Permanent magnet synchronous motor control method and apparatus, and storage medium

Abstract

Embodiments of the present application provide a permanent magnet synchronous motor control method and apparatus, and a storage medium. The control method comprises: obtaining current parameters of a current control period; on the basis of the current parameters, determining a first prediction current of a next control period; on the basis of prediction error parameters of the current control period, correcting the first prediction current of the next control period, and determining a second prediction current of the next control period; on the basis of a tracking error between a reference current of the next control period and the second prediction current of the next control period, determining a target voltage vector; and on the basis of the target voltage vector, controlling a permanent magnet synchronous motor to operate in the next control period. The first prediction current of the next control period is corrected on the basis of the prediction error parameters of the current control period, improving the control accuracy and reliability.

Description

Permanent magnet synchronous motor control method, device and storage medium Technical Field

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

[0002] New energy vehicles are a major development focus for the global automotive industry's transformation and development. They are also a crucial means of optimizing energy consumption structures and enhancing the intelligence of transportation systems and urban operations. After years of sustained effort, technological advancements and industrial systems have steadily improved, and my country's new energy vehicle industry has entered a period of accelerated development. Permanent magnet synchronous motors, with their advantages of small size, high power density, wide speed range, fast response, and safe and reliable operation, are widely used in new energy vehicle drive systems.

[0003] With the increasing requirements for the control performance and accuracy of new energy vehicle motors in recent years, permanent magnet synchronous motors have the characteristics of nonlinearity and multivariables, which makes them difficult to control and require complex control algorithms. Traditional vector control methods often cannot meet the requirements. Summary of the Invention

[0004] In view of this, the embodiments of the present application hope to provide a control method, device and storage medium that can improve the control accuracy and reliability of a permanent magnet synchronous motor.

[0005] To achieve the above objectives, the technical solution of the embodiment of the present application is implemented as follows:

[0006] The present application provides a permanent magnet synchronous motor control method, which includes: obtaining current parameters of a current control cycle; determining a first predicted current of a next control cycle based on the current parameters; correcting the first predicted current of the next control cycle based on a prediction error parameter of the current control cycle to determine a second predicted current of the next control cycle; determining a target voltage vector based on a tracking error between a reference current of the next control cycle and the second predicted current of the next control cycle; and controlling the permanent magnet synchronous motor to operate in the next control cycle based on the target voltage vector.

[0007] In some embodiments, the current parameters of the current control cycle include: a first current in a two-phase rotating coordinate system, a first voltage vector in multiple two-phase rotating coordinate systems, and a rotor electrical angular velocity.

[0008] In some embodiments, determining the first predicted current of the next control cycle based on the current parameters includes: discretizing the continuous state equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system to obtain a discrete state equation; substituting the first current in the two-phase rotating coordinate system of the kth control cycle, multiple first voltage vectors and the rotor electric angular velocity into the discrete state equation to obtain multiple first predicted currents of the k+1th control cycle.

[0009] In some embodiments, The first predicted current of the control cycle 、 The expression is:

[0010] ;

[0011] in: represents the stator resistance, and denote the stator inductance of the d-axis and q-axis respectively, represents the magnetic flux of the rotor permanent magnet, T S represents the control period, is the rotor electrical angular velocity, and represent the first current of the d-axis and q-axis respectively, Respectively represent the n first voltage vectors of the d-axis and the n first voltage vectors of the q-axis; wherein n is an integer greater than or equal to 0 and less than or equal to 7.

[0012] In some embodiments, the prediction error parameter includes a prediction error and a correction error; the prediction error is used to represent the error between the second predicted current corresponding to the target voltage vector and the actual current; the correction error is used to represent the error between the difference between the second predicted current corresponding to the first voltage vector and the actual current and the prediction error.

[0013] In one embodiment, The second predicted current of the control cycle 、 The expression is:

[0014] ;

[0015] ;

[0016] in: and represent the first predicted current of the d-axis and the q-axis respectively, and denote the prediction errors of the d-axis and q-axis respectively, and represent the correction errors of the d-axis and q-axis respectively.

[0017] In some embodiments, The prediction error of the control cycle The expression is:

[0018] ;

[0019] ;

[0020] No. The prediction correction error of the control cycle 、 The expression is:

[0021] ;

[0022] ;

[0023] in:

[0024] ; B ;

[0025] C ;D ;

[0026] represents the d-axis stator reference inductance, represents the predicted d-axis stator inductance;

[0027] represents the q-axis stator reference inductance, represents the predicted q-axis stator inductance.

[0028] In some embodiments, determining the target voltage vector according to the tracking error between the reference current of the next control cycle and the second predicted current of the next control cycle includes: respectively calculating a plurality of the second predicted currents of the k+1th control cycle 、 and the reference current of the k+1th control cycle determining the first voltage vector corresponding to the minimum said difference as the voltage vector.

