Simulation modeling method and device of permanent magnet synchronous motor

Abstract

The invention discloses a simulation modeling method and device for a permanent magnet synchronous motor. The simulation modeling method comprises the following steps: establishing a state equation of the permanent magnet synchronous motor; searching in a preformed first two-dimensional array by taking the stator current as an input quantity to obtain corresponding stator inductance; calculating a stator flux linkage differential value according to a state equation of the permanent magnet synchronous motor and the found stator inductance; integrating the stator flux linkage differential value to obtain a stator flux linkage; and obtaining the adjusted stator current according to the obtained stator flux linkage and the relational expression between the flux linkage and the current. According to the application, the MTPA function can be realized, the values of the inductance and the flux linkage are reduced along with the increase of the current, the MTPA state and the weak magnetic state working area of the real motor can be simulated, and the simulation motor is ensured to be close to the operation condition of the actual motor to the greatest extent.

Description

Technical Field

[0001] This application relates to the field of motor modeling technology, and in particular to a simulation modeling method and apparatus for a permanent magnet synchronous motor. Background Technology

[0002] AC motors are widely used due to their simple manufacturing process and good stability. Among them, permanent magnet synchronous motors are widely used in the market because of their simple rotor structure and small size.

[0003] In fields such as semiconductor manufacturing, rail transportation, and new energy power generation, simulation verification is performed based on the measured motor parameters before field application. This involves using power electronic devices to simulate the characteristics of a real motor, and the accuracy of the motor parameters is a prerequisite for ensuring the accuracy of the simulation.

[0004] In traditional permanent magnet synchronous motor (PMSM) model analysis, the motor is generally idealized. To avoid the high coupling and computational difficulties inherent in natural coordinate systems, the three-phase inductance is transformed into dq-axis inductance in a rotating coordinate system. This simplifies the control of AC variables and makes the PMSM mathematical model more concise. However, treating motor parameters as constants is an assumption based on idealization. In practical applications, they are affected by many real-world factors. For example, the accuracy of parameters such as rotor flux linkage and inductance is influenced by motor temperature and magnetic field.

[0005] Therefore, in direct torque control systems, the variability of stator inductance and rotor flux linkage needs to be considered to obtain a highly accurate motor model, thereby simulating more realistic motor operating conditions. At the same time, to avoid overly idealized simulation results, the motor's harmonic characteristics also need to be considered. A common solution for harmonic suppression is harmonic injection, and the accuracy of harmonic quantity extraction is fundamental to ensuring the effectiveness of the control method. Summary of the Invention

[0006] In view of this, the purpose of this application is to provide a simulation modeling method and device for permanent magnet synchronous motors, so as to more realistically simulate the operating characteristics and harmonic characteristics of actual motors.

[0007] The technical solution adopted in this application to solve the above-mentioned technical problems is as follows:

[0008] This application provides a simulation modeling method for a permanent magnet synchronous motor, the simulation modeling method comprising:

[0009] Establish the state equations for the permanent magnet synchronous motor;

[0010] Using the stator current as the input, the corresponding stator inductance is obtained by searching in a pre-formed first two-dimensional array;

[0011] Based on the state equation of the permanent magnet synchronous motor and the found stator inductance, the differential value of the stator flux linkage is calculated.

[0012] Integrating the differential value of the stator flux linkage yields the stator flux linkage;

[0013] Based on the obtained stator flux linkage and the relationship between flux linkage and current, the adjusted stator current is obtained.

[0014] This application also provides a simulation modeling device for a permanent magnet synchronous motor. The simulation modeling device includes a control unit, which includes a memory and a processor. The memory is configured to store a computer program, and the processor, when executing the computer program, implements the simulation modeling method for the permanent magnet synchronous motor.

[0015] In the simulation model, the existing permanent magnet motor simulation module cannot realize the simulation conditions where the motor parameters can be changed in real time and simulate the harmonic characteristics of the motor. As a result, the performance and functional characteristics of the converter verified by simulation are slightly different from those of the actual motor.

