Torque control method and system for constant torque region of permanent magnet synchronous motor

Abstract

The application provides a permanent magnet synchronous motor constant torque region torque control method and system, the method comprises the following steps: obtaining a d-axis voltage and a q-axis voltage; obtaining a d-axis current and a q-axis current; obtaining estimated values of d-axis and q-axis inductance and flux linkage; determining a d-axis and q-axis current instruction compensation value according to the estimated values of d-axis and q-axis inductance and flux linkage, the d-axis voltage and the q-axis voltage, the d-axis current and the q-axis current. In the above technical solution, the gradient descent method is used to calculate the d-axis and q-axis voltage instruction value and the actual value in view of the change of the motor electromagnetic parameter leading to the change of the d-axis and q-axis voltage, the estimated value of the electromagnetic parameter is applied to deduce the actual value of the d-axis and q-axis voltage, finally, the dq current instruction compensation value part is obtained, the input is respectively the d-axis and q-axis voltage, the d-axis and q-axis actual current and the estimated value of the electromagnetic parameter, and then the compensation value of the d-axis and q-axis current is obtained, and the motor torque precision is further improved.

Description

TECHNICAL FIELD

[0001] The one or more embodiments of the present specification relate to the technical field of automobiles, and particularly relate to a permanent magnet synchronous motor constant torque region torque control method and system. BACKGROUND

[0002] The current permanent magnet synchronous motor control algorithm adopts rotor field orientation vector control. Through a given motor torque instruction value, d-axis and q-axis current instruction values are obtained through MTPA data lookup table, and closed-loop control is performed through a PI controller to achieve current closed-loop control. However, due to the change of motor electromagnetic parameters, the output torque of the motor is low. SUMMARY

[0003] Therefore, the purpose of the one or more embodiments of the present specification is to provide a permanent magnet synchronous motor constant torque region torque control method and system to improve the acceleration performance of a pure electric vehicle.

[0004] In a first aspect, a permanent magnet synchronous motor constant torque region torque control method is provided. The permanent magnet synchronous motor constant torque region torque control method provided by the present application comprises the following steps:

[0005] Obtaining a d-axis voltage and a q-axis voltage;

[0006] Obtaining a d-axis current and a q-axis current;

[0007] Obtaining estimated values of d-axis and q-axis inductance and flux linkage;

[0008] Determining a d-axis and q-axis current instruction compensation value according to the estimated values of the d-axis and q-axis inductance and flux linkage, the d-axis voltage and the q-axis voltage, and the d-axis current and the q-axis current.

[0009] In the above technical solution, the gradient descent method is used to calculate the d-axis and q-axis voltage instruction value and the actual value in view of the change of the d-axis and q-axis voltage caused by the change of the motor electromagnetic parameters. The estimated value of the electromagnetic parameters is applied to deduce the actual value of the d-axis and q-axis voltage, and finally the dq current instruction compensation value part is obtained. The input is the estimated value of the electromagnetic parameters, the d-axis and q-axis voltage, and the d-axis and q-axis actual current, and then the compensation value of the d-axis and q-axis current is obtained, and the motor torque accuracy is further improved.

[0010] In a specific implementation scheme, it further comprises:

[0011] Obtaining a d-axis and q-axis current instruction value;

[0012] Determining an actual current input to the d-axis and q-axis according to the d-axis and q-axis current instruction value and the d-axis and q-axis current instruction compensation value.

[0013] In one specific embodiment, the d-axis and q-axis current command compensation values are determined according to the estimated values of the d-axis and q-axis inductance and flux linkage, the d-axis voltage and the q-axis voltage, the d-axis current and the q-axis current; specifically:

[0014] According to the obtained d-axis voltage and q-axis voltage, and the d-axis voltage and the q-axis voltage after the electromagnetic parameters change, the deviation values of the actual d-axis and q-axis voltages and the d-axis and q-axis voltages after the electromagnetic parameters change are determined.

[0015] The gradient descent method is applied to the obtained deviation values to obtain the minimum values.

[0016] The gradient descent method is applied to the obtained deviation values to obtain the minimum values.