[0029] The present application also provides a permanent magnet synchronous motor control device, which includes: an acquisition module configured to acquire current parameters of a current control cycle; a prediction module configured to determine a first predicted current of a next control cycle based on the current parameters; a compensation module configured to compensate and correct the first predicted current of the next control cycle based on a prediction error parameter of the current control cycle, and determine a second predicted current of the next control cycle; a voltage vector determination module configured to determine a target voltage vector based on a reference current of the next control cycle and the second predicted current of the next control cycle, wherein the target voltage vector is used to control the operation of the permanent magnet synchronous motor in the next control cycle.

[0030] The present application also provides a computer storage medium, which includes: a memory and a processor, wherein the memory is suitable for storing computer instructions; and the processor is suitable for executing the above-mentioned permanent magnet synchronous motor control method when running the computer instructions.

[0031] The permanent magnet synchronous motor control method in the embodiments of the present application determines a first predicted current for the next control cycle based on the current parameters of the current control cycle, and corrects the first predicted current for the next control cycle based on the prediction error parameter of the current control cycle to obtain a second predicted current. The prediction error parameter of the current control cycle is updated in real time, increasing the accuracy of the second predicted current and the accuracy of the target voltage vector selection, reducing the impact of parameter mismatch during permanent magnet synchronous motor operation, and improving the accuracy and reliability of the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a step diagram of a permanent magnet synchronous motor control method according to an embodiment of the present application;

[0033] FIG2 is a control block diagram of a permanent magnet synchronous motor control method according to an embodiment of the present application;

[0034] FIG3 is a diagram showing a voltage vector space distribution in a permanent magnet synchronous motor control method according to an embodiment of the present application;

[0035] FIG4 is a flowchart of a method for controlling a permanent magnet synchronous motor according to an embodiment of the present application;

[0036] FIG5 is a schematic structural diagram of a permanent magnet synchronous motor control device according to an embodiment of the present application;

[0037] FIG6 is a schematic diagram of the structure of a computer storage medium in an embodiment of the present application.

[0038] Description of Reference Numerals

[0039] Control device 10; acquisition module 11; prediction module 12; compensation module 13; voltage vector determination module 14; permanent magnet synchronous motor M;

[0040] Computer storage medium 100 ; memory 110 ; processing unit 120 . DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of this application and the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] In the following description, numerous specific details are provided to provide a more thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present application; that is, all features of actual embodiments are not described herein, nor are well-known functions and structures described in detail.

[0043] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0044] In order to fully understand the present application, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present application. The preferred embodiments of the present application are described in detail below. However, in addition to these detailed descriptions, the present application may also have other implementation methods.

[0045] A permanent magnet synchronous motor is generally composed of components such as a stator, a rotor, and end covers. It is a synchronous motor that uses permanent magnets to establish an excitation magnetic field. It has the characteristics of small size, high power density, wide adjustable speed range, fast response speed, and safe and reliable operation.

[0046] With the continuous development of permanent magnet synchronous motors (PMSMs), the importance of their control technology has become increasingly prominent. Traditional vector control methods use coordinate transformation to decompose the acquired motor's three-phase stator current, flux linkage, and other vectors into two components: one component aligns with the rotor flux, known as the direct-axis excitation current; the other, orthogonal to the rotor flux, known as the quadrature-axis torque current. These methods adjust the excitation and torque currents according to different control objectives, achieving precise speed and torque control. This approach offers excellent steady-state tracking performance, but suffers from the difficulty of adjusting controller parameters, resulting in unstable performance of PMSMs. Model predictive control methods predict future system state variables based on a discrete mathematical model of the controlled object and current system state variables. The target control variable is obtained by solving an optimization problem within the predicted time period. Model predictive control methods offer fast dynamic response, strong adaptability, and excellent robustness, making them crucial for improving the control performance of highly nonlinear systems such as PMSMs.

[0047] In order to improve the control performance of a permanent magnet synchronous motor, an embodiment of the present application provides a permanent magnet synchronous motor control method. The control method steps are shown in FIG1 . The permanent magnet synchronous motor control method specifically includes:

[0048] Step S1: Obtain current parameters of the current control cycle. The current parameters of the current control cycle can be determined by signals such as current, voltage, and speed of the permanent magnet synchronous motor collected during the current control cycle.

[0049] Step S2: Determine a first predicted current for the next control cycle according to the current parameter.

[0050] Step S3: According to the prediction error parameter of the current control cycle, the first predicted current of the next control cycle is corrected to determine the second predicted current of the next control cycle. The prediction error parameter of the current control cycle is used to represent the error between the second predicted current of the current control cycle and the actual current.

