A method and device for current prediction, a model predictive control method, equipment and medium

Abstract

The present invention discloses a current prediction method, device, model predictive control method, equipment and medium. The current prediction method is used to compensate for the execution delay of the model predictive control of a permanent magnet motor. The current prediction method includes: obtaining the real-time phase of the phase current by amplitude transformation and phase calculation of the sampled current value in the current control period; calculating the current phase delay caused by the execution delay of the model predictive control; using the phase delay to compensate the real-time phase of the phase current to predict the current in the next control period. The predicted current is used to complete the calculation of the model predictive control algorithm, and the optimal control signal is selected. This method solves the problem of the execution delay of the model predictive control. Compared with the traditional two-step prediction method, the accuracy is not affected by the control period, and the applicable range can be expanded by improving the control performance of the permanent magnet motor.

Description

Technical Field

[0001] The present invention belongs to the field of permanent magnet motor control, and particularly relates to a current prediction method, device, model predictive control method, equipment and medium. Background Art

[0002] Permanent magnet motors have the advantages of high power density, compact structure and high efficiency, and have been applied to industrial fields such as electric vehicles, numerical control machine tools and household appliances. They are of great significance for improving energy utilization efficiency and contribute to the realization of the goals of "carbon peak and carbon neutrality". To further expand the application scope of permanent magnet motors, it is necessary to develop advanced control algorithms to improve the working performance of the motors and enhance the applicability of permanent magnet electric drive systems.

[0003] Vector control is a high-performance speed regulation control method for permanent magnet motors, usually including a speed control loop and a d,q-axis current control loop structure. In traditional vector control, at least 3 PI controllers are required to achieve speed and current regulation respectively, and a total of 6 parameters need to be calibrated, which makes the system design process complex and unable to achieve optimal control under all working conditions. In addition, the PI controller has a delay effect. Although it can achieve error-free control and has high steady-state performance, it has the disadvantage of slow response speed. To solve these problems, Wang Dongwen et al. proposed a vector control scheme in the literature "Research on Model Predictive Current Controller of Permanent Magnet Synchronous Motor" that uses a model predictive current controller to replace the two PI controllers in the current loop, reducing the number of parameters to be calibrated in the system design process and improving the response speed of the system at the same time.

[0004] However, when using a digital processor to execute the model predictive control algorithm to achieve motor control, there is an execution delay problem: there is a one-step delay between the calculation using the model predictive control algorithm and the execution of the control signal, which affects the control performance of the permanent magnet motor. CN112510755A "Predictive Phase Delay Compensation Method and System for Three-Phase Converters" discloses a method for traditional vector control that calculates and compensates the delayed phase using voltage, but this method is not applicable to the model predictive control algorithm. CN106208744A "Control Method for a Rectifier of a Multiple Unit Based on a Two-Step Predictive Current Controller" discloses a two-step prediction method, but this method requires local linearization of the mathematical model of the permanent magnet motor, and there is a problem that the accuracy of the two-step prediction results decreases as the control period increases.

[0005] Therefore, solving the execution delay problem of the permanent magnet motor model predictive control is still a current research hotspot and has very important value for improving the control performance of the motor. Summary of the Invention

[0006] One of the objectives of the present invention is to provide a current prediction method and device. The current in the next control period is predicted through the current prediction method, and the predicted current is used for model predictive control to solve the problem that the execution delay of model predictive control affects the control performance of a permanent magnet motor. Another objective of the present invention is to provide a model predictive control method. The accuracy of this method is not affected by the control period and it has a wide range of applications.

[0007] In a first aspect, an embodiment of the present application provides a current prediction method. The current prediction method is used to compensate for the execution delay of model predictive control of a permanent magnet motor. The method includes:

[0008] The sampled current value in the current control period is subjected to amplitude transformation and phase calculation to obtain the real-time phase of the phase current;

[0009] Calculate the current phase delay caused by the execution delay of model predictive control;

[0010] Use the phase delay to compensate the real-time phase of the phase current and predict the current in the next control period.

[0011] In one implementation, the step of subjecting the sampled current value in the current control period to amplitude transformation and phase calculation to obtain the real-time phase of the phase current specifically includes:

[0012] Obtain the information of the real-time currents of phases a and b, the rotational speed, and the position of the motor in the current control period;

[0013] Calculate the d-axis and q-axis currents based on the real-time currents of phases a and b and the position information;

[0014] Transform the real-time currents of phases a and b to currents with amplitudes in the range of [-1, 1] based on the d-axis and q-axis currents;

[0015] Determine the real-time phases of the currents of phases a and b through the arcsine function and phase based on the currents with amplitudes in the range of [-1, 1].

