Flux linkage observation method, device and equipment of permanent magnet synchronous motor and storage medium

Abstract

The invention provides a flux linkage observation method and device of a permanent magnet synchronous motor, equipment and a storage medium, and relates to the technical field of motor control. The method comprises the following steps: acquiring a flux linkage observation value before compensation at the current moment; based on the electric period of the permanent magnet synchronous motor, determining a symmetric moment of the current moment, and obtaining a sampling point closest to the symmetric moment; determining a flux linkage observation value before compensation at the symmetric moment according to the flux linkage observation value before compensation of the sampling point; determining a flux linkage observation compensation value according to the flux linkage observation value before compensation at the current moment and the flux linkage observation value before compensation at the symmetric moment; and compensating the flux linkage observation value before compensation at the current moment by using the flux linkage observation compensation value to obtain a flux linkage observation value after compensation at the current moment. According to the method, a compensation mechanism based on electric period symmetry is introduced, the error of the flux linkage observation compensation value is reduced, the flux linkage observation value can be accurately compensated, and the flux linkage observation precision is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of motor control technology, and in particular to a method, device, equipment and storage medium for observing the flux linkage of a permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in new energy vehicles, industrial servos, and other fields due to their high power density, high efficiency, and low torque ripple. Flux observation, at the core of its control algorithm, estimates rotor position and speed through methods such as back-electromotive force, eliminating the need for encoders or resolvers to reduce costs. In the new energy vehicle sector, flux observation technology, combined with position-free control algorithms, can ensure driving safety in the event of a failure in the main drive motor position sensor and is suitable for harsh environments such as high temperature and vibration. Furthermore, the flux during motor operation is affected by a variety of factors, leading to deviations in flux parameters. The flux observation algorithm can monitor and compensate for these deviations in real time. Therefore, high-precision flux observation technology is of great significance for improving motor control performance. Summary of the Invention

[0003] The purpose of the present disclosure is to provide a method, device, equipment and storage medium for observing the flux linkage of a permanent magnet synchronous motor.

[0004] According to a first aspect of an embodiment of the present disclosure, a flux observation method for a permanent magnet synchronous motor is provided, the method comprising: obtaining a pre-compensated flux observation value at a current moment; determining a symmetric moment of the current moment based on an electrical cycle of the permanent magnet synchronous motor, and obtaining a sampling point closest to the symmetric moment; determining a pre-compensated flux observation value at the symmetric moment based on the pre-compensated flux observation value of the sampling point; determining a flux observation compensation value based on the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetric moment; and compensating the pre-compensated flux observation value at the current moment using the flux observation compensation value to obtain a compensated flux observation value at the current moment.

[0005] In some embodiments of the present disclosure, determining the symmetrical moment of the current moment based on the electrical cycle of the permanent magnet synchronous motor and obtaining the sampling point closest to the symmetrical moment include: determining the moment half of the electrical cycle before the current moment as the symmetrical moment; determining the sampling point closest to the symmetrical moment and located before the symmetrical moment as the first sampling point; and determining the sampling point closest to the symmetrical moment and located after the symmetrical moment as the second sampling point.

[0006] In some embodiments of the present disclosure, determining the pre-compensated magnetic flux observation value at the symmetric moment based on the pre-compensated magnetic flux observation value at the sampling point includes: obtaining the pre-compensated magnetic flux observation value at the first sampling point and the pre-compensated magnetic flux observation value at the second sampling point; determining a first time difference between the symmetric moment and the first sampling point, and a second time difference between the symmetric moment and the second sampling point; and calculating the pre-compensated magnetic flux observation value at the symmetric moment based on the first time difference, the second time difference, the pre-compensated magnetic flux observation value at the first sampling point, and the pre-compensated magnetic flux observation value at the second sampling point.

[0007] In some embodiments of the present disclosure, the method further includes: in response to the symmetrical moment being a sampling point, taking the symmetrical moment as a sampling point closest to the symmetrical moment; and obtaining a pre-compensated magnetic flux observation value at the symmetrical moment.

[0008] In some embodiments of the present disclosure, the method further includes: obtaining the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; determining the electrical speed of the permanent magnet synchronous motor based on the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; and determining the electrical period of the permanent magnet synchronous motor based on the electrical speed of the permanent magnet synchronous motor.

[0009] In some embodiments of the present disclosure, determining the flux observation compensation value based on the pre-compensation flux observation value at the current moment and the pre-compensation flux observation value at the symmetric moment includes: obtaining a flux observation mean of the pre-compensation flux observation value at the current moment and the pre-compensation flux observation value at the symmetric moment; and determining the flux observation mean as the flux observation compensation value.

[0010] In some embodiments of the present disclosure, compensating the pre-compensated magnetic flux observation value at the current moment by using the magnetic flux observation compensation value to obtain the compensated magnetic flux observation value at the current moment includes: obtaining the difference between the pre-compensated magnetic flux observation value at the current moment and the magnetic flux observation compensation value; and determining the difference as the compensated magnetic flux observation value at the current moment.

[0011] In some embodiments of the present disclosure, obtaining the pre-compensation flux observation value at the current moment includes: sampling the three-phase current value of the permanent magnet synchronous motor at the current moment; performing coordinate transformation on the three-phase current value to obtain the current value in a two-phase stationary coordinate system; obtaining the voltage value in a two-phase stationary coordinate system based on the voltage instruction of the previous sampling point at the current moment; determining the back electromotive force based on the voltage value in the two-phase stationary coordinate system and the current value in the two-phase stationary coordinate system at the current moment; integrating the back electromotive force to obtain the pre-compensation flux observation value at the current moment.

[0012] According to a second aspect of an embodiment of the present disclosure, a flux observation device for a permanent magnet synchronous motor is provided, the device comprising: a flux observation value acquisition module configured to acquire a pre-compensated flux observation value at a current moment; a sampling point determination module configured to determine a symmetric moment of the current moment based on an electrical cycle of the permanent magnet synchronous motor, and acquire a sampling point closest to the symmetric moment; the flux observation value acquisition module is further configured to determine a pre-compensated flux observation value at the symmetric moment based on the pre-compensated flux observation value of the sampling point; determine a flux observation compensation value based on the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetric moment; and a flux observation value compensation module configured to compensate the pre-compensated flux observation value at the current moment using the flux observation compensation value to obtain a compensated flux observation value at the current moment.

[0013] In some embodiments of the present disclosure, the sampling point determination module is further configured to: determine a moment half the electrical cycle before the current moment as the symmetrical moment; determine a sampling point closest to the symmetrical moment and located before the symmetrical moment as the first sampling point; and determine a sampling point closest to the symmetrical moment and located after the symmetrical moment as the second sampling point.

[0014] In some embodiments of the present disclosure, the flux linkage observation value acquisition module is further configured to: acquire a pre-compensated flux linkage observation value at the first sampling point and a pre-compensated flux linkage observation value at the second sampling point; determine a first time difference between the symmetric moment and the first sampling point, and a second time difference between the symmetric moment and the second sampling point; and calculate the pre-compensated flux linkage observation value at the symmetric moment based on the first time difference, the second time difference, the pre-compensated flux linkage observation value at the first sampling point, and the pre-compensated flux linkage observation value at the second sampling point.

[0015] In some embodiments of the present disclosure, the sampling point determination module is further configured to, in response to the symmetrical moment being a sampling point, use the symmetrical moment as the sampling point closest to the symmetrical moment; and the flux linkage observation value acquisition module is further configured to acquire the pre-compensated flux linkage observation value at the symmetrical moment.

[0016] In some embodiments of the present disclosure, the device also includes an electrical period determination module, which is configured to: obtain the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; determine the electrical speed of the permanent magnet synchronous motor based on the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; determine the electrical period of the permanent magnet synchronous motor based on the electrical speed of the permanent magnet synchronous motor.

