Control method of permanent magnet synchronous motor and related device

Abstract

The invention provides a control method of a permanent magnet synchronous motor and a related device, and relates to the field of permanent magnet synchronous motors. And on the basis of the basic demand torque, the virtual total load torque of the speed ring is compensated to obtain the demand electromagnetic torque, so that the robustness of rotating speed control is improved. And according to the control input voltage corresponding to each switching state combination of the switching tube and a target stator current model, calculating the stator current corresponding to each switching state combination at the next sampling moment, and calculating the electromagnetic torque at the next sampling moment based on the stator current at the next sampling moment, according to the required electromagnetic torque and the electromagnetic torque of the next sampling moment corresponding to each switch state combination, the target switch state combination is selected from all the switch state combinations and the permanent magnet synchronous motor is controlled, the whole process is automatically realized, the control complexity is reduced, and the control efficiency is improved. And the dependence on the engineering experience of a calibration engineer is reduced while the calibration workload is reduced, and the calibration efficiency of the permanent magnet synchronous motor is improved.

Description

Technical Field

[0001] The present application relates to the field of permanent magnet synchronous motors, and more specifically, to a control method and related devices for permanent magnet synchronous motors. Background Art

[0002] Permanent Magnet Synchronous Motor (PMSM) is a synchronous motor that uses permanent magnets to generate a magnetic field.

[0003] Currently, the speed and current control of permanent magnet synchronous motors (PMSMs) are widely controlled using a piecewise PI (Proportional-Integral) control method. This method suffers from the coupling between the proportional and integral control terms. Furthermore, the coupling between the d-axis and q-axis currents in current control further complicates the control of PMSMs. This makes the piecewise PI calibration method, currently widely used in practical engineering, time-consuming and labor-intensive, and difficult to achieve good control results. Therefore, reducing the complexity of PMSM control, reducing the calibration workload for calibration engineers, and improving the control accuracy and efficiency of PMSMs have become urgent challenges. Summary of the Invention

[0004] In view of this, the present application provides a control method and related devices for a permanent magnet synchronous motor, so as to reduce the complexity of the permanent magnet synchronous motor control, reduce the calibration workload of calibration engineers, and improve the control accuracy and efficiency of the permanent magnet synchronous motor.

[0005] In order to solve the above technical problems, this application adopts the following technical solutions:

[0006] A control method for a permanent magnet synchronous motor, comprising:

[0007] Calculating the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment; the required electromagnetic torque is determined based on the basic required torque and the estimated value of the virtual total load torque;

[0008] Obtaining a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances; the target stator current model includes a functional relationship between motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters; the target stator current model is used for current decoupling prediction of the d-axis and q-axis;

[0009] Calculating the stator current at the next sampling moment corresponding to each switching state combination according to the control input voltage corresponding to each switching state combination of the switching tube and the target stator current model;

[0010] Calculating the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination based on the stator current at the next sampling moment corresponding to each switching state combination;

[0011] According to the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, and the control operation of the permanent magnet synchronous motor is performed using the target switch state combination.

[0012] Optionally, calculating the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment includes:

[0013] Obtaining a target motion model of the permanent magnet synchronous motor; the target motion model of the permanent magnet synchronous motor includes at least a rated moment of inertia, a rated damping coefficient, and a virtual total load torque; the virtual total load torque includes system disturbance data;

[0014] determining a calculation model for calculating an estimated value of a virtual total load torque based on a target motion model of the permanent magnet synchronous motor;

[0015] Obtain the estimated coefficients that make the observation error matrix negative;

[0016] Based on the estimation coefficient and the calculation model, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated.

[0017] Optionally, obtaining a target stator current model of the permanent magnet synchronous motor taking into account system-affected disturbances includes:

[0018] Acquiring an initial stator current model of the permanent magnet synchronous motor; the initial stator current model at least includes disturbance quantity data not modeled by the current loop system;

[0019] According to the initial stator current model, a discrete target stator current model taking into account the influence of system disturbance is determined.

[0020] Optionally, calculating the stator current at the next sampling moment corresponding to each switching state combination according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model includes:

[0021] Determine the control input basic voltage and harmonic compensation voltage corresponding to each switching state combination of the switching tube;

[0022] Calculating the control input voltage corresponding to each switch state combination based on the control input basic voltage and the harmonic compensation voltage corresponding to each switch state combination;

[0023] The target stator current model is used to calculate the control input voltage corresponding to each switch state combination to obtain the stator current at the next sampling moment corresponding to each switch state combination.

[0024] Optionally, calculating the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination based on the stator current at the next sampling moment corresponding to each switching state combination includes:

[0025] Obtaining an electromagnetic torque model of the permanent magnet synchronous motor;

[0026] The electromagnetic torque model is used to calculate the stator current at the next sampling moment corresponding to each switch state combination, so as to obtain the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination.

[0027] Optionally, according to the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, including:

[0028] Calculating the square of the difference between the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination;

[0029] The switch state combination with the smallest square difference is taken as the target switch state combination.

[0030] Optionally, performing a control operation of the permanent magnet synchronous motor using the target switch state combination includes:

[0031] The on-off states of different switch tubes in the target switch state combination are used to control the on-off state of the corresponding switch tubes to adjust the current and speed of the permanent magnet synchronous motor.

[0032] A control device for a permanent magnet synchronous motor, comprising:

[0033] a first torque calculation module, configured to calculate a required electromagnetic torque of the permanent magnet synchronous motor at a current sampling moment; the required electromagnetic torque being determined based on a basic required torque and an estimated value of a virtual total load torque;

[0034] A model acquisition module is used to obtain a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances; the target stator current model includes the functional relationship between the motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters; the target stator current model is used for current decoupling prediction of the d-axis and q-axis;

[0035] A current calculation module is used to calculate the stator current at the next sampling moment corresponding to each switching state combination of the switch tube according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model;

[0036] a second torque calculation module, configured to calculate the electromagnetic torque of the permanent magnet synchronous motor at a next sampling moment corresponding to each switching state combination based on the stator current at a next sampling moment corresponding to each switching state combination;

[0037] A control module is used to select a target switch state combination from all switch state combinations based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, and use the target switch state combination to control the permanent magnet synchronous motor.

[0038] An electronic device comprising at least one processor and a memory connected to the processor, wherein:

[0039] The memory is used to store computer programs;

[0040] The processor is used to execute the computer program so that the electronic device can implement the above-mentioned control method of the permanent magnet synchronous motor.

[0041] A computer storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the above-mentioned control method for a permanent magnet synchronous motor.