[0016] In one implementation, the transformation of the signal values of the currents of phases a and b to signal values with amplitudes in the range of [-1, 1] is:

[0017]

[0018] where i am (k) and i bm (k) are the real-time currents of phases a and b, i' am (k) and i' bm (k) are the transformed currents of phases a and b, i d (k) and i q (k) are the d-axis and q-axis currents.

[0019] In one embodiment, obtaining the real-time phases of the a-phase and b-phase currents from the current with an amplitude in the range of [-1, 1] through the arcsine function and phase determination includes:

[0020] Using the arcsine function to obtain the alternative real-time phases of the phase currents;

[0021] Determining the real-time phases of the a-phase and b-phase currents from the alternative real-time phases of the phase currents according to the phase determination formula.

[0022] In one embodiment, the using the arcsine function to obtain the alternative real-time phases of the phase currents specifically includes:

[0023] Using the arcsine function to calculate the real-time phases of the a-phase and b-phase currents as:

[0024]

[0025] where and are the real-time phases of the a-phase and b-phase currents obtained by calculation, and i' am (k) and i' bm (k) are the transformed a-phase and b-phase currents;

[0026] According to the characteristics of the arcsine function, and there are two sets of calculation results in the range of [0, 2π], and the two sets of calculation results are used as the alternative real-time phases of the phase currents, denoted as and i.e., i, j = 1, 2.

[0027] In one embodiment, the phase determination formula is:

[0028]

[0029] where and are the real-time phases of the a-phase and b-phase currents.

[0030] In one embodiment, the phase delay is expressed as:

[0031]

[0032] where is the phase delay, p is the number of pole pairs of the motor, T s is the control period, and ω m (k) is the motor speed.

[0033] In one embodiment, compensating the real-time phases of the phase currents using the phase delay and predicting the current for the next control period as:

[0034]

[0035] where i a_pre (k) and i b_pre (k) are the predicted currents for the next control period, and i d (k) and i q (k) are the d- and q-axis currents, and are the real-time phases of the a- and b-phase currents, is the phase delay.

[0036] In a second aspect, an embodiment of the present application provides a current prediction device, which includes:

[0037] A real-time phase module, configured to obtain the real-time phase of the phase current by performing amplitude transformation and phase calculation on the sampled current value in the current control period;

[0038] A phase delay calculation module, configured to calculate the current phase delay caused by the execution delay of the model predictive control;

[0039] A prediction module, configured to use the phase delay to compensate the real-time phase of the phase current and predict the current for the next control period.

[0040] In an implementation, the real-time phase module includes:

[0041] An acquisition module, configured to acquire the information of the real-time a- and b-phase currents, rotational speed, and position of the motor in the current control period;

[0042] A current signal module, configured to calculate the d- and q-axis currents according to the real-time a- and b-phase currents and the position information;

[0043] An amplitude change module, configured to transform the real-time a- and b-phase currents into currents with amplitudes in the range of [-1, 1] according to the d- and q-axis currents;

[0044] A phase calculation module, configured to obtain the real-time phase of the a- and b-phase currents by using the arcsine function and phase determination for the currents with amplitudes in the range of [-1, 1]

[0045] In a third aspect, an embodiment of the present application provides a permanent magnet motor model predictive control method, which includes:

[0046] Predict the current for the next control period according to any one of the above-mentioned current prediction methods;

[0047] Use the predicted current to complete the calculation of the model predictive control algorithm and select the optimal control signal.

[0048] In one embodiment, the calculation of the model predictive control algorithm is completed using the predicted current, and the optimal control signal is selected, specifically including:

[0049] The predicted current for the next control period is transformed into d-axis and q-axis currents using coordinate transformation;

[0050] The d-axis and q-axis currents are substituted into the permanent magnet motor prediction model to estimate the future current state;

[0051] The cost function is used to evaluate and select the voltage vector that minimizes the value of the cost function, and the corresponding switch state is used as the optimal control signal to be executed in the next control period.

[0052] In a fourth aspect, an embodiment of the present application provides a computer device, including a memory and a processor. A computer-readable instruction is stored in the memory. When the computer-readable instruction is executed by the processor, the processor executes the steps of the above permanent magnet motor model predictive control method.

[0053] In a fifth aspect, an embodiment of the present application provides a storage medium storing computer-readable instructions. When the computer-readable instructions are executed by one or more processors, one or more processors execute the steps of the above permanent magnet motor model predictive control method.

