Rotor permanent magnet synchronous motor resonance suppression method, electronic device, storage medium and program product

Abstract

The embodiment of the application provides a rotor permanent magnet synchronous motor resonance suppression method, electronic equipment, a storage medium and a program product, relates to the motor control technical field, and the method comprises the following steps: determining the rotor eccentric type and parameters according to the structure parameters and operation condition parameters of the permanent magnet synchronous motor, establishing corresponding air gap length functions and air gap permeance functions and calculating radial electromagnetic force waves, carrying out time-frequency joint decomposition on the radial electromagnetic force waves to obtain a target two-dimensional joint distribution, comparing and identifying a specific spatial order electromagnetic force wave component with a non-eccentric reference two-dimensional joint distribution, and adjusting motor control parameters to make the component time-frequency peak value deviate from the inherent modal frequency of the stator related structure. The application can accurately identify abnormal electromagnetic force waves induced by eccentricity, realize resonance suppression, and effectively reduce motor vibration noise.

Description

Technical Field

[0001] This application relates to the field of motor control technology, and in particular to a method for suppressing resonance in a rotor permanent magnet synchronous motor, electronic equipment, storage medium, and program product. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are prone to rotor eccentricity during actual operation. This eccentricity disrupts the uniformity of the air gap magnetic field, altering the distribution characteristics of radial electromagnetic force waves. Existing motor vibration and noise suppression technologies largely focus on uniform air gap operation, neglecting the impact of air gap permeability changes caused by rotor eccentricity. Under rotor eccentricity, the motor is prone to resonance amplification, resulting in persistently high vibration and noise levels. This not only affects the motor's operational stability but also shortens its overall lifespan, failing to meet the requirements for efficient and stable operation of PMSMs. Furthermore, related technologies face the problem of rotor eccentricity-induced resonance. Summary of the Invention

[0003] This application provides a method for suppressing resonance in a rotor permanent magnet synchronous motor, an electronic device, a storage medium, and a program product to alleviate or solve one or more technical problems existing in the prior art.

[0004] In a first aspect, embodiments of this application provide a method for suppressing resonance in a rotor permanent magnet synchronous motor, including: Based on the structural parameters and operating condition parameters of the permanent magnet synchronous motor to be analyzed, determine the rotor eccentricity type and rotor eccentricity parameters; Based on the basic model corresponding to the rotor eccentricity type and the rotor eccentricity parameters, establish the air gap length function and the air gap permeability function; The radial electromagnetic force wave is calculated based on the air gap length function and the air gap permeability function. The radial electromagnetic force wave is decomposed into spatial angle and time dimension using time-frequency joint decomposition to obtain the target two-dimensional joint distribution of the spatial order and time frequency of the radial electromagnetic force wave. The target two-dimensional joint distribution is compared with the reference two-dimensional joint distribution under the rotor uniform air gap state in order by order, and the electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity are identified according to the comparison results. Adjust the motor control parameters so that the peak time frequency of the electromagnetic force wave component at the specific spatial order deviates from the inherent mode frequency of the stator-related structure.

[0005] In some embodiments, calculating the radial electromagnetic force wave based on the air gap length function and the air gap permeability function includes: The air gap magnetic field expression is constructed based on the air gap length function and the air gap permeability function; Calculate the radial air gap magnetic flux density based on the aforementioned air gap magnetic field expression; The radial electromagnetic force wave is calculated based on the radial air gap magnetic flux density.

[0006] In some embodiments, identifying the electromagnetic force wave component of a specific spatial order introduced by rotor eccentricity based on the comparison results includes: In the target two-dimensional joint distribution, the electromagnetic force wave components corresponding to spatial orders that do not exist in the reference two-dimensional joint distribution, as well as the electromagnetic force wave components whose amplitudes are amplified by more than a preset multiple under the same spatial order, are determined to be electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity.

[0007] In some embodiments, the joint time-frequency decomposition of the radial electromagnetic force wave in terms of spatial angle and time dimension includes: Among the pre-established multiple air gap magnetic permeability models, a target air gap magnetic permeability model that matches the rotor eccentricity type is selected; the multiple air gap magnetic permeability models correspond to: rotor uniform air gap state, rotor static eccentricity state, rotor dynamic eccentricity state, and rotor mixed eccentricity state, respectively. Based on the target air gap magnetic permeability model and the magnetomotive force of the permanent magnet synchronous motor, the spatial order and time frequency of the radial electromagnetic force wave are decomposed using two-dimensional Fourier decomposition.

[0008] In some embodiments, the method further includes, prior to selecting a target air gap permeability model that matches the rotor eccentricity type: Establish the air gap length function related to the spatial position angle under the static eccentric state of the rotor; The reciprocal of the air gap length function is taken to obtain the inverse function of air gap length, and a series expansion is performed on the inverse function of air gap length; Extract the air gap magnetic permeability increment containing spatial orders ±1 and ±2 from the series expansion result to form the air gap magnetic permeability model corresponding to the rotor static eccentricity state.

[0009] In some embodiments, the method further includes, prior to selecting a target air gap permeability model that matches the rotor eccentricity type: Establish an air gap length function related to the spatial position angle and the rotor mechanical angular frequency under the rotor dynamic eccentricity state; The reciprocal of the air gap length function is taken to obtain the inverse function of air gap length, and a series expansion is performed on the inverse function of air gap length; Extract the air gap magnetic permeability increment containing spatial order ±1 and ±2 components and corresponding time frequency offset components from the series expansion result to form the air gap magnetic permeability model corresponding to the rotor dynamic eccentricity state.