[0017] In some embodiments of the present disclosure, the flux observation value acquisition module is further configured to: obtain a flux observation average of the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetric moment; and determine the flux observation average as the flux observation compensation value.

[0018] In some embodiments of the present disclosure, the flux observation value compensation module is further configured to: obtain the difference between the pre-compensated flux observation value and the flux observation compensation value at the current moment; and determine the difference as the post-compensated flux observation value at the current moment.

[0019] In some embodiments of the present disclosure, the flux observation value acquisition module is further configured to: sample the three-phase current value of the permanent magnet synchronous motor at the current moment; perform coordinate transformation on the three-phase current value to obtain the current value in the two-phase stationary coordinate system; obtain the voltage value in the two-phase stationary coordinate system based on the voltage instruction of the previous sampling point at the current moment; determine the back electromotive force according to the voltage value in the two-phase stationary coordinate system and the current value in the two-phase stationary coordinate system at the current moment; integrate the back electromotive force to obtain the pre-compensation flux observation value at the current moment.

[0020] According to a third aspect of an embodiment of the present disclosure, a control device is provided, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to implement the above-mentioned flux observation method for a permanent magnet synchronous motor.

[0021] According to a fourth aspect of an embodiment of the present disclosure, a non-temporary computer-readable storage medium is provided, which, when instructions in the storage medium are executed by a processor of a control device, enables the control device to execute the above-mentioned flux observation method of a permanent magnet synchronous motor.

[0022] According to a fifth aspect of an embodiment of the present disclosure, a computer program product is provided, comprising a computer program, which implements the above-mentioned flux observation method of a permanent magnet synchronous motor when executed by a processor.

[0023] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0024] This method obtains the pre-compensated flux observation value at the current moment and determines its symmetric moment based on the electrical cycle characteristics of the permanent magnet synchronous motor to obtain the sampling point closest to the symmetric moment. The pre-compensated flux observation value at the symmetric moment is then determined based on the pre-compensated flux observation values ​​at these two moments. The flux observation compensation value is then determined based on the pre-compensated flux observation value at the symmetric moment and the pre-compensated flux observation value at the current moment. Finally, the flux observation compensation value is used to compensate for the flux observation value at the current moment. It can be seen that this method introduces a compensation mechanism based on electrical cycle symmetry. The pre-compensated flux observation value at the symmetric moment is determined by the pre-compensated flux observation value at the sampling point closest to the symmetric moment, which reduces the error of the flux observation compensation value, can accurately compensate the flux observation value, and improves the accuracy of the flux observation. In addition, this method can improve the dynamic response and stability of the motor control system without increasing hardware costs. It is suitable for application scenarios such as new energy vehicles that have high requirements for system reliability and performance.

[0025] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0027] Figure 1 The flow chart of the flux observation method of the permanent magnet synchronous motor shown in some embodiments of the present disclosure is as follows Figure 1 .

[0028] Figure 2 The flowchart of obtaining the pre-compensation flux observation value at the current moment according to some embodiments of the present disclosure is shown.

[0029] Figure 3 3 is a schematic diagram showing compensation for pre-compensation flux linkage observation values ​​according to an exemplary embodiment of the present disclosure.

[0030] Figure 4 The flowchart of the method for determining the pre-compensation flux observation value at the symmetric moment according to an exemplary embodiment of the present disclosure is shown.

[0031] Figure 5 The flow chart of the flux observation method of the permanent magnet synchronous motor shown in some embodiments of the present disclosure is as follows Figure 2 .

[0032] Figure 6 This is a comparison chart of the center offset error of the magnetic flux trajectory between the embodiment of the present disclosure and the related technology.

[0033] Figure 7It is a block diagram of a flux observation device for a permanent magnet synchronous motor according to some embodiments of the present disclosure.

[0034] Figure 8 is a block diagram of a control device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0035] Some exemplary embodiments of the present disclosure will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. Various changes, modifications and equivalents of the methods, devices and / or systems described herein will become apparent after understanding the present disclosure. For example, the order of operations described herein is merely an example and is not limited to those orders set forth herein, but may be changed as becomes apparent after understanding the present disclosure, except for operations that must be performed in a specific order. In addition, descriptions of features known in the art may be omitted for clarity and brevity.

[0036] The following exemplary embodiments of the present disclosure do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0037] It should be noted that the acquisition, storage, use, and processing of data in the technical solution disclosed herein are in compliance with the relevant provisions of national laws and regulations. Various types of data such as personal identity data, operation data, behavioral data, etc. related to individuals, customers, and groups obtained in the embodiments of the present disclosure have been authorized.

[0038] Figure 1 The flow chart of the flux observation method of the permanent magnet synchronous motor shown in some embodiments of the present disclosure is as follows Figure 1 . Reference Figure 1 , the method may include the following steps.

[0039] Step S110, obtaining the pre-compensation flux observation value at the current moment.

[0040] In the disclosed embodiments, the current moment t1 can also be referred to as the current sampling point. In the control system of a permanent magnet synchronous motor, signals are processed in a discrete-time manner. Key parameters such as current, voltage, and flux are periodically collected and controlled at a fixed frequency. Each collection moment is referred to as a sampling point, and each sampling point corresponds to a set of real-time data at that moment.

[0041] The sampling frequency of a control system determines the time interval between two adjacent sampling points, known as the sampling period Δt. For example, if the sampling frequency of a control system is 10kHz, the corresponding sampling period is Δt = 1 / 10000 = 0.1ms. The sampling period is fundamental to achieving dynamic response and precise control in a control system, affecting the speed with which the control system perceives changes in motor state and the accuracy of its regulation.

[0042] In this step, the pre-compensated flux observation value at the current time t1 is obtained—that is, the raw flux estimation value before compensation. This value can be inferred based on physical quantities such as voltage and current, and reflects a preliminary estimate of the motor's internal magnetic field at the current moment. Because the influence of factors such as back EMF DC bias is not considered, this raw observation value may have some deviation or divergence. Therefore, it is subsequently compensated and optimized to improve overall observation accuracy and control performance.

[0043] Figure 2 FIG. 1 is a flow chart illustrating how to obtain the pre-compensation flux observation value at the current moment according to some embodiments of the present disclosure. Figure 2 , which may include the following steps.

[0044] Step S210: sampling the three-phase current values ​​of the permanent magnet synchronous motor at the current moment.

[0045] Among them, the three-phase current value is the current value in the three-phase stationary coordinate system. The three-phase stationary coordinate system is a coordinate system based on the axis of the three-phase winding of the motor stator, which can be defined as follows: A-axis coincides with the central axis of the stator A-phase winding, and its direction is defined by the positive direction of the winding current; B-axis coincides with the central axis of the stator B-phase winding, and its direction differs from the A-axis by 120° electrical angle; C-axis coincides with the central axis of the stator C-phase winding, and its direction differs from the A-axis by 240° electrical angle (or lags 120°). Three-phase current value i A 、i B and i C Represent the current components on the A-axis, B-axis and C-axis respectively.

[0046] In the embodiment of the present disclosure, the three-phase current value i of the permanent magnet synchronous motor at the current time t1 is collected by the current sensor. A (t1), i B (t1) and i C (t1).

[0047] Step S220 , performing coordinate transformation on the three-phase current values ​​to obtain current values ​​in a two-phase stationary coordinate system.

[0048] In the embodiment of the present disclosure, the three-phase current value is converted from the three-phase stationary coordinate system to the two-phase stationary coordinate system to obtain the current value i in the two-phase stationary coordinate system. α and iβ The two-phase stationary coordinate system is also called the αβ coordinate system, which can be defined as follows: the α axis is aligned with the stator A axis winding, and the β axis leads the α axis by 90°.