[0054] Compared with the prior art, the beneficial effects are:

[0055] In the current control period, the present invention utilizes the sinusoidal characteristic of the current signal to predict the current for the next control period without local linearization operation, and uses the predicted current in the calculation process of the model predictive control algorithm. This method can compensate for the execution delay of the permanent magnet motor model predictive control, make the calculation in the current control period meet the optimal control requirements of the next control period, effectively solve the problem of model predictive control execution delay, and greatly improve the control performance of the permanent magnet motor. Compared with the traditional two-step prediction method, the permanent magnet motor model predictive control method of the present invention has high precision regardless of the control period and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0057] Figure 1 It is a schematic flow chart of a current prediction method provided by an embodiment of the present invention;

[0058] Figure 2 It is a schematic structural diagram of a current prediction device provided by an embodiment of the present invention;

[0059] Figure 3Schematic flow diagram of the model predictive control method for a permanent magnet motor provided by an embodiment of the present invention. Detailed implementation manners

[0060] The following description and the accompanying drawings fully disclose specific implementation manners of the present invention, enabling those skilled in the art to practice them.

[0061] It should be clear that the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0062] The optional embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0063] See Figure 1 As shown, the embodiment of the present disclosure provides a current prediction method, which is used to compensate for the execution delay of the model predictive control of a permanent magnet motor. The specific method steps are as follows:

[0064] S100: Obtain the real-time phase of the phase current by amplitude transformation and phase calculation of the sampled current value in the current control cycle.

[0065] In the embodiment of the present application, obtaining the real-time phase of the phase current by amplitude transformation and phase calculation of the sampled current value in the current control cycle specifically includes:

[0066] S110: Obtain the information of the real-time currents of phases a and b, the rotational speed, and the position of the motor in the current control cycle.

[0067] Specifically, use a current sensor to obtain the real-time currents of phases a and b of the motor in the current control cycle, denoted as i am (k) and i bm (k) respectively, and use a position sensor to obtain the rotational speed ω m (k) and the position θ(k) of the motor.

[0068] S120: Calculate the d-axis and q-axis currents based on the real-time currents of phases a and b and the position information.

[0069] Specifically, the d-axis and q-axis currents i d (k) and i q (k) are:

[0070]

[0071] Among them, i am (k) and i bm (k) are the real-time currents of phases a and b respectively, and i d (k) and i q(k) are the d-axis and q-axis current signals respectively.

[0072] S130: Transform the real-time a-phase and b-phase currents into currents with amplitudes in the range of [-1, 1] according to the d-axis and q-axis currents.

[0073] Specifically, transform the real-time a-phase and b-phase current signals i am (k) and i bm (k) into signal values with amplitudes in the range of [-1, 1] as follows:

[0074]

[0075] where, i am (k) and i bm (k) are the real-time a-phase and b-phase currents, i' am (k) and i' bm (k) are the transformed a-phase and b-phase currents, i d (k) and i q (k) are the d-axis and q-axis currents.

[0076] S140: Determine the real-time phases of the a-phase and b-phase currents through the arcsine function and phase determination.

[0077] In the embodiments of the present application, calculating the real-time phases of the a-phase and b-phase currents includes:

[0078] Using the arcsine function to obtain the alternative real-time phases of the phase currents;

[0079] Determine the real-time phases of the a-phase and b-phase currents from the alternative real-time phases of the phase currents according to the phase determination formula.

[0080] Specifically, using the arcsine function to obtain the alternative real-time phases of the phase currents specifically includes:

[0081] Using the arcsine function to calculate the real-time phases of the a-phase and b-phase currents i' am (k) and i' bm (k) are:

[0082]

[0083] where, and are the calculated real-time phases of the a-phase and b-phase currents. According to the characteristics of the arcsine function, and there are two sets of calculation results in the range of [0, 2π] respectively, denoted as and i.e., i, j = 1, 2.

[0084] Determine the true phases of phase a and phase b currents from and using the following phase determination formula:

[0085]

[0086] where and are the real-time phases of phase a and phase b currents.

[0087] S200: Calculate the current phase delay caused by the execution delay of model predictive control.

[0088] Specifically, use the following formula to calculate the influence of the execution delay on the current phase, and the phase delay is:

[0089]

[0090] where is the phase delay, p is the number of pole pairs of the motor, T s is the control period, ω m (k) is the motor speed.

[0091] S300: Use the phase delay to compensate the real-time phase of the phase current and estimate the current for the next control period.

