eddy current loss.

[0060] To verify the effectiveness of the method of this invention, the calculation results were compared with those of the traditional 3D transient finite element method and the pure 2D model method. The specific data are shown in the table below:

[0061]

[0062] The comparison results show that the relative error between the calculation results of the method of the present invention and the 3D transient finite element method is only 1.31%, and the calculation accuracy is close. At the same time, the calculation time is shortened by about 80% compared with the 3D method, which significantly reduces the consumption of computing resources. It perfectly balances the accuracy and efficiency requirements of the calculation of rotor eddy current loss of high-speed permanent magnet motor, and effectively solves the technical bottleneck of "difficulty in balancing accuracy and efficiency" in the existing technology.

[0063] Finally, it should be noted that those skilled in the art should understand that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made based on the technical solutions of the present invention within the spirit and principles of the present invention should be included within the scope of protection of the present invention. For example, for high-speed permanent magnet motors with different pole numbers, different axial lengths, or different rotor structures, only the model structural parameters, material property parameters, and simulation step size need to be adjusted to achieve rapid and accurate calculation of rotor eddy current losses using the method of the present invention.

Claims

1. A rapid calculation method for 2.5D rotor eddy current loss of a high-speed permanent magnet motor, characterized in that: Includes the following steps: S1. Construct a two-dimensional transient electromagnetic finite element calculation model of a high-speed permanent magnet motor, calculate the control parameters of the motor based on the two-dimensional transient electromagnetic finite element model, and construct a magnetic field-circuit direct coupling model to obtain the winding phase current containing current harmonics. S2. Determine the first axial length of the end effect caused by the magnetic field distribution of the high-speed permanent magnet motor. And the second axial length of the end effect caused by eddy current distribution ; S3, based on the first axial length With the second axial length The larger value in the equation is used to construct a three-dimensional end model to characterize the three-dimensional electromagnetic properties of the motor end. S4. Construct a 2.5D equivalent model by coupling the end three-dimensional model and a middle two-dimensional model through symmetrical boundary conditions; wherein, the middle two-dimensional model is determined based on the two-dimensional transient electromagnetic finite element model of the high-speed permanent magnet motor; S5. Using the winding phase current containing current harmonics as excitation, calculate the first eddy current loss of the rotor in the end region and the second eddy current loss in the middle region using the 2.5D equivalent model. S6. Summing the first eddy current loss and the second eddy current loss, the total eddy current loss of the high-speed permanent magnet motor rotor is obtained.

2. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 1, characterized in that: In step S2, the first axial length is determined. The specific method is as follows: A three-dimensional static electromagnetic finite element model containing the stator core, armature winding, rotor sheath, permanent magnet, and rotor core is constructed. Based on this model, the distribution data of the radial air gap magnetic flux density along the motor axis is obtained. The first axial length is determined based on the length of the transition zone where the magnetic field strength decreases from the end to a stable value in the middle of the axial direction. .

3. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 2, characterized in that: In step S2, the second axial length is determined. The specific method is as follows: Based on the formula for calculating the skin depth of a conductor The calculation yielded, where The maximum skin depth of the rotor-induced eddy current. The resistivity of the rotor's conductive components. The lowest frequency of the asynchronous magnetic field acting on the rotor. ρ represents the permeability of the rotor's conductive components.

4. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 3, characterized in that: In step S3, the axial length of the end three-dimensional model Through formula It is determined that the three-dimensional model at the end is subject to symmetrical boundary conditions on the cross section away from the end of the motor winding.

5. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 4, characterized in that: The effective axial length of the central two-dimensional model in step S4 Satisfy the formula ,in This refers to the effective axial length of the high-speed permanent magnet motor. The axial length of the end three-dimensional model, the stack height of the two-dimensional transient electromagnetic finite element calculation model and the aforementioned equal.

6. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 5, characterized in that: When constructing the direct coupling model of the magnetic field and circuit in step S1, the simulation step size is... Based on the carrier frequency corresponding to the control strategy Set, and satisfy .

7. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 6, characterized in that: Step S4 further includes: applying the Fourier transform method to the winding phase current containing current harmonics. Perform spectrum analysis, where The waveform of the winding phase current in the time domain is shown. Angular frequency, The imaginary unit; identifies the target harmonic frequency that plays a major role in rotor eddy current losses. According to the formula Calculate the skin depth of the corresponding rotor conductive component. A refined skin effect mesh is constructed in the corresponding rotor conductive component, wherein the mesh size is... satisfy .

8. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 7, characterized in that: In step S5, the first eddy current loss is calculated using the three-dimensional transient finite element method based on the end three-dimensional model, and the second eddy current loss is calculated using the two-dimensional transient finite element method based on the middle two-dimensional model; the first eddy current loss With the second eddy current loss All are based on the integral formula of eddy current loss density. The calculation shows that, among which For electric field strength, For current density, To calculate the volume of the region.

9. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 8, characterized in that: In step S6, the total eddy current loss The calculation formula is ,in This is the first eddy current loss. This is the second eddy current loss.

10. The method for rapid calculation of 2.5D eddy current loss of a high-speed permanent magnet motor rotor as described in claim 1, characterized in that: The three-dimensional static electromagnetic finite element calculation model and the two-dimensional transient electromagnetic finite element calculation model use the same structural parameters, including stator core thickness, armature winding turns, rotor sheath thickness, permanent magnet size, and rotor core diameter.

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