[0042] The present application provides a control method and related apparatus for a permanent magnet synchronous motor. In the present application, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated, a target stator current model of the permanent magnet synchronous motor that takes into account the influence of system disturbances is obtained, the stator current at the next sampling moment corresponding to each switching state combination is calculated based on the control input voltage corresponding to each switching state combination and the target stator current model, the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination is calculated based on the stator current at the next sampling moment corresponding to each switching state combination, the target switching state combination is selected from all switching state combinations based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination, and the permanent magnet synchronous motor is controlled using the target switching state combination. The entire process in the present application is automatically implemented and no longer relies on the engineering experience of the calibration engineer. This can avoid the influence of human subjective factors on the control of the permanent magnet synchronous motor, reduce the calibration workload of the engineer, reduce the control complexity of the permanent magnet synchronous motor, and improve the control accuracy and efficiency of the permanent magnet synchronous motor. In addition, the present application simplifies the complexity of current calculation, achieves current decoupling prediction of the permanent magnet synchronous motor taking into account the influence of system disturbances, and improves the control accuracy of the permanent magnet synchronous motor. In addition, the required electromagnetic torque is determined based on the estimated value of the basic required torque and the virtual total load torque, and the speed segmented PI control method is no longer used to obtain the required electromagnetic torque. This can avoid the influence of the mutual coupling of the proportional control term and the integral control term in the speed segmented PI control on the calculation, improve the control accuracy of the permanent magnet synchronous motor, and be more adaptable to changes in speed conditions, thereby improving the robustness of speed control. In addition, based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, the target switch state combination is selected from all switch state combinations, so that the current control does not need to adopt the segmented PI control method, and can avoid the influence of the mutual coupling of the proportional control term and the integral control term in the current segmented PI control on the calculation, thereby improving the control accuracy of the permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0044] Figure 1 A flowchart of a method for controlling a permanent magnet synchronous motor provided in an embodiment of the present application;

[0045] Figure 2A control schematic diagram of a permanent magnet synchronous motor provided in an embodiment of the present application;

[0046] Figure 3 A flow chart of a method for calculating required electromagnetic torque provided in an embodiment of the present application;

[0047] Figure 4 A simplified block diagram of a speed control system provided in an embodiment of the present application;

[0048] Figure 5 A flow chart of a method for calculating stator current provided in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of a stator current sector provided in an embodiment of the present application;

[0050] Figure 7 A schematic structural diagram of a control device for a permanent magnet synchronous motor provided in an embodiment of the present application;

[0051] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in 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.

[0053] At present, the speed control and current control of permanent magnet synchronous motors widely adopt the segmented PI control method. There is a problem of mutual coupling between proportional control terms and integral control terms in segmented PI control. In addition, the problem of mutual coupling between d-axis and q-axis currents in current control further increases the control difficulty of permanent magnet synchronous motors.

[0054] To address these issues, a piecewise PI calibration method is currently widely used in practical engineering for speed and current control. However, the control performance of piecewise PI generally relies on the engineering experience of the calibration engineer, making the calibration process time-consuming and labor-intensive, and difficult to achieve good control results. Therefore, reducing the complexity of permanent magnet synchronous motor control, reducing the calibration workload for calibration engineers, and improving the control accuracy and efficiency of permanent magnet synchronous motors have become urgent issues.

[0055] In order to reduce the calibration workload of calibration engineers, reduce the complexity of permanent magnet synchronous motor control, and improve the control accuracy and efficiency of permanent magnet synchronous motors, an embodiment of the present application provides a control method and related devices for a permanent magnet synchronous motor. In the present application, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated, and the target stator current model of the permanent magnet synchronous motor considering the influence of system disturbance is obtained. According to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model, the stator current at the next sampling moment corresponding to each switching state combination is calculated. Based on the stator current at the next sampling moment corresponding to each switching state combination, the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination is calculated. According to the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination, a target switching state combination is selected from all switching state combinations, and the control operation of the permanent magnet synchronous motor is performed using the target switching state combination. The entire process in this application is automatically implemented and no longer relies on the engineering experience of the calibration engineer, thereby avoiding the influence of human subjective factors on the control of the permanent magnet synchronous motor, reducing the calibration workload of the engineer, reducing the control complexity of the permanent magnet synchronous motor, and improving the control accuracy and efficiency of the permanent magnet synchronous motor.

[0056] In addition, in the present application, the complexity of current calculation is simplified, the current decoupling prediction of the permanent magnet synchronous motor is realized taking into account the influence of system disturbance, and the control accuracy of the permanent magnet synchronous motor is improved.

[0057] In addition, the required electromagnetic torque is determined based on the basic required torque and the estimated value of the virtual total load torque. The speed segmented PI control method is no longer used to obtain the required electromagnetic torque. This can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the speed segmented PI control on the calculation, improve the control accuracy of the permanent magnet synchronous motor, and be more adaptable to changes in speed conditions, thereby improving the robustness of speed control.

[0058] In addition, based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, so that the current control does not need to adopt a segmented PI control method, which can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the current segmented PI control on the calculation, thereby improving the control accuracy of the permanent magnet synchronous motor.

[0059] An embodiment of the present application provides a control method for a permanent magnet synchronous motor, and the execution subject may be a device such as a controller of the permanent magnet synchronous motor.

[0060] Reference Figure 1 , a control method for a permanent magnet synchronous motor may include:

[0061] S11. Calculate the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment.

[0062] The required electromagnetic torque is determined based on a basic required torque and an estimated value of a virtual total load torque.

[0063] In actual scenarios, the required electromagnetic torque of the permanent magnet synchronous motor is expressed as T e_require Specifically refers to Figure 2 The torque demand calculation module in the is used to calculate the result. The required electromagnetic torque serves as the input of the switch prediction current control module. The output of the switch prediction current control module is used for subsequent switch control. The switch in this embodiment can be an electronic switch. In actual scenarios, the three-phase bridge arm of the two-level inverter has a total of six electronic switches.

[0064] In one implementation, referring to Figure 3 , step S11 includes:

[0065] S21. Obtain a target motion model of the permanent magnet synchronous motor.

[0066] The target motion model of the permanent magnet synchronous motor includes at least the rated moment of inertia, the rated damping coefficient, and the virtual total load torque, and the virtual total load torque includes system disturbance data.

[0067] In specific implementation, usually, the motion equation of the permanent magnet synchronous motor can be expressed as:

[0068]

[0069] Among them, T e_require and T L are the required electromagnetic torque and load torque respectively; ω m is the mechanical angular velocity of the permanent magnet synchronous motor; J is the moment of inertia; B is the damping coefficient.

[0070] It should be noted that as the operating time of the permanent magnet synchronous motor increases and the operating conditions change, the rotational inertia J and damping coefficient B of the permanent magnet synchronous motor will change. In addition, the disturbance that actually exists in the permanent magnet synchronous motor motion system but is difficult to model is not reflected in equation (1).

