A motor rotor modal analysis method, device, equipment and storage medium

Abstract

Embodiments of the present application disclose a motor rotor modal analysis method, device, equipment and storage medium, wherein the motor rotor modal analysis method comprises: determining an equivalent elastic modulus of a rotor system based on a preset beam element bending model; the beam element model represents a mapping relationship between the equivalent elastic modulus of the rotor system and respective elastic moduli and inertia moments of different components of the rotor system; calculating based on the equivalent elastic modulus to determine a natural frequency and a vibration mode of the rotor system; and analyzing a mode of the rotor system based on the natural frequency and the vibration mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical dynamics, and in particular to a motor rotor modal analysis method, device, equipment and storage medium. BACKGROUND

[0002] High-speed permanent magnet motors are favored in the fields of high-speed machine tools, flywheel batteries and new energy vehicle electric drive systems due to a series of advantages such as high power density, high operating efficiency and wide speed regulation range. High-speed motor rotors are usually slender, and the likelihood of approaching the critical speed is greatly increased compared to normal-speed motors. When the rated speed of the motor approaches the critical speed, the rotor will vibrate violently, and in severe cases, the rotor will be damaged, endangering the safe operation of the motor. Therefore, it is necessary to accurately analyze the modal characteristics of the high-speed permanent magnet motor rotor.

[0003] Currently, the average value method and the finite element software analysis method are used to calculate the equivalent elastic modulus of the rotor structure as a whole. However, the average value method is simple to calculate, but it is difficult to fully consider the influence of the mechanical properties and geometric properties of different materials in the same cross section on the equivalent elastic modulus of the rotor structure, resulting in large modeling errors of rotor dynamics. The calculation steps of the finite element software analysis method are many, and the solving process is complex. Moreover, when the cross-sectional shapes of the rotor structure are different, the equivalent elastic modulus of each section of the rotor structure with different cross-sectional shapes must be calculated multiple times, which is a large amount of calculation work. SUMMARY

[0004] Embodiments of the present application aim to provide a motor rotor modal analysis method, device, equipment and storage medium.

[0005] The technical solution of the present application is implemented as follows:

[0006] An embodiment of the first aspect of the present application provides a motor rotor modal analysis method, comprising:

[0007] Based on a preset beam element bending model, the equivalent elastic modulus of the rotor system is determined; the beam element model represents the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system;

[0008] Based on the equivalent elastic modulus, the natural frequency and mode shape of the rotor system are determined by calculation;

[0009] Based on the natural frequency and the mode shape, the modal of the rotor system is analyzed.

[0010] Optionally, the equivalent elastic modulus of the rotor system is determined based on the preset beam element bending model, comprising:

[0011] obtaining a first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of at least two components of the rotor system;

[0012] reasoning the first mapping relationship by using inductive method, to determine a mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of a plurality of different components of the rotor system.

[0013] Optionally, the obtaining of the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of at least two components of the rotor system comprises:

[0014] establishing a first equation set based on the deflection of the rotor system and the at least two components of the rotor system at a free end;

[0015] determining the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of the at least two components of the rotor system based on the first equation set and the superposition theorem of the moment of inertia.

[0016] Optionally, the calculating based on the equivalent elastic modulus to determine the natural frequency and the mode shape of the rotor system comprises:

[0017] establishing a mathematical model of the rotor system and determining a dynamic equation corresponding to the mathematical model;

[0018] calculating based on the equivalent elastic modulus and the dynamic equation to determine the natural frequency and the mode shape of the rotor system.

[0019] Embodiments of the second aspect of the application provide a motor rotor modal analysis device, comprising:

[0020] a first determining module configured to determine an equivalent elastic modulus of a rotor system based on a preset beam element bending model; the beam element model represents a mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of different components of the rotor system;

[0021] a second determining module configured to calculate based on the equivalent elastic modulus to determine a natural frequency and a mode shape of the rotor system;

[0022] an analysis module configured to analyze a mode of the rotor system based on the natural frequency and the mode shape.