[0051] Step S4: Determine a target voltage vector according to a tracking error between a reference current of a next control cycle and a second predicted current of the next control cycle, wherein the reference current is used to represent the actual current of the permanent magnet synchronous motor.

[0052] Step S5: Control the permanent magnet synchronous motor to operate in the next control cycle according to the target voltage vector.

[0053] The model predictive control method is a control algorithm based on a predictive model. In the field of permanent magnet motor control, it is generally done by establishing a mathematical model of the permanent magnet motor and using the parameters of the current control cycle to calculate the predicted values ​​corresponding to all possible first voltage vectors; then, by evaluating each predicted value, the target voltage vector is selected from all possible first voltage vectors; and the target voltage vector is applied in the next control cycle to achieve control of the permanent magnet synchronous motor.

[0054] It should be noted that the control period can be determined based on the sampling interval of the current parameter. All possible first voltage vectors refer to first voltage vectors corresponding to all possible valid switching states of an inverter used to control a permanent magnet synchronous motor. The inverter refers to a converter that converts direct current into alternating current. Exemplarily, the inverter can be a three-phase two-level voltage source inverter, which includes six switches and can generate eight valid switch combination states. The eight valid switch states correspond to eight possible first voltage vectors.

[0055] Model predictive control methods can be divided into model predictive torque control and model predictive current control, depending on the primary control objective of the permanent magnet synchronous motor. Model predictive torque control requires simultaneous control of both torque and flux, while model predictive current control uses current as the sole control objective, resulting in a simple algorithm. The permanent magnet synchronous motor control method of this application uses current as the control objective and establishes a permanent magnet motor prediction model.

[0056] Specifically, the current parameters of the permanent magnet synchronous motor are determined using the current, voltage, speed, and other signals collected during the current control cycle. By establishing a permanent magnet motor prediction model and using the current parameters as input to the prediction model, a first predicted current corresponding to all possible first voltage vectors for the next control cycle can be obtained. In practical applications, there is a large error between the first predicted current and the actual current. Since the control performance of the model-predicted current control method depends on the accuracy of the prediction model, if the first predicted current is directly used as the predicted current for determining the target voltage vector to be applied during the next control cycle, the control performance of the permanent magnet motor may be degraded due to a mismatch in the prediction model parameters, thereby reducing control accuracy and stability. Based on this, the present application further proposes using the prediction error parameter of the current control cycle to correct the first predicted current for the next control cycle to obtain a second predicted current for the next control cycle. The target voltage vector to be applied during the next control cycle is determined from all possible first voltage vectors based on the tracking error between the reference current for the next control cycle and the second predicted current for the next control cycle. Compared to the first predicted current for the next control cycle, the second predicted current for the next control cycle, obtained after correction using the prediction error parameter for the current control cycle, is closer to the actual current for the next control cycle. The target voltage vector determined using the second predicted current is more accurate, improving the accuracy and reliability of permanent magnet synchronous motor control. The prediction error parameter for the current control cycle characterizes the error between the second predicted current and the actual current for the current control cycle.

[0057] The permanent magnet synchronous motor control method in the embodiments of the present application determines a first predicted current for the next control cycle based on the current parameters of the current control cycle, and corrects the first predicted current for the next control cycle based on the prediction error parameters of the current control cycle to obtain a second predicted current. By updating the prediction error parameters of the current control cycle in real time, the accuracy of the second predicted current is increased, the accuracy of the target voltage vector selection is improved, the impact of parameter mismatch during permanent magnet synchronous motor operation is reduced, and the accuracy and reliability of the control system are improved.

[0058] In some embodiments, step S1 includes: obtaining current parameters of the current control cycle. The current parameters may specifically include: a first current in a two-phase rotating coordinate system, a first voltage vector in multiple two-phase rotating coordinate systems, and a rotor electrical angular velocity. The control block diagram of the permanent magnet synchronous motor control method is shown in FIG2 , and step S1 specifically includes:

[0059] Step S11: Obtain the first current in the two-phase rotating coordinate system, including the d-axis first current and the q-axis first current As shown in the lower right side of Figure 2, the current of the permanent magnet synchronous motor in the three-phase stationary coordinate system in the kth control cycle is collected. , including current 、 and , the current 、 and Perform Clark transformation to obtain the current in the two-phase stationary coordinate system and , and then the current and Perform Park transformation to obtain the first current in the two-phase rotating coordinate system and .

