Permanent magnet synchronous motor compound flux-weakening control method and device and motor

Abstract

The application provides a permanent magnet synchronous motor composite field weakening control method and device and a motor. The method comprises the following steps: inputting the difference between a reference rotating speed and a current rotating speed into a first proportional integral controller to obtain a q-axis reference current; performing feedforward field weakening calculation according to the q-axis reference current to obtain the torque of the permanent magnet synchronous motor, calculating a first d-axis reference current component according to the torque of the permanent magnet synchronous motor and the reference rotating speed, inputting the difference between a current voltage vector amplitude and a maximum voltage vector amplitude into a second proportional integral controller to obtain a second d-axis reference current component; calculating the sum of the first d-axis reference current component and the second d-axis reference current component to obtain a d-axis reference current; inputting the difference between the q-axis reference current and a current q-axis current into a third proportional integral controller to obtain a q-axis voltage, inputting the difference between the d-axis reference current and a current d-axis current into a fourth proportional integral controller to obtain a d-axis voltage, and controlling the permanent magnet synchronous motor to operate until the current rotating speed is equal to the reference rotating speed.

Description

Technical Field

[0001] This application relates to the field of motor control technology, and more specifically, to a method, apparatus, computer-readable storage medium, computer program product, and motor for composite field weakening control of a permanent magnet synchronous motor. Background Technology

[0002] Permanent magnet synchronous motors are widely used in industrial drive applications due to their high efficiency and high power density. However, due to the non-adjustable nature of permanent magnet excitation, when the motor speed exceeds the base speed, the back electromotive force rises rapidly and approaches the inverter bus voltage limit, preventing the motor from accelerating further and limiting the system's speed range.

[0003] Existing field weakening control technologies are mainly divided into current-based inner-loop field weakening control and voltage-based outer-loop field weakening control. Traditional single-feedforward field weakening control, while offering fast response, is highly sensitive to changes in motor parameters (such as stator resistance, inductance, and permanent magnet flux linkage). When motor parameters drift, the control effect significantly decreases, even leading to instability. While simple voltage-based outer-loop field weakening control offers better robustness and can adapt to parameter changes, its slow dynamic response during startup or dynamic processes such as sudden load changes requires waiting for voltage error accumulation to produce adjustment, making it difficult to meet the rapid response requirements of high-speed, wide-range applications. Therefore, a composite field weakening control strategy that can overcome parameter sensitivity while ensuring good dynamic response is urgently needed. Summary of the Invention

[0004] The main objective of this application is to provide a composite field weakening control method, device, computer-readable storage medium, computer program product, and motor for permanent magnet synchronous motors, so as to at least solve the problems that the field weakening control methods in the prior art cannot simultaneously overcome parameter sensitivity and slow dynamic response.

[0005] To achieve the above objectives, according to one aspect of this application, a composite field weakening control method for a permanent magnet synchronous motor is provided, comprising: acquiring the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor; inputting the difference between the reference speed and the current speed into a first proportional-integral controller to obtain a q-axis reference current; performing feedforward field weakening calculation based on the q-axis reference current to obtain the torque of the permanent magnet synchronous motor; calculating a first d-axis reference current component based on the torque of the permanent magnet synchronous motor and the reference speed; inputting the difference between the current voltage vector amplitude and the maximum voltage vector amplitude into a second proportional-integral controller to obtain a second d-axis reference current component; calculating the sum of the first d-axis reference current component and the second d-axis reference current component to obtain a d-axis reference current; inputting the difference between the q-axis reference current and the current q-axis current into a third proportional-integral controller to obtain a q-axis voltage; inputting the difference between the d-axis reference current and the current d-axis current into a fourth proportional-integral controller to obtain a d-axis voltage; and controlling the operation of the permanent magnet synchronous motor in real time based on the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0006] Optionally, the torque of the permanent magnet synchronous motor is obtained by feedforward field weakening calculation based on the q-axis reference current, including: calculating the product of the q-axis reference current and a first coefficient to obtain the reference torque, where K1 = 1.5pψ f K1 is the first coefficient, p is the number of motor pole pairs, and ψ f The permanent magnet excitation flux is denoted by K2; the product of the reference torque and the second coefficient is calculated to obtain the torque of the permanent magnet synchronous motor, where 0 < K2 < 1, and K2 is the second coefficient.

[0007] Optionally, the first d-axis reference current component is obtained by querying a predetermined mapping relationship based on the torque and reference speed of the permanent magnet synchronous motor, wherein the predetermined mapping relationship is the mapping relationship between the torque, the reference speed and the d-axis reference current.

[0008] Optionally, the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is input to the second proportional-integral controller to obtain the second d-axis reference current component, including: when the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is less than or equal to 0, the second d-axis reference current component output by the second proportional-integral controller is equal to 0; when the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is greater than 0, the second d-axis reference current component output by the second proportional-integral controller is less than 0.

