Permanent magnet synchronous motor parameter calculation method, device and equipment

Abstract

The application provides a permanent magnet synchronous motor parameter calculation method, device and equipment, comprising: collecting working condition parameters in the operation process of the permanent magnet synchronous motor, wherein the working condition parameters include voltage, current, torque and rotating speed; calculating initial inductance parameters and initial stator flux linkage according to the working condition parameters; fusing based on the initial inductance parameters to obtain three-dimensional inductance, fusing the initial stator flux linkage to generate three-dimensional stator flux linkage; smoothing the three-dimensional inductance and three-dimensional stator flux linkage through a high-order polynomial to obtain optimized three-dimensional inductance, three-dimensional stator flux linkage and fitting coefficient matrix; and calculating permanent magnet synchronous motor parameters based on the working condition parameters, optimized three-dimensional inductance, three-dimensional stator flux linkage and fitting coefficient matrix. The accuracy of the permanent magnet synchronous motor parameters is improved.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motor parameter calculation technology, specifically to a method, apparatus, and equipment for calculating permanent magnet synchronous motor parameters. Background Technology

[0002] Due to its advantages such as compact structure, low maintenance cost, and high power density, the permanent magnet synchronous motor (PMSM) is increasingly being used in industries such as automotive drive, agricultural machinery, and construction machinery.

[0003] In permanent magnet synchronous motor control systems, the current loop is a crucial component for achieving precise control, and the setting of the PI (proportional-integral) parameter directly determines the system's dynamic response and stability. Current current loop control employs two decoupling strategies: complex vector decoupling and feedforward decoupling. In PI calculation, a constant DQ-axis inductance is introduced. However, since the DQ-axis inductance changes with the motor's operating state and is not a constant value, the constant DQ-axis inductance parameter is inaccurate, leading to inaccurate PI calculations. This further results in insufficient decoupling in both complex vector and feedforward decoupling, ultimately causing low accuracy in the obtained motor parameters. Summary of the Invention

[0004] In view of this, the present invention aims to provide a method, apparatus and device for calculating the parameters of a permanent magnet synchronous motor, in order to solve the problem in the prior art that the calculation of PI using a constant DQ axis inductance leads to insufficient decoupling of complex vector decoupling and feedforward decoupling, resulting in low accuracy of the obtained motor parameters.

[0005] This invention provides a method for calculating the parameters of a permanent magnet synchronous motor, the method comprising: The operating parameters of the permanent magnet synchronous motor during operation are collected, including voltage, current, torque and speed. The initial inductance parameters and initial stator flux linkage are calculated based on the operating parameters. Based on the initial inductance parameters, a three-dimensional inductance is obtained by fusing them, and the initial stator flux linkage is fused to generate a three-dimensional stator flux linkage. The three-dimensional inductor and three-dimensional stator flux linkage are smoothed by high-order polynomials to obtain the optimized three-dimensional inductor, three-dimensional stator flux linkage and fitting coefficient matrix. Based on the operating parameters, the optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are calculated.

[0006] In one possible embodiment, the initial inductance parameter includes the D-axis initial inductance parameter, and the initial inductance parameter calculated based on the operating condition parameters includes: Subtract the forward Q-axis voltage from the reverse Q-axis voltage to obtain the first voltage difference. Based on the first voltage difference and the angular velocity, a first ratio is obtained; Divide the first ratio by the current to obtain the initial inductance parameters of the D-axis, wherein the angular velocity is calculated from the rotational speed.

[0007] In one possible embodiment, the initial inductance parameter further includes a Q-axis initial inductance parameter, wherein calculating the initial inductance parameter based on the operating condition parameters includes: Find the number of pole pairs of the permanent magnet synchronous motor, and calculate the second ratio based on the torque and the number of pole pairs; Based on the second ratio and the current, the third ratio is calculated; The initial inductance parameter of the D-axis is calculated by subtracting the third ratio.

[0008] In one possible embodiment, calculating the initial stator flux linkage based on the operating parameters includes: Subtract the forward Q-axis voltage from the reverse Q-axis voltage to obtain the first voltage difference. Based on the first voltage difference and angular velocity, a first ratio is obtained, and the first ratio is set as the initial stator flux linkage of the D-axis. Subtract the forward D-axis voltage from the reverse D-axis voltage to obtain the second voltage difference. Based on the second voltage difference and angular velocity, a fourth ratio is obtained, and the fourth ratio is set as the initial stator flux linkage of the Q-axis, wherein the angular velocity is calculated by the rotational speed.

[0009] In one possible embodiment, the fusion based on the initial inductance parameters to obtain the three-dimensional inductance includes: The initial inductance parameters, along with the corresponding direct-axis current id and quadrature-axis current iq, are connected using a bilinear interpolation method to obtain a three-dimensional inductance.