[0049] For example, the coordinate transformation can be performed by Clarke Transform to obtain the current value in the two-phase stationary coordinate system: α (t1)=i A (t1),

[0050] Step S230 : obtaining a voltage value in a two-phase stationary coordinate system based on the voltage command of the previous sampling point at the current moment.

[0051] In the control system of a permanent magnet synchronous motor, the control algorithm operates in a discrete-time manner. The control system samples and processes the motor state at a sampling frequency, with each sampling moment being called a sampling point. Assuming the current moment is t1, the time corresponding to the previous sampling point is t0 = t1 - Δt, where Δt is the sampling period. The voltage command is the three-phase voltage value calculated by the controller based on the current control objective (such as speed or torque control) and is intended to be applied to the motor. These voltage commands are then sent to the inverter, which generates the voltage to drive the permanent magnet synchronous motor.

[0052] In the embodiment of the present disclosure, the voltage instruction based on the previous sampling point at the current moment refers to the voltage instruction data at the previous sampling point t0, rather than the instruction generated at the current moment t1. According to the voltage instruction data at the previous sampling point t0, the three-phase voltage instruction is obtained, and the three-phase voltage instruction is converted from the three-phase stationary coordinate system to the two-phase stationary coordinate system to obtain the voltage value u in the two-phase stationary coordinate system. α and u β .

[0053] In a permanent magnet synchronous motor control system, after the controller collects current, position, and other signals at each sampling point, it takes time to execute the control algorithm and generate a new voltage command. This generated voltage command then needs to be modulated before it can be applied to the inverter, a process that also takes time. The inverter outputs voltage, which acts on the motor windings, causing the motor current to change accordingly, a process that also involves a certain amount of lag. Due to these delays, using the recently calculated voltage command at the current moment t1 does not accurately reflect the voltage applied to the motor at that moment. Using the voltage command from the previous sampling point t0, on the other hand, is more accurate than the voltage applied to the motor at the current moment t1. Therefore, using the voltage command from the previous sampling point better matches the voltage applied to the motor at the current moment, thereby improving the accuracy of back EMF and flux observation.

[0054] Step S240 , determining the back electromotive force according to the voltage value in the two-phase stationary coordinate system and the current value in the two-phase stationary coordinate system at the current moment.

[0055] Step S250 , integrating the back electromotive force to obtain the pre-compensation flux observation value at the current moment.

[0056] In the embodiment of the present disclosure, according to the voltage value u in the two-phase stationary coordinate system α (t1) and u β (t1), and the current value i in the two-phase stationary coordinate system at the current moment α (t1) and i β (t1), determine the back electromotive force, and then integrate the back electromotive force to obtain the pre-compensation flux observation value ψ at the current time t1 α (t1) and ψ β (t1), as shown in the following formula:

[0057]

[0058] In formula (1), ψ α (t1) represents the flux observation value of the α-axis before compensation in the two-phase stationary coordinate system at the current moment, ψ β (i1) represents the pre-compensation flux observation value of the β-axis in the two-phase stationary coordinate system at the current moment, and R represents the resistance of the stator winding of the permanent magnet synchronous motor.

[0059] In the embodiment of the present disclosure, by collecting the three-phase current value of the permanent magnet synchronous motor at the current moment and combining it with the voltage instruction of the previous sampling point, the back electromotive force is calculated and integrated in the two-phase stationary coordinate system to obtain the pre-compensation flux observation value at the current moment, taking into account the signal processing and execution delay in the control system, thereby improving the flux observation accuracy.

[0060] Step S120 : determining the symmetric moment of the current moment based on the electrical cycle of the permanent magnet synchronous motor, and obtaining a sampling point closest to the symmetric moment.

[0061] In the disclosed embodiment, the electrical cycle of the permanent magnet synchronous motor refers to a cycle of changes in the magnetic field inside the motor. The electrical cycle characteristics of the permanent magnet synchronous motor are used to determine the symmetric moment t2 in the electrical cycle relative to the current moment t1, and then select the sampling point closest to the symmetric moment t2.

[0062] Step S130 , determining the pre-compensation flux observation value at the symmetrical moment according to the pre-compensation flux observation value at the sampling point.

[0063] In the embodiment of the present disclosure, after selecting the sampling point closest to the symmetric time t2, the pre-compensated flux observation value at the symmetric time t2 can be estimated based on the pre-compensated flux observation value of the sampling point.

[0064] Step S140 , determining a flux observation compensation value based on the flux observation value before compensation at the current moment and the flux observation value before compensation at the symmetrical moment.

[0065] In the disclosed embodiment, the pre-compensated flux observation value at the current time t1 obtained in step S110 is compared and analyzed with the pre-compensated flux observation value at the symmetrical time t2 obtained in step S130 to determine a flux observation compensation value. This compensation value reflects deviations caused by factors such as temperature, saturation, and aging, and is a key step in adjusting the pre-compensated flux observation value to improve accuracy.

[0066] Step S150 , compensating the pre-compensated magnetic flux observation value at the current moment by using the magnetic flux observation compensation value to obtain the post-compensated magnetic flux observation value at the current moment.

[0067] In the embodiment of the present disclosure, the flux observation compensation value calculated in step S140 is used to compensate the pre-compensated flux observation value at the current time t1 to obtain the post-compensated flux observation value at the current time t1.

[0068] Figure 3 FIG. 1 is a schematic diagram showing compensation of flux linkage observation values ​​before compensation according to an exemplary embodiment of the present disclosure. Figure 3 During the operation of the permanent magnet synchronous motor M, the three-phase current value i is obtained by current sampling. A 、i B and i C , based on the coordinate transformation, the three-phase current value i A 、i B and i C The current value i converted to the two-phase stationary coordinate system α 、i β , combined with the voltage value u in the two-phase stationary coordinate system α 、u β The back EMF is calculated. Factors such as temperature changes may introduce a DC bias into the current sampling result, and initial phase errors may occur when integrating the back EMF using an integrator. This can lead to inaccurate calculated back EMF, causing the integration result (i.e., the pre-compensated flux observation value) to deviate or even diverge. Therefore, the flux observation compensation value is used to compensate the back EMF integration result (i.e., the pre-compensated flux observation value) to obtain the compensated flux observation value.

[0069] In related technologies, the maximum and minimum values ​​of the pre-compensated flux observations are obtained in a two-phase stationary coordinate system within one electrical cycle, and their average is used for compensation to address the divergence of the flux observations caused by the DC bias of the back EMF. In a two-phase stationary coordinate system, the flux observations obtained after integrating the ideal back EMF are sinusoidal signals. The maximum and minimum values ​​within one electrical cycle can be obtained during continuous sampling. For a sinusoidal signal, the sum of the maximum and minimum values ​​is equal to 0. The average of the maximum and minimum values ​​can be calculated as the basis for flux observation compensation.

[0070] However, the sampling of the control system is discrete and discontinuous. Assuming that the sampling frequency remains unchanged, the number of sampling points in one electrical cycle decreases as the motor speed increases. This results in the maximum and minimum values ​​of the flux observation obtained at the sampling moment not being the actual maximum and minimum values. Therefore, the average value of the two is used for compensation, resulting in inaccurate flux observation values.

[0071] In the embodiment of the present disclosure, after obtaining the pre-compensation flux observation value at the current moment, the symmetric moment of the current moment is determined based on the electrical periodic characteristics of the permanent magnet synchronous motor to obtain the sampling point closest to the symmetric moment, and then the pre-compensation flux observation value at the symmetric moment is determined based on the pre-compensation flux observation values ​​at these two moments, and then the flux observation compensation value is determined based on the pre-compensation flux observation value at the symmetric moment and the pre-compensation flux observation value at the current moment, and finally the flux observation compensation value is used to compensate for the flux observation value at the current moment.