[0009] Optionally, controlling the permanent magnet synchronous motor to operate in real time based on the q-axis voltage and the d-axis voltage until the current speed equals the reference speed includes: adjusting the current d-axis current and the current q-axis current of the permanent magnet synchronous motor based on the q-axis voltage and the d-axis voltage, and re-acquiring the current speed to obtain an updated current speed; if the updated current speed is not equal to the reference speed, calculating an updated current voltage vector magnitude based on the q-axis voltage and the d-axis voltage; updating the current voltage vector magnitude using the updated current voltage vector magnitude, and updating the current speed using the updated current speed, to adjust the q-axis current and the d-axis current at least once until the current speed equals the reference speed.

[0010] Optionally, adjusting the current d-axis current and the current q-axis current of the permanent magnet synchronous motor based on the q-axis voltage and the d-axis voltage includes: performing a Park inverse transformation on the q-axis voltage and the d-axis voltage to obtain an α-axis voltage and a β-axis voltage; inputting the α-axis voltage and the β-axis voltage into an adjustment module to obtain three-phase drive pulses; inputting the three-phase drive pulses into a three-phase voltage-type inverter to obtain three-phase currents; performing a Clarke transformation on the three-phase currents to obtain an α-axis current and a β-axis current; and performing a Park transformation on the α-axis current and the β-axis current to obtain the adjusted current d-axis current and the adjusted current q-axis current.

[0011] According to another aspect of this application, a composite field weakening control device for a permanent magnet synchronous motor is provided, comprising: an acquisition unit for acquiring the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor; a first input unit for inputting the difference between the reference speed and the current speed into a first proportional-integral controller to obtain a q-axis reference current; and a first calculation unit for performing feedforward field weakening calculations based on the q-axis reference current to obtain the torque of the permanent magnet synchronous motor, calculating a first d-axis reference current component based on the torque of the permanent magnet synchronous motor and the reference speed, and comparing the current voltage vector amplitude with the maximum voltage vector amplitude. The difference in values ​​is input to a second proportional-integral controller to obtain a second d-axis reference current component; a second calculation unit is used to calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain a d-axis reference current; a second input unit is used to input the difference between the q-axis reference current and the current q-axis current to a third proportional-integral controller to obtain a q-axis voltage, and input the difference between the d-axis reference current and the current d-axis current to a fourth proportional-integral controller to obtain a d-axis voltage; a control unit is used to control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0012] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0013] According to another aspect of this application, a computer program product is provided, comprising a computer program that, when executed by a processor, implements any of the methods described.

[0014] According to another aspect of this application, an electric motor is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of the methods described.

[0015] Applying the technical solution of this application, in the above-mentioned composite field weakening control method for permanent magnet synchronous motors, the difference between the reference speed and the current speed is input to the first proportional-integral controller to obtain the q-axis reference current. Based on the q-axis reference current, feedforward field weakening calculations are performed to obtain the torque of the permanent magnet synchronous motor. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed, thus realizing feedforward field weakening control. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component, thus realizing voltage outer-loop field weakening control. The sum of the first and second d-axis reference current components is calculated to obtain the d-axis reference current, thus realizing feedforward field weakening control. According to the operating requirements of the motor, the d-axis current is increased in reverse to allow the field weakening current to be established in advance, thus obtaining... The first d-axis reference current component is used, and then the second d-axis reference current component obtained through voltage outer loop field weakening control is used to correct the field weakening current, thus obtaining the d-axis reference current. The q-axis voltage and d-axis voltage can be adjusted according to the difference between the q-axis reference current and the current q-axis current, and the difference between the d-axis reference current and the current q-axis current, thereby adjusting the current speed until the current speed equals the reference speed. By combining feedforward field weakening control and voltage outer loop field weakening control, the parameter sensitivity problem of feedforward field weakening control is overcome by voltage outer loop field weakening control, while the field weakening current is established in advance by feedforward field weakening control, overcoming the problem of slow dynamic response. Therefore, it can overcome parameter sensitivity and ensure good dynamic response, solving the problem that existing field weakening control methods cannot simultaneously overcome parameter sensitivity and slow dynamic response. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for implementing a composite field weakening control method for a permanent magnet synchronous motor is shown in an embodiment of this application.

[0018] Figure 2 A schematic flowchart of a composite field weakening control method for a permanent magnet synchronous motor according to an embodiment of this application is shown.

[0019] Figure 3 A schematic diagram of a composite field weakening control permanent magnet synchronous motor speed regulation system according to an embodiment of this application is shown;

[0020] Figure 4 A structural block diagram of a composite field weakening control device for a permanent magnet synchronous motor provided according to an embodiment of this application is shown.

[0021] The above figures include the following reference numerals:

[0022] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] As described in the background section, existing field weakening control methods cannot simultaneously overcome the problems of parameter sensitivity and slow dynamic response. To address this issue, embodiments of this application provide a composite field weakening control method, apparatus, computer-readable storage medium, computer program product, and motor for a permanent magnet synchronous motor, thereby at least solving the problem.

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] The methods and embodiments provided in this application can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a permanent magnet synchronous motor composite field weakening control method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0029] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the permanent magnet synchronous motor composite field weakening control method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0030] This embodiment provides a composite field weakening control method for a permanent magnet synchronous motor that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than that shown here.

[0031] Figure 2 This is a flowchart of a composite field weakening control method for a permanent magnet synchronous motor according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0032] Step S201: Obtain the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor.