[0010] In one possible embodiment, the initial stator flux linkage includes a Q-axis initial stator flux linkage and a D-axis initial stator flux linkage, and the fusion of the initial stator flux linkages to generate a three-dimensional stator flux linkage includes: The initial stator flux linkage, along with the corresponding direct-axis current id and quadrature-axis current iq, are connected using a bilinear interpolation method to obtain a three-dimensional stator flux linkage.

[0011] In one possible embodiment, the calculation of permanent magnet synchronous motor parameters based on the operating parameters, optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix includes: Obtain the bandwidth and carrier frequency of the permanent magnet synchronous motor; Based on the bandwidth of the permanent magnet synchronous motor and the parameters of the optimized three-dimensional inductance, the proportional gain of the controller of the permanent magnet synchronous motor is calculated. The integral gain of the controller of the permanent magnet synchronous motor is calculated based on the carrier frequency of the permanent magnet synchronous motor and the preset resistance. The voltage command is calculated based on the proportional gain, integral gain, current, angular velocity, and optimized three-dimensional stator flux linkage. Based on the voltage command and the fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are obtained, wherein the angular velocity is calculated from the rotational speed.

[0012] In one possible embodiment, after calculating the permanent magnet synchronous motor parameters based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix, the method further includes: Obtain the storage capacity of the controller of the permanent magnet synchronous motor; Based on the storage capacity, determine the parameters to be written to the controller; The determined parameters are written into the controller.

[0013] Secondly, the present invention provides a device for calculating the parameters of a permanent magnet synchronous motor, the device comprising: The acquisition module is used to acquire operating parameters of the permanent magnet synchronous motor during operation, including voltage, current, torque and speed. The first calculation module is used to calculate the initial inductance parameters and the initial stator flux linkage based on the operating condition parameters. The fusion module is used to fuse based on the initial inductance parameters to obtain a three-dimensional inductance, and to fuse the initial stator flux linkage to generate a three-dimensional stator flux linkage. The smoothing module is used to smooth the three-dimensional inductor and the three-dimensional stator flux linkage using a high-order polynomial to obtain the optimized three-dimensional inductor, the three-dimensional stator flux linkage and the fitting coefficient matrix. The second calculation module is used to calculate the parameters of the permanent magnet synchronous motor based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix.

[0014] Thirdly, the present invention provides an electronic device, the device comprising: a memory and a processor; the memory being used to store relevant program code; the processor being used to call the program code to execute the method for calculating the parameters of a permanent magnet synchronous motor as described in any implementation of the first aspect.

[0015] Fourthly, the present invention provides a computer-readable storage medium for storing a computer program for executing the method for calculating the parameters of a permanent magnet synchronous motor as described in any implementation of the first aspect.

[0016] Fifthly, the present invention provides a computer program product, the computer program product comprising a computer program / instruction, which, when executed by a processor, implements the method for calculating the parameters of a permanent magnet synchronous motor as described in any of the implementations of the first aspect.

[0017] In the above implementation of the present invention, operating parameters during the operation of the permanent magnet synchronous motor are collected, including voltage, current, torque, and speed. Initial inductance parameters and initial stator flux linkage are calculated based on these parameters, eliminating the influence of voltage and resistance on these parameters and making the calculated parameters more accurate. The initial inductance parameters are then fused to obtain a three-dimensional inductance, and the initial stator flux linkage is further fused to generate a three-dimensional stator flux linkage. A high-order polynomial is used to smooth the three-dimensional inductance and stator flux linkage, resulting in optimized three-dimensional inductance, three-dimensional stator flux linkage, and a fitting coefficient matrix. Smoothing the three-dimensional inductance and stator flux linkage with a high-order polynomial eliminates local outliers, further improving the accuracy of the inductance parameters and stator flux linkage. This improves the accuracy of the permanent magnet synchronous motor parameters calculated based on the optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix. Attached Figure Description

[0018] Figure 1 A flowchart illustrating a method for calculating parameters of a permanent magnet synchronous motor, as provided in an embodiment of the present invention.

[0019] Figure 2 A flowchart for calculating initial inductance parameters based on the operating condition parameters is provided for an embodiment of the present invention.

[0020] Figure 3 Another flowchart for calculating the initial inductance parameters based on the operating condition parameters is provided for an embodiment of the present invention.

[0021] Figure 4A flowchart for calculating the initial stator flux linkage based on the operating parameters provided in an embodiment of the present invention.

[0022] Figure 5 A schematic diagram of a device for calculating the parameters of a permanent magnet synchronous motor is provided in an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Due to its advantages such as compact structure, low maintenance cost, and high power density, the permanent magnet synchronous motor (PMSM) is increasingly being used in industries such as automotive drive, agricultural machinery, and construction machinery.