[0023] Optionally, the first determining module is specifically configured to:

[0024] obtain a first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of at least two components of the rotor system;

[0025] The first mapping relationship is inferred by using inductive method, and a mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and inertia moment of each of a plurality of different components of the rotor system is determined.

[0026] Optionally, the first determining module is specifically configured to:

[0027] A first equation set is established based on the deflection of the rotor system and at least two components of the rotor system at a free end;

[0028] A first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and inertia moment of each of at least two components of the rotor system is determined based on the first equation set and an inertia moment superposition theorem.

[0029] Optionally, the second determining module is specifically configured to:

[0030] A mathematical model of the rotor system is established, and a dynamic equation corresponding to the mathematical model is determined;

[0031] The natural frequency and mode shape of the rotor system are determined by performing calculation based on the equivalent elastic modulus and the dynamic equation.

[0032] Embodiments of the third aspect of the present application provide an electronic device, comprising a memory and a processor, the memory stores a computer program, and the computer program is executed by the processor, and the processor executes the steps of the method of the first aspect.

[0033] Embodiments of the fourth aspect of the present application provide a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor, and the processor executes the steps of the method of the first aspect.

[0034] This application provides a method, apparatus, device, and storage medium for modal analysis of a motor rotor. The method includes: determining the equivalent elastic modulus of a rotor system based on a preset beam element bending model; the beam element model characterizes the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic moduli and moments of inertia of different components of the rotor system; calculating the natural frequencies and mode shapes of the rotor system based on the equivalent elastic modulus; and analyzing the modes of the rotor system based on the natural frequencies and mode shapes. By employing the technical solution of this application, the equivalent elastic modulus of the rotor system is determined based on a preset beam element bending model. Based on this, the natural frequencies and mode shapes of the rotor system are determined, and the modal characteristics of the rotor are analyzed. This not only simplifies the calculation process of the equivalent elastic modulus and reduces the computational workload, but also fully considers the influence of the mechanical and geometric properties of different materials within the same cross-section on the equivalent elastic modulus of the rotor structure, ensuring the accuracy of the analysis results. Attached Figure Description

[0035] Figure 1 A schematic flowchart illustrating a motor rotor modal analysis method provided in this application embodiment;

[0036] Figure 2 This is a schematic diagram of the stress structure of the rotor system provided in the embodiments of this application;

[0037] Figure 3 Schematic diagram of the cross-sectional structure of the rotor system shaft segment provided in the embodiments of this application Figure 1 ;

[0038] Figure 4 Schematic diagram of the cross-sectional structure of the rotor system shaft segment provided in the embodiments of this application Figure 2 ;

[0039] Figure 5a A schematic diagram of the structure of a rotor system provided in this application embodiment. Figure 1 ;

[0040] Figure 5b A schematic diagram of the structure of a rotor system provided in this application embodiment. Figure 2 ;

[0041] Figure 6a A schematic diagram of the first-order bending vibration calculated by the finite element analysis software provided in the embodiments of this application;

[0042] Figure 6b A schematic diagram of the second-order bending vibration calculated by the finite element analysis software provided in the embodiments of this application;

[0043] Figure 6c A schematic diagram of the third-order bending vibration calculated by the finite element analysis software provided in the embodiments of this application;

[0044] Figure 7a A first-order bending vibration schematic diagram of the motor rotor modal analysis method provided by the embodiment of the present application;

[0045] Figure 7b A second-order bending vibration schematic diagram of the motor rotor modal analysis method provided by the embodiment of the present application;

[0046] Figure 7c A third-order bending vibration schematic diagram of the motor rotor modal analysis method provided by the embodiment of the present application;

[0047] Figure 8 A structural schematic diagram of a motor rotor modal analysis device provided by the embodiment of the present application;

[0048] Figure 9 A structural schematic diagram of an electronic device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0050] In addition, the drawings are only schematic illustrations of the present application, and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus repeated description thereof will be omitted. Some block diagrams shown in the drawings are functional entities, and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0051] The flowcharts shown in the drawings are only exemplary illustrations, and do not necessarily include all the steps. For example, some steps can be further decomposed, and some steps can be combined or partially combined, so that the actual execution order can be changed according to the actual situation.