[0060] Step S12: Obtain the first voltage vector in the two-phase rotating coordinate system, including multiple d-axis first voltage vectors and multiple q-axis first voltage vectors . For example, a three-phase two-level voltage source inverter is selected as the inverter of the permanent magnet synchronous motor, and the eight switching states included in the three-phase two-level voltage source inverter are composed of a voltage vector control set {U0, U1, ···…, U7}. Among them, the eight switching states correspond to eight voltage vectors, including six non-zero voltage vectors and two zero voltage vectors. The spatial distribution diagram of the voltage vector in the two-phase stationary coordinate system is shown in Figure 3. The switch combinations corresponding to different voltage vectors and the voltage vectors in the two-phase stationary coordinate system are shown in Figure 3. and As shown in Table 1, Represents the bus DC voltage. The voltage of the two-phase stationary coordinate system is and Perform Park transformation to obtain 8 d-axis first voltage vectors corresponding to the voltage vectors and 8 q-axis first voltage vectors , where n is an integer greater than or equal to 0 and less than or equal to 7.

[0061]

[0062] Table 1

[0063] Step S13: Obtain the electrical angular velocity of the permanent magnet synchronous motor rotor through the encoder .

[0064] In some embodiments, referring to FIG2 , step S2 includes: according to the current parameter first current of the kth control cycle 、 , 8 d-axis first voltage vectors and 8 q-axis first voltage vectors Rotor electrical angular velocity etc., determine the first predicted current of the d-axis in the k+1th control cycle and the q-axis first predicted current Step S2 specifically includes:

[0065] Step S21: establishing a continuous state equation of the permanent magnet synchronous motor in a two-phase rotating coordinate system.

[0066] Step S22: discretize the above continuous state equation to obtain a discretized equation.

[0067] Step S23: Substitute the current parameters of the current control cycle into the above discrete equation to obtain a plurality of first predicted currents.

[0068] The continuous state equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system established in step S21 is as follows:

[0069] (1);

[0070] In formula (1): represents the stator resistance, and denote the stator inductance of the d-axis and q-axis respectively, represents the magnetic flux of the rotor permanent magnet, T S Indicates the control period.

[0071] Since the algorithm of the model predictive control method generally needs to be implemented on hardware such as a digital signal processor, it is necessary to discretize the continuous state equation formula (1) to obtain a discrete state equation. In some embodiments, considering that in the control period T S When is small enough, the discretization of the forward Euler discretization method can meet the accuracy requirements, and the forward Euler discretization method has the characteristics of simple implementation and small amount of computation. This application uses the forward Euler discretization method to discretize the continuous state equation formula 1. Specifically, the differential term is approximated by forward difference, that is,

[0072] (2),

[0073] Substituting formula (2) into formula (1), we get the discrete state equation, which is as follows:

[0074] (3);

[0075] In formula (3), represents the d-axis first predicted current of the k+1th control cycle, Indicates the q-axis first predicted current in the (k+1)th control period.

[0076] Step S23 specifically includes: converting the first current in the two-phase rotating coordinate system of the kth control period into and , 8 d-axis first voltage vectors and 8 q-axis first voltage vectors , and the rotor electrical angular velocity , respectively, into the discrete state equation formula (3), and obtain the d-axis first predicted current of 8 k+1 control cycles respectively and the q-axis first predicted current of 8 k+1th control cycles .

[0077] In some embodiments, The first predicted d-axis current of the control cycle and the q-axis first predicted current The following formula (4): (4);

[0078] In formula (4): represents the nth first voltage vector of the d-axis, Represents the nth first voltage vector of the q-axis.

[0079] The control performance of the permanent magnet synchronous motor control system depends on the accuracy of the prediction model. However, many factors may cause the prediction model to mismatch, resulting in a large error between the first predicted current directly obtained by the prediction model and the actual current, which in turn affects the selection of the subsequent target voltage vector and causes a decrease in control reliability. In some embodiments, when determining the first predicted current of the d-axis in the k+1th control cycle, and the q-axis first predicted current After that, the control method of the permanent magnet synchronous motor further includes step S3 and step S4. Specifically, according to the prediction error parameter of the kth control cycle, the d-axis first predicted current of the k+1th control cycle is respectively and the q-axis first predicted current Correction is performed to obtain the second predicted current of the d-axis in the k+1th control cycle and the q-axis second predicted current According to the reference current of the k+1th control cycle and the second predicted current of the k+1th control cycle 、 The tracking error between the two is used to determine the first voltage vector of the kth control cycle corresponding to the minimum tracking error. and is the target voltage vector of the k+1th control cycle and .

[0080] In some embodiments, the prediction error parameter includes a prediction error and a correction error. The prediction error for the current control cycle is used to represent the error between the second predicted current corresponding to the target voltage vector of the current control cycle and the actual current. The correction error for the current control cycle is used to represent the error caused by the difference between the first voltage vector of the current control cycle and the target voltage vector of the current control cycle, that is, the error between the difference between the second predicted current corresponding to the first voltage vector of the current control cycle and the actual current and the prediction error.