[0092] Specifically, the estimated current for the next control period is:

[0093]

[0094] where i a_pre (k) and i b_pre (k) are the estimated currents for the next control period, i d (k) and i q (k) are the d-axis and q-axis currents, and are the real-time phases of phase a and phase b currents, is the phase delay.

[0095] In the embodiments of the present disclosure, using the characteristics of the sine function, the real-time phase of the phase current is obtained by amplitude transformation and phase calculation of the sampled current value in the current control period; the execution delay of model predictive control is converted into a representation form of phase delay, and the real-time phase of the phase current is compensated using the phase delay to estimate the current for the next control period. This method can compensate for the execution delay, making the calculation in the current control period meet the optimal control requirements for the next control period and improving the control performance of the permanent magnet motor.

[0096] The following are embodiments of the current estimation device of the present invention, which can be used to execute the embodiments of the current estimation method of the present invention. See Figure 2, which shows a schematic structural diagram of a current prediction device provided by an exemplary embodiment of the present invention. The current prediction device can be implemented as all or part of a terminal through software, hardware, or a combination of both. The current prediction device includes a real-time phase module 401, a phase delay calculation module 402, and a prediction module 403;

[0097] Specifically, the real-time phase module 401 is configured to obtain the real-time phase of the phase current by performing amplitude transformation and phase calculation on the sampled current value in the current control period.

[0098] Optionally, the real-time phase module 401 includes: an acquisition module, a current signal module, an amplitude change module, and a phase calculation module (not shown in Figure 2 ).

[0099] The acquisition module is configured to acquire the real-time currents of phases a and b, the motor speed, and the position signals within the current control period of the motor.

[0100] The current signal module is configured to calculate the d-axis and q-axis currents according to the real-time currents of phases a and b and the position information.

[0101] The amplitude change module is configured to transform the two-phase current signal into a signal value with an amplitude in the range of [-1, 1].

[0102] The phase calculation module is configured to obtain the real-time phases of the currents of phases a and b by using the arcsine function and phase determination for the current with an amplitude in the range of [-1, 1].

[0103] In the embodiment of the present application, the phase calculation module includes:

[0104] The phase current alternative calculation module is configured to obtain the alternative real-time phases of the phase current by using the arcsine function.

[0105] The selection module is configured to determine the real-time phases of the currents of phases a and b from the alternative real-time phases of the phase current according to the phase determination formula.

[0106] The phase delay calculation module 402 is configured to calculate the current phase delay caused by the execution delay of the model predictive control.

[0107] The prediction module 403 is configured to use the phase delay to compensate the real-time phase of the phase current and predict the current in the next control period.

[0108] Specifically, the phase delay obtained by the phase delay calculation module 402 is used to compensate the real-time phase of the phase current to predict the current in the next control period.

[0109] It should be noted that when the current prediction device provided in the above embodiment executes the current prediction method, only the division of the above functional modules is used for illustration. In actual applications, the above functions can be allocated to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the current prediction device provided in the above embodiment and the embodiment of the current prediction method belong to the same concept. For the specific implementation process, please refer to the embodiment of the current prediction method, which will not be elaborated here.

[0110] By analyzing the influence mechanism of the model predictive control execution delay on the motor performance, it can be seen that within the current control cycle of the digital processor, the model predictive control algorithm needs to be calculated using the real-time sampled current, but the generated control signal is executed in the next control cycle. As a result, the calculation completed using the sampled current in the current control cycle cannot meet the requirements of the optimal control in the next control cycle. Therefore, the present invention proposes a model predictive control method to reduce the influence of the execution delay on the control performance. This method uses the predicted current to complete the calculation of the model predictive control algorithm and selects the optimal control signal.

[0111] In one embodiment, a model predictive control method for a permanent magnet motor is proposed, as Figure 3 shown. This method includes:

[0112] S500: According to the above current prediction method, predict the current in the next control cycle;

[0113] S600: Use the predicted current to complete the calculation of the model predictive control algorithm and select the optimal control signal.

[0114] Further, using the predicted current to complete the calculation of the model predictive control algorithm and select the optimal control signal specifically includes:

[0115] S601: Use coordinate transformation to transform the predicted current in the next control cycle into d,q-axis currents i d_pre (k) and i q_pre (k);

[0116] S602: Substitute the d,q-axis currents i d_pre (k) and i q_pre (k) into the permanent magnet motor prediction model to estimate the future current state;

[0117] S603: Use the cost function to evaluate and select the voltage vector that minimizes the value of the cost function, and use the corresponding switch state as the optimal control signal to be executed in the next control cycle.