[0010] In some embodiments, the method further includes, prior to selecting a target air gap permeability model that matches the rotor eccentricity type: Obtain the air gap permeability increment corresponding to the rotor static eccentricity state and the rotor dynamic eccentricity state respectively; The two types of air gap magnetic permeability increments are coupled and superimposed to obtain a comprehensive air gap magnetic permeability increment, forming the air gap magnetic permeability model corresponding to the rotor hybrid eccentric state.

[0011] Secondly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory, wherein the processor implements any of the methods of embodiments of this application when executing the computer program.

[0012] Thirdly, embodiments of this application provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method of any one of the embodiments of this application.

[0013] Fourthly, embodiments of this application provide a computer program product, including a computer program, which, when executed by a processor, implements any of the methods described in the embodiments of this application.

[0014] Based on any of the above technical solutions, this application has at least the following beneficial effects or advantages: This application embodiment determines rotor eccentricity-related parameters based on motor structure and operating condition parameters, builds a matching air gap model to complete radial electromagnetic force wave calculation, accurately identifies specific spatial order electromagnetic force wave components introduced by rotor eccentricity through time-frequency joint decomposition, and then adjusts motor control parameters to make the time frequency peak of this component deviate from the stator structure's inherent modal frequency. This can fundamentally avoid resonance problems caused by rotor eccentricity, effectively reduce motor vibration noise, improve the stability and reliability of motor operation, and adapt to resonance suppression scenarios under various rotor eccentricity conditions.

[0015] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0016] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments according to this application and should not be construed as limiting the scope of this application.

[0017] Figure 1A flowchart of a method for suppressing resonance in a rotor permanent magnet synchronous motor according to an embodiment of this application is shown; Figure 2 This illustration shows a schematic diagram of the air gap length calculation principle under different degrees of eccentricity in a rotor permanent magnet synchronous motor resonance suppression method provided in an embodiment of this application; Figure 3 This paper illustrates the spatial distribution of radial electromagnetic force waves under different degrees of eccentricity in a method for suppressing resonance in a rotor permanent magnet synchronous motor according to an embodiment of this application. Figure 4 This illustration shows a schematic diagram of two-dimensional Fourier decomposition results under different degrees of eccentricity in a resonance suppression method for a rotor permanent magnet synchronous motor provided in an embodiment of this application; Figure 5 This paper presents a schematic diagram illustrating the spatiotemporal characteristics of low-order electromagnetic force waves under different degrees of eccentricity in a resonance suppression method for a rotor permanent magnet synchronous motor provided in an embodiment of this application. Figure 6 This paper illustrates a three-dimensional finite element modal model of the stator-casing in a rotor permanent magnet synchronous motor resonance suppression method provided in an embodiment of this application. Figure 7 A schematic diagram of the vibration acceleration spectrum before implementing the method provided in the embodiments of this application is shown; Figure 8 A schematic diagram of the vibration acceleration spectrum after implementing the method provided in the embodiments of this application is shown; Figure 9 A block diagram of an electronic device provided in an embodiment of this application is shown. Detailed Implementation

[0018] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the concept or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0019] To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies of the embodiments of this application are described below. The following related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. It should be noted that the application scenarios or application examples provided in this application are for ease of understanding, and the embodiments of this application do not specifically limit the application of the technical solutions.

[0020] Current technologies do not consider rotor eccentricity: Under rotor eccentricity, electromagnetic force waves simultaneously expand and migrate in the "order-frequency" dimension due to air gap magnetic permeability modulation. Without an engineering-practical electromagnetic force wave analysis method and a resonance suppression strategy combined with structural modes, it is difficult to stably and predictably suppress electromagnetic vibrations and noise caused by eccentricity. Existing engineering measures for electromagnetic vibration and noise typically include structural stiffness / damping / modal frequency optimization, as well as harmonic suppression and force wave attenuation on the electromagnetic side.

[0021] This application proposes a sideband expansion law for the "spatial order-time frequency" of radial electromagnetic force waves for static / dynamic / hybrid eccentricity. This system can systematically identify newly added or amplified force wave components caused by eccentricity, avoiding the omission of resonance risk points due to relying solely on experience to identify a few spectral lines. This application is based on the electromagnetic vibration noise resonance mechanism: resonance requires not only that the spatial order of the electromagnetic force wave matches the stator mode order, but also that their time frequencies are similar. Furthermore, when the resonance condition is met, the larger the force wave amplitude, the stronger the vibration response. Therefore, this application establishes an analytical / identification process for the spatial order and time frequency of electromagnetic force waves under eccentricity conditions, and, combined with the inherent modal information of the motor, proposes a targeted "avoidance / amplitude reduction" strategy. This strategy aims to keep the key order electromagnetic force waves introduced or amplified by eccentricity away from the structure's natural frequency or reduce their amplitude, thereby suppressing resonance. Therefore, this application establishes an analytical / identification process for the spatial order and temporal frequency of electromagnetic force waves within the framework of the eccentricity mechanism, and combines the inherent modal information of the motor to specifically suppress force waves of specific orders that are prone to resonance, thereby reducing electromagnetic vibration and noise, and improving the NVH performance and operational reliability of the motor.