[0033] Specifically, the current voltage vector amplitude is obtained to determine whether there is a margin for voltage increase. If there is no margin for increase, the speed regulation range will be limited, and field weakening control is required. The current speed and reference speed are obtained to determine whether the current speed has reached the reference speed.

[0034] Step S202: Input the difference between the above reference speed and the above current speed into the first proportional-integral controller to obtain the q-axis reference current;

[0035] Specifically, such as Figure 3 As shown, there is a deviation between the current speed and the reference speed. The difference between the reference speed and the current speed is input into the first proportional-integral controller, which outputs the q-axis reference current to determine the torque magnitude, thereby accelerating or decelerating the current speed to make it close to the reference speed.

[0036] Step S203: The torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the q-axis reference current. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component.

[0037] Specifically, the torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the aforementioned q-axis reference current. The torque required to adjust the speed can then be obtained. The first d-axis reference current component can be determined based on the reference speed and torque. The d-axis current is then increased in reverse to allow the field weakening current to be established in advance. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component. The field weakening current is determined based on the difference between the current voltage vector amplitude and the maximum voltage vector amplitude, thus solving the problem of insufficient voltage boost leading to insufficient speed increase.

[0038] Step S204: Calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current;

[0039] Specifically, the field weakening current established in advance by the feedforward field weakening calculation is the first d-axis reference current component, and the field weakening current determined by voltage feedback is the second d-axis reference current component. The sum of the first d-axis reference current component and the second d-axis reference current component is the d-axis reference current. The field weakening current determined by voltage feedback is used to correct the field weakening current established in advance to obtain the final d-axis reference current.

[0040] Step S205: Input the difference between the above-mentioned q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage; input the difference between the above-mentioned d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage.

[0041] Specifically, the difference between the aforementioned q-axis reference current and the current q-axis current is input to the third proportional-integral controller to obtain the q-axis voltage, so as to adjust the current q-axis current to be close to the q-axis reference current. The difference between the aforementioned d-axis reference current and the current d-axis current is input to the fourth proportional-integral controller to obtain the d-axis voltage, so as to adjust the current d-axis current to be close to the d-axis reference current.

[0042] Step S206: Control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0043] Specifically, by controlling the operation of the permanent magnet synchronous motor in real time based on the q-axis voltage and the d-axis voltage, the speed range limitation can be broken until the current speed equals the reference speed.

[0044] In this embodiment, the above-mentioned composite field weakening control method for permanent magnet synchronous motors involves inputting the difference between the reference speed and the current speed into a first proportional-integral controller to obtain the q-axis reference current. Based on the q-axis reference current, feedforward field weakening calculations are performed to obtain the torque of the permanent magnet synchronous motor. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed, thus achieving feedforward field weakening control. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input into a second proportional-integral controller to obtain the second d-axis reference current component, thus achieving voltage outer-loop field weakening control. The sum of the first and second d-axis reference current components is calculated to obtain the d-axis reference current, thus achieving feedforward field weakening control. According to the motor's operating requirements, the d-axis current is increased in reverse to allow the field weakening current to be established in advance, thus obtaining the first... The d-axis reference current component is obtained, and then the second d-axis reference current component obtained through voltage outer loop field weakening control is used to correct the field weakening current, thus obtaining the d-axis reference current. The q-axis voltage and d-axis voltage can be adjusted according to the difference between the q-axis reference current and the current q-axis current, and the difference between the d-axis reference current and the current q-axis current, thereby adjusting the current speed until the current speed equals the reference speed. By combining feedforward field weakening control and voltage outer loop field weakening control, the parameter sensitivity problem of feedforward field weakening control is overcome by voltage outer loop field weakening control, while the field weakening current is established in advance by feedforward field weakening control, overcoming the problem of slow dynamic response. Therefore, it can overcome parameter sensitivity and ensure good dynamic response, solving the problem that existing field weakening control methods cannot simultaneously overcome parameter sensitivity and slow dynamic response.

[0045] In an optional implementation, to calculate the required torque, step S203 above includes:

[0046] Step S2031: Calculate the product of the q-axis reference current and the first coefficient to obtain the reference torque, where K1 = 1.5pψ f K1 is the first coefficient mentioned above, p is the number of pole pairs of the motor, and ψ f For permanent magnet excitation flux;

[0047] Step S2032: Calculate the product of the reference torque and the second coefficient to obtain the torque of the permanent magnet synchronous motor, where 0 < K2 < 1, and K2 is the second coefficient.

[0048] In the above embodiments, such as Figure 3 As shown, the electromagnetic torque equation is T e =1.5p[ψ f i q +(L d -L q )i d i q ], where i d When =0, T e =1.5pψ f i q Therefore, K1 = 1.5pψ f Reference torque T ref With q-axis reference current i qref Proportional, 0 < K2 < 1, such that the torque T c Less than the reference torque T ref This results in the motor being in a sub-field weakening state under the action of feedforward field weakening control alone, requiring voltage outer loop field weakening control to correct the current command.

[0049] In order to calculate the field weakening current of the feedforward field weakening control, in one optional implementation, step S203 above includes:

[0050] Step S2033: Based on the torque and reference speed of the permanent magnet synchronous motor, query the predetermined mapping relationship to obtain the first d-axis reference current component, wherein the predetermined mapping relationship is the mapping relationship between the torque, the reference speed and the d-axis reference current.

