A permanent magnet synchronous motor eccentric fault modeling method, device, equipment and medium

Abstract

The application discloses a permanent magnet synchronous motor eccentric fault modeling method, device, equipment and medium, relates to the motor fault modeling technical field, and the method comprises the following steps: inputting the mechanical angle of the permanent magnet synchronous motor to the improved air gap distribution function under the eccentric fault, obtaining the improved air gap distribution function and the inverse air gap distribution function under the eccentric fault; obtaining the self-induction parameter, mutual-induction parameter and inductance matrix of the current moment according to the air gap distribution function and the inverse air gap distribution function under the eccentric fault; obtaining the stator current derivative based on the inductance matrix; obtaining the stator current and electromagnetic torque of the next moment, and iterating the stator current obtaining process based on the motor speed and mechanical angle of the next moment until the iteration is finished, and outputting the corresponding stator current waveform. The application considers the air gap distribution function and the inverse air gap distribution function at the permanent magnet as functions related to the space angle, increases the space harmonic component, and improves the accuracy of the eccentric fault judgment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor fault modeling, in particular to a permanent magnet synchronous motor eccentric fault modeling method, device, equipment and medium. BACKGROUND

[0002] Compared with ordinary alternating current variable frequency motor, the permanent magnet synchronous motor has the advantages of high power density, high efficiency, high torque inertia ratio, wide range of constant power speed regulation, small vibration and low noise, etc., and has been widely used in various industrial and power drive systems, and often works in variable speed and variable load conditions, such as new energy vehicles, industrial robots and high-speed rail power systems. Motor is an important device for realizing the conversion of electric energy and mechanical energy in production and life, so the fault should be found and eliminated in the early stage to ensure the reliable operation of the motor. However, due to factors such as production process, manufacturing level and working environment, the permanent magnet synchronous motor may occur rotor eccentric fault, which causes uneven air gap, and thus causes magnetic field distortion, vibration, noise and motor heating, and reduces the service life of the motor. In severe cases, eccentricity may cause the stator and rotor to collide with each other, eventually leading to motor damage. Therefore, it is of great value and practical significance to study the eccentric fault diagnosis of permanent magnet synchronous motor.

[0003] As a typical mechanical fault, eccentric fault can be divided into dynamic eccentric fault, static eccentric fault and mixed eccentric fault according to different eccentric mechanisms. Among them, dynamic eccentric fault refers to that the center of the stator coincides with the rotation center of the rotor, but does not coincide with the geometric center of the rotor; static eccentric fault refers to that the center of the stator does not coincide with the rotation center of the rotor, but the rotation center of the rotor coincides with the geometric center of the rotor; mixed eccentric fault refers to that the center of the stator does not coincide with the rotation center of the rotor and the geometric center of the rotor.

[0004] At present, the eccentric fault diagnosis methods of permanent magnet synchronous motor mainly include three types: vibration signal based diagnosis method, magnetic induction intensity based diagnosis method and stator current based diagnosis method. The vibration signal based diagnosis method is more sensitive to mechanical faults, so it is also more sensitive to eccentric faults. However, due to the difficulty in installing vibration sensors, especially in a relatively compact environment. In addition, the vibration excitation source needs to propagate to the vibration sensor through a long path, which will cause the vibration signal to contain noise and other component coupling vibration information phenomenon, and the vibration signal will be more complex. The above factors limit the wider industrial application of vibration signal. The magnetic induction intensity based diagnosis method can monitor the distortion of the magnetic field, and then diagnose the eccentric fault, but if the magnetic induction sensor is installed inside the motor, the motor needs to be disassembled, which not only complicates the disassembly, but also affects the operation performance of the motor after disassembly; if installed outside, the motor shell usually produces static shielding, which affects the accuracy of the magnetic field signal.

[0005] The stator current-based diagnosis method does not need to install additional sensors inside or outside the motor, and can diagnose motor eccentricity faults by relying on characteristic frequencies of stator current, but the relationship between the characteristic frequencies and motor eccentricity modes and eccentricity degree still needs to be studied, so it is necessary to model and analyze the motor system. The current permanent magnet synchronous motor eccentricity fault modeling methods mainly include finite element method, equivalent magnetic circuit method and improved winding function method. The finite element method has large calculation amount and is affected by grid partition accuracy; the equivalent magnetic circuit method uses lumped parameter modeling, and the calculation amount is still large; and the improved winding function method has small calculation amount and can provide analytical expressions of motor inductance.