[0071] In order to solve the above problems, the embodiment of the present application proposes a more accurate motion equation of the permanent magnet synchronous motor, which is the target motion model in the embodiment of the present application, as follows:

[0072]

[0073] Among them, T e_require and T Lare the required electromagnetic torque and load torque respectively; ω m is the mechanical angular velocity of the permanent magnet synchronous motor, J0 is the nominal moment of inertia of the permanent magnet synchronous motor, specifically the rated moment of inertia; B0 is the nominal damping coefficient, specifically the rated damping coefficient; T other Indicates other system disturbances that affect the speed of the permanent magnet synchronous motor except for the electromagnetic torque, load torque, nominal damping coefficient B0 and nominal moment of inertia J0. other It can also be divided into periodic load disturbance T other_perio and non-periodic load disturbance T other_nonperio , that is, T other =T other_perio +T other_nonperio ;T L_total Represents the virtual total load torque including system disturbance and satisfies T L_total =T other -T L , virtual total load torque T L_total It can be further divided into periodic virtual total load torque T L_total_perio and the non-periodic virtual total load torque T L_total_nonperio , that is, T L_total =T L_total_perio +T L_total_nonperio In the embodiment of the present application, a more accurate motion equation of the permanent magnet synchronous motor is constructed based on the idea of ​​fixed motor parameters (i.e., the above-mentioned J0 and B0) and virtual total load torque, which further reduces the dependence on model parameters and reduces the difficulty of controlling the permanent magnet synchronous motor.

[0074] S22. Determine a calculation model for calculating an estimated value of the virtual total load torque based on a target motion model of the permanent magnet synchronous motor.

[0075] The calculation model includes the sum of frequency-multiple disturbance coefficients of different multiples of the speed, system error differential information, and required electromagnetic torque, etc. The required electromagnetic torque is determined based on the basic required torque and the estimated value of the virtual total load torque.

[0076] In specific implementation, equation (2) is rewritten into the following matrix form:

[0077]

[0078] Among them, T e_require is the required electromagnetic torque; ω m is the mechanical angular velocity of the permanent magnet synchronous motor, J0 is the nominal moment of inertia of the permanent magnet synchronous motor, specifically the rated moment of inertia; B0 is the nominal damping coefficient, specifically the rated damping coefficient; T L_total is the virtual total load torque.

[0079] In order to achieve accurate estimation of the virtual total load torque of the permanent magnet synchronous motor speed loop, the estimation equation of the virtual total load torque of formula (3) is designed based on the system error differential information and the fundamental wave i-multiple frequency disturbance coefficient as follows:

[0080]

[0081] Wherein, J0 is the nominal moment of inertia of the permanent magnet synchronous motor, specifically the rated moment of inertia; B0 is the nominal damping coefficient, specifically the rated damping coefficient; T e_require is the required electromagnetic torque; Represents the mechanical angular velocity ω of the permanent magnet synchronous motor m estimated value of; Indicates the virtual total load torque T of the permanent magnet synchronous motor speed loop L_total The estimated value of ; α1 and α2 represent the estimated coefficients respectively; Q=Q2+Q3+...+Q i , Represents the i-fold frequency disturbance coefficient of the speed, where ω c represents the cutoff frequency, ω i ω m i times the speed, i.e. ω i =iω m , s is the Laplace operator, k r Represents the control gain coefficient, L -1 represents the inverse Laplace transform, i is a positive integer greater than 2; Q is the sum of the i-fold frequency disturbance coefficients of the rotational speed. is the differential information of the system error.

[0082] The above equation 4 is the calculation model for calculating the estimated value of the virtual total load torque in the embodiment of the present application.

[0083] It should be noted that, in the embodiment of the present application, the i-fold frequency disturbance coefficient Q of the rotational speed is added. i The virtual total load torque T of the permanent magnet synchronous motor speed loop is realized. L_total accurate estimate of .

[0084] S23. Obtain the estimated coefficients that make the observation error matrix negative.

[0085] In practical implementation, subtracting equation (3) from equation (4) yields:

[0086]

[0087] in, Represents the error between the estimated value and the actual value of the observation system. In order to ensure the estimation accuracy of the virtual total load torque of the permanent magnet synchronous motor, that is, to ensure that the error e between the estimated value and the actual value of the observation system asymptotically approaches zero, using the theoretical knowledge of linear system stability, it is only necessary to make the eigenvalue of the observation error matrix A_e a negative value.

[0088] Assume that the observation bandwidth of the observation system is ω o ,ω o is a positive number, we can get that when α1=2J0ω o -B0,α2=(ω o ) 2 When J0-Q, the eigenvalue of the observation error matrix A_e can be negative ω o , thus theoretically realizing the virtual total load torque T of the permanent magnet synchronous motor speed loop L_total accurate estimate of .

[0089] S24. Based on the estimated coefficient and the calculation model, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated.

[0090] When it is implemented specifically, Substitute into formula (4), and select a reasonable required electromagnetic torque T e_require Under the calculation formula of , by solving the differential equation, the virtual total load torque T of the permanent magnet synchronous motor speed loop can be accurately determined L_total The estimated value of The value of T e_require .

[0091] In one implementation, when determining The virtual total load torque T of the permanent magnet synchronous motor speed loop can be directly estimated when L_total The estimated value of In another implementation, the periodic virtual total load torque T can be estimated first. L_total_perio and the non-periodic virtual total load torque T L_total_nonperio The estimated value of

[0092] In one implementation, the required electromagnetic torque T e_require The calculation formula is:

[0093]

[0094] Formula (6) is the calculation formula of the required electromagnetic torque with disturbance compensation. Through disturbance compensation, the robustness of speed control can be improved and adaptive adjustment of various speed conditions can be achieved. conventional represents the basic required torque, Indicates the virtual total load torque T of the permanent magnet synchronous motor speed loop L_total Estimated value of T conventional and By making a difference, the calculation model in the embodiment of the present application can have the compensation function of the virtual total load torque, and can perform adaptive compensation under different working conditions, thereby being able to adapt to changes in various complex working conditions.

[0095] In addition, the embodiment of the present application adopts T conventional and Calculate T e_require , the required electromagnetic torque is no longer obtained by using the speed segmented PI control method, which can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the speed segmented PI control on the calculation, improve the control accuracy of the permanent magnet synchronous motor, and be more adaptable to changes in speed conditions, thereby improving the robustness of speed control.

[0096] Substituting formula (6) into formula (2) and ignoring the observation error, the transfer function of the controlled system can be obtained:

[0097]

[0098] Where s represents the Laplace operator.