[0022] The technical solution of this application and how it solves the aforementioned technical problems are described in detail below with specific embodiments. The listed specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0023] See Figure 1 The flowchart shown is a method for suppressing resonance in a rotor permanent magnet synchronous motor. The method specifically includes steps 101 to 106.

[0024] Step 101: Determine the rotor eccentricity type and rotor eccentricity parameters based on the structural parameters and operating condition parameters of the permanent magnet synchronous motor to be analyzed. Step 102: Based on the basic model and rotor eccentricity parameters corresponding to the rotor eccentricity type, establish the air gap length function and the air gap permeability function; Step 103: Calculate the radial electromagnetic force wave based on the air gap length function and the air gap permeability function; Step 104: Perform time-frequency joint decomposition of the radial electromagnetic force wave in terms of spatial angle and time dimension to obtain the target two-dimensional joint distribution of the spatial order and time frequency of the radial electromagnetic force wave. Step 105: Compare the target two-dimensional joint distribution with the reference two-dimensional joint distribution under the rotor uniform air gap state step by step, and identify the electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity based on the comparison results. Step 106: Adjust the motor control parameters so that the peak time frequency of the electromagnetic force wave component at a specific spatial order deviates from the inherent mode frequency of the stator related structure.

[0025] Structural parameters include, but are not limited to, fixed physical parameters such as stator core dimensions, rotor pole pairs, permanent magnet thickness, and core lamination thickness. Operating parameters include, but are not limited to, real-time operating parameters such as steady-state operating speed, load output torque, and stator winding operating current. Based on these two types of parameters, the actual rotor eccentricity of the motor can be comprehensively determined, and eccentricity-related parameters such as eccentricity offset and eccentricity azimuth angle can be quantitatively determined. Rotor eccentricity parameters include, but are not limited to, eccentricity amount and eccentricity direction angle. By matching the corresponding physical modeling framework according to the rotor eccentricity category and substituting the determined rotor eccentricity parameters, a function can be constructed to characterize the actual length of the air gap and the variation of magnetic permeability at various points around the motor circumference.

[0026] Based on the constructed air gap length function and air gap permeability function, the associated physical quantities of the magnetic field can be simultaneously deduced, and the radial electromagnetic force wave during motor operation can be obtained step by step. The radial electromagnetic force wave is simultaneously decomposed from both spatial circumferential angle and temporal variation dimensions, allowing for the extraction of the corresponding two-dimensional distribution patterns of spatial order and temporal frequency. Next, pre-calibrated baseline distribution data under the condition of a rotor without eccentricity and with uniform air gap is retrieved, and feature comparisons are performed at each order to screen out specific spatial order electromagnetic force wave components caused solely by rotor eccentricity. By modifying the relevant operating parameters of the motor control, the frequency peak position of the target electromagnetic force wave component is changed, moving it away from the inherent modal vibration frequencies of the stator and its supporting structures.

[0027] Optionally, the reference two-dimensional joint distribution under the uniform air gap state of the rotor is the spatiotemporal decomposition result of the radial electromagnetic force wave obtained in advance through simulation or experiment under the uniform air gap state of the rotor. The stator-related structure can be the stator body or a combination structure of the stator and the housing. Optionally, the natural modal frequencies of the stator-related structure can be obtained in advance through finite element modal simulation or impact test. For example, the motor control parameters may include at least one of the following: the frequency of the pulsating high-frequency injection signal, the amplitude of the pulsating high-frequency injection signal, and the PWM switching frequency.

[0028] This application embodiment determines rotor eccentricity-related parameters based on motor structure and operating condition parameters, builds a matching air gap model to complete radial electromagnetic force wave calculation, accurately identifies specific spatial order electromagnetic force wave components introduced by rotor eccentricity through time-frequency joint decomposition, and then adjusts motor control parameters to make the time frequency peak of this component deviate from the stator structure's inherent modal frequency. This can fundamentally avoid resonance problems caused by rotor eccentricity, effectively reduce motor vibration noise, improve the stability and reliability of motor operation, and adapt to resonance suppression scenarios under various rotor eccentricity conditions.

[0029] In some implementations, the radial electromagnetic force wave is calculated based on the air gap length function and the air gap permeability function, including: The expression for the air gap magnetic field is constructed based on the air gap length function and the air gap permeability function; Calculate radial air gap magnetic flux density based on the air gap magnetic field expression; The radial electromagnetic force wave is obtained by calculating the radial air gap magnetic flux density.

[0030] Based on the established air gap length function and air gap permeability function, and combined with the magnetic field coupling relationship between the permanent magnet excitation and armature excitation of the motor, an expression for the air gap magnetic field can be constructed. This expression characterizes the distribution law of the magnetic field inside the motor's air gap. The component of the air gap magnetic field along the radial direction of the motor is the key research object for vibration and noise analysis. Based on the constructed air gap magnetic field expression, numerical and analytical solutions are performed, and the radial air gap magnetic flux density at each position on the motor circumference is calculated point by point. Radial air gap magnetic flux density is a fundamental physical quantity for solving electromagnetic force waves. Utilizing the spatial and temporal variation characteristics of the air gap magnetic flux density, combined with the electromagnetic field stress transmission law, the force state at each position on the circumference is integrally deduced, and after layer-by-layer conversion and integration, the radial electromagnetic force wave distribution over the entire domain is obtained.

[0031] This application embodiment establishes the calculation relationship between magnetic field, magnetic flux density and electromagnetic force wave, determines the solution process of intermediate physical quantities, and improves the accuracy and physical fit of radial electromagnetic force wave calculation results.