[0006] In practice, the air gap length at the permanent magnet of the permanent magnet synchronous motor is related to the rotor space angle, which will introduce harmonic components in inductance calculation. However, the existing improved winding function method simplifies the air gap length at the permanent magnet to a constant value in modeling, ignoring the spatial harmonic components, resulting in the absence of some fault characteristic frequencies in the stator current characteristic frequencies, and the inability to accurately judge various types of eccentricity faults. SUMMARY

[0007] Based on the defects of the existing technology, the present application provides a permanent magnet synchronous motor eccentricity fault modeling method, device, equipment and medium, which solves the problem that the existing improved winding function method simplifies the air gap length at the permanent magnet to a constant value in modeling, ignores the spatial harmonic components, results in the absence of some fault characteristic frequencies in the stator current characteristic frequencies, and cannot accurately judge various types of eccentricity faults.

[0008] The application adopts the following technical solutions:

[0009] In a first aspect, the application provides a permanent magnet synchronous motor eccentricity fault modeling method, comprising the following steps:

[0010] The mechanical angle of the permanent magnet synchronous motor at the current time is input to the improved air gap distribution function under eccentricity fault, to obtain the improved air gap distribution function and the inverse air gap distribution function under eccentricity fault at the current time; wherein the spatial angle and the mechanical angle are introduced into the original air gap distribution function to obtain the improved air gap distribution function;

[0011] Based on the improved winding function method, the self-induction parameter and the mutual-induction parameter at the current time are obtained according to the improved air gap distribution function and the inverse air gap distribution function under eccentricity fault at the current time; the self-induction parameter and the mutual-induction parameter at the current time are combined to obtain the inductance matrix at the current time;

[0012] The inductance matrix and the motor speed at the current time are input to the voltage equation and the flux linkage equation to obtain the stator current derivative at the current time; the stator current and the electromagnetic torque of the permanent magnet synchronous motor at the next time are obtained based on the stator current derivative at the current time, and the stator current and the electromagnetic torque at the next time are input to the power equation to obtain the mechanical angle and the motor speed at the next time;

[0013] The process of obtaining the stator current based on the mechanical angle and the motor speed at the next time is iterated until the iteration is completed, and the stator current waveform corresponding to the permanent magnet synchronous motor is output.

[0014] Preferably, the improved air gap distribution function is specifically as follows:

[0015] ;

[0016] In the formula, is the improved air gap distribution function, is the space angle, is the pole pitch angle, is the shortest distance from the rotor center to the inside of the permanent magnet, is the length of the permanent magnet, is the air gap length in the normal state, is the mechanical angle.

[0017] Preferably, the static eccentricity and the dynamic eccentricity are set, and the static eccentricity and the dynamic eccentricity are input to the improved air gap distribution function to obtain the improved air gap distribution function under the eccentric fault, which is specifically as follows:

[0018] ;

[0019] ;

[0020] In the formula,

[0021] ;

[0022] ;

[0023] In the formula, and are the improved air gap distribution function and the inverse air gap distribution function under the eccentric fault respectively, is the static eccentricity, is the dynamic eccentricity, is the improved inverse air gap distribution function, is the mechanical position angle at the minimum air gap, is the mechanical position angle rotating with the rotor, is the eccentricity.

[0024] Preferably, the self-inductance parameters and mutual-inductance parameters are as follows:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] wherein, is a self-inductance parameter of phase A, is a self-inductance parameter of phase B, is a self-inductance parameter of phase C, and is a mutual-inductance parameter of phase A and phase B, and is a mutual-inductance parameter of phase C and phase A, and is a mutual-inductance parameter of phase B and phase C, is a winding function of phase A, is a winding function of phase B, is a winding function of phase C, is an intermediate variable.

[0032] Preferably, the inductance matrix is as follows:

[0033]

[0034] wherein, is an inductance matrix.