[0051] In the above implementation, the applied d-axis reference current is determined by calibration tests under different torques and reference speeds to meet the torque requirements and the requirement to increase the speed to the reference speed, thereby obtaining a predetermined mapping relationship. By querying the d-axis reference current corresponding to the torque and reference speed, the first d-axis reference current component is obtained, thus realizing feedforward field weakening control.

[0052] To achieve voltage outer loop field weakening control, in one optional implementation, step S203 includes:

[0053] Step S2034: When the difference between the current voltage vector amplitude and the maximum voltage vector amplitude is less than or equal to 0, the second d-axis reference current component output by the second proportional-integral controller is equal to 0.

[0054] In step S2035, when the difference between the current voltage vector amplitude and the maximum voltage vector amplitude is greater than 0, the second d-axis reference current component output by the second proportional-integral controller is less than 0.

[0055] In the above embodiments, such as Figure 3As shown, when the current voltage vector magnitude us output by the controller is less than U smax At that time, the output of the second proportional-integral controller is positive, and the second d-axis reference current component i is obtained after the output is limited. dref_2 When the value is 0, the motor operates in i mode. d In the =0 mode, the outer voltage loop is not triggered, and field weakening control is not enabled; when the current voltage vector amplitude us output by the controller is greater than U... smax When the output of the second proportional-integral controller is negative, the second d-axis reference current component i dref_2 When the value is less than 0, the motor enters field weakening control. .

[0056] To achieve closed-loop control, in one optional implementation, step S206 includes:

[0057] Step S2061: Adjust the current d-axis current and the current q-axis current of the permanent magnet synchronous motor according to the q-axis voltage and the d-axis voltage, and re-acquire the current speed to obtain the updated current speed;

[0058] Step S2062: If the updated current rotational speed is not equal to the reference rotational speed, the updated current voltage vector magnitude is calculated based on the q-axis voltage and the d-axis voltage.

[0059] Step S2063: Update the current voltage vector amplitude using the above-mentioned update current voltage vector amplitude, and update the current rotation speed using the above-mentioned update current rotation speed, so as to adjust the q-axis current and the d-axis current at least once, until the current rotation speed is equal to the reference rotation speed.

[0060] In the above embodiments, based on the q-axis voltage u q And the above d-axis voltage u d Adjust the current d-axis current i of the aforementioned permanent magnet synchronous motor. d And the current q-axis current i mentioned above q To achieve speed regulation, the current speed is then reacquired to obtain an updated current speed. If the updated current speed is not equal to the reference speed, it indicates that speed regulation is not complete. The current voltage vector amplitude is updated using the updated current voltage vector amplitude, and the current speed is updated using the updated current speed. The debugging continues until the current speed (feedback speed) equals the reference speed.

[0061] To achieve voltage-to-current conversion control, in one optional implementation, step S2061 includes:

[0062] Step S20611: Perform Park inverse transformation on the above q-axis voltage and the above d-axis voltage to obtain the α-axis voltage and the β-axis voltage;

[0063] Step S20612: Input the above-mentioned α-axis voltage and β-axis voltage into the adjustment module to obtain three-phase drive pulses;

[0064] Step S20613: Input the above three-phase drive pulses into the three-phase voltage-source inverter to obtain three-phase current;

[0065] Step S20614: Perform Clarke transformation on the above three-phase currents to obtain the α-axis current and β-axis current;

[0066] Step S20615: Perform Park transformation on the above-mentioned α-axis current and β-axis current to obtain the adjusted current d-axis current and the adjusted current q-axis current.

[0067] In the above embodiments, such as Figure 3 As shown, for the above q-axis voltage u q And the above d-axis voltage u d Perform the inverse Park transform to obtain the α-axis voltage u. α and β-axis voltage u β The above α-axis voltage u α And the aforementioned β-axis voltage u β Input the SVPWM adjustment module to obtain three-phase drive pulses; input the above three-phase drive pulses to the three-phase voltage-source inverter to obtain the three-phase current i. A i B and i C Performing a Clarke transform on the above three-phase currents yields the α-axis current i. α and β-axis current i β For the aforementioned α-axis current i α and the aforementioned β-axis current i β Perform the Park transformation to obtain the adjusted current d-axis current i. d and the adjusted current q-axis current i q .

[0068] This application also provides a composite field weakening control device for a permanent magnet synchronous motor. It should be noted that this device can be used to execute the composite field weakening control method for a permanent magnet synchronous motor provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0069] The following describes the permanent magnet synchronous motor composite field weakening control device provided in the embodiments of this application.

[0070] Figure 4 This is a schematic diagram of a permanent magnet synchronous motor composite field weakening control device according to an embodiment of this application. Figure 4 As shown, the device includes:

[0071] The acquisition unit 10 is used to acquire the current voltage vector amplitude, current speed and reference speed of the permanent magnet synchronous motor.

[0072] Specifically, the current voltage vector amplitude is obtained to determine whether there is a margin for voltage increase. If there is no margin for increase, the speed regulation range will be limited, and field weakening control is required. The current speed and reference speed are obtained to determine whether the current speed has reached the reference speed.