[0026] In permanent magnet synchronous motor control systems, the current loop is a crucial component for achieving precise control, and the setting of the PI (proportional-integral) parameter directly determines the system's dynamic response and stability. Current current loop control employs two decoupling strategies: complex vector decoupling and feedforward decoupling. In PI calculation, a constant DQ-axis inductance is introduced. However, since the DQ-axis inductance changes with the motor's operating state and is not a constant value, the constant DQ-axis inductance parameter is inaccurate, leading to inaccurate PI calculations. This further results in insufficient decoupling in both complex vector and feedforward decoupling, ultimately causing low accuracy in the obtained motor parameters.

[0027] Therefore, in this invention, dynamically changing operating parameters are used to calculate the initial inductance parameters and initial stator flux linkage. This eliminates the influence of voltage and resistance on the initial inductance parameters and initial stator flux linkage, making the calculated initial inductance parameters and initial stator flux linkage more accurate. Furthermore, optimizing the three-dimensional inductance parameters and stator flux linkage obtained by fusing the initial inductance parameters and initial stator flux linkage eliminates local outliers in the three-dimensional inductance and three-dimensional stator flux linkage, further increasing their accuracy. This improves the accuracy of the permanent magnet synchronous motor parameters calculated based on the optimized three-dimensional inductance parameters and three-dimensional stator flux linkage parameters.

[0028] Specifically, one embodiment of the present invention provides a method for calculating parameters of a permanent magnet synchronous motor. This method involves collecting operating parameters of the permanent magnet synchronous motor during operation, including voltage, current, torque, and speed. Initial inductance parameters and initial stator flux linkage are calculated based on these parameters, eliminating the influence of voltage and resistance on these parameters and making the calculated parameters more accurate. The initial inductance parameters are then fused to obtain a three-dimensional inductance, and the initial stator flux linkage is further fused to generate a three-dimensional stator flux linkage. A high-order polynomial is used to smooth the three-dimensional inductance and stator flux linkage, resulting in optimized three-dimensional inductance, three-dimensional stator flux linkage, and a fitting coefficient matrix. Smoothing the three-dimensional inductance and stator flux linkage with a high-order polynomial eliminates local outliers, further improving the accuracy of the inductance parameters and stator flux linkage. This improves the accuracy of the permanent magnet synchronous motor parameters calculated based on the optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix.

[0029] Please see Figure 1 In one exemplary embodiment, a method for calculating the parameters of a permanent magnet synchronous motor is provided, which is applied in the controller of a permanent magnet synchronous motor control system. The method may include the following steps: S101: Collect operating parameters during the operation of the permanent magnet synchronous motor, including voltage, current, torque and speed.

[0030] Specifically, operating parameters of the permanent magnet synchronous motor are collected during operation. These parameters can be automatically calibrated to typical operating conditions, thus avoiding excessively large data sets across all operating conditions. Operating parameters include voltage, current, torque, and speed. Current may include the direct-axis current i. d and cross-axis current i q Voltage can include D-axis voltage u. d and Q-axis voltage u q Torque is the output torque of a permanent magnet synchronous motor shaft that drives the load to rotate. Rotational speed is a physical quantity that determines how fast the permanent magnet synchronous motor rotates around its shaft. Angular velocity can be calculated from the rotational speed using the following formula: Angular velocity ωe = (2π / 2) rotational speed (Number of pole pairs) / 60. In practical implementation, current can be acquired through a Hall effect current sensor, voltage through an isolation amplifier or resistive voltage divider, and torque through a rotary torque sensor. Rotational speed can be acquired through a rotary transformer or Hall sensor.

[0031] S102: Calculate the initial inductance parameters and the initial stator flux linkage based on the operating parameters.

[0032] In this embodiment, after acquiring the operating parameters, the initial inductance parameters and initial stator flux linkage can be calculated based on these parameters. The motor inductance is an electromagnetic parameter that measures the ability of the stator winding to generate electromotive force when the current changes, reflecting the self-inductance and mutual inductance characteristics of the winding. The initial inductance parameters can include D-axis initial inductance parameters and Q-axis initial inductance parameters. The D-axis initial inductance parameters can be calculated based on the current, voltage, and angular velocity in the operating parameters. The Q-axis initial inductance parameters can be calculated based on the D-axis initial inductance parameters and the torque in the operating parameters. The initial stator flux linkage can be calculated based on the angular velocity in the operating parameters, where the stator flux linkage is divided into D-axis and Q-axis stator flux linkages.

[0033] Specifically, refer to Figure 2 In one exemplary embodiment, a method for calculating initial inductance parameters is provided. When the initial inductance parameters may include D-axis initial inductance parameters, the step of calculating the initial inductance parameters based on the operating condition parameters includes: S1021, Subtract the forward Q-axis voltage from the reverse Q-axis voltage in the voltage to obtain the voltage difference; S1022, Based on the voltage difference and angular velocity, obtain the first ratio; S1023, divide the first ratio by the current to obtain the initial inductance parameters of the D-axis.