[0035] Preferably, the method for obtaining the stator current and electromagnetic torque of the permanent magnet synchronous motor at the next time point based on the derivative of the stator current at the current time point comprises the following steps:

[0036] The stator current at the next time point is updated by using the implicit Euler method, and is as follows:

[0037]

[0038] wherein, is a stator current at the current time point, is a stator current at the current time point, is a stator current at the current time point, is a stator current at the current time point, is a derivative of the stator current, is a time step; ​​

[0039] The stator current at the next moment is input into the electromagnetic torque equation to obtain the electromagnetic torque.

[0040] Preferably, the power equation is specifically as follows:

[0041]

[0042] In the formula, is the mechanical angular velocity at the moment, i.e., the motor speed, is the mechanical angle at the moment, is the mechanical angular velocity at the moment, is the mechanical angle at the moment, is the mechanical angular velocity at the moment, is the mechanical angle at the moment, is the damping coefficient, is the moment of inertia, is the electromagnetic torque, is the load torque. In the second aspect, the application provides a device for modeling eccentric fault of a permanent magnet synchronous motor, comprising:

[0043] An input module is configured to input the mechanical angle of the permanent magnet synchronous motor at the current moment into an improved air gap distribution function under eccentric fault to obtain the improved air gap distribution function and the inverse air gap distribution function at the current moment under eccentric fault; wherein the spatial angle and the mechanical angle are introduced into the original air gap distribution function to obtain the improved air gap distribution function.

[0044] A first calculation module is configured to obtain the self-induction parameter and the mutual-induction parameter at the current moment based on the improved winding function method according to the improved air gap distribution function and the inverse air gap distribution function at the current moment under eccentric fault; and combine the self-induction parameter and the mutual-induction parameter at the current moment to obtain the inductance matrix at the current moment.

[0045] A second calculation module is configured to input the inductance matrix at the current moment and the motor speed into the voltage equation and the flux linkage equation to obtain the derivative of the stator current at the current moment; obtain the stator current and the electromagnetic torque of the permanent magnet synchronous motor at the next moment based on the derivative of the stator current at the current moment; and input the stator current and the electromagnetic torque at the next moment into the power equation to obtain the mechanical angle and the motor speed at the next moment.

[0046] An iteration module is configured to iteratively obtain the stator current based on the mechanical angle and the motor speed at the next moment until the iteration ends, and output the corresponding stator current waveform of the permanent magnet synchronous motor.

[0047] An iteration module is configured to iteratively obtain the stator current based on the mechanical angle and the motor speed at the next moment until the iteration ends, and output the corresponding stator current waveform of the permanent magnet synchronous motor.

[0048] ​​Thirdly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described method for modeling eccentric faults of a permanent magnet synchronous motor.

[0049] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for modeling eccentric faults in a permanent magnet synchronous motor.

[0050] Compared with the prior art, the above-mentioned at least one technical solution adopted by the present invention can achieve the following beneficial effects:

[0051] This invention first incorporates spatial and mechanical angles into the original air gap distribution function, resulting in an improved air gap distribution function that considers the true distribution of the air gap. The air gap distribution function at the permanent magnet and the inverted air gap distribution function are considered as functions related to spatial angles, thus increasing the spatial harmonic component. Then, the mechanical angle of the permanent magnet synchronous motor at the current moment is input into the improved air gap distribution function under eccentric fault conditions, yielding the improved air gap distribution function and the inverted air gap distribution function under eccentric fault conditions at the current moment. Next, the inductance matrix is ​​obtained using the improved winding function method. By utilizing the motor voltage, flux linkage, electromagnetic torque, and dynamic equations, the state parameters such as current, speed, electromagnetic torque, and mechanical angle at different times are updated, ultimately obtaining the stator current waveform considering spatial harmonic components. This invention considers the air gap distribution function at the permanent magnet and the inverted air gap distribution function as functions related to spatial angles, increasing the spatial harmonic component, improving the output stator current waveform, and enhancing the accuracy of eccentric fault detection. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a flowchart of a method for modeling eccentric faults in a permanent magnet synchronous motor according to the present invention;

[0054] Figure 2 This is the current spectrum of the motor at a speed of 605 rpm under experimental conditions according to an embodiment of the present invention;

[0055] Figure 3 The current spectrum of the motor at 605 rpm under the simulation conditions of this embodiment of the invention, without considering the actual internal shape of the motor.