[0073] The first input unit 20 is used to input the difference between the above-mentioned reference speed and the above-mentioned current speed into the first proportional-integral controller to obtain the q-axis reference current;

[0074] Specifically, such as Figure 3 As shown, there is a deviation between the current speed and the reference speed. The difference between the reference speed and the current speed is input into the first proportional-integral controller, which outputs the q-axis reference current to determine the torque magnitude, thereby accelerating or decelerating the current speed to make it close to the reference speed.

[0075] The first calculation unit 30 is used to perform feedforward field weakening calculation based on the q-axis reference current to obtain the torque of the permanent magnet synchronous motor, calculate the first d-axis reference current component based on the torque of the permanent magnet synchronous motor and the reference speed, and input the difference between the current voltage vector amplitude and the maximum voltage vector amplitude into the second proportional-integral controller to obtain the second d-axis reference current component.

[0076] Specifically, the torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the aforementioned q-axis reference current. The torque required to adjust the speed can then be obtained. The first d-axis reference current component can be determined based on the reference speed and torque. The d-axis current is then increased in reverse to allow the field weakening current to be established in advance. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component. The field weakening current is determined based on the difference between the current voltage vector amplitude and the maximum voltage vector amplitude, thus solving the problem of insufficient voltage boost leading to insufficient speed increase.

[0077] The second calculation unit 40 is used to calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current.

[0078] Specifically, the field weakening current established in advance by the feedforward field weakening calculation is the first d-axis reference current component, and the field weakening current determined by voltage feedback is the second d-axis reference current component. The sum of the first d-axis reference current component and the second d-axis reference current component is the d-axis reference current. The field weakening current determined by voltage feedback is used to correct the field weakening current established in advance to obtain the final d-axis reference current.

[0079] The second input unit 50 is used to input the difference between the above-mentioned q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage, and to input the difference between the above-mentioned d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage.

[0080] Specifically, the difference between the aforementioned q-axis reference current and the current q-axis current is input to the third proportional-integral controller to obtain the q-axis voltage, so as to adjust the current q-axis current to be close to the q-axis reference current. The difference between the aforementioned d-axis reference current and the current d-axis current is input to the fourth proportional-integral controller to obtain the d-axis voltage, so as to adjust the current d-axis current to be close to the d-axis reference current.

[0081] The control unit 60 is used to control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0082] Specifically, by controlling the operation of the permanent magnet synchronous motor in real time based on the q-axis voltage and the d-axis voltage, the speed range limitation can be broken until the current speed equals the reference speed.

[0083] In this embodiment, the aforementioned permanent magnet synchronous motor composite field weakening control device inputs the difference between the reference speed and the current speed into a first proportional-integral controller to obtain the q-axis reference current. Based on the q-axis reference current, feedforward field weakening calculations are performed to obtain the torque of the permanent magnet synchronous motor. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed, thus achieving feedforward field weakening control. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input into a second proportional-integral controller to obtain the second d-axis reference current component, thus achieving voltage outer-loop field weakening control. The sum of the first and second d-axis reference current components is calculated to obtain the d-axis reference current, thus achieving feedforward field weakening control. According to the motor's operating requirements, the d-axis current is increased in reverse to allow the field weakening current to be established in advance, thus obtaining the first... The d-axis reference current component is obtained, and then the second d-axis reference current component obtained through voltage outer loop field weakening control is used to correct the field weakening current, thus obtaining the d-axis reference current. The q-axis voltage and d-axis voltage can be adjusted according to the difference between the q-axis reference current and the current q-axis current, and the difference between the d-axis reference current and the current q-axis current, thereby adjusting the current speed until the current speed equals the reference speed. By combining feedforward field weakening control and voltage outer loop field weakening control, the parameter sensitivity problem of feedforward field weakening control is overcome by voltage outer loop field weakening control, while the field weakening current is established in advance by feedforward field weakening control, overcoming the problem of slow dynamic response. Therefore, it can overcome parameter sensitivity and ensure good dynamic response, solving the problem that existing field weakening control methods cannot simultaneously overcome parameter sensitivity and slow dynamic response.

[0084] In an optional implementation, to calculate the required torque, the first calculation unit includes:

[0085] The first calculation module is used to calculate the product of the q-axis reference current and the first coefficient to obtain the reference torque, where K1 = 1.5pψ. f K1 is the first coefficient mentioned above, p is the number of pole pairs of the motor, and ψ f For permanent magnet excitation flux;

[0086] The second calculation module is used to calculate the product of the reference torque and the second coefficient to obtain the torque of the permanent magnet synchronous motor, where 0 < K2 < 1, and K2 is the second coefficient.

[0087] In the above embodiments, such as Figure 3 As shown, the electromagnetic torque equation is T e =1.5p[ψ f i q +(L d -L q )i d i q ], where i d When =0, T e=1.5pψ f i q Therefore, K1 = 1.5pψ f Reference torque T ref With q-axis reference current i qref Proportional, 0 < K2 < 1, such that the torque T c Less than the reference torque T ref This results in the motor being in a sub-field weakening state under the action of feedforward field weakening control alone, requiring voltage outer loop field weakening control to correct the current command.