[0034] In practice, the operating parameters of the permanent magnet synchronous motor are collected during its operation. This can be considered as collecting the initial calibration parameters, i.e., the parameters calibrated for the first time. These operating parameters can include current, voltage, torque, and speed. The current can include the direct-axis current i. d and cross-axis current i q Voltage can include D-axis voltage u. d and Q-axis voltage u q In practice, current can be acquired using a Hall effect current sensor, voltage can be acquired using an isolation amplifier or resistive voltage divider, torque can be acquired using a rotary torque sensor, and rotational speed can be acquired using a rotary transformer or Hall sensor.

[0035] After acquiring the operating parameters, the initial inductance parameters along the D-axis can be derived based on the voltage equation. The voltage equation is as follows: Under standard operating conditions, with forward drive and reverse power supply, i q The same and all positive, angular velocity ω eThe absolute values ​​are the same. i d Since they are the same and both are negative, we can obtain the following by subtracting the forward and reverse voltage equations: therefore, In the specific implementation process, the permanent magnet magnetic flux ϕ f The change is almost negligible, meaning the permanent magnet flux ϕ can be reduced. f The values ​​are set to the motor's nominal values, which can be found in the product manual of the permanent magnet synchronous motor. Therefore, the forward and reverse voltages and angular velocities are substituted into the calculation formula: the Q-axis forward voltage is subtracted from the Q-axis reverse voltage to obtain a first voltage difference. This first voltage difference is then divided by twice the angular velocity to obtain a first ratio. Finally, this first ratio is compared with the direct-axis current i. d By dividing by the given ratio, the initial inductance parameter L along the D-axis can be obtained. d The angular velocity can be calculated from the rotational speed. The specific calculation formula can be found in step S101, and will not be repeated here.

[0036] Specifically, refer to Figure 3 In one exemplary embodiment, another method for calculating the initial inductance parameter is provided. When the initial inductance parameter may include the Q-axis initial inductance parameter, the step of calculating the initial inductance parameter based on the operating condition parameters includes: S1024, find the number of pole pairs of the permanent magnet synchronous motor, and calculate the second ratio based on the torque and the number of pole pairs; S1025, based on the second ratio and the current, the third ratio is calculated; S1026, Subtract the initial inductance parameter of the D-axis from the third ratio to calculate the initial inductance parameter of the Q-axis.

[0037] In the specific implementation process, due to the Q-axis inductance during the operation of the permanent magnet synchronous motor... L q The range of variation is large, while u d and u q The voltage output by the PI control is not the actual voltage, while the torque is the actual torque of the motor. Therefore, the voltage equation is no longer used to calculate the Q-axis inductance. L q L is calculated using the torque formula. q .

[0038] Specifically, the torque formula can be: Where p is the number of pole pairs of the permanent magnet synchronous motor, ϕ is an inherent physical structural parameter of the permanent magnet synchronous motor, which can be obtained by consulting the product manual of the permanent magnet synchronous motor. fFor permanent magnet flux linkage, permanent magnet flux linkage ϕ f The change is almost negligible, meaning the permanent magnet flux ϕ can be reduced. f Set to the motor's nominal value, which can be found in the product manual of the permanent magnet synchronous motor. d For direct-axis current i d i q For quadrature axis current i q Where Te represents torque. Through formula conversion, the formula for calculating Lq is obtained as follows: By substituting the collected torque, direct-axis current, quadrature-axis current, and the number of pole pairs of the permanent magnet synchronous motor obtained from the search into the calculation formula for Lq, Lq can be obtained.

[0039] Specifically, refer to Figure 4 In one exemplary embodiment, a method for calculating the initial stator flux linkage is provided. The steps of calculating the initial stator flux linkage based on the operating parameters include: S1027, Subtract the Q-axis forward rotation voltage from the Q-axis reverse rotation voltage in the voltage to obtain the first voltage difference; S1028, Based on the first voltage difference and angular velocity, obtain a first ratio and set the first ratio as the initial stator flux linkage of the D-axis; S1029, subtract the forward rotation voltage of the D-axis from the reverse rotation voltage of the D-axis to obtain a second voltage difference; based on the second voltage difference and the angular velocity, obtain a fourth ratio, and set the fourth ratio as the initial stator flux linkage of the Q-axis, wherein the angular velocity is calculated by the rotational speed.

[0040] In the specific implementation process, the angular velocity is obtained through rotational speed calculation. Similarly, the initial stator flux linkage can be derived based on the voltage equation. The voltage equation is as follows: To calculate the initial stator flux linkage along the D-axis For example, the voltage equation for the Q-axis is as follows: Under standard operating conditions, with forward drive and reverse power supply, i q The same and all positive, angular velocity ω e Since the absolute values ​​are the same, we can obtain the following by subtracting the forward and reverse voltage equations: therefore, The calculation formula can be: Substituting the forward and reverse rotation voltages and angular velocities into the calculation formula, that is, subtracting the Q-axis forward rotation voltage from the Q-axis reverse rotation voltage to obtain the first voltage difference, and dividing the first voltage difference by twice the angular velocity to obtain the first ratio, which is the initial stator flux linkage on the D-axis. .