[0118] It should be noted that for the description of the current prediction method, please refer to the description of the same or similar parts above, which will not be elaborated here.

[0119] In a specific embodiment, the number of pole pairs p of the motor is selected to be 3, and the control period T s = 0.2 ms. The current sensor is used to obtain the real-time currents i am (k) and i bm (k) of the a and b phases within the current control period of the motor, and i am (k) = 8 A, i bm (k) = -9.2 A are obtained. At the same time, the position sensor is used to obtain the motor speed ω m (k) = 100 rad / s and the position θ(k) = 0.93 rad.

[0120] Calculate the d-axis and q-axis currents i d (k) and i q (k) as follows:

[0121]

[0122] Transform the two-phase current signals i am (k) and i bm (k) into signal values with amplitudes in the range of [-1, 1]:

[0123]

[0124] Among them, i' am (k) and i' bm (k) are the transformed phase currents.

[0125] Using the arcsine function, the alternative real-time phases of the phase currents are obtained as:

[0126]

[0127] Among them, and are the real-time phases of the a and b phase currents calculated. i, j = 1, 2. According to the characteristics of the arcsine function, and There are two possible calculation results in the range of [0, 2π], namely and

[0128] Use the following phase determination formula to determine the real-time phases of the a and b phase currents from and :

[0129]

[0130] Among them, and are the true phases of the a and b phase currents;

[0131] Calculate the influence of the calculation execution delay on the current phase delay

[0132]

[0133] where is the phase delay, p is the number of pole pairs of the motor, T s is the control period, ω m (k) is the motor speed.

[0134] Estimate the current i a_pre (k) and i b_pre (k):

[0135]

[0136] where i d (k) and i q (k) are the d-axis and q-axis currents, and are the real-time phases of the a-phase and b-phase currents, is the phase delay.

[0137] Use coordinate transformation to convert the compensated phase currents i a_pre (k) = 8.34 A and i b_pre (k) = -8.96 A into the d-axis and q-axis currents i d_pre (k) and i q_pre (k); Substitute i d_pre (k) and i q_pre (k) into the permanent magnet motor prediction model to estimate the future current state; Use the cost function to evaluate and select the voltage vector that minimizes the cost function value, and use the corresponding switching state as the optimal control signal to be executed in the next control period.

[0138] In one embodiment, a computer device is proposed. The computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented: Obtain the real-time phase of the phase current by amplitude transformation and phase calculation of the sampled current value of the current control period; Represent the influence of the model predictive control execution delay on the current phase by the phase delay; Compensate the real-time phase of the phase current using the phase delay to estimate the current of the next control period. Use the estimated current to complete the calculation of the model predictive control algorithm and select the optimal control signal.

[0139] In one embodiment, a storage medium storing computer-readable instructions is provided. When the computer-readable instructions are executed by one or more processors, the one or more processors are caused to perform the following steps: obtaining the real-time phase of the phase current from the sampled current value of the current control cycle through amplitude transformation and phase calculation; representing the influence of the model predictive control execution delay on the current phase by phase delay; compensating the real-time phase of the phase current with the phase delay to estimate the current of the next control cycle; using the estimated current to complete the calculation of the model predictive control algorithm and selecting the optimal control signal.

[0140] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the aforementioned storage medium can be a non-volatile storage medium such as a magnetic disk, an optical disc, a read-only memory (ROM), or a random access memory (RAM), etc.

[0141] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0142] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be subject to the appended claims.

Claims

1. A current prediction method, characterized in that The described current prediction method is used to compensate for the execution delay of model predictive control of a permanent magnet motor. The method includes: Obtaining the real-time phase of the phase current by performing amplitude transformation and phase calculation on the sampled current value of the current control cycle; The step of obtaining the real-time phase of the phase current by performing amplitude transformation and phase calculation on the sampled current value of the current control cycle specifically includes: Obtaining the real-time currents of phases a and b, the rotational speed, and the position information of the motor within the current control cycle; Calculating the d-axis and q-axis currents based on the real-time currents of phases a and b and the position information; Transforming the real-time currents of phases a and b into currents with amplitudes in the range of [-1, 1] according to the d-axis and q-axis currents; Determining the real-time phases of the currents of phases a and b from the currents with amplitudes in the range of [-1, 1] through the arcsine function and phase determination; Calculating the current phase delay caused by the execution delay of model predictive control; Compensating the real-time phase of the phase current using the phase delay to predict the current of the next control cycle.