[0088] In an optional implementation, to calculate the field weakening current for feedforward field weakening control, the first calculation unit includes:

[0089] The third calculation module is used to query a predetermined mapping relationship based on the torque and reference speed of the permanent magnet synchronous motor to obtain the first d-axis reference current component, wherein the predetermined mapping relationship is the mapping relationship between the torque, the reference speed and the d-axis reference current.

[0090] In the above implementation, the applied d-axis reference current is determined by calibration tests under different torques and reference speeds to meet the torque requirements and the requirement to increase the speed to the reference speed, thereby obtaining a predetermined mapping relationship. By querying the d-axis reference current corresponding to the torque and reference speed, the first d-axis reference current component is obtained, thus realizing feedforward field weakening control.

[0091] To achieve voltage outer loop field weakening control, in one optional implementation, the first calculation unit includes:

[0092] The first output module is configured to make the second d-axis reference current component output by the second proportional-integral controller equal to 0 when the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is less than or equal to 0.

[0093] The second output module is used to ensure that the second d-axis reference current component output by the second proportional-integral controller is less than 0 when the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is greater than 0.

[0094] In the above embodiments, such as Figure 3 As shown, when the current voltage vector magnitude us output by the controller is less than U smax At that time, the output of the second proportional-integral controller is positive, and the second d-axis reference current component i is obtained after the output is limited. dref_2 When the value is 0, the motor operates in i mode. d In the =0 mode, the outer voltage loop is not triggered, and field weakening control is not enabled; when the current voltage vector amplitude us output by the controller is greater than U... smaxWhen the output of the second proportional-integral controller is negative, the second d-axis reference current component i dref_2 When the value is less than 0, the motor enters field weakening control. .

[0095] To achieve closed-loop control, in one optional implementation, the control unit includes:

[0096] The adjustment module is used to adjust the current d-axis current and the current q-axis current of the permanent magnet synchronous motor according to the q-axis voltage and the d-axis voltage, and to reacquire the current speed to obtain the updated current speed;

[0097] The fourth calculation module is used to calculate the magnitude of the updated current voltage vector based on the q-axis voltage and the d-axis voltage when the updated current rotational speed is not equal to the reference rotational speed.

[0098] The update module is used to update the current voltage vector amplitude using the aforementioned update current voltage vector amplitude and update the current rotation speed using the aforementioned update current rotation speed, so as to adjust the q-axis current and the d-axis current at least once, until the current rotation speed is equal to the reference rotation speed.

[0099] In the above embodiments, based on the q-axis voltage u q And the above d-axis voltage u d Adjust the current d-axis current i of the aforementioned permanent magnet synchronous motor. d And the current q-axis current i mentioned above q To achieve speed regulation, the current speed is then reacquired to obtain an updated current speed. If the updated current speed is not equal to the reference speed, it indicates that speed regulation is not complete. The current voltage vector amplitude is updated using the updated current voltage vector amplitude, and the current speed is updated using the updated current speed. The debugging continues until the current speed (feedback speed) equals the reference speed.

[0100] To achieve voltage-to-current conversion control, in one optional implementation, the adjustment module includes:

[0101] The first conversion module is used to perform Park inverse transformation on the above-mentioned q-axis voltage and d-axis voltage to obtain the α-axis voltage and β-axis voltage;

[0102] The second conversion module is used to input the above-mentioned α-axis voltage and the above-mentioned β-axis voltage into the adjustment module to obtain three-phase drive pulses;

[0103] The third conversion module is used to input the above three-phase drive pulses into the three-phase voltage-source inverter to obtain three-phase current;

[0104] The fourth conversion module is used to perform Clarke transformation on the above three-phase currents to obtain the α-axis current and β-axis current;

[0105] The fifth conversion module is used to perform Park transformation on the above-mentioned α-axis current and β-axis current to obtain the adjusted current d-axis current and the adjusted current q-axis current.

[0106] In the above embodiments, such as Figure 3 As shown, for the above q-axis voltage u q And the above d-axis voltage u d Perform the inverse Park transform to obtain the α-axis voltage u. α and β-axis voltage u β The above α-axis voltage u α And the aforementioned β-axis voltage u β Input the SVPWM adjustment module to obtain three-phase drive pulses; input the above three-phase drive pulses to the three-phase voltage-source inverter to obtain the three-phase current i. A i B and i C Performing a Clarke transform on the above three-phase currents yields the α-axis current i. α and β-axis current i β For the aforementioned α-axis current i α and the aforementioned β-axis current i β Perform the Park transformation to obtain the adjusted current d-axis current i. d and the adjusted current q-axis current i q .

[0107] The aforementioned permanent magnet synchronous motor composite field weakening control device includes a processor and a memory. The acquisition unit, first input unit, first calculation unit, second calculation unit, and control unit are all stored as program units in the memory. The processor executes these program units stored in the memory to achieve the corresponding functions. All of the above modules reside in the same processor; alternatively, the modules may be located in different processors in any combination.

[0108] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can address the limitations of existing field-weakening control methods in simultaneously overcoming parameter sensitivity and slow dynamic response.

[0109] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0110] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the permanent magnet synchronous motor composite field weakening control method.

[0111] Specifically, the composite field weakening control method for permanent magnet synchronous motors includes:

[0112] Step S201: Obtain the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor.