[0041] To calculate the initial stator flux linkage along the Q-axis For example, the voltage equation for the D-axis is as follows: Under standard operating conditions, with forward drive and reverse power supply, the angular velocity... ω e The absolute values ​​are the same. i d Since they are the same and both are negative, we can obtain the following by subtracting the forward and reverse voltage equations: therefore, Substituting the forward and reverse rotation voltages and angular velocities into the calculation formula, i.e., subtracting the D-axis forward rotation voltage from the D-axis reverse rotation voltage, yields the second voltage difference. Dividing this second voltage difference by twice the angular velocity yields the fourth ratio, which is the initial stator flux linkage on the Q-axis. .

[0042] S103: Based on the initial inductance parameters, a three-dimensional inductance is obtained by fusion, and the initial stator flux linkage is fused to generate a three-dimensional stator flux linkage.

[0043] In this embodiment, after calculating the initial inductance parameters and the initial stator flux linkage, they can be fused together to generate a three-dimensional inductance and a three-dimensional stator flux linkage.

[0044] Specifically, the initial inductance parameters include the Q-axis initial inductance parameters, and the step of calculating the initial inductance parameters based on the operating condition parameters includes: The initial inductance parameters and the corresponding direct-axis current i are obtained by bilinear interpolation. d Cross-axis current i q Make connections to obtain a three-dimensional inductance.

[0045] Specifically, bilinear interpolation is used to connect all discrete data points to generate a smooth three-dimensional surface, i.e., a three-dimensional inductor. The data points include the direct-axis current i at each point. d Cross-axis current i q and initial inductance parameters.

[0046] The initial stator flux linkage includes a Q-axis initial stator flux linkage and a D-axis initial stator flux linkage. The step of fusing the initial stator flux linkages to generate a three-dimensional stator flux linkage includes: The initial stator flux linkage and the corresponding direct-axis current i are obtained by bilinear interpolation. d Cross-axis current i q Connect the components to obtain a three-dimensional stator flux linkage.

[0047] In the specific implementation process, bilinear interpolation is used to connect all discrete data points to generate a smooth three-dimensional surface, i.e., a three-dimensional stator flux linkage. The data points include the direct-axis current i at each point. d Cross-axis current i q and initial stator flux linkage.

[0048] S104: The three-dimensional inductor and three-dimensional stator flux linkage are smoothed by high-order polynomials to obtain the optimized three-dimensional inductor, three-dimensional stator flux linkage and fitting coefficient matrix.

[0049] In practical implementation, since the three-dimensional inductance and three-dimensional stator flux linkage may contain abnormal data such as large fluctuations or negative values, after obtaining the three-dimensional inductance and three-dimensional stator flux linkage, a high-order polynomial surface fitting method can be used to perform global smoothing on the three-dimensional inductance and three-dimensional stator flux linkage. An adaptive weighting strategy is used to eliminate local outliers in the three-dimensional inductance or three-dimensional stator flux linkage, ensuring the continuous differentiability of the three-dimensional inductance and three-dimensional stator flux linkage data. Here, the high-order polynomial is a polynomial with a degree (i.e., the degree of the highest-order term) of 3 or higher. The formula for the high-order polynomial surface fitting method can be: in, p The fitting coefficients are the target parameters that need to be fitted, such as the inductance value in a three-dimensional inductor or the stator flux linkage in a three-dimensional stator flux linkage. x and y These are the direct-axis currents i d and cross-axis current i q By fitting the three-dimensional inductor and stator flux linkage using a high-order polynomial surface fitting method, smoother and more continuously differentiable inductors and stator flux linkages can be obtained. Simultaneously, the high-order polynomial coefficient matrix, i.e., the fitting coefficient matrix, is obtained. For example, when the coefficients to be optimized are a three-dimensional inductor, the inductance value in the three-dimensional inductor and the direct-axis current i... d and cross-axis current i q By substituting these values ​​into the formulas for the high-order polynomial surface fitting method, the high-order polynomial inductance coefficient matrix can be obtained. S105: Based on the operating parameters, the optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are calculated.

[0050] In the specific implementation process, the voltage in the feedforward decoupled two-phase rotating coordinate system is calculated by current, rotational speed, three-dimensional inductance, three-dimensional stator flux linkage and fitting coefficient matrix.

[0051] Specifically, the steps for calculating the parameters of the permanent magnet synchronous motor based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix include: Obtain the bandwidth and carrier frequency of the permanent magnet synchronous motor; Based on the bandwidth of the permanent magnet synchronous motor and the optimized three-dimensional inductance parameters, the proportional gain of the controller of the permanent magnet synchronous motor is calculated. The integral gain of the controller of the permanent magnet synchronous motor is calculated based on the carrier frequency of the permanent magnet synchronous motor and the preset resistance. The voltage command is calculated based on the proportional gain, integral gain, current, angular velocity, and optimized three-dimensional stator flux linkage. Based on the voltage command and the fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are obtained, wherein the angular velocity is calculated from the rotational speed.