[0017] In one specific embodiment, the gradient descent method is applied to the obtained deviation values to obtain the minimum values, and the integral processing is performed to obtain the d-axis and q-axis current command compensation values; specifically:

[0018] The formula is introduced:

[0019]

[0020] The integral processing is performed on the introduced formula to obtain:

[0021]

[0022] wherein s is a time domain value, ΔU d and ΔU q are the deviation values of the actual d-axis and q-axis voltages and the d-axis and q-axis voltages after the electromagnetic parameters change; i dc and i qc are the d-axis and q-axis current command compensation values respectively; and ω is the motor electrical speed.

[0023] In one specific embodiment, the actual currents input to the d-axis and the q-axis are determined according to the d-axis and q-axis current command values and the d-axis and q-axis current command compensation values; specifically:

[0024] The actual currents input to the d-axis and the q-axis are determined according to the formula:

[0025]

[0026] wherein, and are the estimated values of the d-axis and q-axis inductance and flux linkage respectively; L d is the d-axis inductance, L q is the q-axis inductance I dcmd and i dcmdd-axis and q-axis current command values.

[0027] In a second aspect, a permanent magnet synchronous motor constant torque region torque system is provided, which comprises:

[0028] The detection module is configured to acquire a d-axis voltage and a q-axis voltage, and acquire a d-axis current and a q-axis current.

[0029] The current processing module is configured to acquire estimated values of d-axis and q-axis inductances and flux linkages, and determine d-axis and q-axis current command compensation values based on the estimated values of the d-axis and q-axis inductances and flux linkages, the d-axis voltage and the q-axis voltage, the d-axis current and the q-axis current.

[0030] In a specific implementation, the detection module is further configured to acquire d-axis and q-axis current command values.

[0031] The current processing module is further configured to determine actual currents input to the d-axis and the q-axis based on the d-axis and q-axis current command values and the d-axis and q-axis current command compensation values.

[0032] In a specific implementation, the current processing module is specifically configured to: determine deviation values of actual d-axis and q-axis voltages and the d-axis and q-axis voltages after the electromagnetic parameters change based on the acquired d-axis voltage and q-axis voltage and the d-axis and q-axis voltages after the electromagnetic parameters change; apply a gradient descent method to the acquired deviation values to obtain minimum values; and perform integral processing on the minimum values to obtain the d-axis and q-axis current command compensation values.

[0033] In a third aspect, a vehicle is provided, which comprises a vehicle body and the permanent magnet synchronous motor constant torque region torque system according to any one of the above aspects.

[0034] In the above technical solution, the gradient descent method is adopted to calculate d-axis and q-axis voltage command values and actual values in view of the fact that changes in electromagnetic parameters of the motor result in changes in the d-axis and q-axis voltages, the actual values of the d-axis and q-axis voltages are deduced by applying estimated values of the electromagnetic parameters, and finally a dq current command compensation value part is obtained, which is input by the d-axis and q-axis voltages, the d-axis and q-axis actual currents and the estimated values of the electromagnetic parameters, so as to obtain compensation values of the d-axis and q-axis currents, and further improve the motor torque precision.

[0035] In a fourth aspect, an electronic device is provided, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the method of the first aspect and any one of the possible designs in the first aspect when executing the program.

[0036] In a fifth aspect, a non-transitory computer-readable storage medium is provided, which stores computer instructions for causing a computer to execute the method of the first aspect and any possible design of the first aspect.

[0037] In a sixth aspect, a computer program product is also provided, which comprises instructions, which, when executed on a computer, cause the computer to execute the method of the first aspect and any possible design of the first aspect.

[0038] In addition, the technical effects brought by any possible design of the fourth aspect to the sixth aspect can refer to the effects brought by different design manners in the method part, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of one or more embodiments of the present disclosure or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description only illustrate one or more embodiments of the present disclosure, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0040] Figure 1 A control block diagram of a permanent magnet synchronous motor in the prior art;

[0041] Figure 2 A constant torque region schematic diagram provided by the embodiment of the present application;

[0042] Figure 3 A permanent magnet synchronous motor torque precision control block diagram provided by the embodiment of the present application;

[0043] Figure 4 A structure block diagram of a permanent magnet synchronous motor constant torque region torque system provided by the embodiment of the present application;

[0044] Figure 5 A structure block diagram of an electronic device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and drawings.