[0072] The flux observation method for a permanent magnet synchronous motor provided in the embodiments of the present disclosure introduces a compensation mechanism based on the symmetry of the electrical cycle. Compared to the compensation method based on the average value of the maximum and minimum values ​​in the related art, the pre-compensation flux observation value at the symmetrical moment is determined by the pre-compensation flux observation value of the sampling point closest to the symmetrical moment. This avoids the problem of inaccurate maximum and minimum values ​​in the related art caused by the decrease in the number of sampling points as the motor speed increases, reduces the error of the flux observation compensation value, can accurately compensate for the flux observation value, and improves the accuracy of the flux observation. In addition, this method can improve the dynamic response and stability of the motor control system without increasing hardware costs, and is suitable for application scenarios such as new energy vehicles that have high requirements for system reliability and performance.

[0073] In some embodiments of the present disclosure, based on the electrical cycle of the permanent magnet synchronous motor, determining the symmetric moment of the current moment and obtaining the sampling point closest to the symmetric moment can include: determining the moment half an electrical cycle before the current moment as the symmetric moment; determining the sampling point closest to the symmetric moment and located before the symmetric moment as the first sampling point; and determining the sampling point closest to the symmetric moment and located after the symmetric moment as the second sampling point.

[0074] In the disclosed embodiments, the electrical cycle of a permanent magnet synchronous motor is the time it takes for its internal magnetic field to complete a periodic change. Within one electrical cycle, the magnetic field changes symmetrically. Utilizing this symmetric nature of the electrical cycle, the moment half an electrical cycle before the current moment t1 is determined as the symmetric moment t2 relative to the current moment t1.

[0075] Since the sampling of the motor control system is discrete, the symmetric moment t2 is not necessarily a sampling point. Therefore, the sampling point closest to the symmetric moment t2 and located before the symmetric moment t2 can be determined as the first sampling point t2_prev, and the sampling point closest to the symmetric moment t2 and located after the symmetric moment t2 can be determined as the second sampling point t2_next. These two sampling points are subsequently used to estimate the pre-compensation flux observation value at the symmetric moment t2.

[0076] In the embodiment of the present disclosure, based on the symmetric characteristics of the electrical cycle, the moment of the half electrical cycle before the current moment is determined as the symmetric moment, which can effectively utilize the periodic law of the change of the magnetic field inside the motor and provide a theoretical symmetric reference point for flux observation; considering the discrete sampling characteristics of the control system, by determining the two nearest sampling points before and after the symmetric moment (i.e., the first sampling point and the second sampling point), the pre-compensated flux observation value at the symmetric moment is subsequently determined using the pre-compensated flux observation values ​​of these two sampling points, so that the pre-compensated flux observation value at the symmetric moment is more accurate, providing a reliable basis for the subsequent control algorithm, and enhancing the dynamic response and stability of the control system.

[0077] In some embodiments of the present disclosure, the magnetic flux observation method of the permanent magnet synchronous motor also includes: obtaining the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; determining the electrical speed of the permanent magnet synchronous motor based on the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; and determining the electrical period of the permanent magnet synchronous motor based on the electrical speed of the permanent magnet synchronous motor.

[0078] In the disclosed embodiment, the mechanical speed Motor_RPM of the permanent magnet synchronous motor refers to the speed at which the permanent magnet synchronous motor rotor rotates. The number of pole pairs Np of the permanent magnet synchronous motor is an inherent parameter of the permanent magnet synchronous motor and is used to represent the number of pairs of magnetic poles of the motor rotor.

[0079] Based on the permanent magnet synchronous motor's mechanical speed (Motor_RPM) and its pole pair number (Np), the motor's electrical speed is calculated as Motor_RPM*Np. This speed reflects the speed of the motor's internal magnetic field. Furthermore, the motor's electrical period (T) is calculated as the inverse of the speed, i.e., T = 1 / (Motor_RPM*Np). The electrical period represents the time required for the motor's internal magnetic field to complete one periodic change.

[0080] In the disclosed embodiments, the electrical period is not only the core parameter characterizing the periodic variation of the motor's magnetic field but also a crucial foundation for achieving high-precision flux observation and improving control performance. By leveraging the symmetric nature of the electrical period, the periodic variation of the permanent magnet synchronous motor's internal magnetic field can be accurately captured, providing a critical time reference for precise flux observation and control.

[0081] In some embodiments of the present disclosure, determining a pre-compensated flux observation value at a symmetric moment based on pre-compensated flux observation values ​​at sampling points may include: obtaining a pre-compensated flux observation value at a first sampling point and a pre-compensated flux observation value at a second sampling point; determining a first time difference between the symmetric moment and the first sampling point, and a second time difference between the symmetric moment and the second sampling point; and calculating the pre-compensated flux observation value at the symmetric moment based on the first time difference, the second time difference, the pre-compensated flux observation value at the first sampling point, and the pre-compensated flux observation value at the second sampling point.

[0082] In the embodiment of the present disclosure, the first sampling point t2_prev and the second sampling point t2_next are the sampling points closest to the symmetric time t2 and located before and after the symmetric time t2, respectively. The pre-compensation flux observation value ψ of the first sampling point t2_prev is obtained. α (t2_prev) and ψ β (t2_prev), and the pre-compensation flux observation value ψ at the second sampling point t2_next α (t2_next) and ψ β (t2_next). The flux linkage observation values ​​before compensation at these two sampling points can be based on Figure 2 The method for determining the flux observation value before compensation is shown.

[0083] In the embodiment of the present disclosure, the first time difference (t2-t2_prev) between the symmetrical moment t2 and the first sampling point t2_prev, and the second time difference (t2_next-t2) between the symmetrical moment t2 and the second sampling point t2_next are calculated. Then, based on the first time difference (t2-t2_prev), the second time difference (t2_next-t2), and the pre-compensation flux observation value ψ of the first sampling point t2_prev, the compensation value ψ is calculated. α (t2_prev) and ψ β (t2_prev), and the flux linkage observation value ψ before compensation at the second sampling point t2_next α (t2_next) and ψ β (t2_next), calculate the pre-compensation flux observation value ψ at the symmetrical time t2 α (t2) and ψ β (t2).

[0084] For example, the pre-compensation flux observation value ψ at the symmetrical time t2 can be calculated based on the first-order weighted average algorithm. α (t2) and ψ β (t2), the formula is as follows:

[0085]

[0086] In formula (2), ψ α (t2) represents the observed value of the magnetic flux before compensation on the α-axis in the two-phase stationary coordinate system at the symmetric moment, ψ β (t2) represents the observed value of the magnetic flux on the β-axis before compensation in the two-phase stationary coordinate system at the symmetrical moment.

[0087] In the embodiment of the present disclosure, a first-order weighted average method based on time difference is used to calculate the pre-compensated flux observation value at the symmetrical moment. Specifically, by selecting the two sampling points closest to the symmetrical moment, combining their pre-compensated flux observation values ​​and their respective time differences with the symmetrical moment for weighted calculation, the pre-compensated flux observation value at the symmetrical moment is obtained. This method effectively solves the problem that the symmetrical moment is not the actual sampling point under discrete sampling, and accurately fits the dynamic change characteristics of the flux. At the same time, this method only relies on existing sampling data and time information, without the need for additional hardware or complex models. While ensuring computational efficiency, it provides more accurate state feedback for motor control and improves overall performance.

[0088] It should be noted that in addition to using the first-order weighted average method based on time difference to calculate the pre-compensation magnetic flux observation value at the symmetrical moment, other methods can also be used to calculate the pre-compensation magnetic flux observation value at the symmetrical moment, such as linear interpolation method, second-order weighted average method, Kalman filtering method, spline interpolation method and neural network method, etc. In the embodiment of the present disclosure, the appropriate method can be flexibly selected according to conditions such as complexity, computing resources and accuracy requirements, and there is no limitation on this.