[0052] In practical implementation, the parameters of a permanent magnet synchronous motor include voltage commands and a fitting coefficient matrix. The specific calculation formulas for the voltage commands, namely the D-axis voltage command and the Q-axis voltage command, are as follows: Among them, K p K is the proportional gain of the controller. i For the controller integral gain, This is a preset current, which can be negative or zero. These represent the stator flux linkages for the D and Q axes, respectively. The controller is the controller for the permanent magnet synchronous motor control system. S is the Laplace operator.

[0053] Among them, K p和 K i The calculation formula is: in, ω cb This refers to the bandwidth of the permanent magnet synchronous motor. f PWMLet L be the carrier frequency of the permanent magnet synchronous motor, and Rs be the smoothed three-dimensional inductance parameter. Rs is the preset resistance, which is the final resistance obtained after compensating for the resistance of the permanent magnet synchronous motor by temperature. It can be seen that after smoothing the three-dimensional inductance parameter and stator flux linkage parameter to improve accuracy, a more accurate PI parameter can be calculated. The PI parameter refers to the two control parameters of the proportional-integral controller, consisting of proportional and integral parts. Using them together allows the PI controller to effectively adjust the dynamic and static performance of the system, achieving a fast and accurate control effect, which is represented by K. p and K i Meanwhile, the PI parameters calculated using the dynamically calculated inductance parameters can avoid the problem of insufficient decoupling caused by the fact that the motor inductance changes with the motor's operating state and is not a constant value. This allows for more accurate elimination of coupling terms, thereby achieving decoupling and improving the stability and accuracy of feedforward decoupling.

[0054] For complex vector decoupling, accurate inductance parameters not only affect the control effect of the local axis, but also affect the decoupling term. Therefore, using smoothed three-dimensional inductance parameters to calculate PI can improve the control effect of complex vector decoupling.

[0055] Furthermore, after calculating the permanent magnet synchronous motor parameters, the parameter storage mode can be selected according to the different storage resource sizes of the controller, and the corresponding permanent magnet synchronous motor parameters can be written. Specifically, after calculating the permanent magnet synchronous motor parameters based on the operating condition parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix, the process further includes: Obtain the storage capacity of the controller of the permanent magnet synchronous motor; Based on the storage capacity, determine the parameters to be written to the controller; The determined parameters are written into the controller.

[0056] In practice, after fitting the inductance and stator flux linkage parameters, the parameter storage mode can be selected based on the varying storage resources of the permanent magnet synchronous motor controller, depending on the controller's storage capacity. For controllers with ample storage space, such as the 61A controller, the optimized inductance, stator flux linkage MAP, and high-order polynomial coefficient matrix can be written simultaneously. For controllers with limited storage, such as the G04 controller, the high-order polynomial coefficient matrix is ​​written directly for lightweight deployment, thus avoiding excessive storage space consumption.

[0057] Based on the method provided in the above embodiments, operating parameters of the permanent magnet synchronous motor during operation are collected, including voltage, current, torque, and speed. Initial inductance parameters and initial stator flux linkage are calculated based on these parameters, eliminating the influence of voltage and resistance on these parameters and making the calculated parameters more accurate. The initial inductance parameters are then fused to obtain a three-dimensional inductance, and the initial stator flux linkage is further fused to generate a three-dimensional stator flux linkage. A high-order polynomial is used to smooth the three-dimensional inductance and stator flux linkage, resulting in optimized three-dimensional inductance, three-dimensional stator flux linkage, and a fitting coefficient matrix. Smoothing with a high-order polynomial eliminates local outliers in the three-dimensional inductance and stator flux linkage, further improving their accuracy. This improves the accuracy of the permanent magnet synchronous motor parameters calculated based on the optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix.

[0058] Based on the above method embodiments, this invention also provides a device for calculating the parameters of a permanent magnet synchronous motor. See also... Figure 4 The diagram shown is a schematic of a device for calculating the parameters of a permanent magnet synchronous motor provided in an embodiment of the present invention.

[0059] The device 400 includes: The acquisition module 401 is used to acquire the operating parameters of the permanent magnet synchronous motor during operation, wherein the operating parameters include voltage, current, torque and speed. The first calculation module 402 is used to calculate the initial inductance parameters and the initial stator flux based on the operating condition parameters. The fusion module 403 is used to fuse based on the initial inductance parameters to obtain a three-dimensional inductance, and to fuse the initial stator flux linkage to generate a three-dimensional stator flux linkage. The smoothing module 404 is used to smooth the three-dimensional inductor and the three-dimensional stator flux linkage using a high-order polynomial to obtain the optimized three-dimensional inductor, the three-dimensional stator flux linkage and the fitting coefficient matrix. The second calculation module 405 is used to calculate the parameters of the permanent magnet synchronous motor based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix.