[0081] Specifically, when the first voltage vector of the current control cycle is the same as the target voltage vector of the current control cycle (one of the first voltage vectors of the previous control cycle), the control cycle If the value is sufficiently small, the operating condition of the permanent magnet synchronous motor can be considered unchanged, and the inductance parameter value remains essentially unchanged. Therefore, if the first voltage vector is the same in adjacent control cycles, the corresponding prediction error is also the same. The prediction error of the current control cycle can be used to compensate the first predicted current of the next control cycle to obtain the second predicted current.

[0082] The reasons for the error between the actual current and the predicted current used to determine the target voltage vector for the next control cycle include the discretization method, the mismatch between the control cycle and the model parameters, among which the model parameters ( 、 、 , ) mismatch has a greater impact. For permanent magnet synchronous motors suitable for new energy vehicles, the model parameters 、 Compared to , The impact on the prediction error is greater, and the d-axis inductance can be mainly considered , q-axis inductance Bias quantifies the prediction error.

[0083] In some embodiments, when The first voltage vector of the control cycle 、 The target voltage vector of the kth control cycle 、 When the target voltage vector 、 is the first voltage vector corresponding to the minimum tracking error in the k-1th control cycle and , the target voltage vector of the kth control cycle 、 The corresponding The prediction error of the control cycle The expressions are as follows:

[0084] (5);

[0085] (6);

[0086] in:

[0087] ; B ;

[0088] C ;D ;

[0089] represents the d-axis stator reference inductance, represents the predicted d-axis stator inductance; represents the q-axis stator reference inductance, represents the predicted q-axis stator inductance; where the error coefficients A, B, C, and D can be obtained through motor bench tests.

[0090] In some embodiments, when The first voltage vector of the control cycle 、 The target voltage vector of the kth control cycle 、 (where the target voltage vector 、 is the first voltage vector corresponding to the minimum tracking error in the k-1th control cycle and ) are different, the prediction error of the kth control cycle corresponding to the target voltage vector of the kth control cycle can be calculated respectively. and the first voltage vector of the k-1th control cycle 、 The corresponding prediction error of the kth control cycle , using the above two prediction errors and The difference, that is, the correction error 、 , the first predicted current after compensation for the k+1th control cycle 、 Correction is performed to obtain the second predicted current 、 .

[0091] Prediction error In the expressions (5) and (6), the d-axis prediction error in the formula (5) is and the q-axis prediction error formula (6) Indicates the influence of voltage disturbance on the prediction result. When the first voltage vector of the kth control cycle is different from the target voltage vector of the kth control cycle, the voltage disturbance term 、 The impact on the prediction results is greater than other disturbance terms. Only the voltage disturbance term can be considered. The first predicted current after compensation using the prediction error is compensated and corrected. d-axis correction error of a control cycle , q-axis correction error The expressions are as follows (7) and (8):

[0092] ; (7)

[0093] ; (8)

[0094] The error coefficients A and C can be obtained through a motor bench test. Specifically, an error coefficient table can be established by measuring the interval differences of the first voltage vectors at different speeds.

[0095] It should be noted that in the The first voltage vector of the control cycle 、 The target voltage vector of the kth control cycle 、 When the target voltage vector 、 is the first voltage vector corresponding to the minimum tracking error in the k-1th control cycle and ), correct the error 、 is zero, and only the prediction error of the kth control cycle can be used The first predicted current after compensation for the k+1th control cycle 、 Correction is performed to obtain the second predicted current 、 .

[0096] In summary, the prediction error parameters can include the prediction error and correct errors 、 Among them, the prediction error Used to represent the error between the second predicted current corresponding to the target voltage vector and the actual current; correct the error 、 It is used to further reduce the error caused by the difference in direction between the first voltage vector of the next control cycle and the target voltage vector of the current control cycle, that is, the correction error 、 It can be expressed as the error between the difference between the second predicted current and the actual current corresponding to the first voltage vector and the prediction error. and correct errors 、 , the first predicted current for the k+1th control cycle 、 Among them, the prediction error of the kth control cycle is Used to represent the target voltage vector of the kth control cycle 、 The corresponding second predicted current 、 The error between the target voltage vector 、 is the first voltage vector corresponding to the minimum tracking error in the k-1th control cycle and ), the correction error of the kth control cycle 、 The first voltage vector representing the kth control period 、 The corresponding second predicted current 、 The difference from the actual current and the prediction error The predicted error and corrected error of the current control cycle are updated in real time, further reducing the inaccuracy of the second predicted current caused by the difference between the first voltage vector direction of the next control cycle and the target voltage vector direction of the current control cycle. This increases the accuracy of the target voltage vector selection, reduces the impact of parameter mismatch during the operation of the permanent magnet synchronous motor, and improves the accuracy and reliability of the control system.