[0052] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting thereof. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of associated items.

[0053] In some embodiments, referring to Figure 1 , Figure 1 A flowchart of a motor rotor modal analysis method provided by an embodiment of the application is shown in FIG. 1. The motor rotor modal analysis method comprises the following steps.

[0054] In step S110, the equivalent elastic modulus of the rotor system is determined based on a preset beam element bending model. The beam element model represents the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system.

[0055] The elastic modulus is a material property. When a material is in the elastic deformation stage, the stress and strain are in a proportional relationship, and the proportional coefficient is the elastic modulus. The moment of inertia is usually used to describe the ability of an object to resist bending.

[0056] In this embodiment, the equivalent elastic modulus represents the elastic modulus of the entire rotor system. Generally, the rotor system is composed of multiple different components, and therefore, the differences in the elastic modulus between the different components need to be considered.

[0057] In an optional embodiment, in step S110, the equivalent elastic modulus of the rotor system is determined based on a preset beam element bending model, which comprises the following steps.

[0058] A first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system is obtained.

[0059] The first mapping relationship is inferred using inductive reasoning to determine the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system.

[0060] In the embodiment, the rotor system can be composed of two components or multiple components. Taking the rotor system composed of two components as an example, an initial mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of the two components can be determined in advance, and then taking the rotor system composed of three components as an example, a secondary mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of the three components is determined. Based on the obtained initial mapping relationship and the secondary mapping relationship, induction and reasoning are performed by using the inductive method, and the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of the multiple components can be determined. The beam element bending model obtained by this method can be universally applied to the rotor system composed of a complex structure.

[0061] In some embodiments, obtaining the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of the at least two components of the rotor system comprises:

[0062] Based on the deflections of the rotor system and the at least two components of the rotor system at the free end, a first equation set is established;

[0063] Based on the first equation set and the moment of inertia superposition theorem, the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and the moment of inertia of each of the at least two components of the rotor system is determined.

[0064] For example, refer to Figure 2 , Figure 2 The force structure schematic diagram of the rotor system provided by the embodiment of the application is shown. Taking the first component 210 and the second component 220 as an example, the rotor system comprises the first component 210 and the second component 220, an external force F is vertically applied to the end of the axis of the rotor system, and the length of the shaft section of the rotor system is L. It is assumed that the equivalent interaction force of the rotor system at the free end is F a According to the bending theory of the beam, the deflections ω, ω1 and ω2 of the shaft section, the first component 210 and the second component 220 at the free end of the rotor system can be respectively represented as:

[0065]

[0066] In the formula, E e and I e are the equivalent elastic modulus and the moment of inertia of the shaft section, E1 and I1 are the elastic modulus and the moment of inertia of the first component 210, and E2 and I2 are the elastic modulus and the moment of inertia of the second component 220. Since the deflections of the first component 210 and the second component 220 at the free end are equal to the deflection of the shaft section, the following equation is obtained:

[0067] ω=ω1=ω2 (2)

[0068] Since the cross-sectional moment of inertia satisfies the superposition theorem, we have

[0069] I e = I1+I2 (3)

[0070] Solving the above three equations, the equivalent elastic modulus of the rotor system shaft section is

[0071]

[0072] In an example, refer to Figure 3 , Figure 3 the cross-sectional structure of the rotor system shaft section provided by the embodiment of the present application is shown in Figure 1 ; wherein the rotor system shaft section is composed of three components of different materials, the third component 330 is located inside the second component 320, and the second component 320 is located inside the first component 310. When a concentrated load F is applied at the free end of the rotor system shaft section, if the interaction force between the first component 310 and the second component 320 is F a , and the interaction force between the second component 320 and the third component 330 is F b , then we have:

[0073]