[0089] In some embodiments of the present disclosure, the flux observation method of the permanent magnet synchronous motor further includes: in response to the symmetric moment being a sampling point, taking the symmetric moment as the sampling point closest to the symmetric moment; and obtaining the pre-compensated flux observation value of the symmetric moment.

[0090] In the embodiment of the present disclosure, after obtaining the symmetrical moment t2, if the symmetrical moment t2 is a sampling point, it can be directly used as the closest sampling point without further estimation from other sampling points, thereby obtaining the pre-compensated magnetic flux observation value at the symmetrical moment t2. This value can be used to subsequently determine the magnetic flux observation compensation value, thereby simplifying the calculation process and improving the efficiency and accuracy of magnetic flux observation.

[0091] Figure 4 FIG. 1 is a flow chart of a method for determining a pre-compensation flux observation value at a symmetrical moment according to an exemplary embodiment of the present disclosure. Figure 4 , which may include the following steps.

[0092] Step S410: determining the symmetric moment of the current moment based on the electrical cycle of the permanent magnet synchronous motor.

[0093] According to the electrical cycle symmetry of the permanent magnet synchronous motor, the current moment t1 is shifted forward by half an electrical cycle to obtain a moment symmetrical with its magnetic field characteristics. This moment is the symmetrical moment t2, which is used as the benchmark for subsequent flux observation compensation.

[0094] Step S420, determining whether the symmetrical moment is a sampling point, if so, executing step S430, if not, executing step S440.

[0095] It is determined whether the symmetrical time t2 is a sampling point. If so, the pre-compensation flux observation value of the sampling point can be directly used. Otherwise, the pre-compensation flux observation value of the symmetrical time t2 can be estimated through the adjacent sampling points of the symmetrical time t2.

[0096] Step S430: Obtain the pre-compensation flux observation value at the symmetrical moment.

[0097] Get the pre-compensation flux observation value ψ at the symmetrical time t2 α (t2) and ψ β (t2).

[0098] Step S440 , determining the sampling point closest to the symmetric moment and located before the symmetric moment as the first sampling point; determining the sampling point closest to the symmetric moment and located after the symmetric moment as the second sampling point.

[0099] Find the previous sampling point closest to the symmetrical moment t2, that is, the first sampling point t2_prev, and the next sampling point closest to the symmetrical moment t2, that is, the second sampling point t2_next.

[0100] Step S450 : obtaining the pre-compensation flux observation value of the first sampling point and the pre-compensation flux observation value of the second sampling point.

[0101] Get the pre-compensation flux observation value ψ of the first sampling point t2_prev α (t2_prev) and ψ β (t2_prev), and the pre-compensation flux observation value ψ at the second sampling point t2_next α (t2_next) and ψ β (t2_next).

[0102] Step S460: Determine a first time difference between the symmetrical moment and the first sampling point, and a second time difference between the symmetrical moment and the second sampling point.

[0103] A first time difference (t2-t2_prev) between the symmetrical time instant t2 and the first sampling point t2_prev, and a second time difference (t2_next-t2) between the symmetrical time instant t2 and the second sampling point t2_next are calculated respectively.

[0104] Step S470 , calculating the pre-compensated flux observation value at the symmetrical moment according to the first time difference, the second time difference, the pre-compensated flux observation value at the first sampling point, and the pre-compensated flux observation value at the second sampling point.

[0105] According to the above formula (2), based on the first-order weighted average algorithm, according to the first time difference (t2-t2_prev), the second time difference (t2_next-t2), the pre-compensation flux observation value ψ of the first sampling point t2_prev α (t2_prev) and ψ β (t2_prev), and the flux linkage observation value ψ before compensation at the second sampling point t2_next α (t2_next) and ψ β (t2_next), calculate the pre-compensation flux observation value ψ at the symmetrical time t2 α (t2) and ψ β (t2).

[0106] Through the above steps, the symmetrical moment of the current moment is determined based on the electrical cycle of the permanent magnet synchronous motor, and it is determined whether the symmetrical moment is a sampling point. If the symmetrical moment is a sampling point, its pre-compensation flux observation value can be directly used, avoiding the complexity and error introduction of additional estimation. If the symmetrical moment is not a sampling point, two adjacent sampling points are selected, and the pre-compensation flux observation value of the symmetrical moment is calculated using the first-order weighted average method based on the time difference. In this way, the estimation accuracy is guaranteed by weighting the time difference.

[0107] In some embodiments of the present disclosure, determining a flux observation compensation value based on a pre-compensated flux observation value at a current moment and a pre-compensated flux observation value at a symmetric moment may include: obtaining a flux observation mean of the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetric moment; and determining the flux observation mean as the flux observation compensation value.

[0108] In the embodiment of the present disclosure, the pre-compensation flux observation value ψ at the current time t1 can be calculated α (t1) and the observed magnetic flux before compensation at the symmetrical time t2 ψ α The mean of (t2) is used to obtain the flux observation compensation value ψ of the α axis under the two-phase stationary coordinates. α-comp =(ψ α (t1)+ψ α (t2)) / 2, and calculate the pre-compensation flux observation value ψ at the current time t1β (t1) and the observed magnetic flux before compensation at the symmetrical time t2 ψ β The mean of (t2) is used to obtain the flux observation compensation value ψ of the β axis under the two-phase stationary coordinates. β-comp =(ψ β (t1)+ψ β (t2)) / 2.

[0109] In some implementations of the present disclosure, using the magnetic flux observation compensation value to compensate the magnetic flux observation value before compensation at the current moment to obtain the magnetic flux observation value after compensation at the current moment may include: obtaining the difference between the magnetic flux observation value before compensation and the magnetic flux observation compensation value at the current moment; and determining the difference as the magnetic flux observation value after compensation at the current moment.

[0110] In the embodiment of the present disclosure, the pre-compensation flux observation value ψ at the current time t1 is α (t1) minus the flux observation compensation value ψ α-com , obtain the compensated magnetic flux observation value (ψ α (t1)-ψ α-c ). And, the flux linkage observation value ψ before compensation at the current time t1 β (t1) minus the flux observation compensation value ψ β-com , obtain the compensated magnetic flux observation value (ψ β (t1)-ψ β-comp ).

[0111] Through the above steps, the mean of the pre-compensated flux observation values ​​at the current moment and the symmetrical moment is calculated as the flux observation compensation value. This compensation value is then used to correct the pre-compensated flux observation value at the current moment. This solves the problem of deviation or even divergence in the pre-compensated flux observation value caused by factors such as DC bias, improves the accuracy and reliability of the flux observation, and provides more accurate data support for the control system, thereby enhancing the system's dynamic response and stability. Furthermore, this simple difference compensation method does not require complex computational models or additional hardware, is easy to implement, and helps improve the overall efficiency and performance of the control algorithm.

[0112] Figure 5 The flow chart of the flux observation method of the permanent magnet synchronous motor shown in some embodiments of the present disclosure is as follows Figure 2 . Reference Figure 5 , the method may include the following steps.

[0113] Step S501 : Calculate the pre-compensation flux observation value at the current time t1 based on the voltage method.

[0114] Specifically, the three-phase current value i of the permanent magnet synchronous motor at the current time t1 is sampled. A(t1), i B (t1) and i C (t1); for the three-phase current value i A (t1), i B (t1) and i C (t1) Perform coordinate transformation to obtain the current value i in the two-phase stationary coordinate system α (t1) and i β (t1); Based on the voltage command of the previous sampling point at the current time t1, the voltage value u in the two-phase stationary coordinate system is obtained α (t1) and u β (t1); According to the voltage value u in the two-phase stationary coordinate system α (t1) and u β (t1), and the current value i in the two-phase stationary coordinate system at the current moment α (t1) and i β (t1), determine the back electromotive force, and then integrate the back electromotive force to obtain the flux observation value ψ before compensation at the current moment α (t1) and ψ β (t1).