[0016] The simulation modeling method and apparatus for permanent magnet synchronous motors provided in this application can largely simulate the operating characteristics of real motors, laying a good testing environment for the joint commissioning of converters and motors. Specifically, it can realize the maximum torque per ampere (MTPA) function, and the values ​​of inductance and flux linkage decrease as the current increases, simulating the MTPA state and field weakening state operating region of a real motor, ensuring that the simulated motor closely approximates the operating conditions of the actual motor. Furthermore, the harmonic control method can provide more implementation paths for harmonic suppression methods from different perspectives, improving the applicability of harmonic control methods. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the converter topology provided in an embodiment of this application;

[0018] Figure 2 A system block diagram of the converter topology provided in the embodiments of this application;

[0019] Figure 3 A schematic diagram of a simulation modeling method for a permanent magnet synchronous motor provided in an embodiment of this application;

[0020] Figure 4 This is a schematic diagram of a two-dimensional array lookup table module provided in an embodiment of this application;

[0021] Figure 5 This is a schematic diagram of a two-dimensional array lookup table module for magnetic linkage provided in an embodiment of this application;

[0022] Figure 6 This is a schematic diagram of a flux linkage harmonic model provided in an embodiment of this application.

[0023] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer and more understandable, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit the scope of this application.

[0025] The variables and their definitions involved in the embodiments of this application are as follows:

[0026] u a u b u c Stator three-phase phase voltage

[0027] i a i b i c Stator three-phase phase current

[0028] R s Equivalent resistance of stator winding

[0029] i d d-axis component of stator current

[0030] i q q-axis component of stator current

[0031] u d d-axis component of stator voltage

[0032] u q q-axis component of stator voltage

[0033] L d d-axis inductance

[0034] L q : q-axis inductance

[0035] L d_int d-axis inductance matrix related to current

[0036] L q_int q-axis inductance matrix related to current

[0037] ψ d d-axis component of stator flux linkage

[0038] ψ q : Stator flux linkage q-axis component

[0039] ψ f Rotor flux

[0040] L s Equivalent inductance of stator winding

[0041] θ: Motor angle calculated based on the given motor speed.

[0042] T e Electromagnetic torque output by the motor

[0043] ω r Rotor electrical angle (rad / s)

[0044] θ r Rotor angle value

[0045] One embodiment of this application provides a simulation modeling method for a permanent magnet synchronous motor, applicable to two-level and three-level converter topologies. For example... Figure 1 The converter topology shown includes converters, specifically a grid-side converter and a machine-side converter. The grid-side converter and the machine-side converter are connected via a DC bus, for example, a positive DC bus and a negative DC bus. A DC bus capacitor is connected between the positive and negative DC buses, and a chopper module may also be connected. The AC terminal of the grid-side converter is connected to the power grid, and the AC terminal of the machine-side converter is connected to a wind turbine, such as a permanent magnet synchronous motor.

[0046] Figure 2 yes Figure 1 The system block diagram of the converter topology shown includes a main circuit section and a motor model and power supply module. The main circuit section includes current-limiting impedance, chopper drive, bus section, generator-side RL circuit, soft-start logic, waveform generation module, grid-side RLC circuit, measurement module, etc. The motor model and power supply module includes a power supply module, main circuit breaker closing and opening logic, motor equivalent model, power calculation / current conversion module, etc. The motor model and power supply module outputs the calculated motor current value to the main circuit section, and the main circuit section feeds back the motor voltage detection results to the motor model and power supply module.

[0047] like Figure 3 As shown, the simulation modeling method includes the following steps:

[0048] S11. Establish the state equations of the permanent magnet synchronous motor;

[0049] In one example, establishing the state equations of the permanent magnet synchronous motor includes:

[0050] Based on the voltage equations of the permanent magnet synchronous motor in the three-phase stationary coordinate system, the state equations of the permanent magnet synchronous motor in the dq-axis coordinate system are established.

[0051] In the state equation of the permanent magnet synchronous motor in the dq axis coordinate system, the input quantity is the ripple voltage, and the state variables are the stator current value and the stator flux linkage value; wherein, the angle value used for coordinate change is calculated based on the given speed value.

[0052] Specifically, the voltage equations of a permanent magnet synchronous motor in the three-phase stationary coordinate system are as follows:

[0053]

[0054] Among them, u a u b u c These are the three-phase phase voltages of the stator, i a i b i c These are the three-phase stator currents, R s ψ is the equivalent resistance of the stator winding. f For rotor flux linkage, θ r This represents the rotor angle value.