[0046] It should be noted that the technical terms or scientific terms used in one or more embodiments of the present disclosure should be understood as the general meaning understood by those skilled in the art to which the present disclosure belongs, unless otherwise defined. The terms "first", "second", and the like used in one or more embodiments of the present disclosure do not represent any order, number, or importance, but are only used to distinguish different components. "Include" or "contain" and the like mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, and do not exclude other elements or objects. "Connected" or "connected" and the like are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right", and the like are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0047] In order to facilitate understanding of the permanent magnet synchronous motor constant rotation region torque control method provided by the embodiments of the present application, the application scenario is first explained. The permanent magnet synchronous motor constant rotation region control method provided by the embodiments of the present application is used to improve the control method of the permanent magnet synchronous motor.

[0048] In order to facilitate understanding of the above-mentioned scheme provided by the embodiments of the present application, the following will be described in detail in conjunction with the drawings.

[0049] Reference Figure 1 , Figure 1 The control block diagram of the permanent magnet synchronous motor is shown in the figure, which does not include the corresponding part of the d-axis and q-axis voltage of the decoupling part. In Figure 1 , only the d-axis and q-axis current command closed loop part is retained. Among them, Trqcmd is the motor torque command value, the d-axis and q-axis current command values are obtained through the MTPA data lookup table, and the closed loop control is carried out through the PI controller to achieve the purpose of current closed loop. However, at present, for the change of motor working condition, the change of motor electromagnetic parameters is caused, the actual output torque of motor is reduced, and the acceleration performance of pure electric vehicle is affected.

[0050] In Figure 1 the control block diagram shown in the figure, but for the setting of low voltage, formula 1 and formula 2 are used to determine. Formula 1 and formula 2 are motor voltage equations ignoring stator resistance.

[0051] Among them, formula 1 and formula 2 are as follows:

[0052] U d =-ωL q i q (1)

[0053] U q =ωL d i d+ωψ f (2)

[0054] Among them, U d U is the d-axis voltage. q L is the q-axis voltage, ω is the electric speed of the motor, and L is the electric speed of the motor. d For the d-axis inductance, L q For q-axis inductance, i q and i d These are the qd-axis currents, ψ f This is the motor flux linkage value.

[0055] The following is in conjunction with the appendix Figure 2 and attached Figure 3 This application provides a description of the control method for the constant torque region of a permanent magnet synchronous motor.

[0056] First refer to Figure 2 , Figure 2 A schematic diagram of the constant torque region of a permanent magnet synchronous single motor is shown. Figure 2 In the diagram, the horizontal axis *spd* represents the motor torque, and the vertical axis *Trq* represents the motor torque value. The torque of a permanent magnet synchronous motor is divided into a constant torque region and a constant power region. The control method disclosed in this application is a control method for the constant torque region.

[0057] refer to Figure 3 , Figure 3 This application discloses a control block diagram for controlling the torque in the constant torque region of a permanent magnet synchronous single motor. In this embodiment, to improve the control of the permanent magnet synchronous single motor, d-axis and q-axis current command compensation values ​​are added. The inputs are the voltage of the d-axis and q-axis, the actual current of the d-axis and q-axis, and the estimated values ​​of the electromagnetic parameters, respectively, to obtain the compensation values ​​for the d-axis and q-axis currents, further improving the motor torque accuracy.

[0058] The following details how to improve the control of permanent magnet synchronous motors.

[0059] The method for controlling the torque in the constant torque region of a permanent magnet synchronous motor provided in this application includes the following steps:

[0060] Step 001: Obtain the d-axis voltage and q-axis voltage;

[0061] Step 002: Obtain the d-axis current and q-axis current;

[0062] Step 003: Obtain estimated values ​​of d-axis and q-axis inductance and flux linkage;

[0063] Step 004: Determine the command compensation values ​​for the d-axis and q-axis currents based on the estimated values ​​of the d-axis and q-axis inductance and flux linkage, the d-axis and q-axis voltages, and the d-axis and q-axis currents.

[0064] Specifically, according to the acquired d-axis voltage and q-axis voltage, and the acquired d-axis and q-axis voltage after the electromagnetic parameter change, the deviation value of the actual d-axis and q-axis voltage and the d-axis and q-axis voltage after the electromagnetic parameter change is determined.

[0065] The gradient descent method is applied to the acquired deviation value to obtain the minimum value.

[0066] The gradient descent method is applied to the acquired deviation value to obtain the minimum value, and integral processing is performed to obtain the d-axis and q-axis current command compensation value.