[0056] Figure 4 The current spectrum diagram of the motor at a rotating speed of 605 rpm under the consideration of the real shape inside the motor in the simulation condition of the embodiment of the application;

[0057] Figure 5 The current spectrum diagram of the motor at a rotating speed of 908 rpm under the experimental condition of the embodiment of the application;

[0058] Figure 6 The current spectrum diagram of the motor at a rotating speed of 908 rpm under the consideration of the real shape inside the motor in the simulation condition of the embodiment of the application;

[0059] Figure 7 The current spectrum diagram of the motor at a rotating speed of 908 rpm under the consideration of the real shape inside the motor in the simulation condition of the embodiment of the application. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the application will be apparently and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0061] In order to overcome the defects of the prior art, the purpose of the application is to provide a permanent magnet synchronous motor eccentric fault simulation method considering the real distribution of air gap. The method adopts the real geometric structure inside the motor, considers the air gap distribution function and the inverse air gap distribution function at the permanent magnet as functions related to the space angle, and then calculates the inductance matrix by means of the improved winding function method, and introduces it into the four basic equations of the motor. The simulation model is constructed to obtain the stator current waveform.

[0062] With reference to Figure 1 , the application provides a permanent magnet synchronous motor eccentric fault modeling method, including the following steps:

[0063] S1: setting the simulation time , so as to determine the start and end time of the simulation, and initialize the static eccentricity and the dynamic eccentricity ; obtain the parameters such as the inner diameter of the motor stator , the number of pole pairs of the permanent magnet , and the stator resistance .

[0064] S2: introducing the space angle and the mechanical angle into the original air gap distribution function to obtain the improved air gap distribution function.

[0065] The air gap distribution function is a function form describing the distribution law of the air gap length between the stator and the rotor of the motor along the spatial angle of the rotor.

[0066] The original air gap distribution function and the inverse air gap distribution function without considering the internal real shape are as follows:

[0067] ;

[0068] ;

[0069] In the formula, is the spatial angle, is the pole pitch angle, is the shortest distance from the rotor center to the inner side of the permanent magnet, is the length of the permanent magnet, is the air gap length in the normal state, is the mechanical angle. It can be seen from the above formula that the air gap length at the permanent magnet is a constant, and the spatial harmonic component is ignored.

[0070] The present application considers the real shape of the internal rotor of the motor, considers the air gap distribution function and the inverse air gap distribution function at the permanent magnet as functions related to the spatial angle, and obtains the improved air gap distribution function and the inverse air gap distribution function. The spatial harmonic component is considered, and the air gap distribution function of the normal motor is calculated g And the inverse air gap distribution function is as follows:

[0071]

[0072]

[0073] S3: Set the static eccentricity and the dynamic eccentricity, input the static eccentricity and the dynamic eccentricity to the improved air gap distribution function, and obtain the improved air gap distribution function under the eccentric fault.

[0074] The improved air gap distribution function and the improved inverse air gap distribution function between the stator and the rotor under the eccentric fault are calculated as follows:

[0075]

[0076]

[0077]

[0078]

[0079] In the formula, is the static eccentricity in S1, is the dynamic eccentricity in S1, is the normal motor air-gap distribution function, is the mechanical angle, is the mechanical position angle at the minimum air-gap, is the mechanical position angle with the rotation of the rotor, is the eccentricity.

[0080] The mechanical angle of the permanent magnet synchronous motor at the current time is obtained, and the mechanical angle of the permanent magnet synchronous motor at the current time is input to the improved air-gap distribution function under eccentric fault, to obtain the improved air-gap distribution function under eccentric fault at the current time and the air-gap distribution function.

[0081] According to the real geometric structure inside the permanent magnet synchronous motor, the air-gap distribution functions and the air-gap distribution functions under normal motor and eccentric fault motor are calculated, which can improve the accuracy when modeling, more truly reflect the change of air-gap due to eccentric fault, and more accurately calculate the self-induction and mutual induction.