[0055] The mathematical model of the permanent magnet synchronous motor in the three-phase stationary coordinate system is transformed into the state equations in the two-phase rotating coordinate system using Clark and Park transformations. The Clark and Park transformation matrices are as follows:

[0056]

[0057] The angle value θ used in the Park transform is... r It is calculated based on the given rotational speed. The calculation formula is: θ r =∫ω r dt, where ω r The rotor electrical angle is calculated using the formula ω. r =2πf, f represents the generator frequency, p represents the number of pole pairs, and n represents the setpoint speed. The conversion relationship between current and voltage in a two-phase rotating coordinate system and current and voltage in a three-phase stationary coordinate system is as follows:

[0058]

[0059] Substituting equations (2) and (3) into equation (1) and simplifying, we get:

[0060]

[0061] in, Substituting into equation (4), we get:

[0062]

[0063] A mathematical model of the permanent magnet synchronous motor is established based on equation (5), with the input being the ripple voltage and the state variable being the stator flux linkage ψ. d ψ q and stator current i d i q The observed quantity is the stator current i d i q .

[0064] S12. Using the stator current as the input quantity, search in the pre-formed first two-dimensional array to obtain the corresponding stator inductance;

[0065] In one example, the first two-dimensional array is obtained as follows:

[0066] Based on the test data or simulation data of the stator current and the stator inductance, the stator current and the stator inductance are coupled by interpolation to form the first two-dimensional array.

[0067] Taking Simulink modeling as an example, the implementation logic for a variable inductance is as follows:

[0068] 1) Based on the actual measured data of the motor provided by the motor manufacturer, use methods such as cubic spline or linear interpolation to calculate i d i q With L d L q Coupled as a two-dimensional array L d_int and L q_int The coupling function uses Matlab's built-in two-dimensional interpolation function 'interp2', which can accept various interpolation methods, such as cubic spline, linear interpolation, and nearest neighbor interpolation.

[0069] 2) Referencing the Simulink lookup table module '2-D Lookup Table', using i d i q Current is the input quantity, in the two-dimensional array L d_int and L q_int Find the current d-axis inductance L d and q-axis inductance L q The two-dimensional array lookup table module for inductors is implemented as follows: Figure 4 As shown: iqs represents the current value of the q-axis component of the motor stator current, ids is the current value of the d-axis component of the motor stator current, iqs_f represents the absolute value of the q-axis component of the motor stator current, 2-DT(u) represents a two-dimensional array lookup table, z -1 L represents the transfer function of the delay module.d L represents the d-axis inductance of the motor. q Let |u| represent the q-axis inductance of the motor, and |u| be the transfer function of the absolute value module. This module is based on the d-axis component of the motor stator current, i. d Stator current q-axis i q By searching for the d-axis inductance L of the motor stator in a two-dimensional array d and q-axis inductance L q It is used to simulate the actual numerical changes of motor inductance parameters;

[0070] 3) L obtained from the table d L q In the equivalent mathematical model of a permanent magnet synchronous motor, iterative calculations are performed to obtain the differential values ​​of the d-axis flux linkage and the q-axis flux linkage. The formula used for the calculation is shown in equation (5).

[0071] 4) To After integration, the d-axis flux linkage value and the q-axis flux linkage value ψ are obtained. d ψ q Based on the relationship between magnetic flux and current, we obtain i d i q The formula used is as follows:

[0072]

[0073] 5) Repeat steps 2)-4) in a loop to obtain the stator current value in real time.

[0074] S13. Based on the state equation of the permanent magnet synchronous motor and the found stator inductance, calculate the differential value of the stator flux linkage;

[0075] S14. Integrate the differential value of the stator flux linkage to obtain the stator flux linkage;

[0076] S15. Based on the obtained stator flux linkage and the relationship between flux linkage and current, the adjusted stator current is obtained.

[0077] Specifically, the adjusted stator current d-axis component is obtained based on the stator flux linkage d-axis component and the relational expression; the adjusted stator current q-axis component is obtained based on the stator flux linkage q-axis component and the relational expression.

[0078] In one example, the simulation modeling method further includes:

[0079] Using the motor temperature and the q-axis component of the stator current as inputs, the corresponding rotor flux is obtained by searching in a pre-formed second two-dimensional array.

[0080] Based on the found rotor flux linkage, stator flux linkage d-axis component, and the relationship, the adjusted stator current d-axis component is obtained.