[0099] T conventional pass Figure 4 The control system shown in Figure 1 is obtained, where k p is the proportionality coefficient, k i is the integral coefficient, and the calculation formula is Among them, J0 is the nominal moment of inertia of the permanent magnet synchronous motor, specifically the rated moment of inertia; B0 is the nominal damping coefficient, specifically the rated damping coefficient; P is the proportional adjustment coefficient, that is,

[0100]

[0101] in, Indicates the speed reference value (specifically Figure 2 The required speed in the process is generally given by the vehicle control module.

[0102] By combining formulas (4), (6) and (8), we can get the virtual total load torque T of the permanent magnet synchronous motor speed loop: L_total Estimated value of and the required electromagnetic torque T e_require .

[0103] In this embodiment, a more accurate equation of motion for a permanent magnet synchronous motor is proposed based on the concept of fixed motor parameters and consideration of the virtual total load torque. This reduces reliance on system model parameters, avoids the influence of the coupling between the proportional and integral control terms in the speed-segmented PI control, and more realistically simulates the behavior of the permanent magnet synchronous motor. Furthermore, the i-frequency perturbation coefficient, based on the system error differential information and speed information, accurately estimates the virtual total load torque.

[0104] S12. Obtain a target stator current model of the permanent magnet synchronous motor considering the influence of system disturbances.

[0105] The target stator current model includes the functional relationship between the motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters. The target stator current model is used for decoupling prediction of the d-axis and q-axis currents.

[0106] The current sampling parameter may be a current value, and the voltage sampling parameter may be a voltage value.

[0107] In an embodiment of the present application, the target stator current model of the permanent magnet synchronous motor considering the influence of system disturbances is determined based on the stator current equation of the permanent magnet synchronous motor. The target stator current model can realize the current decoupling prediction of the d-axis and q-axis of the permanent magnet synchronous motor considering the influence of system disturbances only by determining the voltage at the current sampling moment, obtaining the current at the current sampling moment, storing partial information (such as the current and voltage at the previous sampling moment) and the rated parameters of the motor. Without the need for complex mathematical calculations, current prediction can be performed more quickly and accurately, avoiding the problem of low current prediction accuracy caused by the mutual coupling of the stator dq axis currents.

[0108] S13. Calculate the stator current at the next sampling moment corresponding to each switching state combination according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model.

[0109] In real-world scenarios, a two-level inverter's three-phase bridge leg has six electronic switches, corresponding to eight switching state combinations. Different electronic switches behave differently in different switching state combinations. Each switching state combination has a corresponding control input voltage. Using the target stator current model described above, this control input voltage is calculated to determine the stator current at the next sampling moment for each switching state combination.

[0110] S14. Calculate the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination based on the stator current at the next sampling moment corresponding to each switch state combination.

[0111] In the embodiment of the present application, the stator current at the next sampling moment has a functional relationship with the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment. Therefore, the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment can be calculated using this functional relationship.

[0112] S15. Select a target switch state combination from all switch state combinations based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, and use the target switch state combination to control the permanent magnet synchronous motor.

[0113] Specifically, in the present application, in order to compensate for the sampling delay and PWM (Pulse Width Modulation) execution delay of the permanent magnet synchronous motor system, the required electromagnetic torque at the next moment is considered to be the required electromagnetic torque at the current moment. Therefore, the required electromagnetic torque at the current sampling moment can be used as a reference. The closer the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination is to the required electromagnetic torque at the current sampling moment, the more the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment is the required electromagnetic torque. Therefore, the electromagnetic torque that is closest to the required electromagnetic torque is selected from the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination. This electromagnetic torque is the optimal electromagnetic torque, and the switch state combination corresponding to this electromagnetic torque is the target switch state combination. The target switch state combination can be used to control the permanent magnet synchronous motor subsequently.

[0114] In one implementation, the on-off states of different switch tubes in the target switch state combination can be used to control the on-off state of the corresponding switch tubes to adjust the current and speed of the permanent magnet synchronous motor.

[0115] When implementing it specifically, Figure 2 As shown, the switch prediction current control module can be used to determine the target switch state combination, which is configured with the on-off states of 6 electronic switch tubes. The on-off states of these 6 electronic switch tubes are used to control the corresponding electronic switch tubes to be turned on or off, thereby changing the current and speed of the permanent magnet synchronous motor and realizing the control of the permanent magnet synchronous motor.

[0116] In this embodiment, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated, and a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances is obtained. Based on the control input voltage corresponding to each switch state combination of the switch tube and the target stator current model, the stator current at the next sampling moment corresponding to each switch state combination is calculated. Based on the stator current at the next sampling moment corresponding to each switch state combination, the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination is calculated. Based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, and the target switch state combination is used to control the permanent magnet synchronous motor. The entire process in this application is automatically implemented and no longer relies on the engineering experience of the calibration engineer. This can avoid the influence of human subjective factors on the control of the permanent magnet synchronous motor, reduce the calibration workload of the engineer, reduce the control complexity of the permanent magnet synchronous motor, and improve the control accuracy and efficiency of the permanent magnet synchronous motor.

[0117] In addition, in the present application, the complexity of current calculation is simplified, the current decoupling prediction of the permanent magnet synchronous motor is realized taking into account the influence of system disturbance, and the control accuracy of the permanent magnet synchronous motor is improved.

[0118] In addition, the required electromagnetic torque is determined based on the basic required torque and the estimated value of the virtual total load torque. The speed segmented PI control method is no longer used to obtain the required electromagnetic torque. This can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the speed segmented PI control on the calculation, improve the control accuracy of the permanent magnet synchronous motor, and be more adaptable to changes in speed conditions, thereby improving the robustness of speed control.

[0119] In addition, based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, so that the current control does not need to adopt a segmented PI control method, which can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the current segmented PI control on the calculation, thereby improving the control accuracy of the permanent magnet synchronous motor.

[0120] Based on any of the above embodiments, obtaining a target stator current model of the permanent magnet synchronous motor considering the influence of system disturbances may include the following steps:

[0121] 1) Obtain the initial stator current model of the permanent magnet synchronous motor.

[0122] The initial stator current model at least includes disturbance data that is not modeled in the current loop system.

[0123] For permanent magnet synchronous motors, in addition to the above-mentioned motion equations, there are also electromagnetic torque equations and stator current equations.

[0124] Among them, the electromagnetic torque equation of the permanent magnet synchronous motor can be expressed as:

[0125]

[0126] Among them, L d and L q are the stator d-axis and q-axis inductances respectively; i d and i q are the stator d-axis and q-axis currents respectively; is the magnetic flux of the rotor permanent magnet; p n is the number of pole pairs of the permanent magnet synchronous motor; T e Represents the electromagnetic torque of the permanent magnet synchronous motor.