[0097] In some embodiments, step S3 includes: modifying the first predicted current of the next control cycle according to the prediction error parameter of the current control cycle, and determining the second predicted current of the next control cycle. The prediction error of the control cycle and and correct errors and , for The first predicted current of the control cycle and Compensate and correct to get The second predicted current of the control cycle 、 . No. The second predicted current of the control cycle 、 The expressions are as follows (9) and (10):

[0098] (9);

[0099] (10).

[0100] In one embodiment, a flowchart of a program for calculating the second predicted current of the k+1th control cycle is shown in FIG4 , where step S3 specifically includes:

[0101] Step S31: Calculate the prediction error of the kth control cycle according to the above formulas (5)-(6) and .

[0102] Step S32: Calculate the error coefficients A and C of the kth control cycle.

[0103] Steps S33 to S37: Calculate the first predicted current of the kth control cycle in sequence according to the above formula (3): and , and according to the above formulas (7)-(10), the 8 first predicted currents per control cycle and Compensation and correction are performed to obtain 8 second predicted currents 、 . Further reducing the first voltage vector of the kth control cycle 、 and the target voltage vector of the kth control cycle 、 The second predicted current caused by the difference 、 The accuracy of the second predicted current is not enough, so 、 Closer to the actual current, the target voltage vector of the k+1th control cycle is added 、 The accuracy of the selection reduces the impact of parameter mismatch during the operation of the permanent magnet synchronous motor and increases the accuracy and reliability of the control system.

[0104] In some embodiments, step S4 includes: according to the reference current of the k+1th control cycle and the second predicted current of the k+1th control cycle 、 The tracking error between them is used to determine the target voltage vector of the k+1th control cycle. and . Specifically including:

[0105] Step S41: constructing a cost function with current prediction as the control target and the minimum tracking error between the reference current and the predicted current as the constraint condition.

[0106] Step S42: Calculate the tracking error of the k+1th control cycle.

[0107] Step S43: Calculate the cost function of the k+1th control cycle.

[0108] Step S44: Determine the second predicted current and the first voltage vector corresponding to the minimum cost function, and use the first voltage vector as the target voltage vector.

[0109] Among them, the tracking error of the k+1th control cycle is and The expressions are as follows (11) and (12): the value function of the k+1th control cycle is The expression is as follows (13).

[0110] (11);

[0111] (12);

[0112] (13).

[0113] Step S42: Calculate the tracking error of the k+1th control cycle. Specifically, calculate the multiple second predicted currents of the k+1th control cycle respectively. 、 and the reference current of the k+1th control cycle and The difference between the two determines the second predicted current 、 The d-axis tracking error of each in the k+1th control cycle and q-axis tracking error .

[0114] Among them, the reference current and It can be obtained through the speed outer loop, which can be controlled by a controller.

[0115] Step S43: Calculate the cost function of the k+1th control cycle. Specifically, calculate the multiple d-axis tracking errors of the k+1th control cycle respectively. and q-axis tracking error The sum of the squares of the multiple second predicted currents in the k+1th control cycle is used to determine their respective value functions .

[0116] Step S44: Determine the minimum value function The corresponding second predicted current 、 and the first voltage vector and , the first voltage vector and As the target voltage vector of the k+1th control cycle and .

[0117] In some embodiments, step S5 specifically includes: according to the target voltage vector of the k+1th control cycle and , controlling the permanent magnet synchronous motor to operate in the k+1th control cycle.

[0118] Based on the same inventive concept, the embodiment of the present application also provides a permanent magnet synchronous motor control device. As shown in Figure 5, the control device 10 includes: an acquisition module 11, a prediction module 12, a compensation module 13 and a voltage vector determination module 14. The acquisition module 11 is configured to acquire the current parameters of the current control cycle; the prediction module 12 is configured to determine the first predicted current of the next control cycle based on the current parameters; the compensation module 13 is configured to compensate and correct the first predicted current of the next control cycle based on the prediction error parameters of the current control cycle, and determine the second predicted current of the next control cycle; the voltage vector determination module 14 is configured to determine the target voltage vector based on the reference current of the next control cycle and the second predicted current of the next control cycle. The target voltage vector is used to control the operation of the permanent magnet synchronous motor in the next control cycle.