[0081] The second two-dimensional array can be obtained in the following way:

[0082] Based on the test data or simulation data of the motor temperature, the q-axis component of the stator current, and the rotor flux linkage, a second two-dimensional array of the rotor flux linkage is formed, with the motor temperature as the row matrix and the q-axis component of the stator current as the column matrix.

[0083] Specifically, rotor flux linkage ψ f The accuracy of the calculation also affects the stator current. In ideal motor models, the rotor flux linkage is often considered constant, but in actual systems, the rotor flux linkage is affected by temperature and stator current. To simulate the characteristics of a real motor, the variation in rotor flux linkage must be considered. As the motor temperature increases, the flux linkage decreases; while the q-axis component of the stator current I... q This will affect the magnetic flux in the air gap of the motor, causing magnetic circuit saturation, and to some extent, affecting the motor's flux linkage. According to the actual measured or simulated data provided by the motor manufacturer, the logic for implementing variable rotor flux linkage is: based on the motor temperature and I... q As input, a two-dimensional array of flux linkages is formed. The variability of the flux linkages is realized through a '2-D Lookup Table' module and used for iterative calculations of the motor model. The two-dimensional array lookup table module for flux linkages is implemented as follows: Figure 5 As shown: iqs_f represents the absolute value of the q-axis component of the motor stator current, 2-DT(u) represents a two-dimensional array lookup table, and z -1 This is the transfer function of the delay module, where Tr represents the motor temperature value and psi_r represents the motor rotor flux linkage. Based on the motor temperature value Tr and the absolute value of the q-axis component of the motor stator current, this module searches a two-dimensional array for the corresponding motor rotor flux linkage at the current temperature and stator current, simulating the influence of motor temperature and stator current on the rotor flux linkage.

[0084] In one example, the simulation modeling method further includes:

[0085] Inject the 5th or 7th harmonic into the rotor flux linkage;

[0086] If the 5th harmonic is negative sequence, a negative sequence 6th harmonic component needs to be injected at an angle of -6θ; if the 7th harmonic is positive sequence, a positive sequence 6th harmonic component needs to be injected at an angle of 6θ; the amplitude of the 5th or 7th harmonic is 5% of the rotor flux linkage amplitude.

[0087] Specifically, due to factors such as cogging effect, magnetic circuit saturation effect, winding distribution, and rotor pole structure, the motor's air gap magnetic field distortion and the inverter's dead time and tube voltage drop, among other nonlinear characteristics, induce 3rd, 5th, 7th, and 9th harmonics within the motor. The 5th and 7th harmonics significantly impact torque pulsation and vibration noise, easily causing torque fluctuations. To approximate the characteristics of a real motor, a system is built... Figure 6 The flux linkage harmonic model shown is used to simulate the harmonic characteristics of the motor: psi_r represents the motor rotor flux linkage, angle1 represents the motor fundamental angular frequency, psiqs1 represents the 7th harmonic injected into the rotor flux linkage, psiqs2 represents the 5th harmonic injected into the rotor flux linkage, and psi_r_Harm represents the rotor flux linkage with harmonics. This model simulates the operating conditions where the motor rotor flux linkage contains the 5th and 7th harmonics by artificially injecting harmonics with an amplitude of 5% and phases of the 5th and 7th harmonics of the fundamental angular frequency, respectively.

[0088] In one example, the simulation modeling method further includes:

[0089] When harmonics exist in the rotor flux linkage, the harmonic quantity is extracted from the back electromotive force according to the relationship between rotor flux linkage and back electromotive force, and closed-loop control is performed; and / or, when harmonics exist in the rotor flux linkage, the harmonic quantity is extracted from the flux linkage observer according to the relationship between rotor flux linkage and torque, and open-loop control or closed-loop control is used to suppress the harmonics.

[0090] Specifically, in the dq coordinate system, a sixth harmonic exists on the rotor flux linkage. Therefore, with iterative model calculations, harmonics are present in the machine-side voltage, stator flux linkage, and back-electromagnetic field. A common solution is harmonic injection, but the dependencies for harmonic extraction can be selected from various variables. The following three control strategies are used to pre-eliminate motor torque and bus pulsations, thereby enhancing the converter's control performance.