[0032] In some implementations, identifying electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity based on comparison results includes: in the target two-dimensional joint distribution, determining electromagnetic force wave components corresponding to spatial orders that do not exist in the reference two-dimensional joint distribution, as well as electromagnetic force wave components whose amplitude is amplified by more than a preset multiple under the same spatial order, as electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity.

[0033] The target two-dimensional joint distribution is the feature dataset after electromagnetic force wave decomposition under the current eccentric operating condition, while the reference two-dimensional joint distribution is the standard feature dataset calibrated under the condition of a completely eccentric rotor with a uniform air gap. The order-by-order comparison process uses spatial order as the matching benchmark, comparing the amplitude and frequency characteristics corresponding to each order one by one. Some spatial orders only appear under the rotor eccentric operating condition, and there are no corresponding feature components in the standard benchmark distribution; these newly appearing order components are directly identified as eccentrically introduced components. Some spatial orders originally existed under the benchmark operating condition but had low amplitudes; the eccentric effect changes the air gap magnetic permeability modulation characteristics, causing a significant increase in the amplitude of components of the same order. Optionally, the aforementioned preset multiple can be preset according to the noise limit or vibration performance index of the permanent magnet synchronous motor; amplitude components of the same order exceeding the set threshold are determined to be within the specific spatial order component range introduced by eccentricity.

[0034] This application's embodiments distinguish between two types of abnormal components: newly added order and amplitude amplification. By setting quantitative discrimination criteria, the identification process of eccentric related electromagnetic force wave components becomes more objective and accurate, and has a unified judgment basis.

[0035] In some implementations, the radial electromagnetic force wave is decomposed into spatial angle and time dimension using a time-frequency joint decomposition, including: selecting a target air gap magnetic permeability model that matches the rotor eccentricity type from multiple pre-established air gap magnetic permeability models; the multiple air gap magnetic permeability models correspond to: rotor uniform air gap state, rotor static eccentricity state, rotor dynamic eccentricity state, and rotor mixed eccentricity state, respectively; and using two-dimensional Fourier decomposition of the spatial order and time frequency of the radial electromagnetic force wave based on the target air gap magnetic permeability model and the magnetomotive force of the permanent magnet synchronous motor.

[0036] The air gap magnetic permeability model is a standardized mathematical model built separately for different eccentric states. In this application embodiment, four types of operating condition models are pre-constructed and stored, covering all eccentric forms of normal motor operation. Based on the rotor eccentricity type, a single model matching the operating condition is selected from the pre-stored models as the calculation benchmark. The motor magnetomotive force includes two types: the permanent magnet magnetomotive force generated by the permanent magnet itself and the armature magnetomotive force generated by the stator winding energization. Both types of magnetomotive forces serve as the magnetic field excitation source in the electromagnetic force wave analysis. Two-dimensional Fourier decomposition can decompose the spatiotemporal features. Based on the matched air gap magnetic permeability model and combined with the magnetomotive force excitation conditions, the radial electromagnetic force wave is decomposed globally, separating and analyzing independent spatial order parameters and corresponding time frequency parameters. This provides standardized data for subsequent feature comparison, ensuring the reliability of subsequent comparison and identification.

[0037] In some implementations, before selecting a target air gap permeability model that matches the rotor eccentricity type, the method further includes: establishing an air gap length function related to the spatial position angle under the rotor static eccentricity state; taking the reciprocal of the air gap length function to obtain an inverse air gap length function, and performing a series expansion on the inverse air gap length function; extracting air gap permeability increments containing spatial orders of ±1 and ±2 from the series expansion results to form an air gap permeability model corresponding to the rotor static eccentricity state.

[0038] Under static eccentricity, the rotor's geometric center is fixedly offset from the stator's geometric center, exhibiting no periodic rotational change. The air gap length function is only related to the spatial position angle of the motor's circumference and does not change with time. Using the stator's inner circumference as a coordinate reference, a globally continuously distributed air gap length solution function is established, which can characterize the actual size of the air gap at various points under static eccentricity. The air gap permeability is inversely proportional to the air gap length; therefore, taking the reciprocal of the constructed air gap length function yields the corresponding reciprocal air gap length function.

[0039] For example, the above series expansion can be a Fourier series expansion. The inverse function is subjected to a Fourier series expansion, decomposing the continuous function into a superposition of multiple harmonic components. Characteristic components with spatial orders of ±1 and ±2 after the series expansion are selected and extracted. Irrelevant higher-order components are removed. The selected characteristic components are used to construct an incremental expression, forming an air gap permeability model adapted to the static eccentricity condition.

[0040] This application embodiment constructs the air gap variation law corresponding to static eccentricity, filters key order components based on series expansion, eliminates redundant information in the model, and balances the modeling accuracy and computational efficiency of the static eccentric magnetic permeability model.

[0041] In some implementations, before selecting a target air gap permeability model that matches the rotor eccentricity type, the method further includes: establishing an air gap length function related to the spatial position angle and the rotor mechanical angular frequency under the rotor dynamic eccentricity state; taking the reciprocal of the air gap length function to obtain the air gap length inverse function, and performing a series expansion on the air gap length inverse function; extracting the air gap permeability increment containing spatial order ±1, ±2 components and corresponding time frequency offset components from the series expansion result to form an air gap permeability model corresponding to the rotor dynamic eccentricity state.