[0115] Step S502 : Calculate the electrical period T according to the mechanical speed and the number of pole pairs of the permanent magnet synchronous motor.

[0116] Step S503 , according to the electrical cycle symmetry of the permanent magnet synchronous motor, the current moment t1 is shifted forward by half an electrical cycle to obtain a moment symmetrical to the magnetic field characteristics thereof, which is the symmetrical moment t2 .

[0117] Step S504: determine the sampling point closest to the symmetric time t2.

[0118] For example, if the symmetrical time t2 is a non-sampling point, the sampling point closest to the symmetrical time t2 and located before the symmetrical time t2 is determined as the first sampling point t2_prev, and the sampling point closest to the symmetrical time t2 and located after the symmetrical time t2 is determined as the second sampling point t2_next.

[0119] Exemplarily, if the symmetrical time t2 is a sampling point, it is directly determined as the closest sampling point.

[0120] Step S505 : Calculate the pre-compensation flux observation value at the symmetrical time t2 based on the pre-compensation flux observation value of the determined sampling point.

[0121] For example, if the symmetrical moment t2 is a non-sampling point, the pre-compensation flux observation value ψ of the first sampling point t2_prev is obtained. α (t2_prev) and ψ β(t2_prev), and the pre-compensation flux observation value ψ at the second sampling point t2_next α (t2_next) and ψ β (t2_next); respectively calculate the first time difference (t2-t2_prev) between the symmetrical moment t2 and the first sampling point t2_prev, and the second time difference (t2_next-t2) between the symmetrical moment t2 and the second sampling point t2_next; according to the above formula (2), based on the first-order weighted average algorithm, according to the first time difference (t2-t2_prev), the second time difference (t2_next-t2), the pre-compensation magnetic flux observation value ψ of the first sampling point t2_prev α (t2_prev) and ψ β (t2_prev), and the flux linkage observation value ψ before compensation at the second sampling point t2_next α (t2_next) and ψ β (t2_next), calculate the pre-compensation flux observation value ψ at the symmetrical time t2 α (t2) and ψ β (t2).

[0122] For example, if the symmetrical moment t2 is the sampling point, the pre-compensation flux observation value ψ at the symmetrical moment t2 is directly obtained. α (t2) and ψ β (t2).

[0123] Step S506 , calculating a flux observation compensation value based on the flux observation value before compensation at the current time t1 and the flux observation value before compensation at the symmetrical time t2 .

[0124] Specifically, calculate the flux observation value ψ before compensation at the current time t1 α (t1) and the observed magnetic flux before compensation at the symmetrical time t2 ψ α The mean of (t2) is used to obtain the flux observation compensation value ψ of the α axis under the two-phase stationary coordinates. α-comp =(ψ α (t1)+ψ α (t2)) / 2, and calculate the pre-compensation flux observation value ψ at the current time t1 β (t1) and the observed magnetic flux before compensation at the symmetrical time t2 ψ β The mean of (t2) is used to obtain the flux observation compensation value ψ of the β axis under the two-phase stationary coordinates. β-comp =(ψ β (t1)+ψ β (t2)) / 2.

[0125] Step S507 : Compensate the pre-compensated flux observation value at the current moment t1 using the flux observation compensation value to obtain the post-compensated flux observation value at the current moment.

[0126] Specifically, the flux linkage observation value ψ before compensation at the current time t1 is α (t1) minus the flux observation compensation value ψ α-comp , obtain the compensated magnetic flux observation value (ψ α (t1)-ψ α-com ). And, the flux linkage observation value ψ before compensation at the current time t1 β (t1) minus the flux observation compensation value ψ β-com , obtain the compensated magnetic flux observation value (ψ β (t1)-ψ β-co ).

[0127] Figure 6 This figure compares the flux trajectory center offset error of the embodiment of the present disclosure and the related art. This figure compares the impact of the flux observation method provided by the embodiment of the present disclosure and the flux observation method provided by the related art on the flux trajectory center offset extraction error. It shows the flux trajectory center offset error obtained using the two different methods at different motor speeds.

[0128] Figure 6 In the figure, the horizontal axis represents the speed of the motor in r / min, and the vertical axis represents the center offset error of the flux trajectory. According to the flux observation method of the permanent magnet synchronous motor provided in the embodiment of the present disclosure, the compensated flux observation value is obtained, and the value is compared with the actual value to obtain the center offset error curve of the flux trajectory of the embodiment of the present disclosure. According to the mean value based on the maximum and minimum values ​​provided in the related art, the compensated flux observation value is obtained, and the value is compared with the actual value to obtain the center offset error curve of the flux trajectory of the related art. Comparing the two curves, it is found that the center offset error of the flux trajectory of the embodiment of the present disclosure shows a smaller error value in the entire speed range, and the fluctuation is relatively smooth, indicating that the compensated flux observation value obtained by the method provided in the embodiment of the present disclosure is more accurate.

[0129] The flux observation method for a permanent magnet synchronous motor of the disclosed embodiment introduces a compensation mechanism based on the symmetry of the electrical cycle. Compared to the compensation method based on the average of the maximum and minimum values ​​in the related art, the pre-compensation flux observation value at the symmetrical moment is determined by the pre-compensation flux observation value of the sampling point closest to the symmetrical moment. This avoids the problem of inaccurate maximum and minimum values ​​in the related art caused by the decrease in the number of sampling points as the motor speed increases, reduces the error of the flux observation compensation value, can accurately compensate for the flux observation value, and improves the accuracy of the flux observation. In addition, this method can improve the dynamic response and stability of the motor control system without increasing hardware costs, and is suitable for application scenarios such as new energy vehicles that have high requirements for system reliability and performance.

[0130] It should be noted that the above figures are merely illustrative of the processes included in the methods according to some embodiments of the present disclosure and are not intended to be limiting. It is readily understood that the processes illustrated in the above figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0131] The following are embodiments of the apparatus disclosed herein, which can be used to implement the method embodiments disclosed herein. For details not disclosed in the apparatus embodiments disclosed herein, please refer to the method embodiments disclosed herein.

[0132] Figure 7 1 is a block diagram of a magnetic flux observation device for a permanent magnet synchronous motor according to some embodiments of the present disclosure. Figure 7 The device 700 may include: a magnetic flux observation value acquisition module 710, a sampling point determination module 720 and a magnetic flux observation value compensation module 730.

[0133] The flux observation value acquisition module 710 is configured to obtain the pre-compensated flux observation value at the current moment. The sampling point determination module 720 is configured to determine the symmetric moment at the current moment based on the electrical cycle of the permanent magnet synchronous motor and obtain the sampling point closest to the symmetric moment. The flux observation value acquisition module 710 is further configured to determine the pre-compensated flux observation value at the symmetric moment based on the pre-compensated flux observation value at the sampling point; and to determine the flux observation compensation value based on the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetric moment. The flux observation value compensation module 730 is configured to compensate the pre-compensated flux observation value at the current moment using the flux observation compensation value to obtain the compensated flux observation value at the current moment.

[0134] In some embodiments of the present disclosure, the sampling point determination module 720 is further configured to: determine a moment half an electrical cycle before a current moment as a symmetrical moment; determine a sampling point closest to the symmetrical moment and located before the symmetrical moment as a first sampling point; and determine a sampling point closest to the symmetrical moment and located after the symmetrical moment as a second sampling point.