[0113] Step S202: Input the difference between the above reference speed and the above current speed into the first proportional-integral controller to obtain the q-axis reference current;

[0114] Step S203: The torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the q-axis reference current. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component.

[0115] Step S204: Calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current;

[0116] Step S205: Input the difference between the above-mentioned q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage; input the difference between the above-mentioned d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage.

[0117] Step S206: Control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0118] This invention provides a processor for running a program, wherein the program executes the aforementioned composite field weakening control method for permanent magnet synchronous motors.

[0119] Specifically, the composite field weakening control method for permanent magnet synchronous motors includes:

[0120] Step S201: Obtain the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor.

[0121] Step S202: Input the difference between the above reference speed and the above current speed into the first proportional-integral controller to obtain the q-axis reference current;

[0122] Step S203: The torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the q-axis reference current. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component.

[0123] Step S204: Calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current;

[0124] Step S205: Input the difference between the above-mentioned q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage; input the difference between the above-mentioned d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage.

[0125] Step S206: Control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0126] This invention provides a motor, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0127] Step S201: Obtain the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor.

[0128] Step S202: Input the difference between the above reference speed and the above current speed into the first proportional-integral controller to obtain the q-axis reference current;

[0129] Step S203: The torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the q-axis reference current. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component.

[0130] Step S204: Calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current;

[0131] Step S205: Input the difference between the above-mentioned q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage; input the difference between the above-mentioned d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage.

[0132] Step S206: Control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0133] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0134] Step S201: Obtain the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor.

[0135] Step S202: Input the difference between the above reference speed and the above current speed into the first proportional-integral controller to obtain the q-axis reference current;

[0136] Step S203: The torque of the permanent magnet synchronous motor is obtained by performing feedforward field weakening calculation based on the q-axis reference current. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component.

[0137] Step S204: Calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current;

[0138] Step S205: Input the difference between the above-mentioned q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage; input the difference between the above-mentioned d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage.

[0139] Step S206: Control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

[0140] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0141] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0142] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0143] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0144] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0145] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0146] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0147] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, 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, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0148] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0149] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0150] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0151] 1) In the composite field weakening control method for permanent magnet synchronous motors of this application, the difference between the reference speed and the current speed is input into a first proportional-integral controller to obtain the q-axis reference current. Based on the q-axis reference current, feedforward field weakening calculations are performed to obtain the torque of the permanent magnet synchronous motor. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed, thus realizing feedforward field weakening control. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input into a second proportional-integral controller to obtain the second d-axis reference current component, thus realizing voltage outer-loop field weakening control. The sum of the first d-axis reference current component and the second d-axis reference current component is calculated to obtain the d-axis reference current, thus realizing feedforward field weakening control. According to the operating requirements of the motor, the d-axis current is increased in reverse to allow the field weakening current to be established in advance, thus obtaining the first d-axis reference current. The field weakening current is corrected by the second d-axis reference current component obtained through voltage outer loop field weakening control, thus obtaining the d-axis reference current. The q-axis voltage and d-axis voltage can then be adjusted based on the difference between the q-axis reference current and the current q-axis current, and the difference between the d-axis reference current and the current q-axis current, thereby adjusting the current speed until the current speed equals the reference speed. By combining feedforward field weakening control and voltage outer loop field weakening control, the parameter sensitivity problem of feedforward field weakening control is overcome by voltage outer loop field weakening control, while the field weakening current is established in advance by feedforward field weakening control, overcoming the problem of slow dynamic response. Therefore, it can overcome parameter sensitivity and ensure good dynamic response, solving the problem that existing field weakening control methods cannot simultaneously overcome parameter sensitivity and slow dynamic response.

[0152] 2) In the permanent magnet synchronous motor composite field weakening control device of this application, the difference between the reference speed and the current speed is input to the first proportional-integral controller to obtain the q-axis reference current. Based on the q-axis reference current, feedforward field weakening calculations are performed to obtain the torque of the permanent magnet synchronous motor. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed, thus realizing feedforward field weakening control. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component, thus realizing voltage outer-loop field weakening control. The sum of the first d-axis reference current component and the second d-axis reference current component is calculated to obtain the d-axis reference current, thus realizing feedforward field weakening control. According to the operating requirements of the motor, the d-axis current is increased in reverse to allow the field weakening current to be established in advance, thus obtaining the first d-axis reference current. The field weakening current is corrected by the second d-axis reference current component obtained through voltage outer loop field weakening control, thus obtaining the d-axis reference current. The q-axis voltage and d-axis voltage can then be adjusted based on the difference between the q-axis reference current and the current q-axis current, and the difference between the d-axis reference current and the current q-axis current, thereby adjusting the current speed until the current speed equals the reference speed. By combining feedforward field weakening control and voltage outer loop field weakening control, the parameter sensitivity problem of feedforward field weakening control is overcome by voltage outer loop field weakening control, while the field weakening current is established in advance by feedforward field weakening control, overcoming the problem of slow dynamic response. Therefore, it can overcome parameter sensitivity and ensure good dynamic response, solving the problem that existing field weakening control methods cannot simultaneously overcome parameter sensitivity and slow dynamic response.