[0091] (1) According to the expression for magnetic flux linkage and back electromotive force: E=ω r ψ f ……(7)

[0092] When harmonics exist in the rotor flux linkage of a motor, harmonics are also introduced into the back electromotive force (EMF). Therefore, the harmonics in the motor's back EMF can be extracted. The implementation steps are as follows:

[0093] a. The rotor flux is transformed into a flow rate in a 6th harmonic coordinate system by changing the dual dq coordinate system, and the harmonics are extracted by a low-pass filter;

[0094] b. A PI controller is used to adjust the output to a target value of 0. The controller output undergoes a 6-fold inverse Park change and is superimposed on the generator voltage of the machine-side converter for motor harmonic suppression.

[0095] (2) According to the torque formula:

[0096] When the rotor flux linkage ψ of the motor f When the sixth harmonic exists, ψ f It can be written as ψ f =ψ f0 +ψ f6 cos(6θ), if you want to eliminate ψ f The fluctuations in i then need to be addressed. d Injecting harmonics into the current The current value can suppress fluctuations in the flux linkage. This implementation method is an open-loop harmonic injection.

[0097] (3) Based on the open-loop harmonic injection method in (2), considering its poor adaptability, a closed-loop harmonic injection method is proposed. The specific implementation steps are as follows:

[0098] a. When the rotor flux linkage ψ of the motor f When there is a 6th harmonic, Park is performed at the 6th harmonic to convert the harmonic into a DC quantity;

[0099] b. Filter out harmonics using a low-pass filter;

[0100] c. A PI controller will be used to adjust the harmonic quantity with a target value of 0. The controller output will undergo an inverse Park change at a 6th harmonic, superimposed on i. d_Ref i q_Ref Perform closed-loop operation of the machine-side converter;

[0101] d. The current output is superimposed on the generator voltage of the machine-side converter to suppress harmonics in the flux linkage.

[0102] To enable real-time variation of the inductance and flux linkage parameters of a permanent magnet motor, this application introduces a two-dimensional lookup table model of inductance and current, temperature and flux linkage based on measured data, and constructs an equivalent model of the permanent magnet synchronous motor. Simultaneously, a harmonic model of the motor is constructed to simulate the harmonic characteristics of a real motor, and the harmonic control method is theoretically explained and implemented in code. The constructed motor model is applied to a hardware-in-the-loop (HIL) testing device, and the performance and function of the converter are verified by combining a control box and harmonic control algorithm, laying a solid testing environment for the stable operation of the converter in the wind farm.

[0103] Specifically, because traditional motor simulation modules cannot simulate L... d L qSimulating changes in current using only a fixed inductance value fails to accurately simulate the actual operating conditions of the motor, resulting in the inability to adjust the control parameters of the generator-side converter to optimal values. This increases the converter's commissioning cycle in wind farm applications. To address this issue, this application establishes a relationship between motor current and inductance L based on measured motor data provided by the motor manufacturer. d L q The coupling relationship is used to form a lookup table array, which enables a variable modeling method for motor inductance;

[0104] Furthermore, in practical systems, besides the variable inductance of the motor's dq-axis, the permanent magnets of the motor also weaken as the motor temperature increases. The magnitude of the flux linkage has the most significant impact on the stator current, which is detrimental to the evaluation and verification of the hardware overcurrent point and wave-by-wave current limiting point of the machine-side converter. To address this issue, this application establishes a motor simulation model, using current as input to achieve a real-time variable inductance modeling method, and using motor temperature and motor current i... q To input the flux linkage, a two-dimensional lookup table array is established to enable real-time variable modeling of the motor flux linkage. During the modeling process, the motor angle value is calculated based on the given speed value for coordinate transformation. The voltage and current values ​​in the abc three-phase stationary coordinate system are converted into voltage and current values ​​in the dq two-phase rotating coordinate system for iterative calculations of the motor mathematical model.

[0105] Based on the above points, a simulation model with real-time variable motor parameters was built. Simultaneously, a hardware-in-the-loop simulation was performed using the converter's control box. The simulation results were compared with those of a motor model with fixed parameters. The control parameters and stator current exhibited different behaviors, consistent with the simulation results of the Real-Time Laboratory (RTLAB) model with variable motor parameters. This demonstrates the reliability of the simulation system construction process and its reference value.

[0106] To address the torque pulsation problem caused by the 5th and 7th harmonics in permanent magnet synchronous machines, harmonic injection is often used for harmonic suppression. The accuracy of harmonic extraction is fundamental to the control method. This application uses flux linkage and back electromotive force as dependencies for harmonic extraction, and elaborates on harmonic control methods using open-loop and closed-loop control to eliminate torque pulsation in the motor and improve the control performance of the converter.