[0074] In another example, refer to Figure 4 , Figure 4 the cross-sectional structure of the rotor system shaft section provided by the embodiment of the present application is shown in Figure 2 ; wherein the rotor system shaft section is composed of three components of different materials, and the second component 420 and the third component 430 are both located inside the first component 410, and the second component 420 and the third component 430 do not contact each other, which is different from the above example. When a concentrated load F is applied at the free end of the rotor system shaft section, if the interaction force between the first component 410 and the second component 420 is F a , and the interaction force between the first component 410 and the third component 430 is F b , then we have:

[0075]

[0076] Solving the above two equations, the equivalent elastic modulus of the rotor system shaft section can be expressed as:

[0077]

[0078] Using induction, the above calculation formula can be extended to a rotor system composed of N components, and the equivalent elastic modulus E e of the rotor system can be expressed as

[0079]

[0080] Formula (8) shows that for a rotor system containing multiple components in a section, the equivalent elastic modulus of the rotor system in the section is equal to the ratio of the sum of the products of the elastic modulus and the moment of inertia of each component to the sum of the moments of inertia of each component.

[0081] In step S120, the natural frequency and mode shape of the rotor system are determined based on the calculation of the equivalent elastic modulus.

[0082] After the beam element bending model is determined, the dynamic model of the motor rotor system can be established using the transfer matrix method, and the dynamic equation of the system is solved using the parabolic method to obtain the corresponding eigenvalues and eigenvectors, which represent the natural frequency and mode shape of the rotor system, respectively.

[0083] In an optional embodiment, in step S120, the natural frequency and mode shape of the rotor system are determined based on the calculation of the equivalent elastic modulus, including:

[0084] A mathematical model of the rotor system is established, and a dynamic equation corresponding to the mathematical model is determined;

[0085] The natural frequency and mode shape of the rotor system are determined based on the calculation of the equivalent elastic modulus and the dynamic equation.

[0086] In this embodiment, the transfer relationship between the cross-section state vectors at both ends of a typical component (such as the first component) can be established based on the transfer matrix, and the relationship between the cross-section state vectors at both ends of the entire rotor system is obtained through the continuity condition. Finally, the natural frequency of the rotor system is obtained by solving the whirl frequency that satisfies the boundary conditions.

[0087] For example, the rotor system can be discretized into a mathematical model based on the transfer matrix method and the specific size and characteristics of the rotor system structure. The rotor system model can contain N rigid disks and N-1 elastic beams. The equivalent rigid disk and the equivalent elastic beam between the mth and nth components contain not only the shaft structure but also the rotor lamination and permanent magnet structure.

[0088] The state vector of the kth element can be represented as:

[0089]

[0090] In the formula, x k and θ k represent the linear displacement and angular displacement of the element, M k and Q k represent the bending moment and shear force acting on the element

[0091] According to the D'Alembert principle, the motion equation of the kth disc element is:

[0092]

[0093] In the formula, D k Let be the transfer matrix of the k-th disk element. This is the right-hand state vector of the disk element. This represents the left-hand state vector of the disk element. Specifically:

[0094]

[0095] In the formula, m is the mass of the disk element, J p and J p Let be the polar moment of inertia and the diametrical moment of inertia of the disk, respectively; ω represent the frequency of the rotor system; and K represent the bearing stiffness, which is zero at the location without bearings. Similarly, for the k-th beam element:

[0096] Z k+1 =B k Z′ k (12)

[0097] In the formula, Z′ k For Z k The derivative of B k Let be the transfer matrix of the k-th beam element, i.e.:

[0098]

[0099] In the formula, l, E, and I represent the length, elastic modulus, and moment of inertia of each beam element, respectively. Specifically, when a beam element contains multiple components within the same cross-section, E represents its equivalent elastic modulus. The continuity condition between the k-th disk element and the k-th beam element is:

[0100]

[0101] By combining equations (10), (12) and (14), we can obtain:

[0102] Z k+1 =T k Z k =B k D k Z k (15)

[0103] Therefore, the recursive relationship of the rotor system from the left end to the right end can be expressed as:

[0104] Z N+1 =T N T N-1 …T1Z1 (16)

[0105] Since the left end boundary condition of the rotor is M1=0 and Q1=0, and the right end boundary condition of the rotor is M N+1 =0 and Q N+1 =0, there are:

[0106]

[0107] Thus, the frequency equation of the rotor system is obtained as:

[0108]

[0109] The parabolic method is used to solve the equation (18), and the characteristic root ω of the equation is obtained, which is the natural frequency of the rotor system. The characteristic vector corresponding to the characteristic root ω represents the vibration mode of the rotor system.