[0153] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A composite field weakening control method for a permanent magnet synchronous motor, characterized in that, include: Obtain the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor; The difference between the reference speed and the current speed is input into the first proportional-integral controller to obtain the q-axis reference current; The torque of the permanent magnet synchronous motor is obtained by feedforward field weakening calculation based on the q-axis reference current. The first d-axis reference current component is calculated based on the torque of the permanent magnet synchronous motor and the reference speed. The difference between the current voltage vector amplitude and the maximum voltage vector amplitude is input to the second proportional-integral controller to obtain the second d-axis reference current component. The sum of the first d-axis reference current component and the second d-axis reference current component is calculated to obtain the d-axis reference current; The difference between the q-axis reference current and the current q-axis current is input to the third proportional-integral controller to obtain the q-axis voltage. The difference between the d-axis reference current and the current d-axis current is input to the fourth proportional-integral controller to obtain the d-axis voltage. The permanent magnet synchronous motor is controlled in real time based on the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

2. The method according to claim 1, characterized in that, The torque of the permanent magnet synchronous motor is obtained by feedforward field weakening calculation based on the q-axis reference current, including: The reference torque is obtained by calculating the product of the q-axis reference current and the first coefficient, where K1 = 1.5pψ. f K1 is the first coefficient, p is the number of motor pole pairs, and ψ f For permanent magnet excitation flux; The torque of the permanent magnet synchronous motor is obtained by multiplying the reference torque by the second coefficient, where 0 < K2 < 1 and K2 is the second coefficient.

3. The method according to claim 1, characterized in that, The first d-axis reference current component is calculated based on the torque and reference speed of the permanent magnet synchronous motor, including: The first d-axis reference current component is obtained by querying a predetermined mapping relationship based on the torque and reference speed of the permanent magnet synchronous motor, wherein the predetermined mapping relationship is the mapping relationship between the torque, the reference speed and the d-axis reference current.

4. The method according to claim 1, characterized in that, The difference between the current voltage vector magnitude and the maximum voltage vector magnitude is input to the second proportional-integral controller to obtain the second d-axis reference current component, including: When the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is less than or equal to 0, the second d-axis reference current component output by the second proportional-integral controller is equal to 0. When the difference between the current voltage vector magnitude and the maximum voltage vector magnitude is greater than 0, the second d-axis reference current component output by the second proportional-integral controller is less than 0.

5. The method according to claim 1, characterized in that, The permanent magnet synchronous motor is controlled in real time based on the q-axis voltage and the d-axis voltage until the current speed equals the reference speed, including: The current d-axis current and current q-axis current of the permanent magnet synchronous motor are adjusted according to the q-axis voltage and the d-axis voltage, and the current speed is reacquired to obtain the updated current speed; When the updated current rotational speed is not equal to the reference rotational speed, the updated current voltage vector magnitude is calculated based on the q-axis voltage and the d-axis voltage. The current voltage vector magnitude is updated using the updated current voltage vector magnitude, and the current rotational speed is updated using the updated current rotational speed, so as to adjust the q-axis current and the d-axis current at least once, until the current rotational speed is equal to the reference rotational speed.

6. The method according to claim 5, characterized in that, Adjusting the current d-axis current and current q-axis current of the permanent magnet synchronous motor based on the q-axis voltage and the d-axis voltage includes: Perform an inverse Park transform on the q-axis voltage and the d-axis voltage to obtain the α-axis voltage and the β-axis voltage; The α-axis voltage and the β-axis voltage are input into the adjustment module to obtain three-phase drive pulses; The three-phase drive pulses are input into a three-phase voltage-source inverter to obtain three-phase current; The three-phase currents are subjected to Clarke transformation to obtain the α-axis current and β-axis current; Perform a Park transformation on the α-axis current and the β-axis current to obtain the adjusted current d-axis current and the adjusted current q-axis current.

7. A composite field weakening control device for a permanent magnet synchronous motor, characterized in that, include: The acquisition unit is used to acquire the current voltage vector amplitude, current speed, and reference speed of the permanent magnet synchronous motor. The first input unit is used to input the difference between the reference speed and the current speed into the first proportional-integral controller to obtain the q-axis reference current; The first calculation unit is used to perform feedforward field weakening calculation based on the q-axis reference current to obtain the torque of the permanent magnet synchronous motor, calculate the first d-axis reference current component based on the torque of the permanent magnet synchronous motor and the reference speed, and input the difference between the current voltage vector amplitude and the maximum voltage vector amplitude into the second proportional-integral controller to obtain the second d-axis reference current component. The second calculation unit is used to calculate the sum of the first d-axis reference current component and the second d-axis reference current component to obtain the d-axis reference current. The second input unit is used to input the difference between the q-axis reference current and the current q-axis current into the third proportional-integral controller to obtain the q-axis voltage, and to input the difference between the d-axis reference current and the current d-axis current into the fourth proportional-integral controller to obtain the d-axis voltage. The control unit is used to control the operation of the permanent magnet synchronous motor in real time according to the q-axis voltage and the d-axis voltage until the current speed equals the reference speed.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 6.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1 to 6.

10. An electric motor, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising methods for performing any one of claims 1 to 6.

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