[0082] S4: Calculate the winding function , for For the pole distribution winding, the winding function expression is as follows:

[0083]

[0084]

[0085]

[0086] In the formula, y is the winding function of the A phase, a or b or c a, b and c are the A phase, B phase and C phase respectively, is the winding function of the A phase, is the winding function of the B phase, is the winding function of the C phase, is the equivalent number of turns of the stator phase winding, is the angle corresponding to the stator slot.

[0087] S5: Calculate the self-induction parameters and mutual induction parameters according to the improved winding function method , to obtain the inductance matrix , as follows:

[0088]

[0089] In the formula, is the self-induction parameter of the A phase, is the self-induction parameter of the B phase, ​Ls is a self-inductance parameter of phase C, and Lm is a mutual-inductance parameter of phase A and phase B, and Lm is a mutual-inductance parameter of phase C and phase A, and Lm is a mutual-inductance parameter of phase B and phase C.

[0090] The self-inductance part is:

[0091]

[0092]

[0093]

[0094] The mutual-inductance part is:

[0095]

[0096]

[0097]

[0098] In the formula, is an intermediate variable, , is an air permeability, is an average air gap length, is an effective length of the core.

[0099] By improving the winding function method, the self-inductance and mutual-inductance at each moment can be calculated, and the relationship between the mechanical angle , the air gap distribution function and the inverse air gap distribution function between the stator and the rotor can be calculated, and the inductance parameters are more refined, which provides support for the inductance parameters in the four basic equations of the motor.

[0100] S6: Calculate the derivative of the stator current according to the motor voltage equation and the flux linkage equation.

[0101] ;

[0102] ;

[0103] In the formula, is a three-phase voltage, , is the resistance input in step S1, is a stator current, is a stator three-phase winding flux linkage, is a permanent magnet flux linkage matrix, is a permanent magnet flux linkage amplitude, T is a transpose symbol.

[0104] The motor speed at the current time is obtained, the inductance matrix at the current time and the motor speed are input into the voltage equation and the flux linkage equation, and the derivative of the stator current at the current time is obtained, as follows:

[0105]

[0106] In the formula, , is the resistance input in step S1, is the stator current, is the three-phase voltage, is the permanent magnet flux linkage, is the mechanical angular velocity (rotational speed).

[0107] According to the voltage equation and the flux linkage equation of the motor, the derivative of the current can be obtained, which provides support for subsequent calculation of the size of the stator current at the next time.

[0108] S6: Update the stator current at the next time by implicit Euler method size, and calculate the electromagnetic torque size, as follows:

[0109]

[0110]

[0111] In the formula, is the current at the next time, is the current at the current time, is the time step.

[0112] By implicit Euler method, the current is updated according to the current derivative calculated in step S5, and the electromagnetic torque is calculated, which provides support for subsequent calculation of the mechanical speed and the mechanical angle.

[0113] S7: Update the motor mechanical angular velocity at the next time by implicit Euler method and the mechanical angle at the next time until the simulation time in step 1 is reached , as follows:

[0114]

[0115] In the formula, is the damping coefficient, is the moment of inertia, is the electromagnetic torque in step 6, is the load torque.

[0116] Step 8: Output the stator current waveform.

[0117] Embodiment

[0118] With the eccentricity experiment data of the MDFM F152L1H6M type permanent magnet synchronous motor as an example, the effectiveness of the present application is verified. The simulation scheme adopts the Simulink software to establish a double closed loop control permanent magnet synchronous motor simulation model. Among them, the motor module is based on the four basic equations of the motor, and the inductance calculation method based on the real structure of the motor is adopted to replace the inductance term in the motor equation. Two groups of experiments are carried out, respectively at the speed of 605 rpm and 908 rpm, and the current signal is collected, and the Fourier transform is verified to verify the effectiveness of the simulation model; four groups of simulation are carried out, respectively at the speed of 605 rpm and 908 rpm, and the real shape inside the motor is compared with the real shape inside the motor, and the Fourier transform is verified to verify the superiority of the simulation model considering the real shape inside the motor.

[0119] According to Figures 2-4 It can be known that, at the speed of 605 rpm, the fault characteristic frequency in the current spectrum when considering the internal shape of the motor is obviously higher than that when not considering, and is more consistent with the experimental current fault characteristic spectrum. According to Figures 5-7 It can be known that, at the speed of 908 rpm, the fault characteristic frequency in the current spectrum when considering the internal shape of the motor is obviously higher than that when not considering, and is more consistent with the experimental current fault characteristic spectrum. Figures 2-7 In the figure, X is the abscissa, and Y is the ordinate.