[0127] The stator current equation of the permanent magnet synchronous motor, that is, the initial stator current model can be expressed as:

[0128]

[0129] in, Represents the control input, where u d and u q are the control input voltages of the stator d-axis and q-axis respectively; Represents the system state, where i d and i q are the stator d-axis and q-axis currents respectively; R s and ω e are the stator resistance and rotor flux electric angular velocity respectively; is the rotor flux; represents the disturbance quantity not modeled in the current loop system, where f d and f q are the unmodeled disturbances of the stator d-axis and q-axis of the current loop; L d and L q are the stator d-axis and q-axis inductances respectively.

[0130] 2) Based on the initial stator current model, a discrete target stator current model is determined that takes into account the influence of system disturbances.

[0131] In the specific implementation, in order to facilitate the decoupling control of the d-axis and q-axis currents of the permanent magnet synchronous motor, the motor parameters in formula (10) are fixed to nominal parameters, which are the rated parameters. In addition, the expression form of the parameters that couple the d-axis and q-axis currents is adjusted. Based on this principle, formula (10) is simply transformed into:

[0132]

[0133] in, represents the nominal system state matrix after normalization, which is the same as the one in formula (10) In contrast, the elements in the secondary diagonal become 0, realizing the function of dq axis current decoupling. Similarly, represents the nominal control input matrix after normalization, which has the function of decoupling the dq-axis current. By decoupling the dq-axis current, the problem of inaccurate control of the permanent magnet synchronous motor caused by the mutual coupling of the stator dq-axis current can be avoided. represents the rate of change of the system state quantity, where represents the rate of change of the d-axis current, Indicates the rate of change of q-axis current; L d0 and L q0 Respectively represent the nominal inductance values ​​of the d-axis and q-axis, that is, the rated inductance values; R s0 Indicates the nominal resistance value, which is also the rated resistance value. Represents the total disturbance of the current loop system, where F d and F q They are the total disturbances of the current loop stator d-axis and q-axis, f d and f q are the unmodeled disturbances of the current loop stator d-axis and q-axis respectively; ω e is the rotor flux electrical angular velocity; i d and i q are the stator d-axis and q-axis currents respectively; Δf d and Δf q Represents the d-axis and q-axis of the current loop respectively because the real-time changing permanent magnet synchronous motor parameters are fixed (i.e. the above L d0 、L q0 、R s0 and ) caused by the disturbance value, It represents the nominal rotor permanent magnet flux, which is also the rated rotor permanent magnet flux.

[0134] It should be noted that the missing parts caused by setting the elements on the sub-diagonal of A and B to zero and setting some elements to zero are supplemented to F. d and F q Middle, that is, F d in and F q in

[0135] When making a preliminary estimate of the disturbance of the permanent magnet synchronous motor current loop system, according to formula (11), the stator current equation of the permanent magnet synchronous motor in discrete form can be expressed as:

[0136]

[0137] Where k is the current sampling time, k+1 is the next sampling time; T s is the sampling period (also called the current loop control period); F d (k) and F q (k) represents the total disturbance of the stator d-axis and q-axis of the current loop at sampling time k; i d (k+1) and i q (k+1) represents the stator d-axis and q-axis currents at sampling time k+1 respectively; i d (k) and i q (k) represents the stator d-axis and q-axis currents at sampling time k; u d (k) and u q (k) represents the control input voltage of the stator d-axis and q-axis at sampling time k; L d0 and L q0 Respectively represent the nominal inductance values ​​of the d-axis and q-axis, that is, the rated inductance values; R s0 Indicates the nominal resistance value, which is also the rated resistance value.

[0138] By recursion of formula (12), we can get:

[0139]

[0140] Among them, k-1 is the previous sampling time; i d (k-1) and i q (k-1) represents the stator d-axis and q-axis currents at sampling time k-1 respectively; u d (k-1) and u q (k-1) represents the control input voltage of the stator d-axis and q-axis at the sampling time k-1; F d (k-1) and F q (k-1) represents the total disturbance of the stator d-axis and q-axis of the current loop at the sampling time k-1; T s is the sampling period (also called the current loop control period); L d0 and L q0 Respectively represent the nominal inductance values ​​of the d-axis and q-axis, that is, the rated inductance values; R s0 Indicates the nominal resistance value, which is also the rated resistance value.

[0141] Since the current loop control period T of the permanent magnet synchronous motor s Usually very short. In actual engineering, it is generally assumed that the control period of two adjacent current loops is T s The total disturbance F of the stator d-axis and q-axis of the permanent magnet synchronous motor is d and Fq No change, that is

[0142]

[0143] By combining equations (12), (13) and (14), we can obtain the stator current equation of the permanent magnet synchronous motor in discrete form considering the influence of system disturbance:

[0144]

[0145] The target stator current model is the formula (15) in the embodiment of the present application, which includes the motor rated parameters (L d0 、L q0 and R s0 ), the functional relationship between the current sampling parameters and the voltage sampling time at different sampling times. Among them, the current sampling parameters at different sampling times refer to:

[0146] i at time k-1 d (k-1) and i q (k-1), i at time k d (k) and i q (k), and i at time k+1 d (k+1) and i q (k+1).

[0147] The voltage sampling parameters at different sampling times are:

[0148] u at time k-1 d (k-1) and u q (k-1), and u at time k d (k) and u q (k).

[0149] It can be seen from formula (15) that in the embodiment of the present application, no complicated mathematical calculations are required, and it is only necessary to determine u d (k) and u q (k), and then through the sampling information of the current moment (i d (k) and i q (k)), stored data information (u d (k-1),u q (k-1), i d (k-1) and i q (k-1)) and motor rated parameters (L d0 、L q0 , and R s0 ) can realize the current prediction of the d-axis and q-axis of the permanent magnet synchronous motor at time k+1 considering the influence of system disturbance.

[0150] In this embodiment, the unmodeled disturbance of the current loop control system can be calculated through the stored sampling information and the rated parameters of the motor, a more accurate stator current equation of the permanent magnet synchronous motor is constructed, and the prediction of the d-axis and q-axis currents of the permanent magnet synchronous motor considering the influence of the unmodeled disturbance of the system is realized.

[0151] Based on any of the above embodiments, refer to Figure 5 , calculating the stator current at the next sampling moment corresponding to each switching state combination according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model, may include:

[0152] S31 , determining a control input basic voltage and a harmonic compensation voltage corresponding to each combination of switching states of the switching tube.

[0153] When performing switch predictive current control of a permanent magnet synchronous motor, the permanent magnet synchronous motor has two voltage values, namely, a control input basic voltage and a harmonic compensation voltage.

[0154] For the control input base voltage of the permanent magnet synchronous motor, the three-phase bridge arm of the two-level inverter has a total of 6 electronic switch tubes, corresponding to 8 switch state combinations. By traversing these 8 switch state combinations, the electromagnetic torque corresponding to each switch state combination can be obtained. The electromagnetic torque corresponding to each switch state combination may be different. By comparing the difference between these 8 electromagnetic torques and the target torque (that is, the required electromagnetic torque mentioned above), the optimal switch state of the 6 electronic switch tubes can be determined. Definition S a , S b , S c Respectively represent the switch status values ​​of the switch tubes on phase A, phase B and phase C, 0 means off and 1 means on.