[0107] Another embodiment of this application provides a simulation modeling device for a permanent magnet synchronous motor. The simulation modeling device includes a control unit, which includes a memory and a processor. The memory is configured to store a computer program, and the processor, when executing the computer program, implements the simulation modeling method for the permanent magnet synchronous motor described in the foregoing embodiment.

[0108] The preferred embodiments of this application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and spirit of this application shall be within the scope of the claims.

Claims

1. A simulation modeling method of a permanent magnet synchronous motor, characterized by, The simulation modeling method comprises: establishing a state equation of the permanent magnet synchronous motor; taking the stator current as an input quantity, searching in a first two-dimensional array formed in advance to obtain corresponding stator inductance; calculating a stator flux linkage differential value according to the state equation of the permanent magnet synchronous motor and the searched stator inductance; integrating the stator flux linkage differential value to obtain a stator flux linkage; obtaining an adjusted stator current according to the obtained stator flux linkage and a relationship between the flux linkage and the current.

2. The simulation modeling method of claim 1, wherein, The state equation of the permanent magnet synchronous motor comprises: establishing a state equation in a dq-axis coordinate system of the permanent magnet synchronous motor according to a voltage equation in a three-phase stationary coordinate system of the permanent magnet synchronous motor.

3. The simulation modeling method of claim 2, wherein, In the state equation in the dq-axis coordinate system of the permanent magnet synchronous motor, the input quantity is a wave launch voltage, and the state variable is a stator current value and a stator flux linkage value; wherein an angle value used for coordinate conversion is calculated according to a speed given value.

4. The simulation modeling method of claim 1, wherein, The first two-dimensional array is obtained by: coupling the stator current and the stator inductance by an interpolation method according to test data or simulation data of the stator current and the stator inductance to form the first two-dimensional array.

5. The simulation modeling method of claim 1, wherein, The adjusted stator current is obtained according to the obtained stator flux linkage and the relationship between the flux linkage and the current, comprising: obtaining a d-axis component of the adjusted stator current according to a d-axis component of the stator flux linkage and the relationship; obtaining a q-axis component of the adjusted stator current according to a q-axis component of the stator flux linkage and the relationship.

6. The simulation modeling method of claim 5, wherein, The simulation modeling method further comprises: taking a motor temperature and a q-axis component of a stator current as input quantities, searching in a second two-dimensional array formed in advance to obtain corresponding rotor flux linkage; obtaining an adjusted d-axis component of the stator current according to the searched rotor flux linkage, a d-axis component of the stator flux linkage and the relationship.

7. The simulation modeling method of claim 6, wherein, The second two-dimensional array is obtained by: forming the second two-dimensional array of the rotor flux linkage according to test data or simulation data of the motor temperature, the q-axis component of the stator current and the rotor flux linkage, taking the motor temperature as a row matrix and the q-axis component of the stator current as a column matrix.

8. The simulation modeling method of claim 1, wherein, The simulation modeling method further comprises: injecting a 5th harmonic or a 7th harmonic on the rotor flux linkage; wherein the 5th harmonic is a negative sequence, and a 6 times frequency component of the negative sequence needs to be injected with an angle of -6θ; the 7th harmonic is a positive sequence, and a 6 times frequency component of the positive sequence needs to be injected with an angle of 6θ; the amplitude of the 5th harmonic or the 7th harmonic is 5% of the amplitude of the rotor flux linkage.

9. The simulation modeling method of claim 1, wherein, The simulation modeling method further comprises: when there is a harmonic in the rotor flux linkage, extracting a harmonic quantity from a back electromotive force according to a relationship between the rotor flux linkage and the back electromotive force and performing closed-loop control; and / or, when there is a harmonic in the rotor flux linkage, extracting a harmonic quantity from a flux linkage observer according to a relationship between the rotor flux linkage and torque and performing open-loop control or closed-loop control to suppress the harmonic.

10. A simulation modeling device of a permanent magnet synchronous motor, characterized by, The simulation modeling device comprises a control unit, the control unit comprises a memory and a processor, the memory is configured to store a computer program, and the processor realizes the simulation modeling method of the permanent magnet synchronous motor according to any one of claims 1-9 when executing the computer program.

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