[0042] Under dynamic eccentricity, the rotor offset center undergoes periodic circular motion as the rotor rotates. The air gap length not only changes with the spatial position angle but is also synchronously correlated with the rotor's mechanical angular frequency, exhibiting periodic time-varying characteristics. Combining spatial coordinates and rotor rotational angular velocity parameters, a bivariate coupled air gap length function is established to characterize the air gap value at any time and any circular position in real time. Taking the reciprocal of the air gap length function yields the inverse air gap length function, which is then subjected to series expansion to decompose multi-dimensional harmonic components. In addition to fixed spatial order components, dynamic eccentricity also generates time-frequency shift characteristics due to rotation. From the expansion results, ±1 and ±2 spatial order components, along with corresponding frequency shift components, are extracted simultaneously. Combining these two types of features forms the air gap permeability increment, constructing an air gap permeability model adapted to the dynamic eccentricity condition.

[0043] The embodiments of this application take into account the dual changes in spatial position and rotor rotation, and simultaneously extract the order and frequency offset components, which can more accurately characterize the time-varying modulation characteristics of magnetic permeability under dynamic eccentricity.

[0044] In some implementations, before selecting a target air gap permeability model that matches the rotor eccentricity type, the method further includes: obtaining the air gap permeability increments corresponding to the rotor static eccentricity state and the rotor dynamic eccentricity state respectively; coupling and superimposing the two types of air gap permeability increments to obtain a comprehensive air gap permeability increment, forming an air gap permeability model corresponding to the rotor mixed eccentricity state.

[0045] Rotor hybrid eccentricity is a complex operating condition where static and dynamic eccentricity coexist. A single model cannot fully characterize the variation law of the composite air gap permeability, so it is necessary to construct a model by combining two basic eccentricity models. The pre-solved air gap permeability increments for static and dynamic eccentricity of the rotor can be retrieved separately. According to the principle of electromagnetic field superposition, the two types of permeability increments are coupled and superimposed. The air gap permeability model corresponding to the rotor hybrid eccentricity state constructed in this embodiment retains the original characteristic components of static and dynamic eccentricity, and can accurately match the complex operating conditions of actual motor hybrid eccentricity.

[0046] In some implementations, after adjusting the motor control parameters, the vibration acceleration spectrum of the motor can be obtained again to verify whether the amplitude of the electromagnetic force wave component at a specific spatial order has decreased.

[0047] The following is in conjunction with the appendix Figures 2-8 The embodiments of this application will be further described.

[0048] Taking an 8-pole, 36-slot permanent magnet motor as an example, this paper presents an engineering-applicable method for electromagnetic force wave analysis and resonance suppression through the link modeling and verification of "rotor eccentricity-electromagnetic force wave-modal resonance" to reduce electromagnetic vibration and noise (NVH) induced by rotor eccentricity. The analytical approach of this embodiment is consistent with the basic understanding that "electromagnetic force wave-modal frequency coupling determines whether resonance occurs": the spatial order and temporal frequency of the electromagnetic force wave determine its excitation characteristics on the stator structure, and lower orders (such as 0th order, 2nd order, etc.) are more likely to couple with structural modes, causing significant vibration and noise.

[0049] Figure 2 The top left, top right, bottom left, and bottom right images represent the following scenarios: uniform air gap (i.e., rotor without eccentricity), static rotor eccentricity, dynamic rotor eccentricity, and mixed rotor eccentricity, respectively. Figure 2 In the diagram, Os is the stator geometric center, Or is the rotor geometric center, Or0 is the rotor rotation center or static eccentric position, and Or1 is the instantaneous position of the rotor geometric center under dynamic / hybrid eccentricity; R is the stator inner diameter, r is the rotor outer diameter, δ0 is the uniform air gap length, δ(θ) is the air gap length under static eccentricity, and δ(θ,t) is the air gap length under dynamic or hybrid eccentricity; θ is the mechanical angle in the stator coordinate system, and ωt is the mechanical angle rotated by the rotor, where ω is the mechanical angular velocity and t is time.

[0050] The PMSM air gap length calculation model is established in the stator coordinate system. The air gap length when the rotor is not eccentric is a constant value δ0, and the air gap permeability λs(θ,t) is as follows:

[0051] In the above formula, For the DC / constant component of the uniform air gap permeability, denoted as the fundamental value of the air gap permeability. In a uniform air gap with high permeability, the first The amplitude of the second slotted harmonic component, =1,2,3…, where… It is the order of magnetic permeability harmonics caused by stator slotting. It is the number of stator slots in the motor, used to describe the spatial harmonic distribution caused by the slotting. It is a mechanical angle (spatial position angle) in the stator coordinate system, describing the position in the circumferential direction. When the motor rotor has static eccentricity, the air gap length at different positions in the air gap is only related to the position angle θ, and the air gap permeability λ(θ,t) can be regarded as a function of the position angle θ; while when dynamic eccentricity occurs, the air gap permeability is a two-dimensional function λ(θ,t) of position θ and time t, so static eccentricity can be regarded as a special case of dynamic eccentricity (i.e., t=0 in the air gap permeability function of dynamic eccentricity); when the motor rotor has mixed eccentricity, it will have the characteristics of both static and dynamic eccentricity.