[0119] In some embodiments, referring to FIG2 , the prediction module 12 obtains the current parameter of the kth control cycle according to the acquisition module. 、 and , determine the first predicted current of the kth control cycle ; Compensation module 13 according to the second predicted current of the kth control cycle and actual current The first predicted current Perform compensation correction to obtain the second predicted current of the k+1th control cycle The voltage vector determination module 14 is based on the second predicted current The reference current provided by the controller The tracking error between , select the minimum value function The corresponding first voltage vector As the target voltage vector of the k+1th control cycle And the permanent magnet synchronous motor M is controlled by the inverter to operate in the k+1th control cycle. Among them, the first predicted current Including the d-axis first predicted current and the q-axis first predicted current ; Second predicted current Including the d-axis second predicted current and the q-axis second predicted current ; Reference current Including d-axis reference current and q-axis reference current Tracking error Including d-axis tracking error and q-axis tracking error ; Target voltage vector Including d-axis target voltage vector and q-axis target voltage vector .

[0120] In some embodiments, the acquisition module 11 is configured to acquire the current parameters of the kth control cycle. The current parameters may specifically include: the first current in the two-phase rotating coordinate system and , multiple d-axis first voltage vectors and multiple q-axis first voltage vectors and the rotor electrical angular velocity For example, if a three-phase two-level voltage source inverter is selected as the inverter of the permanent magnet synchronous motor M, the eight switching states in the three-phase two-level voltage source inverter correspond to eight voltage vectors, including six non-zero voltage vectors and two zero voltage vectors, and the current parameters include eight d-axis first voltage vectors and 8 q-axis first voltage vectors .

[0121] In some embodiments, the prediction module 12 is configured to be based on the current parameters of the kth control cycle: the first current and , 8 d-axis first voltage vectors and 8 q-axis first voltage vectors and the rotor electrical angular velocity , determine the first predicted current of the d-axis in the k+1th control cycle and the q-axis first predicted current .

[0122] In some embodiments, the compensation module 13 is configured to calculate the d-axis first predicted current of the k+1th control cycle based on the prediction error parameter of the kth control cycle. and the q-axis first predicted current Compensate and correct to determine the d-axis second predicted current of the k+1th control cycle and the q-axis second predicted current .

[0123] In some embodiments, when The first voltage vector of the control cycle 、 The target voltage vector of the kth control cycle 、 When the same, the prediction error parameters can include the The prediction error of the control cycle Among them, the prediction error The target voltage vector of the kth control cycle 、 Corresponding. Specific The prediction error of the control cycle The expressions are shown in formulas (5) and (6). The first voltage vector of the control cycle 、 The target voltage vector of the kth control cycle 、 If different, the prediction error parameters can include the The prediction error of the control cycle and correct errors 、 Among them, the prediction error The target voltage vector of the kth control cycle 、 Corresponding. Specific The prediction error of the control cycle The expressions are shown in formulas (5) and (6). Correction error of control cycle 、 The expressions are shown in formulas (7) and (8). The second predicted current of the control cycle 、 The expressions are shown in equations (9) and (10) above.

[0124] In summary, the prediction error parameter configured to compensate and correct the first predicted current in the compensation module 13 may include the prediction error and correct errors 、 Among them, the prediction error Used to represent the error between the second predicted current corresponding to the target voltage vector and the actual current; correct the error 、 This parameter represents the difference between the second predicted current and the actual current corresponding to the first voltage vector and the prediction error. The first predicted current for the next control cycle is corrected using the current cycle's prediction error and correction error. The current cycle's prediction error and correction error are updated in real time, further minimizing the inaccuracy of the second predicted current caused by different first voltage vector directions. This improves the accuracy of target voltage vector selection, reduces the impact of parameter mismatch during permanent magnet synchronous motor operation, and enhances the accuracy and reliability of the control system.

[0125] In some embodiments, the voltage vector determination module 14 is configured to be based on the reference current of the k+1th control cycle 、 and the second predicted current of the k+1th control cycle 、 , determine the target voltage vector 、 , target voltage vector 、 It is used to control the permanent magnet synchronous motor to operate in the k+1th control cycle. Among them, the reference current of the k+1th control cycle is 、 The voltage vector determination module 14 determines the target voltage vector of the k+1th control cycle. 、 Specific methods may include:

[0126] Step S41: With the current prediction as the control target and the minimum tracking error between the reference current and the predicted current as the constraint condition, construct the cost function. The tracking error of the k+1th control cycle is and The expressions are as shown in equations (11) and (12). The value function of the k+1th control cycle is The expression is as above formula (13).

[0127] Step S42: Calculate the tracking error of the k+1th control cycle and .

[0128] Step S43: Calculate the value function J of the k+1th control cycle.

[0129] Step S44: Determine the minimum value function The corresponding second predicted current and first voltage vector are used as the target voltage vector of the k+1th control cycle. and .