[0135] In some embodiments of the present disclosure, the flux linkage observation value acquisition module 710 is further configured to: acquire a pre-compensated flux linkage observation value at a first sampling point and a pre-compensated flux linkage observation value at a second sampling point; determine a first time difference between the symmetrical moment and the first sampling point, and a second time difference between the symmetrical moment and the second sampling point; and calculate the pre-compensated flux linkage observation value at the symmetrical moment based on the first time difference, the second time difference, the pre-compensated flux linkage observation value at the first sampling point, and the pre-compensated flux linkage observation value at the second sampling point.

[0136] In some embodiments of the present disclosure, the sampling point determination module 720 is further configured to, in response to the symmetric moment being the sampling point, use the symmetric moment as the sampling point closest to the symmetric moment; the flux linkage observation value acquisition module is further configured to acquire the pre-compensated flux linkage observation value at the symmetric moment.

[0137] In some embodiments of the present disclosure, Figure 7 As shown, the device 700 also includes an electrical period determination module 740, which is configured to: obtain the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; determine the electrical speed of the permanent magnet synchronous motor according to the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; determine the electrical period of the permanent magnet synchronous motor according to the electrical speed of the permanent magnet synchronous motor.

[0138] In some embodiments of the present disclosure, the flux observation value acquisition module 710 is further configured to: obtain the flux observation mean of the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetrical moment; and determine the flux observation mean as the flux observation compensation value.

[0139] In some embodiments of the present disclosure, the flux observation value compensation module 730 is further configured to: obtain the difference between the pre-compensated flux observation value and the flux observation compensation value at the current moment; and determine the difference as the post-compensated flux observation value at the current moment.

[0140] In some embodiments of the present disclosure, the flux observation value acquisition module 710 is further configured to: sample the three-phase current value of the permanent magnet synchronous motor at the current moment; perform coordinate transformation on the three-phase current value to obtain the current value in the two-phase stationary coordinate system; obtain the voltage value in the two-phase stationary coordinate system based on the voltage instruction of the previous sampling point at the current moment; determine the back electromotive force according to the voltage value in the two-phase stationary coordinate system and the current value in the two-phase stationary coordinate system at the current moment; integrate the back electromotive force to obtain the flux observation value before compensation at the current moment.

[0141] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0142] Figure 8 800 is a block diagram illustrating a control device according to some embodiments of the present disclosure. The control device 800 can be various types of control devices, specifically described in the fields of new energy vehicles, industrial servos, aerospace, and smart homes.

[0143] In the field of new energy vehicles, permanent magnet synchronous motors, as the core of the main drive system, determine the vehicle's power performance and endurance performance. The control device 800 can not only achieve efficient acceleration and smooth braking of the vehicle by precisely regulating the motor's torque and speed, but also maximize the energy conversion efficiency in the energy recovery link, thereby extending the vehicle's range.

[0144] In the industrial servo field, the Control Device 800, paired with a permanent magnet synchronous motor, provides high-precision position and speed control for CNC machine tools, automated production lines, and other equipment. In precision machining scenarios, the motor's low torque ripple characteristics, combined with the Control Device 800's real-time feedback and adjustment, can control machining errors to the micron level, significantly improving product machining accuracy and surface quality. In high-speed automated assembly lines, the two work together to rapidly respond to complex motion commands, significantly improving production efficiency.

[0145] The aerospace industry places extremely high demands on equipment reliability and lightweighting, fully leveraging the high power density of permanent magnet synchronous motors. In this field, the Control Device 800 leverages advanced algorithms to ensure stable motor operation in extreme temperature and pressure environments, providing reliable power for aircraft fly-by-wire systems and onboard equipment. In satellite attitude adjustment mechanisms, it collaborates with motors to achieve precise micro-step control, ensuring accurate satellite alignment.

[0146] In smart home scenarios, the combination of the control device 800 and a permanent magnet synchronous motor delivers a quieter, more energy-efficient experience. In high-end smart air conditioners, the motor automatically and continuously adjusts its speed based on ambient temperature. Combined with the intelligent algorithms of the control device 800, this achieves constant temperature control while reducing energy consumption. The motor and control device 800 on robot vacuums flexibly plan cleaning paths and precisely control speed to suit different floor surfaces, improving cleaning performance.

[0147] Reference Figure 8 The control device 800 may include one or more of the following components: a processing component 802 , a memory 804 , a power component 806 , a multimedia component 808 , an audio component 810 , an input / output (I / O) interface 812 , a sensor component 814 , and a communication component 816 .

[0148] The processing component 802 generally controls the overall operation of the control device 800, such as operations associated with display, phone calls, data communications, camera operation, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to perform all or part of the steps of the above-described method. In addition, the processing component 802 may include one or more modules to facilitate interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate interaction between the multimedia component 808 and the processing component 802.

[0149] The memory 804 is configured to store various types of data to support operations on the control device 800. Examples of such data include instructions for any application or method operating on the control device 800, contact data, phone book data, messages, pictures, videos, etc. The memory 804 can be implemented by any type of volatile or non-volatile storage device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0150] The power supply component 806 provides power to the various components of the control device 800. The power supply component 806 can include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the control device 800.

[0151] The multimedia component 808 includes a screen that provides an output interface between the control device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen can be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor can not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the control device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera can receive external multimedia data. Each front camera and rear camera can be a fixed optical lens system or have a focal length and optical zoom capability.

[0152] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC), which is configured to receive external audio signals when the control device 800 is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signal can be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, the audio component 810 also includes a speaker for outputting audio signals.

[0153] I / O interface 812 provides an interface between processing component 802 and peripheral interface modules, such as a keyboard, click wheel, buttons, etc. These buttons may include but are not limited to: a home button, volume buttons, a start button, and a lock button.

[0154] The sensor assembly 814 includes one or more sensors for providing various aspects of the status assessment of the control device 800. For example, the sensor assembly 814 can detect the open / closed state of the control device 800, the relative positioning of components, such as the display and keypad of the control device 800. The sensor assembly 814 can also detect changes in the position of the control device 800 or a component of the control device 800, the presence or absence of user contact with the control device 800, the orientation or acceleration / deceleration of the control device 800, and temperature changes of the control device 800. The sensor assembly 814 can include a proximity sensor configured to detect the presence of a nearby object without any physical contact. The sensor assembly 814 can also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 can also include a magnetic sensor, a pressure sensor, or a temperature sensor.

[0155] The communication component 816 is configured to facilitate wired or wireless communication between the control device 800 and other devices. The control device 800 can access a wireless network based on a communication standard, such as WiFi, 3G, 4G, 5G, other communication standards, or a combination thereof. In some embodiments of the present disclosure, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In some embodiments of the present disclosure, the communication component 816 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0156] In some embodiments of the present disclosure, the control device 800 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above-mentioned method.

[0157] In some embodiments of the present disclosure, a non-transitory computer-readable storage medium including instructions is further provided, such as a memory 804 including instructions, and the instructions can be executed by the processor 820 of the control device 800 to perform the above method. For example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0158] An embodiment of the present disclosure provides a non-transitory computer-readable storage medium. When instructions in the storage medium are executed by a processor of a control device, the control device is capable of executing a flux observation method for a permanent magnet synchronous motor. The method includes: obtaining a pre-compensated flux observation value at a current moment; determining a symmetric moment at the current moment based on an electrical cycle of the permanent magnet synchronous motor, and obtaining a sampling point closest to the symmetric moment; determining a pre-compensated flux observation value at a symmetric moment based on the pre-compensated flux observation value of the sampling point; determining a flux observation compensation value based on the pre-compensated flux observation value at the current moment and the pre-compensated flux observation value at the symmetric moment; and compensating the pre-compensated flux observation value at the current moment using the flux observation compensation value to obtain a compensated flux observation value at the current moment.