[0052] In a normal motor with a uniform air gap, the stator geometric center Os coincides with the rotor geometric center Or, and the rotor rotation center is also Or. δ0 is the uniform air gap length of the normal motor, R is the stator inner diameter, r is the rotor outer diameter, θ is the mechanical angle, and ωm is the mechanical angular velocity. Considering the slotted stator, the air gap permeability λs(θ,t) of the uniform air gap can be obtained from the following formula:

[0053] After setting the eccentric geometric parameters, based on the spacetime harmonic interaction mechanism of the air gap magnetic field (the analytical expression of the air gap magnetic flux density can be obtained using the magnetomotive force-permeability method, and the radial electromagnetic force wave can be obtained further using the Maxwell stress tensor), the working conditions of uniform air gap / static eccentricity / dynamic eccentricity / mixed eccentricity are compared to obtain the spatial distribution differences of the radial electromagnetic force wave. This process clearly shows that eccentricity introduces additional permeability harmonics and magnetic flux density sideband components, which are manifested as new spatial orders and frequency components in the radial force wave. Figure 3 The spatial distribution of radial electromagnetic force waves under different degrees of eccentricity is given to visually demonstrate the force wave distortion and asymmetric enhancement caused by eccentricity.

[0054] To be Figure 3 To decouple the "overlapping" force wave information, this embodiment performs two-dimensional Fourier decomposition (spatial order-time frequency two-dimensional spectrum) on the radial electromagnetic force wave to obtain the spatial order and time frequency distribution of each electromagnetic force wave component. This method is also a commonly used approach for analyzing the spatiotemporal characteristics of electromagnetic force waves. It can be used to identify "which spatial orders and which frequencies" are significantly enhanced after eccentricity, thereby identifying potential resonance risk components. Figure 4 The diagram shows the two-dimensional Fourier decomposition results of radial electromagnetic force waves: the horizontal and vertical axes correspond to the spatial order and time frequency (or their equivalent expressions), respectively, and the position of the spectral peak corresponds to the force wave component of a certain order / frequency.

[0055] Considering that low-order radial force waves (such as 0th and 2nd order) are most likely to induce strong structural responses in engineering, the spatiotemporal characteristics of low-order force waves are further extracted based on the two-dimensional spectrum to obtain their dominant frequency trajectory and amplitude variation trend with rotational speed and eccentricity, which is used to establish a "resonance risk map". The reason why low-order force waves are critical is that they are more likely to couple with the low-order modes of the stator system and amplify vibration and noise. Figure 5 The spatiotemporal characteristics of low-order electromagnetic force waves are demonstrated, including the variation of their main time frequencies with operating conditions and the corresponding spatial order characteristics.

[0056] The table below lists the amplitudes of electromagnetic force wave components of orders 0, 4, and 8 under different eccentricities of the motor. It can be observed that with rotor eccentricity, the amplitudes of electromagnetic force waves of relevant orders increase or change to some extent, which may lead to resonance and thus exacerbate motor vibration noise. Furthermore, theoretical derivation and finite element simulation show that under different eccentricities, the newly introduced sideband electromagnetic force wave components exhibit spectral shifts in both spatial order and temporal frequency compared to the original orders of electromagnetic force waves, potentially triggering resonances near more modal orders and thus generating greater vibration noise.

[0057]

[0058] Table 1. Comparison of the amplitudes of the 0th order electromagnetic force wave and the related order of the number of pole pairs p under different eccentric conditions when the motor is powered by a sinusoidal wave. On the structural side, to accurately assess resonance conditions, it is necessary to obtain the natural modal frequencies of the motor stator system. Since the actual motor stator is tightly coupled to the outer casing, the modal calculations should consider the casing's influence. Therefore, this embodiment establishes the following... Figure 6 The stator-casing three-dimensional finite element modal model shown is used to calculate the modal frequencies of the stator-casing system (and compare it with the stator-only model to show that casing coupling changes the modal frequency distribution). The natural mode shapes and corresponding frequencies of the permanent magnet synchronous motor stator-casing system can be obtained through modal calculations, as shown in the table below.

[0059]

[0060] Table 2. Stator natural mode frequencies of permanent magnet synchronous motors When the time frequency of a certain low-order radial electromagnetic force wave component approaches or crosses a certain natural mode frequency in a specific rotational speed range, it is determined that there is a significant risk of resonance in that rotational speed range (the probability of strong vibration / strong noise increases).

[0061] To address the aforementioned resonance risk, embodiments of this application provide two types of suppression methods that can be used individually or in combination: Based on the relationship between force wave frequency and rotational speed, we plan and avoid resonance-sensitive speed zones (e.g., rapidly crossing these zones during start-stop / acceleration, or avoiding prolonged stops near these speeds during steady-state operation). This approach is consistent with the experimental phenomenon that "the peak vibration noise at different speeds increases significantly near the force wave frequency mode."

[0062] By altering the equivalent stiffness / mass distribution of the stator-casing system (e.g., casing thickness, stiffeners, end cap structure, assembly pre-tightening, etc.), the target modal natural frequencies can be shifted upwards or downwards, thereby creating a gap between the dominant frequency of the "newly introduced eccentric force wave" and the natural modal frequencies. The very fact that modal calculations are performed using casing-coupled modeling demonstrates that the casing significantly influences the modal frequencies, thus providing a clear and effective basis for structural parameter tuning.