[0130] Based on the same inventive concept, an embodiment of the present application further provides a computer storage medium 100. As shown in FIG6 , the computer storage medium 100 includes a memory 110 and a processor 120. The memory 110 is adapted to store computer instructions, and the processor 120 is adapted to execute the above-mentioned permanent magnet synchronous motor control method when executing the computer instructions. Because the processor 120 in the computer storage medium 100 is used to execute the above-mentioned permanent magnet synchronous motor control method, the storage medium has the same beneficial technical effects as the above-mentioned permanent magnet synchronous motor control method. Therefore, the beneficial technical effects of the computer storage medium will not be further described herein.

[0131] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments.

[0132] Those skilled in the art will understand that all or part of the steps of the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, and other media that can store program codes.

[0133] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0134] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A permanent magnet synchronous motor control method, characterized in that The control method includes: Obtaining current parameters of the current control period; Determining a first predicted current for the next control period according to the current parameters; Correcting the first predicted current for the next control period according to the prediction error parameter of the current control period to determine a second predicted current for the next control period; Determining a target voltage vector according to the tracking error between the reference current for the next control period and the second predicted current for the next control period; Controlling the permanent magnet synchronous motor to operate in the next control period according to the target voltage vector.

2. The permanent magnet synchronous motor control method according to claim 1, characterized in that The current parameters of the current control period include: A first current in a two-phase rotating coordinate system, a plurality of first voltage vectors in the two-phase rotating coordinate system, and a rotor electrical angular velocity.

3. The permanent magnet synchronous motor control method according to claim 2, wherein, The determining a first predicted current for the next control period according to the current parameters includes: Discretizing the continuous state equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system to obtain a discrete state equation; Substituting the first current in the two-phase rotating coordinate system, the plurality of first voltage vectors, and the rotor electrical angular velocity of the k-th control period into the discrete state equation to obtain a plurality of first predicted currents for the (k + 1)-th control period.

4. The permanent magnet synchronous motor control method according to claim 3, wherein Article The first predicted current of a control period 、 The expression is: ； Wherein: Represents the stator resistance, And represent the stator inductances of the d-axis and q-axis, respectively, denotes the rotor permanent magnet flux linkage, T S denotes the control period is the rotor electrical angular velocity, and The first currents respectively representing the d-axis and the q-axis respectively represent n first voltage vectors on the d-axis and n first voltage vectors on the q-axis; where n is an integer greater than or equal to 0 and less than or equal to 7.

5. The permanent magnet synchronous motor control method according to claim 4, wherein, The prediction error parameter includes a prediction error and a correction error; the prediction error is used to represent the error between the second predicted current corresponding to the target voltage vector and the actual current; the correction error is used to represent the error between the difference between the second predicted current corresponding to the first voltage vector and the actual current and the prediction error.

6. The permanent magnet synchronous motor control method according to claim 5, wherein Article The second predicted current of a control period 、 The expression is: ； ； Wherein: And The first predicted currents respectively representing the d-axis and the q-axis and respectively represent the prediction errors of the d-axis and the q-axis and respectively represent the correction errors on the d-axis and the q-axis.

7. The permanent magnet synchronous motor control method according to claim 6, wherein Article The prediction error of a control period The expression is: ； ； Article The prediction correction error of a control period 、 The expression is: ； ； Wherein: ；B ； C ；D ； Indicates the d-axis stator reference inductance, represents the d-axis stator predicted inductance; Denotes the q-axis stator reference inductance, represents the q-axis stator predicted inductance.

8. The permanent magnet synchronous motor control method according to claim 7, wherein The determining a target voltage vector according to the tracking error between the reference current for the next control period and the second predicted current for the next control period includes: Calculate the multiple second predicted currents in the (k + 1)-th control period respectively 、 with the reference current of the (k + 1)-th control period the difference between; Determining the first voltage vector corresponding to the minimum difference as the voltage vector.

9. A permanent magnet synchronous motor control device, characterized in that, The control device includes: An acquisition module configured to acquire current parameters of the current control period; A prediction module configured to determine a first predicted current for the next control period based on the current parameters; A compensation module configured to compensate and correct the first predicted current for the next control period based on the prediction error parameter of the current control period to determine a second predicted current for the next control period; A voltage vector determination module, configured to determine a target voltage vector based on a reference current of a next control period and the second predicted current of the next control period, where the target voltage vector is used to control a permanent magnet synchronous motor to operate in the next control period.

10. A computer storage medium, characterized in that, The computer storage medium includes: a memory and a processor, where the memory is adapted to store computer instructions; the processor is adapted to execute the permanent magnet synchronous motor control method according to any one of claims 1 to 8 when running the computer instructions.

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