[0155] The control input basic voltage u of the stator d-axis and q-axis corresponding to the eight switching state combinations of the three-phase bridge arm of the two-level inverter dj_basic and u qj_basic As shown in Table 1:

[0156] Table 1 Switching state and control input basic voltage of stator d-axis and q-axis

[0157]

[0158]

[0159] In Table 1, u dj_basic and u qj_basic Respectively represent the control input basic voltages of the stator d-axis and q-axis corresponding to the j-th switching state, j is the switching state number, each switching state number corresponds to a switching state combination, and its value is an integer from 0 to 7.e Indicates the rotor position; U dc is the DC bus voltage.

[0160] For the harmonic compensation voltage of permanent magnet synchronous motor, the stator current sector is divided as follows: Figure 6 shown.

[0161] The schematic diagram of the stator current sector division can be found in Figure 6 As shown, Figure 6 The stator current sectors shown in the figure include: sector 1 (Sector1), sector 2 (Sector2), sector 3 (Sector3), sector 4 (Sector4), sector 5 (Sector5) and sector 6 (Sector6). The first positive and negative sign of each sector represents the direction of phase A current, the second positive and negative sign of each sector represents the direction of phase B current, and the third positive and negative sign of each sector represents the direction of phase C current, where "+" indicates that the phase current direction is positive and "-" indicates that the phase current direction is negative.

[0162] It should be noted that Figure 6 Sector 1 in Table 1 corresponds to the case where the switch state number j in Table 1 is 1; Figure 6 Sector 2 (Sector 2) in Table 1 corresponds to the case where the switch state number j is 2; Figure 6 Sector 3 in Table 1 corresponds to the case where the switch state number j is 3; Figure 6 Sector 4 in Table 1 corresponds to the case where the switch state number j is 4; Figure 6 Sector 5 (Sector 5) in Table 1 corresponds to the case where the switch state number j is 5; Figure 6 Sector 6 in FIG. 1 corresponds to the case where the switch state number j in Table 1 is 6.

[0163] The power module in the motor controller of the permanent magnet synchronous motor generates a large amount of harmonic voltage during each commutation process. Therefore, it is necessary to compensate for the harmonic voltage generated by the commutation process of the power module in the motor controller.

[0164] Take sector 1 and sector 2 as an example. Figure 6As shown, in sector 1 (Sector 1), +-- represents the direction of the current in phase A is positive, the direction of the current in phase B is negative, and the direction of the current in phase C is negative; in sector 2 (Sector 2), -+- represents the direction of the current in phase A is negative, the direction of the current in phase B is positive, and the direction of the current in phase C is negative; the directions of the three-phase currents in other sectors are similar. The stator current sector division method in the embodiment of the present application ensures that the direction of the stator current is fixed in each sector, thereby minimizing the impact of changes in the stator current direction on the harmonics caused by the current loop of the permanent magnet synchronous motor.

[0165] In one implementation, the embodiment of the present application controls the input basic voltage matrix u jbasic (k), the compensation for harmonic voltage is added. Stator dq axis harmonic compensation voltage matrix The method to obtain is as follows:

[0166] In the embodiments of this application, according to Figure 6 The current direction in determines the harmonic compensation voltage, the switch state number j, and the stator d-axis harmonic compensation voltage u dj_com and stator q-axis harmonic compensation voltage u qj_com The corresponding relationship is shown in Table 2:

[0167] Table 2 Correspondence between switch state number and stator dq axis harmonic compensation voltage

[0168]

[0169]

[0170] In Table 2, θ e Indicates the rotor position; u swcom is the compensation voltage, compensation voltage u swcom The calculation formula is as follows:

[0171]

[0172] Among them, t d is the dead time of power devices (such as SIC MOSFET (Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistor)); t on is the turn-on delay time of the power device (such as SIC MOSFET); t off is the turn-off delay time of the power device (such as SICMOSFET); U dc is the DC bus voltage; T s Indicates the current loop control period.

[0173] S32 . Calculate the control input voltage corresponding to each switch state combination based on the control input basic voltage and the harmonic compensation voltage corresponding to each switch state combination.

[0174] Specifically, the calculation formula for the control input voltage of the permanent magnet synchronous motor is as follows:

[0175]

[0176] in, represents the control input voltage matrix of the stator d-axis and q-axis corresponding to the switch state number j at time k, where u dj (k) and u qj (k) represents the control input voltage of the stator d-axis and the control input voltage of the stator q-axis corresponding to the switch state number j at time k, and the value of j is an integer from 0 to 7; represents the control input basic voltage matrix of the stator d-axis and q-axis corresponding to the switch state number j at time k, where u dj_basic (k) and u qj_basic (k) represents the control input basic voltage of the stator d-axis and the control input basic voltage of the stator q-axis corresponding to the switch state number j at time k, and the value of j is an integer from 0 to 7; represents the harmonic compensation voltage matrix of the stator d-axis and q-axis corresponding to the switch state number j at time k, where u dj_com (k) and u qj_com (k) represents the harmonic compensation voltage of the stator d-axis and the harmonic compensation voltage of the stator q-axis corresponding to the switch state number j at time k, and the value of j is an integer from 0 to 7.

[0177] The control input basic voltage matrix u corresponding to the switch state number j at time k j_basic (k) According to Table 1, the harmonic compensation voltage matrix u corresponding to the switch state number j at time k j_com (k) Determined according to Table 2.

[0178] By using formula (17), the control input voltage corresponding to a switch state combination can be calculated, that is, the above u j (k).

[0179] S33. Calculate the control input voltage corresponding to each switch state combination using the target stator current model to obtain the stator current at the next sampling moment corresponding to each switch state combination.

[0180] In specific implementation, the control input voltage u of the stator d axis at the current sampling moment corresponding to the above 8 switching state combinations is dj (k) and the control input voltage u of the q axis qj(k) is introduced into formula (15) to obtain the sampling information at the current moment (i d (k) and i q (k)), get the stored data information (u d (k-1),u q (k-1), i d (k-1) and i q (k-1)) and motor rated parameters (L d0 、L q0 , and R s0 ), the stator d-axis current i of each switch state combination at the next sampling moment can be calculated by formula (15): d (k+1) and the stator q-axis current i q (k+1).

[0181] In this embodiment, the target stator current model directly predicts the current based on the functional relationship between the motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters. There is no need for a switch prediction current control link in the modulation link, thereby achieving accurate tracking of the subsequent required electromagnetic torque and reducing the complexity of the permanent magnet synchronous motor current loop control.