[0063] Figure 7 The diagram shows the vibration acceleration spectra of the motor's driven end (DE) and non-driven end (HE) before resonance suppression. Figure 8 This diagram illustrates the vibration acceleration spectra of the driving and non-driving ends of a rotor permanent magnet synchronous motor after implementing the resonance suppression method provided in this application. The vibration at the driving end is predominantly low-frequency mechanical vibration, with weaker mid-to-high-frequency electromagnetic vibration. The vibration at the non-driving end is mainly mid-to-high-frequency electromagnetic vibration, especially the vibration caused by high-frequency electromagnetic force waves. According to... Figure 7 and Figure 8 The comparison shows that, under the same degree of eccentricity and load / operating conditions, after adopting resonant speed planning and / or structural mode adjustment, the vibration acceleration and noise spectrum peaks in the target frequency band are significantly reduced, thereby effectively suppressing electromagnetic vibration noise induced by rotor eccentricity.

[0064] The method provided in this application addresses the problem of radial electromagnetic force wave sideband proliferation and resonance amplification caused by coupling with the inherent modes of the motor structure when the rotor has static eccentricity, dynamic eccentricity, or mixed eccentricity. It obtains the structural parameters and operating condition parameters of the permanent magnet motor to be analyzed, determines the rotor eccentricity type and eccentricity parameters, and establishes an air gap length function based on the eccentricity parameters. and air gap permeability function Construct an expression for the air gap magnetic field and calculate the radial air gap magnetic flux density. Furthermore, radial electromagnetic pressure or radial electromagnetic force wave can be obtained based on Maxwell's stress method. And further, the radial electromagnetic force wave Two-dimensional Fourier decomposition of spatial angle and time is performed to obtain the spatial order and temporal frequency distribution of electromagnetic force waves. Specific order electromagnetic force wave components introduced or significantly amplified by rotor eccentricity are identified, thereby establishing a modal model of the stator or stator-casing system and obtaining the natural modal frequencies and orders. Next, the specific order electromagnetic force wave components are matched with the natural modes for order matching and frequency proximity determination to identify the electromagnetic force wave components at risk of resonance and their corresponding risk operating ranges. For these components, at least one resonance suppression measure is adopted to make the temporal frequency of the electromagnetic force wave components move away from the motor's natural modal frequency range or reduce their amplitude, thereby suppressing resonance and reducing electromagnetic vibration and noise.

[0065] The aforementioned permanent magnet motors include, but are not limited to, built-in permanent magnet motors, surface-mounted permanent magnet motors, permanent magnet synchronous motors, or permanent magnet generators. Rotor eccentricity types include static eccentricity, dynamic eccentricity, and hybrid eccentricity; wherein the eccentricity direction of static eccentricity is fixed in the stator coordinate system, the eccentricity direction of dynamic eccentricity rotates with the rotor, and hybrid eccentricity includes both static and dynamic eccentricity components.

[0066] Furthermore, low-order components can be screened from the two-dimensional spectrum, and these low-order components include, but are not limited to, spatial order. The electromagnetic force wave components were identified, and the dominant frequency trajectory of their amplitude variation with operating conditions was extracted to construct a resonance risk map.

[0067] In some implementations, resonance suppression measures include measures to reduce eccentricity excitation, which include, but are not limited to: assembly correction, bearing maintenance or replacement, shaft straightening, rotor dynamic balancing and concentricity adjustment, in order to reduce eccentricity and weaken the amplitude of the sideband electromagnetic force wave caused by eccentricity.

[0068] In some other embodiments, resonance suppression measures include operating condition avoidance measures, which are resonance risk operating condition intervals. These risk intervals are avoided in the equipment operation plan or the dwell time in the risk intervals is shortened, thereby reducing the probability of continuous resonance.

[0069] Compared with existing technologies, this application proposes a sideband expansion law of "spatial order-time frequency" for radial electromagnetic force waves under static / dynamic / hybrid eccentricity. This system can systematically identify newly added or amplified force wave components caused by eccentricity, avoiding the omission of resonance risk points by relying solely on experience to lock in a few spectral lines. By matching "force wave order + frequency" with "modal order + natural frequency," it meets the necessary conditions for resonance, enabling rapid location of high-risk resonance points and generating executable avoidance / frequency shifting / amplitude reduction schemes. Furthermore, this application prioritizes and suppresses key components that may exhibit low-order and high-amplitude force wave components under eccentricity and load, inducing resonance at zero-order, fourth-order, and other modes, significantly reducing electromagnetic vibration and noise peaks.

[0070] Figure 9 This is a block diagram of an electronic device used to implement embodiments of this application. For example... Figure 9 As shown, the electronic device includes a memory 901 and a processor 902. The memory 901 stores a computer program that can run on the processor 902. When the processor 902 executes the computer program, it implements the method described in the above embodiments. The number of memories 901 and processors 902 can be one or more. In a specific implementation, the electronic device may also include a communication interface 903 for communicating with external devices and exchanging data.

[0071] In practical implementation, if the memory 901, processor 902, and communication interface 903 are implemented independently, they can be interconnected via a bus to communicate with each other. This bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 9 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0072] Optionally, in a specific implementation, if the memory 901, processor 902, and communication interface 903 are integrated on a single chip, then the memory 901, processor 902, and communication interface 903 can communicate with each other through an internal interface.

[0073] This application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method provided in this application.

[0074] This application provides a computer program product, including a computer program that, when executed by a processor, implements the method provided in this application.

[0075] This application also provides a chip including a processor for calling and executing instructions stored in a memory, causing a communication device with the chip installed to perform the method provided in this application.