[0159] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0160] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for observing the flux linkage of a permanent magnet synchronous motor, characterized in that: The method comprises: Get the magnetic flux observation value before compensation at the current moment; Determine a symmetrical moment of the current moment based on an electrical cycle of the permanent magnet synchronous motor, and obtain a sampling point closest to the symmetrical moment; determining the pre-compensation magnetic flux observation value at the symmetrical moment according to the pre-compensation magnetic flux observation value of the sampling point; determining a flux observation compensation value according to the flux observation value before compensation at the current moment and the flux observation value before compensation at the symmetrical moment; The pre-compensated magnetic flux observation value at the current moment is compensated using the magnetic flux observation compensation value to obtain the post-compensated magnetic flux observation value at the current moment.

2. The method according to claim 1, characterized in that The determining of the symmetrical moment of the current moment based on the electrical cycle of the permanent magnet synchronous motor and obtaining the sampling point closest to the symmetrical moment includes: Determining the moment half the electrical cycle before the current moment as the symmetrical moment; The sampling point closest to the symmetric moment and located before the symmetric moment is determined as the first sampling point; and the sampling point closest to the symmetric moment and located after the symmetric moment is determined as the second sampling point.

3. The method according to claim 2, characterized in that The determining the pre-compensation magnetic flux observation value at the symmetric moment according to the pre-compensation magnetic flux observation value at the sampling point includes: Acquire a pre-compensation magnetic flux observation value of the first sampling point and a pre-compensation magnetic flux observation value of the second sampling point; determining a first time difference between the symmetrical moment and the first sampling point, and a second time difference between the symmetrical moment and the second sampling point; The pre-compensated flux observation value at the symmetrical moment is calculated according to the first time difference, the second time difference, the pre-compensated flux observation value of the first sampling point, and the pre-compensated flux observation value of the second sampling point.

4. The method according to claim 2, characterized in that The method further comprises: In response to the symmetrical moment being a sampling point, the symmetrical moment is used as a sampling point closest to the symmetrical moment; and a pre-compensated magnetic flux observation value at the symmetrical moment is obtained.

5. The method according to claim 1 or 2, characterized in that The method further comprises: Obtaining the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; Determining the electrical speed of the permanent magnet synchronous motor according to the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; An electrical cycle of the permanent magnet synchronous motor is determined according to the electrical rotation speed of the permanent magnet synchronous motor.

6. The method according to claim 1, wherein The determining of the flux observation compensation value according to the flux observation value before compensation at the current moment and the flux observation value before compensation at the symmetrical moment includes: Obtaining a magnetic flux observation mean of the pre-compensation magnetic flux observation value at the current moment and the pre-compensation magnetic flux observation value at the symmetric moment; The flux linkage observation mean value is determined as the flux linkage observation compensation value.

7. The method according to claim 1, characterized in that The compensating the pre-compensated magnetic flux observation value at the current moment by using the magnetic flux observation compensation value to obtain the post-compensated magnetic flux observation value at the current moment includes: Obtaining a difference between the pre-compensation flux observation value and the flux observation compensation value at the current moment; The difference is determined as the compensated flux observation value at the current moment.

8. The method according to claim 1, characterized in that The obtaining of the pre-compensation magnetic flux observation value at the current moment includes: Sampling the three-phase current value of the permanent magnet synchronous motor at the current moment; Performing coordinate transformation on the three-phase current values ​​to obtain current values ​​in a two-phase stationary coordinate system; Obtaining a voltage value in a two-phase stationary coordinate system based on a voltage command of a previous sampling point at the current moment; Determining a back electromotive force according to the voltage value in the two-phase stationary coordinate system and the current value in the two-phase stationary coordinate system at the current moment; The back electromotive force is integrated to obtain the pre-compensation flux observation value at the current moment.

9. A magnetic flux observation device for a permanent magnet synchronous motor, characterized in that: The device comprises: A magnetic flux observation value acquisition module is configured to acquire a magnetic flux observation value before compensation at a current moment; a sampling point determination module configured to determine a symmetrical moment of the current moment based on an electrical cycle of the permanent magnet synchronous motor, and obtain a sampling point closest to the symmetrical moment; The flux linkage observation value acquisition module is further configured to determine the pre-compensation flux linkage observation value at the symmetrical moment based on the pre-compensation flux linkage observation value at the sampling point; and determine the flux linkage observation compensation value based on the pre-compensation flux linkage observation value at the current moment and the pre-compensation flux linkage observation value at the symmetrical moment; The flux observation value compensation module is configured to compensate the pre-compensated flux observation value at the current moment by using the flux observation compensation value to obtain the post-compensated flux observation value at the current moment.

10. The device according to claim 9, characterized in that The sampling point determination module is further configured to: Determining the moment half the electrical cycle before the current moment as the symmetrical moment; The sampling point closest to the symmetric moment and located before the symmetric moment is determined as the first sampling point; and the sampling point closest to the symmetric moment and located after the symmetric moment is determined as the second sampling point.

11. The device according to claim 10, characterized in that The magnetic flux observation value acquisition module is further configured to: Acquire a pre-compensation magnetic flux observation value of the first sampling point and a pre-compensation magnetic flux observation value of the second sampling point; determining a first time difference between the symmetrical moment and the first sampling point, and a second time difference between the symmetrical moment and the second sampling point; The pre-compensated flux observation value at the symmetrical moment is calculated according to the first time difference, the second time difference, the pre-compensated flux observation value of the first sampling point, and the pre-compensated flux observation value of the second sampling point.

12. The device according to claim 9, characterized in that The sampling point determination module is further configured to, in response to the symmetrical moment being a sampling point, use the symmetrical moment as the sampling point closest to the symmetrical moment; The flux linkage observation value acquisition module is further configured to acquire the pre-compensation flux linkage observation value at the symmetrical moment.

13. The device according to claim 9 or 10, characterized in that The apparatus further includes an electrical cycle determination module configured to: Obtaining the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; Determining the electrical speed of the permanent magnet synchronous motor according to the mechanical speed of the permanent magnet synchronous motor and the number of pole pairs of the permanent magnet synchronous motor; An electrical cycle of the permanent magnet synchronous motor is determined according to the electrical rotation speed of the permanent magnet synchronous motor.

14. The device according to claim 9, characterized in that The magnetic flux observation value acquisition module is further configured to: Obtaining a magnetic flux observation mean of the pre-compensation magnetic flux observation value at the current moment and the pre-compensation magnetic flux observation value at the symmetric moment; The flux linkage observation mean value is determined as the flux linkage observation compensation value.

15. The device according to claim 9, characterized in that The flux linkage observation value compensation module is further configured to: Obtaining a difference between the pre-compensation flux observation value and the flux observation compensation value at the current moment; The difference is determined as the compensated flux observation value at the current moment.

16. The device according to claim 9, characterized in that The magnetic flux observation value acquisition module is further configured to: Sampling the three-phase current value of the permanent magnet synchronous motor at the current moment; Performing coordinate transformation on the three-phase current values ​​to obtain current values ​​in a two-phase stationary coordinate system; Obtaining a voltage value in a two-phase stationary coordinate system based on a voltage command of a previous sampling point at the current moment; Determining a back electromotive force according to the voltage value in the two-phase stationary coordinate system and the current value in the two-phase stationary coordinate system at the current moment; The back electromotive force is integrated to obtain the pre-compensation flux observation value at the current moment.

17. A control device, characterized in that: include: processor; A memory for storing processor-executable instructions; wherein the processor is configured to implement the flux observation method for a permanent magnet synchronous motor according to any one of claims 1 to 8.

18. A non-transitory computer-readable storage medium, which, when instructions in the storage medium are executed by a processor of a control device, enables the control device to execute the flux observation method for a permanent magnet synchronous motor according to any one of claims 1 to 8.

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