[0182] On the basis of any of the above embodiments, calculating the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination based on the stator current at the next sampling moment corresponding to each switching state combination may include:

[0183] An electromagnetic torque model of the permanent magnet synchronous motor is obtained, and the stator current at the next sampling moment corresponding to each switch state combination is calculated using the electromagnetic torque model to obtain the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination.

[0184] In specific implementation, the electromagnetic torque model of the permanent magnet synchronous motor is the electromagnetic torque equation of the permanent magnet synchronous motor represented by the above formula (9).

[0185] The stator d-axis current i of each switching state combination at the next sampling moment is d (k+1) and the stator q-axis current i q (k+1) is brought into formula (9) to obtain the electromagnetic torque T of the permanent magnet synchronous motor at the next sampling moment. e (k+1).

[0186] In this embodiment, the electromagnetic torque model is directly used to calculate the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, which has a simple implementation process, convenient operation and high efficiency.

[0187] On the basis of any of the above embodiments, selecting a target switching state combination from all switching state combinations according to the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination may include:

[0188] The square of the difference between the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination is calculated, and the switch state combination with the smallest square of the difference is used as the target switch state combination.

[0189] In specific implementation, in order to compensate for the sampling delay and PWM execution delay of the permanent magnet synchronous motor system, the required electromagnetic torque at the next moment is considered to be the required electromagnetic torque at the current moment. Therefore, the required electromagnetic torque at the current sampling moment can be used as a reference. The closer the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination is to the required electromagnetic torque at the current sampling moment, the better the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment is.

[0190] Based on this principle, a cost function calculation formula for selecting the target switch state combination is designed, as follows:

[0191]

[0192] Among them, T e_require (k) represents the current sampling moment, that is, the required electromagnetic torque at moment k; T ej (k+1) represents the electromagnetic torque of the permanent magnet synchronous motor corresponding to the switch state number j at the next sampling moment, that is, the (k+1) moment. According to formula (18), the optimal switch state combination can be determined, which is the target switch state combination.

[0193] It should be noted that the above-mentioned torque equation and stator current equation of PMSM and the switch prediction current control of permanent magnet synchronous motor are Figure 2 The switch prediction current control module in the system is implemented. The switch prediction current control module does not require additional modulation links, which saves calculation amount and reduces the computing power requirements of the system hardware.

[0194] In this embodiment, the selected optimal target switch state combination is the optimal control strategy of the permanent magnet synchronous motor. Controlling the permanent magnet synchronous motor according to the control strategy can improve the accuracy of the permanent magnet synchronous motor control.

[0195] Based on the embodiment of the control method of the permanent magnet synchronous motor, another embodiment of the present application provides a control device for a permanent magnet synchronous motor, referring to Figure 7 , which may include:

[0196] A first torque calculation module 11 is configured to calculate a required electromagnetic torque of the permanent magnet synchronous motor at a current sampling moment; the required electromagnetic torque is determined based on a basic required torque and an estimated value of a virtual total load torque;

[0197] A model acquisition module 12 is used to obtain a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances; the target stator current model includes the functional relationship between the motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters; the target stator current model is used for decoupling prediction of currents of the d-axis and q-axis;

[0198] The current calculation module 13 is used to calculate the stator current at the next sampling moment corresponding to each switching state combination of the switch tube according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model;

[0199] A second torque calculation module 14 is configured to calculate the electromagnetic torque of the permanent magnet synchronous motor at a next sampling moment corresponding to each switching state combination based on the stator current at a next sampling moment corresponding to each switching state combination;

[0200] The control module 15 is used to select a target switch state combination from all switch state combinations based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, and use the target switch state combination to control the permanent magnet synchronous motor.

[0201] In one implementation, the first torque calculation module 11 includes:

[0202] The model acquisition submodule is used to obtain the target motion model of the permanent magnet synchronous motor; the target motion model of the permanent magnet synchronous motor includes at least the rated moment of inertia, the rated damping coefficient and the virtual total load torque; the virtual total load torque includes system disturbance data;

[0203] a model determination submodule, configured to determine a calculation model for calculating an estimated value of a virtual total load torque based on a target motion model of the permanent magnet synchronous motor;

[0204] The coefficient acquisition submodule is used to obtain the estimated coefficients that make the observation error matrix negative;

[0205] The torque calculation submodule is used to calculate the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment based on the estimated coefficient and the calculation model.

[0206] In one implementation, the model acquisition module 12 is specifically configured to:

[0207] An initial stator current model of the permanent magnet synchronous motor is obtained; the initial stator current model at least includes disturbance quantity data that is not modeled in the current loop system; and a discrete target stator current model that takes into account the influence of system disturbances is determined based on the initial stator current model.

[0208] In one implementation, the current calculation module 13 includes:

[0209] The voltage determination submodule is used to determine the control input basic voltage and harmonic compensation voltage corresponding to each switching state combination of the switch tube;

[0210] A voltage calculation submodule, configured to calculate the control input voltage corresponding to each switch state combination based on the control input basic voltage and harmonic compensation voltage corresponding to each switch state combination;

[0211] The current calculation submodule is used to calculate the control input voltage corresponding to each switch state combination using the target stator current model to obtain the stator current at the next sampling moment corresponding to each switch state combination.

[0212] In one implementation, the second torque calculation module 14 is specifically configured to:

[0213] An electromagnetic torque model of the permanent magnet synchronous motor is obtained, and the stator current at the next sampling moment corresponding to each switch state combination is calculated using the electromagnetic torque model to obtain the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination.

[0214] In one implementation, the control module 15 includes:

[0215] A data calculation submodule, used to calculate the square of the difference between the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination;

[0216] The combination determination submodule is used to take the switch state combination with the smallest square difference as the target switch state combination.

[0217] In one implementation, the control module 15 includes:

[0218] The motor control submodule is used to use the on-off states of different switch tubes in the target switch state combination to control the on-off of the corresponding switch tubes to adjust the current and speed of the permanent magnet synchronous motor.

[0219] In this embodiment, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated, and a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances is obtained. Based on the control input voltage corresponding to each switch state combination of the switch tube and the target stator current model, the stator current at the next sampling moment corresponding to each switch state combination is calculated. Based on the stator current at the next sampling moment corresponding to each switch state combination, the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination is calculated. Based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, and the target switch state combination is used to control the permanent magnet synchronous motor. The entire process in this application is automatically implemented and no longer relies on the engineering experience of the calibration engineer. This can avoid the influence of human subjective factors on the control of the permanent magnet synchronous motor, reduce the calibration workload of the engineer, reduce the control complexity of the permanent magnet synchronous motor, and improve the control accuracy and efficiency of the permanent magnet synchronous motor.