[0067] In the integral processing of the acquired deviation value to obtain the minimum value by applying the gradient descent method to obtain the d-axis and q-axis current command compensation value, the formula is introduced.

[0068]

[0069] The integral processing of the introduced formula obtains:

[0070]

[0071] Wherein, s is a time domain value, ΔU d and ΔU q are the deviation values of the actual d-axis and q-axis voltage and the d-axis and q-axis voltage after the electromagnetic parameter change; i dc and i qc are the d-axis and q-axis current command compensation values, respectively; and ω is the motor electrical speed.

[0072] Step 005: acquiring the d-axis and q-axis current command values;

[0073] Step 006: determining the actual current input to the d-axis and q-axis according to the d-axis and q-axis current command values and the d-axis and q-axis current command compensation values.

[0074] Specifically, the actual current input to the d-axis and q-axis is determined according to the formula:

[0075]

[0076]

[0077] Wherein, and are the estimated values of the d-axis and q-axis inductance and flux linkage, respectively; L d is the d-axis inductance, L q is the q-axis inductance I dcmd and i dcmd are the d-axis and q-axis current command values, respectively.

[0078] The derivation process of the above formula is described in detail as follows:

[0079] In combination with the circuit shown in Figure 3 , the change of d-axis and q-axis voltage caused by the change of motor electromagnetic parameters, for which, formula 3 and formula 4 are constructed. Wherein, formula 3 and formula 4 are:

[0080] ΔU d = U d * -U d = U d * + ωL q i q (3)

[0081] ΔU q = U q * -U q = U q * - ωL d i d - ωψ f (4)

[0082] Wherein, U d * and U q * are the d-axis and q-axis voltage after the change of d-axis and q-axis electromagnetic parameters;

[0083] ΔU d and ΔU q are the deviation values of actual d-axis and q-axis voltage and theoretically calculated d-axis and q-axis voltage, the smaller the deviation value is, the closer the actual motor torque is to the target torque value.

[0084] Formula 5 and formula 6 take the d-axis and q-axis voltage deviation values and apply gradient descent method to take their minimum values. Formula 5 and formula 6 are respectively:

[0085] F = α (ΔU d 2 + ΔU q 2 ) (5)

[0086]

[0087] Integrating formula 6 obtains formula 7, that is, the expression of d-axis and q-axis current command compensation value;

[0088]

[0089] Wherein, s is a time domain value, and the d-axis and q-axis voltage deviation values are unknown items.

[0090] Introducing formula 8 and formula 9 to obtain the expression of actual d-axis and q-axis voltage;

[0091]

[0092]

[0093] wherein K p and K i are PI parameter values;

[0094] and are estimated values of d-axis and q-axis inductance and flux linkage respectively;

[0095] I dcmd and i dcmd are d-axis and q-axis current command values respectively.

[0096] Introducing formula 10 and formula 11

[0097]

[0098]

[0099] wherein i dc and i qc in formula 10 and formula 11 are d-axis and q-axis current command compensation values respectively.

[0100] In the above technical solution, in view of the change of motor electromagnetic parameters leading to the change of d-axis and q-axis voltage, the gradient descent method is used to calculate the d-axis and q-axis voltage command value and the actual value, the estimated value of electromagnetic parameters is applied to deduce the actual value of d-axis and q-axis voltage, and finally the dq current command compensation value part is obtained, the input is the estimated value of d-axis and q-axis voltage, d-axis and q-axis actual current and electromagnetic parameters, and then the compensation value of d-axis and q-axis current is obtained, and the motor torque precision is further improved.

[0101] With reference to Figure 4 , the embodiment of the application further provides a permanent magnet synchronous motor constant torque region torque system, which comprises:

[0102] The detection module 100 is used for acquiring d-axis voltage and q-axis voltage, and acquiring d-axis current and q-axis current;

[0103] The current processing module 200 is used for acquiring the estimated value of d-axis and q-axis inductance and flux linkage, and determining the d-axis and q-axis current command compensation value according to the estimated value of d-axis and q-axis inductance and flux linkage, d-axis voltage and q-axis voltage, d-axis current and q-axis current. The functions of the above detection module 100 and current processing module 200 can be specifically referred to the description in the method steps, which will not be described in detail here.