[0120] Based on the same concept, the present application also provides a permanent magnet synchronous motor eccentricity fault modeling device, which comprises an input module, a first calculation module, a second calculation module and an iteration module.

[0121] The input module is used for inputting the mechanical angle of the permanent magnet synchronous motor at the current time to the improved air gap distribution function under the eccentricity fault, obtaining the improved air gap distribution function under the eccentricity fault at the current time and the inverse air gap distribution function; wherein the space angle and the mechanical angle are introduced into the original air gap distribution function to obtain the improved air gap distribution function.

[0122] The first calculation module is used for obtaining the self-induction parameter and the mutual-induction parameter at the current time based on the improved winding function method according to the improved air gap distribution function and the inverse air gap distribution function under the eccentricity fault at the current time; the self-induction parameter and the mutual-induction parameter at the current time are combined to obtain the inductance matrix at the current time.

[0123] The second calculation module is configured to input the inductance matrix and the motor speed at the current moment into the voltage equation and the flux linkage equation to obtain the stator current derivative at the current moment; and obtain the stator current and the electromagnetic torque of the permanent magnet synchronous motor at the next moment based on the stator current derivative at the current moment, and input the stator current and the electromagnetic torque at the next moment into the power equation to obtain the mechanical angle and the motor speed at the next moment.

[0124] The iteration module is configured to iterate the obtaining process of the stator current based on the mechanical angle and the motor speed at the next moment until the iteration ends, and output the stator current waveform corresponding to the permanent magnet synchronous motor.

[0125] The application further provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the permanent magnet synchronous motor eccentric fault modeling method when executing the program.

[0126] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by the processor to implement the permanent magnet synchronous motor eccentric fault modeling method.

[0127] The application provides a permanent magnet synchronous motor eccentric fault simulation model considering the real distribution of air gap, first, input the basic parameters such as motor geometric size and resistance, and set the dynamic eccentricity and the static eccentricity as initial conditions; second, consider the real shape of the motor, consider the air gap distribution function and the inverse air gap distribution function at the permanent magnet as functions related to the space angle, and solve the air gap distribution function and the inverse air gap distribution function under the eccentric state by introducing the eccentric factor; then, according to the three-phase winding distribution, obtain the winding function; then, according to the improved winding function method, obtain the inductance matrix; and update the state parameters such as current, speed, torque and mechanical angle by means of motor voltage, flux linkage, electromagnetic torque and power equation. According to the output stator current, Fourier transform is performed. By means of this method, theoretical support can be provided for the modeling of the motor under the eccentric state, so as to realize subsequent eccentric fault analysis.

[0128] Although the preferred embodiments of the application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the application.

[0129] Obviously, those skilled in the art can make various modifications and changes to the application without departing from the spirit and scope of the application. Thus, if these modifications and changes of the application fall within the scope of the claims of the application and their equivalent technologies, the application also intends to include these modifications and changes.