[0110] In step S130, the modal of the rotor system is analyzed based on the natural frequency and the vibration mode.

[0111] The natural frequency is also called the natural frequency. When an object is in free vibration, the displacement varies with time according to the sine or cosine law, and the frequency of vibration is independent of the initial condition, but only related to the inherent characteristics of the system (such as mass, shape, material, etc.). It is called natural frequency. The vibration mode refers to the inherent vibration form of an elastic body or elastic system. It can be described by the relative position of the mass point during vibration, i.e. the vibration curve. Since the multi-mass system has multiple degrees of freedom, multiple vibration modes and multiple natural frequencies can occur. The natural frequency and the vibration mode can reflect the modal characteristics of the motor rotor.

[0112] The embodiment of the present application determines the equivalent elastic modulus of the rotor system based on the preset beam element bending model, and determines the natural frequency and vibration mode of the rotor system on this basis, and analyzes the modal characteristics of the rotor. Not only simplifies the calculation process of the equivalent elastic modulus, reduces the calculation workload, but also fully considers the influence of the mechanical properties and geometric properties of different materials in the same cross section on the equivalent elastic modulus of the rotor structure, and ensures the accuracy of the analysis results.

[0113] In a specific embodiment, an embedded double-V-shaped permanent magnet rotor is taken as an example, and the above model is verified by using a finite element analysis software. At the same time, in order to illustrate the superiority of the proposed analytical algorithm compared with the average value method, the calculation results of the motor rotor modal analysis method and the average value method proposed in the present application are compared with the finite element calculation results.

[0114] Please refer to 5a and 5b, Figure 5a A structure diagram of a rotor system provided by the embodiment of the present application Figure 1 , which is the structure of an embedded double-V-shaped permanent magnet rotor. Figure 5bA structure diagram of a rotor system provided by an embodiment of the present application Figure 2 A 1 / 6 structure of a rotor assembly; the equivalent elastic modulus of the rotor system can be represented as:

[0115]

[0116] In the formula, E Sh , E La , E Pm , and I Sh , I La , I Pm are the elastic modulus and the moment of inertia of the shaft 510, the rotor laminations 520, and the permanent magnets 530 respectively.

[0117] The material parameters of the rotor system can be as shown in Table 1, and the calculation results of the first three order natural frequencies of the free mode of the rotor system are shown in Table 2. As can be seen from Table 2, the calculation error of the equivalent elastic modulus of the proposed permanent magnet rotor structure is within 4%. The calculation error of the modal frequency result based on the average value method of the equivalent elastic modulus of the rotor system is obviously greater than the calculation error of the present method, and the maximum error is about 12%.

[0118] Table 1

[0119]

[0120] Table 2

[0121]

[0122] In one example, refer to Figure 6a , Figure 6b and Figure 6c ; Figure 6a is a first order bending vibration diagram calculated by the finite element analysis software provided by the embodiment of the present application; Figure 6b is a second order bending vibration diagram calculated by the finite element analysis software provided by the embodiment of the present application; Figure 6c is a third order bending vibration diagram calculated by the finite element analysis software provided by the embodiment of the present application. Figure 6a , Figure 6b and Figure 6c respectively represent the first order, second order and third order vibration modes of the rotor system calculated by the finite element analysis software.

[0123] In another example, refer to Figure 7a , Figure 7b and Figure 7c ; Figure 7a is a first order bending vibration diagram of the motor rotor modal analysis method provided by the embodiment of the present application; Figure 7b is a second order bending vibration diagram of the motor rotor modal analysis method provided by the embodiment of the present application;Figure 7c A third-order bending vibration schematic diagram of the motor rotor modal analysis method provided in the embodiments of the present application. Figure 7a 、 Figure 7b and Figure 7c respectively represent the first-order, second-order and third-order vibration modes of the rotor system calculated by the motor rotor modal analysis method provided in the present application.