[0104] In one specific implementation, the detection module 100 is further configured to obtain d-axis and q-axis current command values; and the current processing module 200 is further configured to determine actual currents input to the d-axis and q-axis according to the d-axis and q-axis current command values and d-axis and q-axis current command compensation values. The functions of the detection module 100 and the current processing module 200 can be specifically referred to the description in the method steps, which will not be described in detail here.

[0105] In one specific implementation, the current processing module 200 is specifically configured to: determine deviation values of actual d-axis and q-axis voltages and the d-axis and q-axis voltages after the electromagnetic parameters change, according to the obtained d-axis and q-axis voltages and the d-axis and q-axis voltages after the electromagnetic parameters change; apply a gradient descent method to the obtained deviation values to obtain minimum values; and integrate the minimum values to obtain the d-axis and q-axis current command compensation values.

[0106] The application further provides an automobile, which comprises a vehicle body and the permanent magnet synchronous motor constant torque region torque system according to any one of the above.

[0107] In the above technical solution, the gradient descent method is used to calculate the d-axis and q-axis voltage command values and actual values in view of the changes of the d-axis and q-axis voltages caused by the changes of the electromagnetic parameters of the motor, the estimated values of the electromagnetic parameters are applied to deduce the actual values of the d-axis and q-axis voltages, and finally the dq current command compensation value part is obtained, which is input by the d-axis and q-axis voltages, the d-axis and q-axis actual currents and the estimated values of the electromagnetic parameters, so as to obtain the compensation values of the d-axis and q-axis currents, and further improve the motor torque precision.

[0108] It should be noted that the method of one or more embodiments of the present specification can be executed by a single device, such as a computer or a server, etc. The method of the present embodiment can also be applied to a distributed scenario, and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only execute one or more steps in the method of one or more embodiments of the present specification, and the multiple devices can interact with each other to complete the method.

[0109] The above describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be executed in an order different than the order in the embodiments and still achieve the desired result. In addition, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve the desired results. In some implementations, multitasking and parallel processing can be advantageous or necessary.

[0110] For ease of description, the above apparatus is described in various modules respectively in terms of functions. Of course, the functions of each module can be implemented in one or more software and / or hardware when implementing one or more embodiments of the present specification.

[0111] The apparatus of the above embodiments is used to implement the corresponding method in the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described here again.

[0112] Figure 5 A more specific hardware structure schematic diagram of an electronic device provided by the present embodiment is shown. The device can include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other in the device through the bus 1050.

[0113] The processor 1010 can be implemented in the form of a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, etc., for executing related programs to implement the technical solutions provided by the present embodiment.

[0114] The memory 1020 can be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1020 can store an operating system and other application programs. When the technical solutions provided by the present embodiment are implemented by software or firmware, the related program codes are stored in the memory 1020 and called and executed by the processor 1010.

[0115] The input / output interface 1030 is used to connect input / output modules to realize information input and output. The input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. The input device can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device can include a display, a speaker, a vibrator, an indicator light, etc.

[0116] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0117] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0118] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0119] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0120] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this specification as described above, which are not provided in detail for the sake of brevity.

[0121] Additionally, to simplify the description and discussion, and so as not to obscure one or more embodiments of the description, well-known power supply / ground connections to integrated circuit (IC) chips and other components can or can not be shown in the provided figures. Furthermore, devices can be shown in block diagram form in order to avoid obscuring one or more embodiments of the description, and this also acknowledges the fact that the details in regard to the implementation of such block device are highly dependent on the platform within which the one or more embodiments of the description are being implemented (i.e., such details should be well within the purview of one of ordinary skill in the art). Where specific details are set forth in order to describe an illustrative embodiment of the disclosure, it will be apparent to one of ordinary skill in the art that the one or more embodiments of the description can be practiced without, or with variation of, these specific details. Thus, the description is to be considered as illustrative and not restrictive, and the scope of the one or more embodiments of the description is to be determined not with the assistance of the foregoing description alone, but rather in light of the appended claims in conjunction with recognizing the one or more embodiments of the description can over come a variety of non-anticipated

[0122] While the present disclosure has been described in connection with specific embodiments thereof, many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) can use the embodiments discussed.

[0123] The one or more embodiments of the description are intended to cover all such alternatives, modifications and variations as can come within the scope of the appended claims. Accordingly, any and all such modifications, variations or equivalents that fall within the scope of the one or more embodiments of the description should be considered within the scope of the disclosure.