Claims

1. A method for modeling eccentricity faults in a permanent magnet synchronous motor, characterized in that, Includes the following steps: The mechanical angle of the permanent magnet synchronous motor at the current moment is input into the improved air gap distribution function under eccentric fault, so as to obtain the improved air gap distribution function and the reverse air gap distribution function under eccentric fault at the current moment; wherein, the spatial angle and mechanical angle are introduced into the original air gap distribution function to obtain the improved air gap distribution function; Based on the improved winding function method, the self-inductance parameters and mutual inductance parameters at the current moment are obtained according to the improved air gap distribution function and the reverse air gap distribution function under the current eccentric fault. The self-inductance parameters and mutual inductance parameters at the current moment are combined to obtain the inductance matrix at the current moment. The current inductance matrix and motor speed are input into the voltage equation and flux linkage equation to obtain the current stator current derivative. Based on the current stator current derivative, the stator current and electromagnetic torque of the permanent magnet synchronous motor at the next moment are obtained. The stator current and electromagnetic torque at the next moment are input into the dynamic equation to obtain the mechanical angle and motor speed at the next moment. The process of obtaining the stator current is iterated based on the mechanical angle and motor speed at the next moment until the iteration ends, and the stator current waveform corresponding to the permanent magnet synchronous motor is output. The improved air gap distribution function is as follows: ； In the formula, To improve the air gap distribution function, From a spatial perspective, The polar distance angle, This is the shortest distance from the rotor center to the inside of the permanent magnet body. The length of the permanent magnet. This is the air gap length under normal conditions. For mechanical angles, This is the inner diameter of the motor stator; By defining static and dynamic eccentricities, and inputting them into the improved air gap distribution function, the improved air gap distribution function under eccentricity faults is obtained, as shown below: ； ； in, ； ； In the formula, and These represent the improved air gap distribution function and the inverted air gap distribution function under eccentric fault conditions, respectively. For static eccentricity, For dynamic eccentricity, To improve the inverted air gap distribution function, This refers to the mechanical position angle at the minimum air gap. The mechanical position angle that varies with the rotor's rotation. Eccentricity; The specific self-inductance parameters and mutual inductance parameters are as follows: In the formula, Here are the self-inductance parameters for phase A. For the self-inductance parameters of phase B, For the self-inductance parameters of phase C, and Here are the mutual inductance parameters for phases A and B. and The mutual inductance parameters for phase C and phase A are given. and Here are the mutual inductance parameters for phases B and C. For phase A winding function, For the B-phase winding function, For the C-phase winding function, As an intermediate variable; The inductor matrix is ​​specifically shown below: ； In the formula, This is the inductance matrix.

2. The method for modeling eccentricity faults in a permanent magnet synchronous motor as described in claim 1, characterized in that, The method of obtaining the stator current and electromagnetic torque of the permanent magnet synchronous motor at the next moment based on the stator current derivative at the current moment includes the following steps: The stator current at the next time step is updated using the implicit Euler method, as shown below: ； In the formula, for Stator current at time t, for Stator current at time t, The derivative of the stator current. For time step; The stator current at the next moment is input into the electromagnetic torque equation to obtain the electromagnetic torque.

3. The method for modeling eccentricity faults in a permanent magnet synchronous motor as described in claim 2, characterized in that, The specific dynamic equations are as follows: ； In the formula, for The mechanical angular velocity at a given moment, i.e., the motor speed. for The mechanical angle at any moment for The mechanical angular velocity at a given moment. for The mechanical angle of time, The damping coefficient is... For rotational inertia, For electromagnetic torque, This represents the load torque.

4. A modeling apparatus based on the permanent magnet synchronous motor eccentricity fault modeling method according to claim 1, characterized in that, include: The input module is used to input the mechanical angle of the permanent magnet synchronous motor at the current moment into the improved air gap distribution function under eccentric fault, so as to obtain the improved air gap distribution function and the reverse air gap distribution function under the eccentric fault at the current moment; wherein, the spatial angle and mechanical angle are introduced into the original air gap distribution function to obtain the improved air gap distribution function; The first calculation module is used to obtain the self-inductance parameters and mutual inductance parameters at the current moment based on the improved air gap distribution function and the reverse air gap distribution function under the current moment of eccentric fault, using the improved winding function method; and to combine the self-inductance parameters and mutual inductance parameters at the current moment to obtain the inductance matrix at the current moment. The second calculation module is used to input the inductance matrix and motor speed at the current moment into the voltage equation and flux linkage equation to obtain the stator current derivative at the current moment; based on the stator current derivative at the current moment, it obtains the stator current and electromagnetic torque of the permanent magnet synchronous motor at the next moment, and inputs the stator current and electromagnetic torque at the next moment into the dynamic equation to obtain the mechanical angle and motor speed at the next moment. The iteration module is used to iterate the process of obtaining the stator current based on the mechanical angle and motor speed at the next moment until the iteration ends, and outputs the stator current waveform corresponding to the permanent magnet synchronous motor.

5. A computer device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the eccentric fault modeling method for permanent magnet synchronous motors as described in any one of claims 1-3.

6. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the eccentricity fault modeling method for permanent magnet synchronous motors as described in any one of claims 1-3.

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