[0076] This application also provides a chip, including: an input interface, an output interface, a processor, and a memory. The input interface, output interface, processor, and memory are connected through an internal connection path. The processor is used to execute code in the memory. When the code is executed, the processor is used to execute the method provided in the application embodiment.

[0077] It should be understood that the aforementioned processor can be a CPU (Central Processing Unit), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors can be microprocessors or any conventional processor. It is worth noting that the processor can be a processor supporting Advanced Reduced Instruction Set Machines (ARM) architecture.

[0078] Further, optionally, the aforementioned memory may include read-only memory and random access memory. The memory may be volatile memory or non-volatile memory, or may include both. Non-volatile memory may include read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available. Examples include Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Sync Link DRAM (SLDRAM), and Direct Rambus RAM (DR RAM).

[0079] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another.

[0080] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0082] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process. Furthermore, the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functionality involved.

[0083] The logic and / or steps described in the flowchart or otherwise herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer-based system, a processor-included system or other system that can fetch and execute instructions from, an instruction execution system, apparatus or device).

[0084] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. All or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware, the program being stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiments.

[0085] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. This storage medium can be a read-only memory, a disk, or an optical disk, etc.

[0086] The above description is merely an exemplary embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope described in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for suppressing resonance in a rotor permanent magnet synchronous motor, characterized in that, include: Based on the structural parameters and operating condition parameters of the permanent magnet synchronous motor to be analyzed, determine the rotor eccentricity type and rotor eccentricity parameters; Based on the basic model corresponding to the rotor eccentricity type and the rotor eccentricity parameters, establish the air gap length function and the air gap permeability function; The radial electromagnetic force wave is calculated based on the air gap length function and the air gap permeability function. The radial electromagnetic force wave is decomposed into spatial angle and time dimension using time-frequency joint decomposition to obtain the target two-dimensional joint distribution of the spatial order and time frequency of the radial electromagnetic force wave. The target two-dimensional joint distribution is compared with the reference two-dimensional joint distribution under the rotor uniform air gap state in order by order, and the electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity are identified according to the comparison results. Adjust the motor control parameters so that the peak time frequency of the electromagnetic force wave component at the specific spatial order deviates from the inherent mode frequency of the stator-related structure.

2. The method according to claim 1, characterized in that, The calculation of the radial electromagnetic force wave based on the air gap length function and the air gap permeability function includes: The air gap magnetic field expression is constructed based on the air gap length function and the air gap permeability function; Calculate the radial air gap magnetic flux density based on the aforementioned air gap magnetic field expression; The radial electromagnetic force wave is calculated based on the radial air gap magnetic flux density.

3. The method according to claim 1, characterized in that, The step of identifying the electromagnetic force wave component of a specific spatial order introduced by rotor eccentricity based on the comparison results includes: In the target two-dimensional joint distribution, the electromagnetic force wave components corresponding to spatial orders that do not exist in the reference two-dimensional joint distribution, as well as the electromagnetic force wave components whose amplitudes are amplified by more than a preset multiple under the same spatial order, are determined to be electromagnetic force wave components of a specific spatial order introduced by rotor eccentricity.

4. The method according to claim 1, characterized in that, The time-frequency joint decomposition of the radial electromagnetic force wave in terms of spatial angle and time dimension includes: Among the pre-established multiple air gap magnetic permeability models, a target air gap magnetic permeability model that matches the rotor eccentricity type is selected; the multiple air gap magnetic permeability models correspond to: rotor uniform air gap state, rotor static eccentricity state, rotor dynamic eccentricity state, and rotor mixed eccentricity state, respectively. Based on the target air gap magnetic permeability model and the magnetomotive force of the permanent magnet synchronous motor, the spatial order and time frequency of the radial electromagnetic force wave are decomposed using two-dimensional Fourier decomposition.

5. The method according to claim 4, characterized in that, Before selecting a target air gap permeability model that matches the rotor eccentricity type, the method further includes: Establish the air gap length function related to the spatial position angle under the static eccentric state of the rotor; The reciprocal of the air gap length function is taken to obtain the inverse function of air gap length, and a series expansion is performed on the inverse function of air gap length; Extract the air gap magnetic permeability increment containing spatial orders ±1 and ±2 from the series expansion result to form the air gap magnetic permeability model corresponding to the rotor static eccentricity state.

6. The method according to claim 4, characterized in that, Before selecting a target air gap permeability model that matches the rotor eccentricity type, the method further includes: Establish an air gap length function related to the spatial position angle and the rotor mechanical angular frequency under the rotor dynamic eccentricity state; The reciprocal of the air gap length function is taken to obtain the inverse function of air gap length, and a series expansion is performed on the inverse function of air gap length; Extract the air gap magnetic permeability increment containing spatial order ±1 and ±2 components and corresponding time frequency offset components from the series expansion result to form the air gap magnetic permeability model corresponding to the rotor dynamic eccentricity state.

7. The method according to claim 4, characterized in that, Before selecting a target air gap permeability model that matches the rotor eccentricity type, the method further includes: Obtain the air gap permeability increment corresponding to the rotor static eccentricity state and the rotor dynamic eccentricity state respectively; The two types of air gap magnetic permeability increments are coupled and superimposed to obtain a comprehensive air gap magnetic permeability increment, forming the air gap magnetic permeability model corresponding to the rotor hybrid eccentric state.

8. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory, wherein the processor, when executing the computer program, implements the method of any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1-7.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method according to any one of claims 1-7.

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