[0060] In one possible implementation, the initial inductance parameters include D-axis initial inductance parameters, and the calculation of the initial inductance parameters based on the operating condition parameters includes: Subtract the forward Q-axis voltage from the reverse Q-axis voltage to obtain the first voltage difference. Based on the first voltage difference and the angular velocity, a first ratio is obtained; Divide the first ratio by the current to obtain the initial inductance parameters of the D-axis, wherein the angular velocity is calculated from the rotational speed.

[0061] In one possible implementation, the initial inductance parameter further includes a Q-axis initial inductance parameter, wherein calculating the initial inductance parameter based on the operating condition parameters includes: Find the number of pole pairs of the permanent magnet synchronous motor, and calculate the second ratio based on the torque and the number of pole pairs; Based on the second ratio and the current, the third ratio is calculated; The initial inductance parameter of the D-axis is calculated by subtracting the third ratio.

[0062] In one possible implementation, calculating the initial stator flux linkage based on the operating parameters includes: Subtract the forward Q-axis voltage from the reverse Q-axis voltage to obtain the first voltage difference. Based on the first voltage difference and angular velocity, a first ratio is obtained, and the first ratio is set as the initial stator flux linkage of the D-axis. Subtract the forward D-axis voltage from the reverse D-axis voltage to obtain the second voltage difference. Based on the second voltage difference and angular velocity, a fourth ratio is obtained, and the fourth ratio is set as the initial stator flux linkage of the Q-axis, wherein the angular velocity is calculated by the rotational speed.

[0063] In one possible implementation, the fusion based on the initial inductance parameters to obtain the three-dimensional inductance includes: The initial inductance parameters and the corresponding direct-axis current i are obtained by bilinear interpolation. d Cross-axis current i q Make connections to obtain a three-dimensional inductance.

[0064] In one possible implementation, the initial stator flux linkage includes a Q-axis initial stator flux linkage and a D-axis initial stator flux linkage, and the step of fusing the initial stator flux linkages to generate a three-dimensional stator flux linkage includes: The initial stator flux linkage and the corresponding direct-axis current i are obtained by bilinear interpolation. d Cross-axis current i q Connect the components to obtain a three-dimensional stator flux linkage.

[0065] In one possible implementation, the calculation of permanent magnet synchronous motor parameters based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix includes: Obtain the bandwidth and carrier frequency of the permanent magnet synchronous motor; Based on the bandwidth of the permanent magnet synchronous motor and the parameters of the optimized three-dimensional inductance, the proportional gain of the controller of the permanent magnet synchronous motor is calculated. The integral gain of the controller of the permanent magnet synchronous motor is calculated based on the carrier frequency of the permanent magnet synchronous motor and the preset resistance. The voltage command is calculated based on the proportional gain, integral gain, current, angular velocity, and optimized three-dimensional stator flux linkage. Based on the voltage command and the fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are obtained, wherein the angular velocity is calculated from the rotational speed.

[0066] In one possible implementation, after calculating the permanent magnet synchronous motor parameters based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix, the method further includes: Obtain the storage capacity of the controller of the permanent magnet synchronous motor; Based on the storage capacity, determine the parameters to be written to the controller; The determined parameters are written into the controller.

[0067] See Figure 6 , Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of the present invention.

[0068] The electronic device 600 includes a memory 601 and a processor 602; the memory 601 is used to store relevant program code; the processor 602 is used to call the program code to execute the method for calculating the parameters of the permanent magnet synchronous motor described in the above method embodiment.

[0069] Furthermore, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program for executing the method for calculating the parameters of a permanent magnet synchronous motor as described in the above method embodiments.

[0070] This invention also provides a computer program product, which includes a computer program / instruction. When the computer program / instruction is executed by a processor, it implements the method for calculating the parameters of a permanent magnet synchronous motor as described in the above method embodiments.

[0071] It should be noted that the computer-readable medium described above in this invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0072] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0073] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. In particular, for system or device embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The device embodiments described above are merely illustrative. The units or modules described as separate components may or may not be physically separate. The components shown as units or modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the units or modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0074] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions, and operations that may be implemented according to various embodiments of the invention, including methods, apparatus, and devices. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0075] It should be understood that in this invention, "at least one (item)" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0076] It should also be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0077] The steps of the methods or algorithms described in conjunction with the embodiments disclosed in this invention can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calculating parameters of a permanent magnet synchronous motor, characterized in that, The method includes: The operating parameters of the permanent magnet synchronous motor during operation are collected, including voltage, current, torque and speed. The initial inductance parameters and initial stator flux linkage are calculated based on the operating parameters. Based on the initial inductance parameters, a three-dimensional inductance is obtained by fusing them, and the initial stator flux linkage is fused to generate a three-dimensional stator flux linkage. The three-dimensional inductor and three-dimensional stator flux linkage are smoothed by high-order polynomials to obtain the optimized three-dimensional inductor, three-dimensional stator flux linkage and fitting coefficient matrix. Based on the operating parameters, the optimized three-dimensional inductance, three-dimensional stator flux linkage, and fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are calculated.