Claims

1. A method for controlling the torque in the constant torque region of a permanent magnet synchronous motor, characterized in that, Includes the following steps: Obtain the d-axis voltage and q-axis voltage; Obtain the d-axis current and q-axis current; Obtain estimated values ​​for d-axis and q-axis inductance and flux linkage; The command compensation values ​​for d-axis and q-axis currents are determined based on the estimated values ​​of d-axis and q-axis inductance and flux linkage, d-axis and q-axis voltage, and d-axis and q-axis currents. Specifically: Based on the obtained d-axis and q-axis voltages, and the obtained d-axis and q-axis voltages after changes in the electromagnetic parameters, determine the deviation between the actual d-axis and q-axis voltages and the d-axis and q-axis voltages after changes in the electromagnetic parameters. The minimum value of the obtained deviation is obtained by applying gradient descent. The minimum value of the obtained deviation value is taken by applying the gradient descent method and then integrated to obtain the current command compensation values ​​for the d-axis and q-axis.

2. The method for controlling the torque in the constant torque region of a permanent magnet synchronous motor according to claim 1, characterized in that, Also includes: Obtain the d-axis and q-axis current command values; The actual current input to the d-axis and q-axis is determined based on the current command values ​​of the d-axis and q-axis and the compensation values ​​of the current command of the d-axis and q-axis.

3. The method for controlling the torque in the constant torque region of a permanent magnet synchronous motor according to claim 1, characterized in that, The obtained deviation value is obtained by applying the gradient descent method to take its minimum value and then integrating it to obtain the d-axis and q-axis current command compensation values; specifically: Introducing the formula: Integrating the introduced formula yields: in, For time domain values, and These are the deviations of the d-axis and q-axis voltages after changes in the actual d-axis and q-axis voltages and electromagnetic parameters; and These are the current command compensation values ​​for the d-axis and q-axis, respectively. The electric speed of the motor; For d-axis inductance, It is the q-axis inductance.

4. The method for controlling the torque in the constant torque region of a permanent magnet synchronous motor according to claim 3, characterized in that, The determination of the actual current input to the d-axis and q-axis based on the d-axis and q-axis current command values ​​and the d-axis and q-axis current command compensation values ​​is specifically as follows: The actual current input to the d-axis and q-axis is determined using the formula: ； ； in, The voltage along the d-axis. This is the q-axis voltage. , and These are the estimated values ​​for inductance and flux linkage along the d-axis and q-axis, respectively. For d-axis inductance, It is the q-axis inductance. This is the motor flux linkage value. and The current command values ​​for the d-axis and q-axis are respectively.

5. A system for constant torque region of a permanent magnet synchronous motor, characterized in that, include: Detection module: used to acquire d-axis voltage, q-axis voltage; and d-axis current, q-axis current; The current processing module is used to obtain the estimated values ​​of d-axis and q-axis inductance and flux linkage; and to determine the d-axis and q-axis current command compensation values ​​based on the estimated values ​​of d-axis and q-axis inductance and flux linkage, d-axis voltage and q-axis voltage, d-axis current and q-axis current. Specifically, the current processing module is used to: determine the deviation between the actual d-axis and q-axis voltages and the d-axis and q-axis voltages after the electromagnetic parameter changes, based on the acquired d-axis and q-axis voltages and the acquired d-axis and q-axis voltages after the electromagnetic parameter changes; apply the gradient descent method to the acquired deviation value to obtain its minimum value; and perform integration processing on the acquired deviation value to obtain the d-axis and q-axis current command compensation values.

6. The system for constant torque region of a permanent magnet synchronous motor according to claim 5, characterized in that, The detection module is also used to acquire d-axis and q-axis current command values; The current processing module is also used to determine the actual current input to the d-axis and q-axis based on the d-axis and q-axis current command values ​​and the d-axis and q-axis current command compensation values.

7. A car, characterized in that, The system includes a vehicle body and a system for a permanent magnet synchronous motor with constant torque region as described in any one of claims 5 to 6, which is disposed within the vehicle body.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the constant torque region torque control method for a permanent magnet synchronous motor as described in any one of claims 1 to 4.

9. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions for causing the computer to execute the control method for the constant torque region torque of the permanent magnet synchronous motor according to any one of claims 1 to 4.

Images