[0124] From the above schematic diagrams, it can be analyzed that the calculation results of the first three orders of vibration modes of the rotor system based on the transfer matrix method are in good agreement with the results of the finite element analysis software. Therefore, it can be determined that the motor rotor modal analysis method provided in the present application is accurate and effective, and it achieves better calculation accuracy compared with the average value method.

[0125] In some embodiments, referring to Figure 8 , Figure 8 a structural schematic diagram of a motor rotor modal analysis device provided in the embodiments of the present application; the motor rotor modal analysis device 800 comprises:

[0126] a first determination module 810, configured to determine the equivalent elastic modulus of the rotor system based on a preset beam element bending model; the beam element model represents the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system;

[0127] a second determination module 820, configured to determine the natural frequency and vibration mode of the rotor system by calculation based on the equivalent elastic modulus;

[0128] an analysis module 830, configured to analyze the modal of the rotor system based on the natural frequency and vibration mode.

[0129] In some embodiments, the first determination module 810 is specifically configured to:

[0130] obtain a first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system;

[0131] deduce the first mapping relationship by induction to determine the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system.

[0132] In some embodiments, the first determination module 810 is specifically further configured to:

[0133] establish a first equation set based on the deflection of the rotor system and at least two components of the rotor system at the free end;

[0134] determine the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system based on the first equation set and the moment of inertia superposition theorem.

[0135] In some embodiments, the second determining module 820 is specifically configured to:

[0136] establish a mathematical model of the rotor system and determine a dynamic equation corresponding to the mathematical model;

[0137] perform calculation based on the equivalent elastic modulus and the dynamic equation to determine the natural frequency and mode shape of the rotor system.

[0138] The embodiments of the present application determine the equivalent elastic modulus of the rotor system based on the preset beam element bending model, and determine the natural frequency and mode shape of the rotor system on this basis, to analyze the modal characteristics of the rotor. This not only simplifies the calculation process of the equivalent elastic modulus and reduces the calculation workload, but also fully considers the influence of the mechanical properties and geometric properties of different materials in the same cross section on the equivalent elastic modulus of the rotor structure, to ensure the accuracy of the analysis results.

[0139] It should be noted that: the above description of the motor rotor modal analysis device embodiments is similar to the description of the above motor rotor modal analysis method embodiments, and has similar beneficial effects to the motor rotor modal analysis method embodiments. For technical details not disclosed in the motor rotor modal analysis device embodiments of the present application, please refer to the description of the motor rotor modal analysis method embodiments of the present application for understanding, which will not be repeated here.

[0140] The embodiments of the third aspect of the present application provide an electronic device, please refer to Figure 9 , Figure 9 The electronic device provided by the embodiments of the present application has the structure shown in the figure, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program. When the computer program is executed by the processor, the processor executes the steps of the motor rotor modal analysis method described above.

[0141] The electronic device can be a terminal, a server, or a similar computing device. The electronic device can vary greatly in configuration or performance, and can include one or more central processing units (CPUs), including but not limited to microprocessors (MCUs) or programmable logic devices (FPGAs), a memory for storing data, and one or more storage media (e.g., one or more mass storage devices) for storing applications or data. The memory and the storage media can be temporary or persistent storage. The programs stored in the storage media can include one or more modules, each of which can include a series of instructions for operating the electronic device. Further, the CPU can be configured to communicate with the storage media and execute the series of instructions in the storage media on the electronic device. The electronic device can also include one or more power supplies, one or more wired or wireless network interfaces, one or more input / output interfaces, and / or one or more operating systems, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, etc. The input / output interfaces can be used to receive or send data via a network. Examples of the network can include a wireless network provided by a communication provider of the electronic device.

[0142] In one example, the input / output interface includes a network interface controller (NIC) that can connect to other network devices through a base station to communicate with the Internet. In an exemplary embodiment, the input / output interface can be a radio frequency (RF) module that is configured to communicate with the Internet wirelessly.