2. The method according to claim 1, characterized in that, The initial inductance parameters include the D-axis initial inductance parameters, and the initial inductance parameters calculated based on the operating condition parameters include: Subtract the forward Q-axis voltage from the reverse Q-axis voltage to obtain the first voltage difference. Based on the first voltage difference and the angular velocity, a first ratio is obtained; Divide the first ratio by the current to obtain the initial inductance parameters of the D-axis, wherein the angular velocity is calculated from the rotational speed.

3. The method according to claim 2, characterized in that, The initial inductance parameters also include the Q-axis initial inductance parameters, and the calculation of the initial inductance parameters based on the operating condition parameters includes: Find the number of pole pairs of the permanent magnet synchronous motor, and calculate the second ratio based on the torque and the number of pole pairs; Based on the second ratio and the current, the third ratio is calculated; The initial inductance parameter of the D-axis is calculated by subtracting the third ratio.

4. The method according to claim 1, characterized in that, The calculation of the initial stator flux linkage based on the operating parameters includes: Subtract the forward Q-axis voltage from the reverse Q-axis voltage to obtain the first voltage difference. Based on the first voltage difference and angular velocity, a first ratio is obtained, and the first ratio is set as the initial stator flux linkage of the D-axis. Subtract the forward D-axis voltage from the reverse D-axis voltage to obtain the second voltage difference. Based on the second voltage difference and angular velocity, a fourth ratio is obtained, and the fourth ratio is set as the initial stator flux linkage of the Q-axis, wherein the angular velocity is calculated by the rotational speed.

5. The method according to claim 1, characterized in that, The process of fusing the initial inductance parameters to obtain a three-dimensional inductance includes: The initial inductance parameters and the corresponding direct-axis current i are obtained by bilinear interpolation. d Cross-axis current i q Make connections to obtain a three-dimensional inductance.

6. The method according to claim 1, characterized in that, The initial stator flux linkage includes a Q-axis initial stator flux linkage and a D-axis initial stator flux linkage. The process of fusing the initial stator flux linkages to generate a three-dimensional stator flux linkage includes: The initial stator flux linkage and the corresponding direct-axis current i are obtained by bilinear interpolation. d Cross-axis current i q Connect the components to obtain a three-dimensional stator flux linkage.

7. The method according to claim 1, characterized in that, The parameters of the permanent magnet synchronous motor are calculated based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix, including: Obtain the bandwidth and carrier frequency of the permanent magnet synchronous motor; Based on the bandwidth of the permanent magnet synchronous motor and the parameters of the optimized three-dimensional inductance, the proportional gain of the controller of the permanent magnet synchronous motor is calculated. The integral gain of the controller of the permanent magnet synchronous motor is calculated based on the carrier frequency of the permanent magnet synchronous motor and the preset resistance. The voltage command is calculated based on the proportional gain, integral gain, current, angular velocity, and optimized three-dimensional stator flux linkage. Based on the voltage command and the fitting coefficient matrix, the parameters of the permanent magnet synchronous motor are obtained, wherein the angular velocity is calculated from the rotational speed.

8. The method according to claim 1, characterized in that, After calculating the permanent magnet synchronous motor parameters based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix, the process further includes: Obtain the storage capacity of the controller of the permanent magnet synchronous motor; Based on the storage capacity, determine the parameters to be written to the controller; The determined parameters are written into the controller.

9. A device for calculating parameters of a permanent magnet synchronous motor, characterized in that, The device includes: The acquisition module is used to acquire operating parameters of the permanent magnet synchronous motor during operation, including voltage, current, torque and speed. The first calculation module is used to calculate the initial inductance parameters and the initial stator flux linkage based on the operating condition parameters. The fusion module is used to fuse based on the initial inductance parameters to obtain a three-dimensional inductance, and to fuse the initial stator flux linkage to generate a three-dimensional stator flux linkage. The smoothing module is used to smooth the three-dimensional inductor and the three-dimensional stator flux linkage using a high-order polynomial to obtain the optimized three-dimensional inductor, the three-dimensional stator flux linkage and the fitting coefficient matrix. The second calculation module is used to calculate the parameters of the permanent magnet synchronous motor based on the operating parameters, the optimized three-dimensional inductance, the three-dimensional stator flux linkage, and the fitting coefficient matrix.

10. An electronic device, characterized in that, The device includes: a memory and a processor; the memory is used to store relevant program code; the processor is used to call the program code to execute the method for calculating the parameters of the permanent magnet synchronous motor according to any one of claims 1 to 8.

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