[0220] In addition, in the present application, the complexity of current calculation is simplified, the current decoupling prediction of the permanent magnet synchronous motor is realized taking into account the influence of system disturbance, and the control accuracy of the permanent magnet synchronous motor is improved.

[0221] In addition, the required electromagnetic torque is determined based on the basic required torque and the estimated value of the virtual total load torque. The speed segmented PI control method is no longer used to obtain the required electromagnetic torque. This can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the speed segmented PI control on the calculation, improve the control accuracy of the permanent magnet synchronous motor, and be more adaptable to changes in speed conditions, thereby improving the robustness of speed control.

[0222] In addition, based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, so that the current control does not need to adopt a segmented PI control method, which can avoid the influence of the mutual coupling between the proportional control term and the integral control term in the current segmented PI control on the calculation, thereby improving the control accuracy of the permanent magnet synchronous motor.

[0223] It should be noted that, for the working process of each module and sub-module in this embodiment, please refer to the corresponding description in the above embodiment, which will not be repeated here.

[0224] An embodiment of the present application further provides an electronic device, including at least one processor and a memory connected to the processor, wherein:

[0225] Memory is used to store computer programs;

[0226] The processor is used to execute the computer program so that the electronic device can implement the above-mentioned control method of the permanent magnet synchronous motor.

[0227] refer to Figure 8 , which shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiments of the present application. The electronic device in the embodiments of the present application may include, but is not limited to, fixed terminals such as mobile phones, laptops, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, motor controllers, and the like. Figure 8 The electronic device shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0228] like Figure 8 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage device 608 into a random access memory (RAM) 603. When the electronic device is powered on, the RAM 603 also stores various programs and data required for the operation of the electronic device. The processing device 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0229] Typically, the following devices may be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 608 including, for example, a memory card, a hard disk, etc.; and a communication device 609. The communication device 609 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Figure 8 The electronic device is shown with various devices, but it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed instead.

[0230] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any one of the permanent magnet synchronous motor control methods provided in the embodiments of the present application.

[0231] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any permanent magnet synchronous motor control method provided in the embodiment of the present application.

[0232] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that: include: Calculate the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment; The required electromagnetic torque is determined based on a basic required torque and an estimated value of a virtual total load torque; Obtaining a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances; the target stator current model includes a functional relationship between motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters; the target stator current model is used for current decoupling prediction of the d-axis and q-axis; Calculating the stator current at the next sampling moment corresponding to each switching state combination according to the control input voltage corresponding to each switching state combination of the switching tube and the target stator current model; Calculating the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination based on the stator current at the next sampling moment corresponding to each switching state combination; According to the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, and the control operation of the permanent magnet synchronous motor is performed using the target switch state combination.

2. The control method of the permanent magnet synchronous motor according to claim 1, characterized in that: Calculate the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment, including: Obtaining a target motion model of the permanent magnet synchronous motor; the target motion model of the permanent magnet synchronous motor includes at least a rated moment of inertia, a rated damping coefficient, and a virtual total load torque; the virtual total load torque includes system disturbance data; determining a calculation model for calculating an estimated value of a virtual total load torque based on a target motion model of the permanent magnet synchronous motor; Obtain the estimated coefficients that make the observation error matrix negative; Based on the estimation coefficient and the calculation model, the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment is calculated.

3. The control method of the permanent magnet synchronous motor according to claim 1, characterized in that: Obtaining a target stator current model of the permanent magnet synchronous motor considering the influence of system disturbances includes: Acquiring an initial stator current model of the permanent magnet synchronous motor; the initial stator current model at least includes disturbance quantity data not modeled by the current loop system; According to the initial stator current model, a discrete target stator current model taking into account the influence of system disturbance is determined.

4. The control method of the permanent magnet synchronous motor according to claim 1, characterized in that: Calculating the stator current at the next sampling moment corresponding to each switching state combination according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model, including: Determine the control input basic voltage and harmonic compensation voltage corresponding to each switching state combination of the switching tube; Calculating the control input voltage corresponding to each switch state combination based on the control input basic voltage and the harmonic compensation voltage corresponding to each switch state combination; The target stator current model is used to calculate the control input voltage corresponding to each switch state combination to obtain the stator current at the next sampling moment corresponding to each switch state combination.

5. The control method of the permanent magnet synchronous motor according to claim 1, characterized in that: Calculating the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switching state combination based on the stator current at the next sampling moment corresponding to each switching state combination includes: Obtaining an electromagnetic torque model of the permanent magnet synchronous motor; The electromagnetic torque model is used to calculate the stator current at the next sampling moment corresponding to each switch state combination, so as to obtain the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination.

6. The control method of the permanent magnet synchronous motor according to claim 1, characterized in that: According to the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, a target switch state combination is selected from all switch state combinations, including: Calculating the square of the difference between the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination; The switch state combination with the smallest square difference is taken as the target switch state combination.

7. The control method of a permanent magnet synchronous motor according to claim 1, characterized in that: Using the target switch state combination, performing a control operation of the permanent magnet synchronous motor includes: The on-off states of different switch tubes in the target switch state combination are used to control the on-off state of the corresponding switch tubes to adjust the current and speed of the permanent magnet synchronous motor.

8. A control device for a permanent magnet synchronous motor, characterized in that: include: A first torque calculation module is used to calculate the required electromagnetic torque of the permanent magnet synchronous motor at the current sampling moment; The required electromagnetic torque is determined based on a basic required torque and an estimated value of a virtual total load torque; A model acquisition module is used to obtain a target stator current model of the permanent magnet synchronous motor taking into account the influence of system disturbances; the target stator current model includes the functional relationship between the motor rated parameters, current sampling parameters at different sampling times, and voltage sampling parameters; the target stator current model is used for current decoupling prediction of the d-axis and q-axis; A current calculation module is used to calculate the stator current at the next sampling moment corresponding to each switching state combination of the switch tube according to the control input voltage corresponding to each switching state combination of the switch tube and the target stator current model; a second torque calculation module, configured to calculate the electromagnetic torque of the permanent magnet synchronous motor at a next sampling moment corresponding to each switching state combination based on the stator current at a next sampling moment corresponding to each switching state combination; A control module is used to select a target switch state combination from all switch state combinations based on the required electromagnetic torque and the electromagnetic torque of the permanent magnet synchronous motor at the next sampling moment corresponding to each switch state combination, and use the target switch state combination to control the permanent magnet synchronous motor.

9. An electronic device, characterized in that: comprising at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is configured to execute the computer program so that the electronic device can implement the control method for the permanent magnet synchronous motor according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that The storage medium carries one or more computer programs, and when the one or more computer programs are executed by an electronic device, the electronic device can implement the control method of the permanent magnet synchronous motor according to any one of claims 1 to 7.

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