2. The method according to claim 1, wherein The current with an amplitude in the range of [-1, 1] is: ， Among them, and are the real-time currents of phases a and b, and are the transformed currents of phases a and b, and are the d-axis and q-axis currents.

3. The method according to claim 2, wherein The step of determining the real-time phases of the currents of phases a and b from the currents with amplitudes in the range of [-1, 1] through the arcsine function and phase determination includes: Using the arcsine function to obtain alternative real-time phases of the phase current; Determining the real-time phases of the currents of phases a and b from the alternative real-time phases of the phase current according to the phase determination formula.

4. The method according to claim 3, wherein Using the arcsine function to obtain alternative real-time phases of the phase current specifically includes: Using the arcsine function to calculate the real-time phases of the currents of phases a and b as: ， Among them, and are the real-time phases of the calculated phase currents of phases a and b, and are the phase currents of phases a and b after transformation; According to the characteristics of the arcsine function, and there are two sets of calculation results within the range of [0, 2π]. These two sets of calculation results are used as the real-time phase candidates for the phase current, denoted as , and , , that is .

5. The method according to claim 4, wherein The phase determination formula is: ， Among them, and are the real-time phases of the a-phase and b-phase currents.

6. The method according to claim 5, wherein The phase delay is: ， Among them, is the phase delay, is the number of pole pairs of the motor, is the control period, motor speed.

7. The method according to claim 6, characterized in that, The step of compensating the real-time phase of the phase current using the phase delay to predict the current of the next control cycle is: Among them, and are the estimated currents for the next control cycle, and are the d-axis and q-axis currents, and are the real-time phases of the a-phase and b-phase currents, is the phase delay.

8. A current prediction device, characterized in that, The device includes: A real-time phase module for obtaining the real-time phase of the phase current by performing amplitude transformation and phase calculation on the sampled current value of the current control cycle; The step of obtaining the real-time phase of the phase current by performing amplitude transformation and phase calculation on the sampled current value of the current control cycle specifically includes: Obtaining the real-time currents of phases a and b, the rotational speed, and the position information of the motor within the current control cycle; Calculating the d-axis and q-axis currents based on the real-time currents of phases a and b and the position information; Transforming the real-time currents of phases a and b into currents with amplitudes in the range of [-1, 1] according to the d-axis and q-axis currents; Determining the real-time phases of the currents of phases a and b from the currents with amplitudes in the range of [-1, 1] through the arcsine function and phase determination; A phase delay calculation module for calculating the current phase delay caused by the execution delay of model predictive control; A prediction module for compensating the real-time phase of the phase current using the phase delay to predict the current of the next control cycle.

9. The device according to claim 8, characterized in that, The real-time phase module includes: An acquisition module for obtaining the real-time currents of phases a and b, the rotational speed, and the position information of the motor; A current signal module for calculating the d-axis and q-axis currents based on the real-time currents of phases a and b and the position information; An amplitude change module for transforming the real-time currents of phases a and b into currents with amplitudes in the range of [-1, 1] according to the d-axis and q-axis currents; A phase calculation module, which is used to determine the real-time phases of the currents of phases a and b by means of the arcsine function and phase determination for the currents with amplitudes in the range of [-1, 1].

10. A model predictive control method for a permanent magnet motor, characterized in that: The method includes: Estimating the current for the next control period according to the current estimation method described in any one of claims 1 to 7; Using the estimated current to complete the calculation of the model predictive control algorithm and selecting the optimal control signal.

11. The model predictive control method for a permanent magnet motor according to claim 10, characterized in that: Using the estimated current to complete the calculation of the model predictive control algorithm and selecting the optimal control signal, specifically including: Converting the estimated current for the next control period into d-axis and q-axis currents by means of coordinate transformation; Substituting the d-axis and q-axis currents into the permanent magnet motor prediction model to estimate the future current state; Evaluating with a cost function and selecting the voltage vector that minimizes the value of the cost function, and taking the corresponding switching state as the optimal control signal to be executed in the next control period.

12. A computer device, comprising a memory and a processor, wherein computer-readable instructions are stored in the memory, and when the computer-readable instructions are executed by the processor, the processor is caused to execute the steps of the permanent magnet motor model predictive control method described in any one of claims 10 to 11.

13. A storage medium storing computer-readable instructions, which when executed by one or more processors, cause the one or more processors to execute the steps of the permanent magnet motor model predictive control method described in any one of claims 10 to 11.

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