[0143] Those of ordinary skill in the art can understand that Figure 9 The structures shown are merely illustrative and do not limit the structure of the electronic device described above. For example, the electronic device can include more or fewer components than those shown in Figure 9 or have a different configuration than that shown in Figure 9 .

[0144] In some embodiments, the embodiments of the present application provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the motor rotor modal analysis method.

[0145] It should be noted that the above electronic device embodiments and storage medium embodiments are similar to the description of the motor rotor modal analysis method embodiments, and have similar beneficial effects to the motor rotor modal analysis method embodiments. For technical details not disclosed in the electronic device embodiments and storage medium embodiments of the present application, please refer to the description of the motor rotor modal analysis method embodiments of the present application for understanding, which will not be repeated here.

[0146] In several embodiments provided in the present application, it should be understood that the disclosed motor rotor modal analysis method, device, system and storage medium can be implemented in other ways. The above described method, device and system embodiments are only illustrative.

[0147] The motor rotor modal analysis method, device, electronic device and storage medium described in the embodiments of the present application are only taken as examples, but are not limited thereto. As long as the motor rotor modal analysis method, device, electronic device and storage medium are involved, they are within the protection scope of the present application.

[0148] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily mean the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the execution order, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The sequence number of the above embodiments of the present application is only for description, not representing the advantages and disadvantages of the embodiments.

[0149] It should be noted that in this paper, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a…" does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0150] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the modification or replacement within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of modal analysis of an electric machine rotor, characterized in that, The method comprises the steps of: determining the equivalent elastic modulus of the rotor system based on a preset beam element bending model; the beam element bending model represents the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system; calculating the natural frequency and mode shape of the rotor system based on the equivalent elastic modulus; analyzing the modal of the rotor system based on the natural frequency and mode shape; wherein the step of determining the equivalent elastic modulus of the rotor system based on the preset beam element bending model comprises the steps of: obtaining a first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system; using inductive reasoning to infer the first mapping relationship to determine the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system.

2. The motor rotor modal analysis method of claim 1, wherein, The step of obtaining the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system comprises the steps of: establishing a first equation set based on the deflection of the free end of the rotor system and at least two components of the rotor system; determining the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system based on the first equation set and the moment of inertia superposition theorem.

3. The motor rotor modal analysis method of claim 1, wherein The step of calculating the natural frequency and mode shape of the rotor system based on the equivalent elastic modulus comprises the steps of: establishing a mathematical model of the rotor system and determining the corresponding dynamic equation of the mathematical model; calculating the natural frequency and mode shape of the rotor system based on the equivalent elastic modulus and the dynamic equation.

4. An electric motor rotor modal analysis apparatus, characterized by, The method comprises the steps of: a first determination module for determining the equivalent elastic modulus of the rotor system based on a preset beam element bending model; the beam element bending model represents the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system; a second determination module for calculating the natural frequency and mode shape of the rotor system based on the equivalent elastic modulus; an analysis module for analyzing the modal of the rotor system based on the natural frequency and mode shape; wherein the first determination module is specifically configured to: obtain a first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system; use inductive reasoning to infer the first mapping relationship to determine the mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system.

5. The electric machine rotor modal analysis apparatus of claim 4, wherein, The first determination module is specifically further configured to: establish a first equation set based on the deflection of the free end of the rotor system and at least two components of the rotor system; determine the first mapping relationship between the equivalent elastic modulus of the rotor system and the elastic modulus and moment of inertia of each component of the rotor system based on the first equation set and the moment of inertia superposition theorem.

6. The electric machine rotor modal analysis apparatus of claim 4, wherein, The second determination module is specifically configured to: establishing a mathematical model of the rotor system and determining a dynamic equation corresponding to the mathematical model; calculating based on the equivalent elastic modulus and the dynamic equation to determine the natural frequency and mode shape of the rotor system. 7.An electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the steps of the method according to any one of claims 1 to 3. 8.A computer readable storage medium, having stored thereon a computer program, wherein the computer program is executed by a processor to implement the steps of the method according to any one of claims 1 to 3.

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